Environmental sustainability in cardiovascular practice: current challenges and future directions

Abstract

Cardiovascular disease is the leading cause of morbidity and mortality worldwide, with a substantial amount of health-care resources targeted towards its diagnosis and management. Environmental sustainability in cardiovascular care can have an important role in reducing greenhouse gas emissions and pollution and could be beneficial for improving health metrics and societal well-being and minimizing the cost of health care. In this Review, we discuss the motivations and frameworks for sustainable cardiovascular care with an emphasis on the reduction of the climate-related and environmental effects of cardiovascular care. We also provide an overview of greenhouse gas emissions related to the provision of health care, including their measurement and quantification, carbon accounting, carbon disclosures and climate effects. The principles of life-cycle assessment, waste prevention and circular economics in health care are discussed, and the emissions associated with various sectors of cardiovascular care as well as the rationale for prevention as a powerful approach to reduce these emissions are presented. Finally, we highlight the challenges in environmental sustainability and future directions as applicable to cardiovascular practice.

Introduction

Although the health effects of pollution and climate change are increasingly recognized, the environmental effects of health-care delivery and the forthcoming challenges posed by climate change to hospital operations, supply chains and costs have received much less attention^1–3. The environmental footprint of health-care provision, which includes various air, water and soil pollutants, has an unintended negative effect on health care and its associated costs³. Given the primacy and interdependence of human and planetary health and the escalating potential for harm from pollution and climate change, the engagement of health-care professionals in sustainable practices is an existential priority^4,5. The outsized burden of cardiovascular disease (CVD) on global morbidity and mortality, and the reality that cardiovascular and metabolic care practices drive not only health-care costs but also climate and environmental effects, justifies this increased attention. The substantial links between cardiovascular and planetary health, including their common drivers of disease, has been previously discussed^6–8. Given that substantial health-care resources are expended on the diagnosis and management of CVD, a sound understanding of the scale of greenhouse gas (GHG) emissions and pollution attributable to cardiovascular practice is important, not only to modify current health-care delivery processes dependent on fossil fuels but also to simultaneously reduce non-GHG-related pollution to improve cardiovascular health. In this Review, we provide an overview of sustainability concepts and recent evidence supporting sustainable cardiovascular care.

Health-care-related sustainability

Although the 2022 Lancet Countdown on health and climate change reported several signs of progress⁹, the pace and scale of climate change adaptation, planning and resilience are far from what is necessary to reduce the health effects of climate change. GHG mitigation, and more broadly, environmental sustainability, has consequently become a crucial issue in the past decade. At its core, sustainability pertains to the responsible use of resources to meet the needs of the current population, without compromising the ability of future generations to meet their own needs¹⁰. Sustainable practices encompass three key pillars: economic, environmental and social practices¹¹. Placing the economic argument at the forefront of sustainability can provide the appropriate incentive to influence the other two pillars. In health care, the economic pillar of sustainability, which entails the fostering of alternate practices to reduce costs, while maintaining excellent health outcomes, is necessary to ensure uptake and long-term viability. Paradoxically, although the economic argument for sustainable practices should be the leading reason for adoption, these practices have not been widely implemented by either private or public organizations, given the cost and time needed to adopt these sustainability measures¹². At present, although some regulatory levers exist in several global regions, there remains a need for refined levers that might force hospitals and health systems to lower their GHG emissions or issue financial penalties for pollution attributable to health-care delivery, especially in countries that have a high health-care-related environmental footprint (such as the USA).

Health-care facilities are large consumers of resources, including energy, water and materials. By adopting sustainable practices, such as energy-efficient technologies and waste-reduction initiatives, health systems can contribute to the conservation of these valuable resources. Furthermore, the adoption of these measures can lead to savings in operational expenses^13,14, and health systems can demonstrate social responsibility by contributing to a healthier environment for the immediate communities they serve. Examples of initiatives that promote social responsibility and create a safer and more sustainable living environment include those that aim to reduce water pollution, maintain community and urban farms, and increase tree cover¹⁵.

Although complying with regulations is a key driver of sustainable practices, it is often not explicitly acknowledged as such. ‘Polluter pays’ models are increasingly common, especially among industries that generate large amounts of air pollution or other types of industrial pollutants¹⁶, but enforcing such models in health care can be complicated owing to the primacy of saving lives over other factors⁴. In the USA, there has been opposition to mandatory disclosure of emissions by health-care organizations, as evidenced by the rejection of efforts to implement minimal standards of reporting via the Joint Commission, a US-based entity that accredits >20,000 health-care organizations¹⁷. The lack of transparency and effective regulatory levers hampers efforts from health-care organizations to transition to sustainable models of health care⁴.

The environmental footprint of health care

Health-care systems are substantial contributors to environmental pollution and GHG emissions^1,3. A multiregional environmentally extended input–output (EEIO) tool has been used to calculate the environmental footprint of health care in 189 countries from 2000 to 2015. During this period, 4.4% of GHG emissions, 2.8% of pollution by PM_2.5 (particulate matter ≤ 2.5 μm in diameter), 3.4% of nitrogen oxide emissions and 3.6% of sulfur dioxide pollution globally were attributable to health-care activities³. Of note, substantial regional variations were observed. Health-care-related activities in China, India and the USA generated the highest total levels of PM_2.5 pollution³. Although PM_2.5 emissions in China and India were low when calculated per capita, the PM_2.5 intensity of health care per US dollar (which calculates the attribution of each US dollar spent towards fossil fuel activities that are expected to generate high levels of PM_2.5) was high in these countries. In terms of carbon emissions, the health-care industry is among the most carbon-intensive service sectors, responsible for 4–5% of worldwide GHG emissions^3,18,19. A breakdown of the global sources of health-care-related GHG emissions shows that 51% is from CO₂ (predominantly from fuel combustion and land use for the health-care supply chain), 22% is from nitrous oxide (predominantly from agriculture), 15% is from methane (predominantly from agriculture and energy transformation) and the rest from fluorinated gases. In perhaps the most comprehensive national estimate of GHG emissions from the health-care industry, the National Health Services in the UK reported emissions of approximately 25 mega tonnes of CO₂ equivalent (CO₂e; a reference unit used to compare emissions between different GHGs on the basis of their global warming potential), which amounts to 540 kg of CO₂e per capita²⁰. In comparison, GHG emissions per capita from the health-care industry in the USA are the highest among all countries, at approximately 1.51 tonnes of CO₂e per capita¹⁸, which is partially attributable to the fact that health-care expenditure in the USA, as a percentage of gross domestic product (GDP), is among the highest in the world at 19%²¹. Of note, the rate of death as a result of pollution emitted by the health-care industry in the USA is estimated to be similar in magnitude to that of preventable medical errors during the delivery of health care^22,23.

GHG emissions in health care can be considered from the standpoint of their scope (Box 1). Scope 1 emissions are the result of direct operational activities, such as direct combustion of fuel and transportation; scope 2 emissions result from purchased electricity; and scope 3 emissions include those produced by the supply chain of the health-care industry, such as the production and disposal of medical products and supplies, pharmaceutical manufacturing and waste management¹⁹. The majority of the CO₂ emissions produced by the health-care industry (the carbon hotspots) are attributable to the procurement supply chain, with medical equipment and pharmaceuticals representing the largest CO₂e contributor^3,24. Scope 3 emissions are difficult to track, given that they require tracking of carbon emissions from all upstream and downstream activities from an immensely complex supply chain.

Box 1 |. GHG emissions in health care.

Scope 1 emissions: from direct operational activities  ● Onsite energy  ● Fleet vehicles  ● Anaesthetic gas waste  ● Refrigerants

Scope 2 emissions: indirect emissions released outside the facility  ● Purchased electricity  ● Purchased steam

Scope 3 emissions: from the supply chain  ● Business travel  ● Employee commute  ● Waste disposal  ● Medical equipment  ● Pharmaceuticals  ● Meat procurement

Common greenhouse gases released from health-care activities  ● Carbon dioxide  ● Methane  ● Chlorofluorocarbons  ● Nitrous oxide  ● Hydrofluorocarbons  ● Perfluorocarbons  ● Nitrogen trifluoride  ● Sulfur hexafluoride

Emissions assessment and reporting

In 1995, the UN climate programme required developed countries to report emissions on an annual basis²⁵. Two years later, the Kyoto protocol defined GHGs (Kyoto gases; specifically CO₂, methane, nitrous oxide, sulfur hexafluoride, nitrogen trifluoride, chloroflurocarbons, hydrofluorocarbons and perfluorocarbons), which are the focus of present accounting methods. To estimate emissions, an emissions factor is multiplied by the corresponding activity or consumption of materials, products or services (for example, the mass of plastic, combustion of fuel or consumption of electricity; Fig. 1). Emissions can be either direct, such as the combustion of gas at a hospital for heating, or indirect, such as the consumption of electricity by the activities of the health-care organization, even though the direct emissions occur at power plants combusting fuel to generate electricity at a distant location. The calculation of GHG emissions from the electrical grid of a hospital requires an emissions factor that proportionally averages the various power suppliers and their fuel sources used to supply electricity to the customers of a utility company. Therefore, the emissions factor would be higher for hospitals using coal-powered fuel than for another hospital using suppliers that provide clean energy.

Fig. 1 |. Measuring greenhouse gas emissions and the carbon footprint of health care.

a, Estimating CO₂ emissions using emission factors. b, The CO₂ emissions for power consumption in a health-care organization (HCO) is calculated by multiplying the operations emissions factor by the power consumption of the organization. The emissions factor in this example would be dependent on the source (or sources) of power. c, The global warming potential (GWP) of various greenhouse gases (GHGs). The GWP was developed to allow comparisons of the global warming effects of different gases. Specifically, the GWP is a measure of how much energy the emission of 1 tonne of a type of gas will absorb over a given period, relative to the emission of 1 tonne of CO₂. The larger the GWP, the more that a given gas warms the Earth than CO₂ over that same time period (usually 100 years for GWP). d, The relationship between carbon intensity, energy intensity and fuel mix. Data in panel c are derived from the Intergovernmental Panel on Climate Change Assessment Report 4 (AR4) and Assessment Report 5 (AR5)^114,115. tCO₂e, tonnes of CO₂ equivalent.

Life-cycle assessment

For scope 3 activities that mostly correspond to emissions from the supply chain of the health-care industry, life-cycle assessment (LCA) is the most recognized strategy for quantifying emissions. LCA can either be calculated using EEIO financial analysis or be fully process-based²⁶. EEIO analysis uses economic data produced by all major economies that track the flow of money between industries (for example, energy, pharmaceuticals, food, fishing or service sectors). Using input–output tables, carbon emissions can be calculated on a per US dollar basis for goods or services purchased from a given sector (kg CO₂e per US$)²⁷. Although EEIO analyses are a good sector-based model, they have limited applicability when examining specific products or interventions, given that all products and services in a given sector have the same emissions intensity, on the basis of cost. For example, the carbon emissions from purchasing US$100 of any type of pharmaceutical is approximately 46 kg CO₂e, regardless of what is being purchased^27,28. Therefore, the price differential between a drug being on or off patent, or as a generic formulation, can result in the same drug having substantially different emissions per US dollar.

Process LCA quantifies emissions from the whole life cycle of a product, process or service (including raw material extraction, manufacture, use and end of life; Fig. 2), using a series of interlinked processes. The process of performing and reporting LCAs is governed by the International Organization for Standardization (ISO 14040 and ISO 14044). Process-based LCA can further be described as attributional or consequential²⁷. Attributional LCA estimates the proportion of the total carbon footprint of a health-care service that can be attributed to a specific clinical activity, whereas consequential LCA is important to gauge the marginal effect of changing a specific activity; for instance, the consequence of switching to reusable surgical aprons for all surgeries. The majority of health-care organizations worldwide lack the internal resources to compile a full LCA and are therefore reliant on suppliers to perform the analysis and disclose the results, both of which can be barriers to adopting more environmentally friendly practices. This challenge and the opacity of the upstream effects of health-care supplies mean that the cost–basis EEIO methodology is the most widely used method of calculating scope 3 supply chain emissions.

Fig. 2 |. Life-cycle assessment framework.

The four stages of goal and scope definition, inventory analysis, impact assessment and direct applications are depicted. The direct applications of this framework include product development and capacity building.

GHG disclosures and regulatory reporting

With the increasing demand for transparent, equitable and sustainable practices, corporations across various sectors are adopting new forms of accounting that capture not only financial performance but also efforts to mitigate the environmental and social effects of their operations²⁹. In a 2018 survey of 49 health-care organizations in the USA, only 6 published sustainability reports³⁰, suggesting that the health-care sector is lagging behind other sectors in GHG disclosures and sustainability reporting. Numerous non-regulatory initiatives are aiming to provide actionable pathways for health-care organizations to take leadership in climate disclosures and pave the way for standardized disclosures and strategies that would reduce overall emissions from health-care practices^4,31,32. The American Hospital Association, which represents >5,000 hospitals and health systems across the USA, now provides tools to assess sustainability maturity, track progress and actions (sustainability accelerator tool), and offers strategies to assist health-care systems to decarbonize facilities (health-care decarbonization code overlay) and sustainable solutions to reduce carbon footprint³³. To date, the progress of these non-regulatory initiatives in countries with large GHG footprints has been small^5,31, in part related to the lack of regulatory levers, such as mandatory disclosures, to increase transparency and shift behaviour.

Several initiatives have facilitated the participation of non-healthcare organizations in GHG accounting. Although these initiatives are voluntary, the prospect of distant regulatory action, loss of competitive advantage and other profit considerations, if a company does not shift its behaviours, have been powerful drivers of change. The Science Based Targets Initiative formed in 2015 as a collaboration between the CDP (formerly the Carbon Disclosure Project), the Worldwide Fund for Nature and the United Nations Global Compact to facilitate science-based environmental target-setting as a standard corporate practice³⁴. The Science Based Targets Initiative provides a framework of actions and targets to help companies to achieve net zero status. This framework consists of three steps: to achieve emission reduction targets in the near-term (5–10 years); set long-term goals to attain net zero status (the elimination of carbon footprint and balancing GHG emissions with GHG removal); and, finally, neutralize any residual GHG emissions by the target date and beyond³⁴. The Task Force on Nature Related Financial Disclosures provides a set of recommendations that take into account the effects of GHG emissions on nature-related dependencies in the domains of ocean, freshwater, land and atmosphere, and provides an approach to environmental corporate reporting³⁵. These frameworks, although not directly related to health care, might serve as a useful backdrop for approaches that could form part of future reporting requirements after adequate refinement for the health-care context. In 2022, the US Department of Health and Human Services launched a voluntary pledge with >1,100 private and federal signatory hospitals that requires these organizations to measure their GHG emissions in a transparent manner, and reduce their emissions in alignment with the Paris Accord³⁶. In 2024, the Joint Commission launched a new GHG voluntary certification programme that requires transparent measurement of the GHG emissions of an organization and to have a reduction plan among other institutional requirements to support the commitments³⁷. An important aspect unique to health care that has not been addressed by these frameworks is how to reduce emissions while not adversely affecting health outcomes, given that the fundamental expectation of health-care delivery places the health of the patient first and foremost.

Carbon emissions in cardiovascular practice

In 2021, global spending on health reached a new high of US$9.8 trillion or 10.3% of the global GDP³⁸. In the USA, health-care expenditure accounted for 17.3% of the GDP³⁹. The USA represents a prototypical use case scenario for opportunities to limit carbon emissions, given its large contribution to emissions. In 2022, the cost of hospital care services in the USA was US$1.4 trillion (30% of total health-care spending), whereas the cost of retail prescription drugs was US$405.9 billion³⁹. When considering only the cost of managing and treating CVD and its risk factors, >US$320 billion is spent annually, which equates to approximately 15% of health-care spending in 2016. The Disease Expenditure Project conducted by the Institute for Health Metrics and Evaluation estimated that the total spending on cardiovascular care in US adults in 2016 was US$320.1 billion (95% CI 299.2–345.6 billion)⁴⁰. Of note, more than half of cardiovascular expenditure was paid by public payers.

Interventional cardiology

Cardiac catheterization procedures are commonly performed around the world. In the USA alone, >1 million procedures are performed annually⁴. Although no worldwide estimates are available, interventional procedures in the catheterization laboratory are commonly perceived to have a high carbon footprint, owing to high levels of material consumption and product waste⁴¹. Most cardiac catheterization laboratories use prepacked kits containing items that are often never used during a procedure, because these packages are often designed with a goal of generalizability. A reduction in consumption of these single-use items, which are either incinerated or destined for landfill, represents an important improvement in sustainable practices. Cardiac catheterization procedures are currently performed without guidance, education or expectation regarding carbon footprint or recycling⁴². A prospective, single-centre study of a catheterization laboratory in an urban tertiary care academic centre involving 70 procedures over 5 days had a total of 50.6 kg (0.72 kg per case) of potentially recyclable material (mostly paper and plastic), which was highest for percutaneous coronary interventions (1.4 kg per case) and lowest for right heart catheterization procedures (0.66 kg per case)⁴³. In addition to the carbon cost of manufacturing these consumables, the disposal of these products is also associated with an environmental footprint if the products are not appropriately recycled.

The identification of areas for resource optimization in the catheterization laboratory on the basis of local practices and the operationalization of efficient practices are important strategies to reduce waste and decrease cost⁴⁴. These strategies include customizing catheterization laboratory kits to reduce waste and redundancy, providing a lean inventory of devices and stents to facilitate prioritization of equipment utilization and reducing non-use of products owing to expiration dates. An example from the surgical literature suggests that tray customization can also lead to reduced cost⁴⁵. Other strategies include ensuring that renewable power is used for both the laboratory and the washing and sterilizing of equipment; reducing the use of single-use items such as gloves, gowns and drapes; implementing recycling programmes for materials, such as metal and plastic that can be feasibly recycled; the installation of energy-efficient equipment and lighting; reducing power use during down times; and eliminating paper usage by implementing electronic medical records and digital communication⁴¹. Angiographic and interventional catheters pose a challenge for re-processing (that is, the processes involved in the cleaning, disinfecting, sterilizing and repackaging of used catheters for reuse in subsequent procedures), given the long narrow lumens and the need to ensure integrity of the system before reuse. Deflated balloons generally do not regain the tight shape of new balloons and might harbour organic debris that can be detectable by electron spectroscopy, which might preclude their use, except in under-resourced situations⁴⁶.

Electrophysiology

Cardiac arrhythmias are common, and the incidence of the disease is likely to increase, given the ageing population. Annually in the USA, >75,000 ablations for atrial fibrillation are performed⁴⁷ and approximately 250,000 pacemakers are implanted⁴⁸. An analysis of the environmental cost of atrial fibrillation ablation procedures limited to the operating room (including anaesthesia) was performed in France⁴⁹. The investigators surveyed 30 procedures over 8 weeks (18 pulmonary vein isolation, 7 complex radiofrequency ablation and 5 cryoablation procedures). The mean emission was 76.9 kg of CO₂e, 75% of which was attributable to the ablation procedure and 25% to anaesthesia. Among the life-cycle phases examined in this study, material production and manufacturing represented 71% and 17% of the total sources of pollution, respectively, whereas 11% was attributable to transport and 1% to product use. Electrophysiology catheters contributed to 39% of GHG emissions and electrocardiogram patches contributed to 9%. The researchers estimated that worldwide emission from atrial fibrillation ablations (assuming 600,000 procedures annually) was 125 tonnes of CO₂ every day, equivalent to driving 700,000 km (ref. 49). Similarly, another single-centre study of 160 patients undergoing pacemaker implantation and enrolled in a remote monitoring programme between 2016 and 2017 in Spain quantified the carbon footprint of each patient journey. The investigators estimated that the carbon footprint was 138 ± 114 kg of CO₂e, with an estimated saving of 15 ± 33 kg of CO₂ per remote-monitoring cycle⁵⁰.

Remote monitoring is especially applicable in electrophysiology and can reduce transportation-related GHG emissions. For example, a review of a national remote monitoring provider involving 32,811 patients from 67 device clinics in the USA assessed the degree of carbon-saving on the basis of national fuel efficiency data. Remote monitoring resulted in total travel saving of 31.7 million miles, a cost saving of US$3.5 million and a net saving of 12,596 tons of CO₂ emissions, equivalent to approximately 15,000 acres of forest saved and >200,000 new trees planted for 10 years⁵¹. However, this study did not account for increased energy use for cloud computing and hardware manufacturing required for a remote-monitoring clinic.

In a survey of 278 electrophysiologists in 42 centres across Europe, these physicians reported that 50% of mapping catheters and 53% of ablation catheters were discarded to medical waste, with only 20% and 14% of mapping and ablation catheters, respectively, being reused⁵². Physicians identified reuse of these catheters, as well as a reduction and recycling of packaging materials, as potential solutions to improve sustainability. Physicians identified a lack of engagement from host institutions to be the most common barrier to implementing these sustainability solutions (59%), followed by complexity of the process and challenges to behavioural change (48% and 47%, respectively). The most-mentioned strategies to improve sustainable practices were regulatory changes, education and product after-use recommendations⁵². In concordance with these survey results, other studies have suggested that reutilization of catheters might have a substantial effect on the carbon footprint of electrophysiology procedures. A modelling study used LCA to estimate that utilization of re-manufactured catheters in electrophysiology procedures could reduce carbon footprint by 50% and abiotic resource use by 29%⁵³. A 2024 position paper by the Working Group of Cardiac Pacing and Electrophysiology of the French Society of Cardiology has emphasized the importance of sustainability in cardiac electrophysiology and highlighted the potential of reprocessing single-use medical devices to reduce its environmental effects, calling for collaboration among stakeholders to drive innovation and explore sustainable practices, and emphasizing the importance of disease prevention programmes⁵⁴. Single-use medical devices, particularly electrophysiology catheters, can be reprocessed in many Western countries, including the USA, but this practice is not yet widely adopted. In Europe, debates are ongoing to harmonize the recommendations for the use of reprocessed devices.

Surgery and perioperative emissions

The operating room contributes substantially to GHG emissions via the use of inhaled anaesthetics, cooling and electrical facilities, and the need for surgical supplies and personal protective equipment. Much of the LCA work in anaesthesia and critical care has focused on comparing reusable and single-use equipment, with a few studies detailing emission rates on the basis of surgery type, surgical approaches, perioperative pharmaceuticals and perioperative services⁵⁵. Most studies have shown a cost benefit for single-use anaesthesia devices compared with reusable equipment, such as face masks, rigid and video laryngoscope handles and blades, and breathing circuits, with some studies demonstrating a carbon benefit for single-use anaesthesia devices^55,56. The reuse of equipment that can be purchased in bulk and thus has economies of scale, such as surgical linens, might be more beneficial than single-use forms, given that its reuse could generate less carbon emissions and be associated with lower costs⁵⁷. Of note, much less is known about the cost of pharmaceuticals in cardiovascular care, given that the LCA of the manufacture and use of active ingredients are challenging and seldom disclosed by companies. Specific LCAs in the cardiothoracic operating room have not yet been conducted.

Volatile hydrofluorocarbons (such as desflurane, isoflurane and sevoflurane) and non-volatile anaesthetics (such as nitrous oxide) are used routinely during intraoperative cardiac care. All inhaled anaesthetics are potent GHGs, with a global warming potential 100–1,000 times that of CO₂. Nitrous oxide also contributes to the depletion of the ozone layer⁵⁵. The contribution of anaesthetic gases during intraoperative cardiac care to total global GHG emissions is estimated to range from 0.01% to 0.1%, with desflurane and nitrous oxide accounting for most of the measured emissions from anaesthetic gases⁵⁵. A study comparing the operating rooms of a hospital in Canada, the UK and the USA found that anaesthesia could produce greater CO₂ emissions than that from all surgical equipment used and the heating, ventilation and air conditioning (HVAC) system of the operating theatre combined, if desflurane was used as the anaesthetic gas. However, when sevolurane was used, this anaesthetic gas contributed only 4% of the CO₂ emissions of the procedure, with 84% arising from the HVAC system and 12% from the surgical equipment⁵⁸. Of note, none of the institutions assessed in the study used nitrous oxide for anaesthesia. Therefore, substituting the use of desflurane and nitrous oxide with other anaesthetic gases could have the greatest effect in reducing the carbon footprint of the operating theatre, alongside improvements in the energy efficiency of HVAC systems. Box 2 details some of the measures to reduce the carbon footprint of anaesthetic use during cardiac procedures. Additional areas of focus include the use of providers of renewable electricity, reducing waste via recycling, and reusing supplies and equipment. A study of 28 cardiac surgeries over a 4-week period in France showed that the mean estimated GHG emissions per surgery was 124.3 kg of CO₂e; 10% of this emission rate was related to anaesthesia (predominantly halogenated gases) and 89% was related to the use of disposable medical products⁵⁹. In another study that estimated emissions from intensive care units, the CO₂ emissions in both the USA (178 kg CO₂e per patient) and Australia (88 kg CO₂e per patient) were mostly attributable to energy use of the HVAC systems (75%), with plastic waste, nutrition, laundering, and ventilator and machine use contributing only minor emissions⁶⁰. Implementing operating room ventilation setbacks while the room is not in use is one key strategy to reduce the GHG burden of the operating suite. Existing systems are designed to ensure that environmental conditions are returned to appropriate levels before procedures begin^61–63.

Box 2 |. Strategies to reduce pollution from anaesthetic gas.

Cardiothoracic operating rooms 116

● Reduce inhaled anaesthetic use; when possible, substitute with intravenous, regional or neuraxial anaesthesia

● Avoid use of desflurane and nitrous oxide

● Reduce fresh gas flow rates, including during induction

Buildings

● Decommission old buildings and avoid central piping of nitrous oxide, substituting portable tanks when possible

● Consider technologies to treat and reuse anaesthetic gas, only after all other strategies are exhausted

Regulations and standards

● Avoid nitrous oxide use as a refrigerant during cryosurgery

● Enforce national reporting and mitigation of inhaled anaesthetic use, consistent with international guidelines

Cardiovascular imaging

An estimated 10 billion medical radiology exams are conducted worldwide each year, with the medical imaging field estimated to contribute to approximately 1–10% of the carbon footprint attributed to health care⁶⁴. This percentage ranges from 4% in the UK to 10% in the USA. The carbon emissions from CT scanners and MRI units are expected to increase by 30% between 2018 and 2030 (from 0.344 gigatonnes to 0.497 gigatonnes)⁶⁵. Cardiac imaging specialists should therefore be educated on the carbon footprint of cardiac imaging and should contribute to devising more sustainable solutions⁶⁶ (Table 1). An LCA comparing echocardiography, MRI and single-photon emission computed tomography (SPECT) imaging has shown that MRI had the highest carbon footprint, with SPECT producing between 4% and 11% of the carbon cost of MRI and echocardiography having the smallest carbon footprint (0.5–2.0% of the carbon cost of MRI, although contrast and stress agents were not accounted for)⁶⁷. Emissions from imaging accrue from purchased electricity related to the heating and cooling of the buildings housing the imaging equipment, the carbon cost of the equipment (scanner parts and intravenous lines), and the associated pharmacological and contrast agents required (such as iodine and gadolinium). In addition to these sources of emissions, other hidden carbon costs are associated with equipment maintenance. Of note, this study did not include the environmental effect of radionuclide contrast agents used in nuclear cardiology, which are associated with substantial carbon footprint and other environmental costs related to the production, transportation, emission and waste management of radioactive isotopes. Radioactive waste expenses have increased substantially over time, with increasing use of nuclear medical imaging, and the ecological consequences of radioactive contamination should not be overlooked. Considering the high volume of procedures and the rising costs associated with radioactive waste management, the environmental effects of nuclear cardiology are likely to be substantial.

Table 1 |.

Estimated CO₂-equivalent emissions and evidence gaps for cardiovascular procedures

Cardiovascular examination or procedure	Estimated CO2-equivalent emissions	Evidence gaps
Cardiac MRI	17.5 kg per scan	Limited data on environmental effects of contrast agent; environmental effects of older equipment not considered
Cardiac CT	9.2 kg per scan	Limited data on environmental effects of contrast agent; variability in environmental effects of equipment and protocols
Echocardiography	0.5 kg per scan	Limited data on environmental effects of contrast agent; variability in environmental effects of equipment
Cardiac positron emission tomography	NA	Comprehensive life-cycle assessment needed, including radiotracer production
SPECT myocardial perfusion imaging	NA	Comprehensive life-cycle assessment needed, including radiotracer production
Coronary angiography	NA	Environmental effects of single-use equipment and contrast agents not quantified
Percutaneous coronary intervention	NA	Environmental effects of single-use equipment, contrast agents and waste management not quantified
Electrophysiology study and ablation	76.9 kg per procedure	Limited data on environmental burden, given the variability in equipment type and procedure duration
Pacemaker implantation	138 kg per patient	Environmental effects of device manufacturing and waste management not fully quantified

Data from refs. 27,49,50,67. NA, not available; SPECT, single-photon emission computed tomography.

In an LCA of five imaging modalities in Australia, the mean CO₂ emissions were 17.5 kg per scan for MRI, 9.2 kg per scan for CT, 0.8 kg per scan for chest radiography and 0.5 kg per scan for ultrasonography⁶⁸. When expressed as emissions per scan using consequential analysis, which excludes emissions from standby power, the emission rates were substantially lower: 1.1 kg per scan for MRI, 1.1 kg per scan for CT, 0.6 kg per scan for chest radiography and 0.1 kg per scan for ultrasonography. Importantly, this LCA excluded the energy expenditure from the hospital HVAC systems and the room-specific air conditioning requirements needed to maintain the CT and MRI scanner rooms at 18 °C. This exclusion was made to ensure more generalizable results, irrespective of geographical location and time of year. In addition to the direct carbon emissions from imaging equipment and facilities, the environmental effect of contrast agents used in various imaging modalities should also be considered. Iodine-based and gadolinium-based contrast agents used in CT, fluoroscopy and MRI have been found in sewage and drinking water^69–71, raising concerns about their ecological consequences. Contrast agents used for ultrasonography, which often contain GHGs such as sulfur hexafluoride⁷² or perflutrens⁷³, have a notable global warming potential. Although the carbon footprint of contrast agents per examination might be relatively small compared with the emissions from the imaging equipment itself, the cumulative effect on a population scale can be substantial, given the widespread use of these agents.

Using 100% renewable energy sources to power the imaging equipment will eliminate much of the carbon footprint associated with medical imaging. Until then, activation of energy-saving modes for CT and MRI scanners when the machines are not in use will reduce overall emissions, as will reducing associated supplies, such as intravenous injection lines and contrast material, and lowering the use of ancillary peripherals. Finally, the energy used to maintain climate control when the imaging suite is not in use might contribute substantially to emissions, and so the machines should be turned off whenever possible. Careful consideration of the need for advanced imaging and using low-cost alternatives might also reduce emissions.

For example, using gatekeeper calcium scoring in the work-up of patients with chest pain might prevent additional unnecessary testing⁷⁴. The effects of patient transportation also contribute to the carbon footprint of cardiovascular imaging⁷⁵. Many patients require imaging studies that are performed at a different location from their primary care facility. Optimizing location-based imaging resources, improving geographical access and using point-of-care imaging when possible could potentially reduce overall carbon footprint, given that the alternative option of having fewer scanners that are heavily used, with patients travelling to the location, might still generate fewer emissions. This comparison requires further assessment. Finally, choosing an imaging modality on the basis of carbon emissions, and using carbon emissions as part of a multi-decision criteria analysis or included as an additional cost in a cost-effectiveness analysis might shift choices around imaging modalities. Educating cardiac imaging specialists about the carbon emissions associated with radiological testing might help to reduce unnecessary testing and promote a shift towards high-value, low-cost tests⁷⁶.

Integrating GHG emissions into health-care decisions

Emerging data suggest that sustainable health care does not require large investments and could have a net positive benefit very early after the introduction of such practices¹². The National Health Service in England has reported that the costs of reducing emissions associated with energy use can be cost-neutral for nearly 80% of emissions⁷⁷. For the remaining 20% of emissions, there is an upfront investment cost, but this cost can be recouped in 3.5 years. According to the Commonwealth Fund, cost savings accrued by efficiencies in energy use and improvements in waste management in operating rooms could be substantial⁷⁸.

Strategies to reduce carbon emissions, such as a formal economic and societal analyses of the cost of damage from an additional tonne of CO₂ emitted, establishing the price of carbon-offsetting credits (purchasing credits or certificates to compensate for emissions elsewhere) and marginal abatement costs (additional costs incurred to reduce one unit of pollution to meet targets), calculated on the basis of costs to reduce emissions to reach a given target, are all largely irrelevant to health care, given the priority afforded to saving lives. A more restrictive approach in which carbon emissions can be thought of as an additional factor in decision-making for health care (provided that the interventions themselves are equally efficacious and safe) has been proposed²⁷. This approach includes choosing a medical or surgical intervention on the basis of carbon emissions (assuming that cost, efficacy and safety are the same); adopting a multi-decision criteria analysis, which is a method for systematically evaluating and ranking alternative interventions on the basis of multiple criteria to support decision-making; and monetization and inclusion in a cost–benefit analysis or being included as an additional cost in a cost-effectiveness analysis. For any of these strategies, a full process-based LCA is typically required to provide input for further modelling. Although the work required to catalogue the LCAs for each health-care activity (for example, substituting a new stent) will initially require considerable effort, a catalogue or inventory of the emissions associated with common procedures and interventions can be developed to serve as a repository. The emission levels associated with the addition of a new health technology (such as the use of a new sustainable fluoroscopy system) can subsequently be derived from such a repository. Incorporating the cost of carbon emissions into cost–benefit assessments for health-care interventions could also provide a more comprehensive evaluation of their true economic burden. For example, the additional carbon cost for a cardiac MRI or CT scan could be calculated on the basis of the estimated CO₂ emissions per scan and the assumed cost per unit of carbon emissions. Although the per-scan carbon cost might be relatively low, the aggregated economic burden across high-volume procedures could be substantial. Future research should aim to quantify this burden and develop standardized methodologies for integrating carbon costs into economic evaluations of health-care interventions.

Expanding the scope: system-wide sustainability initiatives

Sustainable hospital food and cafeterias

Reducing food wastage is one approach to reduce carbon emissions, given the embodied carbon emissions required to both produce and dispose of food⁷⁹. Food waste makes up approximately 10–15% of all waste atan average hospital⁸⁰. Foodwaste is typically defined as waste resulting from primary production, distribution, preparation and consumption of food. Disposal of uneaten food is the leading cause of hospital-related food waste, with evidence indicating that hospitals generate three times more plate waste (food served but not eaten) than cafes and restaurants⁸¹. Many hospital cafeterias in the USA do not have composting programmes or do not even routinely recycle plastics and other components, and only a few examples of food donation from hospitals were noted in the literature⁸².

In 2019, the American Medical Association called on health-care facilities in the USA to eliminate all processed meats and foods high in saturated and trans fatty acids from daily menus, and provide healthier, plant-based meals⁸³. The WHO European Office for the Prevention and Control of Noncommunicable Diseases published a statement supporting healthy plant-based diets, which will reduce or eliminate the intake of animal products and have benefits on human, animal and environmental health⁸⁴. A 2019 Lancet commission report has emphasized the urgent need to transform our global food system to achieve sustainable development and climate goals. The report advocates for a shift towards healthy, plant-based diets and sustainable agricultural practices, and defines a ‘planetary health diet’ that is adaptable to different cultural contexts. Achieving a sustainable food system requires a multisectoral, collaborative approach involving policymakers, industry partners, health-care professionals and consumers⁸⁵. However, despite these declarations, hospital cafeterias tend to have less-than-optimal choices for patients and personnel requiring healthy, sustainable diets⁸⁶.

Cardiovascular meetings

To mitigate the carbon footprint of in-person scientific meetings, conference attendees can consider alternative solutions, such as virtual conferences, which can reduce the need for long-haul transportation, particularly air travel. For example, a study of 949 registered participants attending a preventive cardiology conference in 2020 in Spain estimated that 1,157 tonnes of CO₂ emission was saved by converting the physical conference to a virtual conference. This emission rate is equivalent to the annual CO₂ production of 108 people living in high-income countries⁸⁷. Replacing printed posters with digital copies, reducing plastic use and optimizing conference location using emission data can also help to reduce the environmental footprint of cardiovascular meetings, but the trade-off of increased emissions related to the production of displays for digital posters should be further investigated. Accordingly, innovative solutions for cardiovascular meetings, lectures and grand rounds need to be considered to optimize learning and interaction, and yet reduce waste. However, cardiovascular societies have missed opportunities to adopt more sustainable practices and educational sessions to inform practitioners and guide research on environmental sustainability.

CVD prevention as a primordial principle in achieving sustainability

Much of the environmental footprint in cardiovascular practice is related to interventional treatment. As such, shifting the current therapeutic paradigm in CVD towards primordial and primary prevention is important to achieve environmental, social and financial sustainability. Earlier and more transformative interventions can be most effective and deliver the lowest overall intensity per unit of well-being over the long term⁸⁸. Over time, such an approach will have substantial environmental benefits. Preventive measures can include initiatives such as reducing the costs of preventive services, earlier lifestyle interventions and policies to reduce sugar-laden beverages and tobacco sales, which in addition to lowering emissions related to health-care utilization can also reduce the emissions associated with the production of these products. Sustainable cardiovascular practice requires social determinants of disease to be addressed by promoting healthy lifestyles, improving access to health care and addressing the root causes of poverty and inequality. Many win–win opportunities have a long latency period before pay-off. Aside from addressing sustainability goals, innovative primordial prevention programmes might offer superior customer satisfaction and loyalty to health-care organizations because they are generally associated with the creation of well-being before disease onset, include investment in the health of employees rather than treatment of disease, and provide new revenue streams and potentially larger reimbursements for avoidable care and hospitalizations in value-driven frameworks.

Prevention of plastic waste

Single-use and short-lived plastics account for 35–40% of current plastic production and are pervasive in urban environments⁸⁹. In the USA, only a small percentage of plastic health-care equipment is reused⁹⁰. During use and disposal, plastics can release toxic chemicals, including carcinogens and neurotoxicants, as well as endocrine disruptors such as phthalates, bisphenols, perfluoroalkyl and polyfluoroalkyl substances, organophosphate flame retardants and residual monomers into the environment⁸⁹. The reduction of single-use plastics in health care can reduce pollution and contribute to a reduction in GHG emissions⁸⁹. The Minderoo–Monaco Commission on Plastics and Human Health has recommended that a central provision of the Global Plastics Treaty should be a global cap on plastic production guided by targets and timetables and supported by national commitments⁸⁹. Additional recommendations include the elimination of unnecessary uses of plastics, especially single-use plastics, in health care; the need for plastic manufacturers to take full financial responsibility for their products across their life cycle (extended producer responsibility); the need for a reduction in the complexity of plastics; the need for health-protective standards for plastic-associated chemicals; and the possibility of listing plastics as persistent organic pollutants, under the Stockholm Convention⁸⁹. Crucially, potential trade-offs and alternatives should be considered, such as reusable medical devices and supplies. However, this approach requires reliable sterilization infrastructure and protocols to prevent the spread of infection. In certain contexts, single-use plastics might be necessary for infection prevention and control. A balanced approach that prioritizes patient safety while reducing unnecessary plastic waste is needed, along with research and development of more sustainable materials and technologies for medical applications.

Circular economic principles in health care

The circular economy concept has attracted considerable attention in the past decade, including the work commissioned by the Ellen Mac-Arthur Foundation and the European Commission’s Circular Economy Package, as well as the development of a standard for implementing the principles of the circular economy in organizations⁹¹. The circular economic framework originally comprised the four Rs: reduce, reuse, recycle and recover. However, this framework has since expanded to the nine Rs: refuse, rethink, reduce, reuse, repair, refurbish, remanufacture, repurpose, recycle and recover. A circular economy necessitates substantial changes in design, consumption and reuse practices⁹². Circular economic principles have been implemented in numerous health-care contexts, in which health-care organizations plan to develop circular product solutions, such as the refurbishment or remanufacture of scanning equipment or surgical instruments (including blood pressure cuffs, catheters and oxygen masks) and the reuse or recycling of packaging material. The use of reusable surgical gowns, laundered hats and dedicated theatre footwear (removing the need for single-use overshoes) reduces the financial costs and carbon emissions of single-use clothing, without jeopardizing infection control standards^93,94. Circular economic principles can also be adopted in food systems and in the pharmaceutical industry to allow the generation of biochemical feedstock and power⁹⁵ (Fig. 3). Cities and governments can contribute to laying the foundations and incentivizing systems that support a circular economy in these areas⁹⁶. For example, government leaders can develop urban planning strategies that encourage collaboration between health-care facilities and other industries, invest in eco-industrial parks and provide financial incentives for organizations adopting sustainable practices. Governments can also establish regulations and standards, invest in local recycling and remanufacturing infrastructure, and promote public–private partnerships to conduct research and develop innovative circular economy solutions. Box 3 summarizes high-level actions for a health-care organization that might accelerate decarbonization efforts^31,97.

Fig. 3 |. Butterfly representation of the circular economy principle adapted for health care.

The figure depicts the reduce, recycle and reuse principles as they apply to foods, pharmaceuticals and medical supplies and various stages in their manufacturing, use and disposal. Data from ref. 91.

Box 3 |. Strategies to achieve net zero carbon emissions.

● Use clean, renewable electricity: decarbonize electricity purchased by the health industry

● Invest in buildings and infrastructure that are energy efficient and have zero emissions: support the design and construction of energy-efficient and climate-resilient hospitals and clinics, using green building standards

● Improve sustainable travel practices and transition to the use of zero-emission vehicles: promote the use of public or shared transportation, and transition to the use of low-emission or zero-emission vehicles

● Promote healthy and sustainably grown food and reduce food waste: provide healthy, sustainably sourced plant-based meals, and establish strategies to reduce food waste and avoid the use of single-use plastic cutlery and packaging

● Incentivize the production of low-carbon pharmaceuticals and reduce unnecessary pharmaceutical use: replace high-emission products with more environmentally friendly products and avoid unnecessary prescription of medicine

● Use the circular economy principles to managing supply procurement and waste disposal: establish strategies to reduce health-care waste and address circularity concepts during product and service procurement

● Improve health system efficiencies: minimize unnecessary practices and maximize effectiveness in operations and supply chain purchasing

Strategies to implement sustainable health care

Green bundling in health care

Extensive research indicates that consumer demand or stated commitments towards eco-friendly products often diverge from actual purchasing behaviours, termed the green paradox⁹⁸. The concept of green bundling suggests that the combination of private benefits of a product or service with public or environmental benefits creates complementarity and results in a greater likelihood of a consumer following through on their sustainability commitment⁹⁹. Accordingly, with the bundling of environmental effects and health, health-care professionals and organizations can prioritize environmentally friendly services to safeguard the health of the communities they serve.

Systems thinking and innovation

Health-care systems are complicated by multiple feedback loops, time delays and non-linearities. Specific tools and processes are need to help health-care organizations and their leadership to embrace system complexity, facilitate individual and organizational learning, and promote the technical, economic and social transformation required for a sustainable system⁴. A health systems audit to assess operational aspects, resource utilization and sustainability practices can help to identify leverage points, with a substantial effect on cost and emissions framework. A systems framework can also help to identify and engage multiple stakeholders, including patients, policymakers and the public (Box 4), and help them to understand the effect of health-care decision-making on the environmental footprint. Policies to improve sustainability in the health sector must consider the complexity and the needs of multiple stakeholders. Systems dynamics modelling and other modes of simulation can help to identify the most effective interventions and solutions. Understanding capability traps is crucial, whereby organizations are consumed with immediate challenges (‘firefighting’) and struggle to allocate resources to error prevention. Capability traps can explain why organizations might neglect investments in sustainability and efficiency, despite the clear positive returns on such investments^100–103. In regions with limited resources, frugal innovations to improve sustainability without compromising patient safety or clinical outcomes are needed⁹⁴. Frugal innovations have been most widely implemented in low-income and middle-income countries where the primary objective is providing care for more people, with environmental gains being a co-benefit⁹³. Empirical evidence from both high-resource and low-resource settings has demonstrated the safety of reusing and extending the shelf-life of catheters^104–106 and devices^107,108. Recommendations for reducing the health-care-related environmental footprint for practising cardiologists are listed in Box 5.

Box 4 |. Policy framework to reduce health-care emissions.

National  ● Nationally mandated air pollution and carbon accounting for the health sector  ● Integrating accountability for environmental sustainability into the current value framework   ‐ Developing performance metrics for measuring air pollution and greenhouse gas emissions for health systems   ‐ Technology-enabled data sharing   ‐ Financial incentives for decarbonization  ● Payment reform   ‐ Inclusion of limits on facility emissions as a new variable for compliance with Medicare coverage (in the USA)   ‐ Integrating emissions metrics with population health metrics with an incentive to lower emissions and increase value in a value-based health-care framework

Regional or statewide  ● Statewide air pollution and carbon accounting of hospitals and health facilities  ● Reduce carbon emissions by procuring from suppliers with lower carbon footprints, environmental product declarations, sustainability reports and other third-party databases

Hospital or individual  ● Establishing a hospital-wide oversight body for monitoring greenhouse gas and air pollution emissions  ● Setting goals to reduce carbon footprint, accounting for patient medical complexity  ● Educating and spreading awareness on measures to reduce environmental pollution and carbon footprint

Box 5 |. Recommendations for cardiologists.

Stewardship of judicious cardiovascular testing Cardiologists should be stewards of judicious cardiovascular testing and reduce unnecessary and inappropriate examinations. Up to 30% of cardiovascular imaging tests might be inappropriate, and reducing these unnecessary tests can have a substantial effect on the environmental footprint of cardiovascular care.  ● Consider carbon footprint when choosing imaging modalities: when choosing between different imaging modalities, in addition to diagnostic accuracy, safety and cost, cardiologists should consider the environmental footprint of the imaging scan. Echocardiography has a substantially lower carbon footprint than cardiac MRI or nuclear cardiac imaging. The judicious use of a contrast agent during imaging procedures should be encouraged.  ● Educate patients about environmental costs: cardiologists should educate patients about the carbon and environmental costs of cardiovascular procedures. They can develop an informed consent form that transparently discloses the economic costs, radiation exposure (when relevant) and carbon emissions associated with the procedure or imaging test. Having patients understand these economic and environmental costs will positively influence prescription patterns and patient decision-making.  ● Reduce waste in the catheterization and electrophysiology laboratories: in the invasive cardiovascular laboratories, cardiologists should work to reduce waste by optimizing inventory, using reprocessed devices when safe and feasible, and implementing recycling programmes. They should collaborate with the supply chain providers to optimize catheterization and electrophysiology laboratory packages to reduce unnecessary waste.  ● Advocate for renewable energy sources: cardiologists should advocate for the use of renewable energy sources to power cardiovascular care facilities. They should support energy efficiency measures and reduced energy consumption during off-peak hours.  ● Leverage telehealth and digital health technologies: when possible, cardiologists should leverage telehealth, remote monitoring and digital health technologies to reduce patient travel and associated emissions. However, they should also be cognizant of the environmental effect of digital technologies.  ● Professional activities: in professional activities, cardiologists should make sustainable choices, such as reducing air travel to meetings, choosing plant-based meals and reducing reliance on single-use plastics. They should support sustainability initiatives from their professional societies.  ● Advocacy: cardiologists should advocate for sustainability as a core component of value-based cardiovascular care. They should educate policymakers and payers about the environmental and public health co-benefits of a sustainable, prevention-oriented approach to cardiovascular health.

Future challenges in sustainability

The idea of ‘sustainable growth’ might be an oxymoron¹⁰⁹. Herman Daly articulated three necessary conditions for sustainability in any finite environment: first, renewable resources cannot be used faster than they can be replenished; second, pollution and waste cannot be generated faster than they accumulate or are rendered harmless; and third, non-renewable resources cannot be used at all¹⁰⁹. Under this paradigm, we are nowhere close to being a sustainable society, with further growth in population and affluence that is rapidly deepening unsustainability¹¹⁰.

Technological solutions and market incentives have also been suggested to spur innovations to substantially shift carbon emissions. A modelling study has suggested that a reduction in emissions cannot be achieved in a growth framework of increasing GDP even under conditions of steady-state population, unless there are simultaneous and substantial reductions in emissions intensity, through technological innovation, which might not always be realistic¹¹¹. However, in the near term, before reaching a steady state in economic growth, there might be opportunities for creative solutions that foster sustainability and yet allow and facilitate monetary incentives to develop new growth opportunities in climate technologies, which might serve the purpose of reducing GHG emissions and pollution. Reducing the environmental burden of health care can have economic benefits. The Inflation Reduction Act in the USA and the European Green Deal includes provisions that could help the health-care sector to reduce its GHG emissions^12,112,113. Of note, although implementing sustainability solutions in health care is crucial, these solutions might have potential risks and trade-offs that should be carefully studied and addressed. For example, if not properly managed, efforts to make the supply chain more ‘frugal’ and minimize waste could inadvertently increase the risk of shortages. Similarly, strategies to reduce energy consumption by turning off or powering down capital equipment during off-hours could potentially lead to delays in patient care if the equipment is not readily available when needed. As health-care organizations adopt sustainable practices, they must carefully balance the benefits with the potential risks and ensure that patient care and safety remain the top priority. Conducting thorough risk assessments, developing contingency plans and engaging stakeholders in the decision-making process can help to mitigate potential drawbacks.

Conclusions

Health-care organizations have a crucial role in reducing their environmental burden by reducing global GHG emissions. Cardiovascular practice is associated with a substantial environmental burden owing to high-energy-consumption procedures and waste generated during the production and disposal of devices. Implementing more sustainable practices, such as improvements in energy efficiency, adoption of renewable energy and the development of sustainable transportation and cardiovascular practices can help health-care organizations to reduce their carbon and environmental footprint and contribute to global efforts to mitigate climate change in a cost-effective manner.

Key points.

• Cardiovascular health and environmental health are interlinked; sustainable cardiovascular care is crucial for reducing emissions and pollution while improving outcomes.

• Cardiovascular care has a large environmental footprint owing to high energy use and waste from devices and procedures; this footprint needs further quantification.

• Strategies such as energy efficiency, renewable energy, waste reduction, disease prevention, innovation and circular economy principles can reduce carbon emissions and costs.

• Lack of transparency and regulatory levers hampers current sustainability efforts, but frameworks for disclosures, target setting and reporting emissions are emerging.

• Health-care leaders should measure emissions, set reduction targets, redesign care and engage stakeholders to transition towards sustainable models that improve value, outcomes and planetary health.