The American College of Cardiology/American Heart Association 2017 hypertension guideline: Implications for incorporation in Latin America, the Caribbean, and other resource‐limited settings

1. INTRODUCTION

The American College of Cardiology (ACC), the American Heart Association (AHA), and several other organizations jointly produced the 2017 Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults, which was published in late 2017.1 While comprehensive and instructive, some components of this guideline were met by controversy and welcomed debate. The major controversial issues include the redefinition and reclassification of hypertension, new blood pressure (BP) treatment thresholds and targets, and the inclusion of individual cardiovascular risk evaluation in treatment decisions. Additionally, the guideline places increased emphasis on lifestyle modification, out‐of‐office BP measurements, fixed‐dose combination drug therapy, and a team‐based approach to the management of hypertension.

The evidence behind these bold recommendations, as well as the practicality of their inclusion in real‐world practice, have been questioned in the United States and other Western, high‐income countries. Many of these nations have well‐developed healthcare systems, and, despite this, might find it difficult to adopt some aspects of this new guideline. Consequently, societies such as the American College of Physicians, the American Academy of Family Physicians, and Hypertension Canada, have disagreed with some aspects of the new ACC/AHA hypertension guideline. Arguments have been made against the new classification of hypertension, the lower BP treatment thresholds, and the new BP targets now being recommended. To this end, these organizations have opted not to make significant changes to their existing treatment guidelines.2, 3 However, the discussion surrounding the application of this new hypertension guideline in Latin America and the Caribbean, a setting that lacks country‐specific or up‐to‐date regional guidelines,4 has been sparse.

Here, we will explore the practicality of the ACC/AHA 2017 hypertension guideline on the management of hypertension in low‐ and middle‐income countries (LMICs), particularly those in Latin America and the Caribbean. We will also discuss strategies to improve cardiovascular outcomes in these settings.

2. NEW GUIDELINE WITH NEW TARGETS

The 2017 ACC/AHA hypertension guideline is an update of the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7), published in 2003.5 The theme “lower is better” is dominant in the new 2017 ACC/AHA guideline with a complete reclassification of BP. Hypertension is here defined as a BP ≥ 130/80 mm Hg, a threshold that previously would be considered prehypertension. Other significant changes include new BP ranges for defining stage 1 and stage 2 hypertension, as well as the elimination of the category “prehypertension” (Table 1).

Table 1.

New BP classification compared with JNC 7

Systolic BP	Diastolic BP	AHA/ACC 2017	JNC 7
< 120 mm Hg	< 80 mm Hg	Normal BP	Normal BP
120–129 mm Hg	< 80 mm Hg	Elevated BP	Prehypertension
130–139 mm Hg	80–90 mm Hg	Stage 1 hypertension	Prehypertension
> 140 mm Hg	> 90 mm Hg	Stage 2 hypertension	Stage 1 hypertension
> 160 mm Hg	> 100 mm Hg	Stage 2 hypertension	Stage 2 hypertension

ACC, American College of Cardiology; AHA, American Heart Association; BP, blood pressure; JNC 7, Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure.

Along similar lines, the treatment BP target, irrespective of cardiovascular risk factors, has been lowered to < 130/80 mm Hg. This is significantly lower than the previous 140/90 mm Hg target for the general population in prior versions of the guideline.

2.1. Evidence behind the ACC/AHA guideline

Driving a number of the changes in the 2017 ACC/AHA hypertension guideline were the findings of the SPRINT (Systolic Blood Pressure Intervention Trial). SPRINT demonstrated that in patients with hypertension at high risk for developing cardiovascular complications, reducing systolic BP (SBP) to a goal of < 120 mm Hg, when compared with a standard treatment goal of < 140 mm Hg, resulted in a 25% reduction in primary cardiovascular end points and all‐cause mortality. This was led primarily by a reduction in the rate of the development of congestive heart failure in the < 120‐mm Hg treatment arm.6

Although noteworthy, the clinical applicability of SPRINT has been questioned. Important considerations, which may also be relevant to LMICs, particularly those in Latin America and the Caribbean, include the following:

• The patient population had a high cardiovascular risk (on average 20% according to Framingham criteria), was elderly, and was already treated with approximately two antihypertensive agents. In addition, participants were deemed to be adherent to drug therapy before inclusion in the study.

• Intensive facility and staff resources were available during the trial.

• The method of measuring BP (automated and largely nonobserved) differed significantly from previous landmark hypertension clinical trials and standard clinical practice. This methodology has led some to suggest that the actual BPs obtained in SPRINT, if taken under typical, real‐world conditions, might have been as much as 10 mm Hg higher than those obtained during the study.7

Despite these observations, SPRINT was well designed and conducted and the results obtained are valid. It is the first study to demonstrate that intensive lowering of SBP to a goal of < 120 mm Hg in high‐risk patients with hypertension improves cardiovascular outcomes, including mortality.

2.2. Application of SPRINT: Can LMICs in Latin America and the Caribbean keep up with the pace?

From the outset, applying the findings of SPRINT to real‐world medicine has been deemed challenging and is likely to be impractical. Perhaps realizing some of the concerns of SPRINT, including the limited patient population and the methodology employed, as well as conflicting results from studies such as the HOPE‐3 (Heart Outcomes Prevention Evaluation) trial,8 the ACC/AHA guideline set the BP treatment target to < 130/80 mm Hg. This target is higher than the 120/80 mm Hg target set in SPRINT.

However, different than the well‐defined, high‐risk, restricted population of SPRINT, the ACC/AHA guideline extends the same BP treatment target of < 130/80 mm Hg to adults with hypertension of all ages, including persons with diabetes mellitus. This sweeping application to individuals who do not fit the SPRINT inclusion criteria was surprising to many, especially in the face of contradictory results from other trials2, 9; specifically, intense lowering of SBP to < 120 mm Hg in patients with diabetes mellitus, as was studied in the ACCORD (Action to Control Cardiovascular Risk in Diabetes) trial, which failed to demonstrate significant benefit in reducing the composite of primary cardiovascular outcomes when compared with an SBP < 140 mm Hg in the standard treatment group.10 However, the longer‐term, 9‐year follow‐up of the ACCORD participants, in what the investigators are calling ACCORDION (ACCORD Follow‐on) trial, suggests benefit in the < 120‐mm Hg treatment group.11

To date, there are limited data to confirm whether a reduction in cardiovascular outcomes can be achieved through the aggressive lowering of SBP achieved in SPRINT in other hypertensive settings, particularly, in patients with lower cardiovascular risk, younger individuals, current real‐world clinical care settings, and in populations such as the very elderly where greater harm caused by adverse effects may occur. These questions might be amplified when considering the implications of the guideline and SPRINT outcomes to LMICs in Latin America and the Caribbean.

2.3. Hypertension in Latin America and the Caribbean: a problem greater than guidelines, diagnostic thresholds, and targets

Hypertension is now a global public health problem and its impact on disease burden is amplified in the resource‐limited settings that define Latin America and the Caribbean. In this context, hypertension affects one third of the adult population. Of these hypertensive individuals, more than half are undiagnosed, approximately two third are untreated, and more than 80% are not adequately controlled to a BP of < 140/90 mm Hg.12 In Latin America and the Caribbean, this has resulted in an immense disease burden attributable to hypertension, quantified at 6.62% of disability‐adjusted life‐years.13

The barriers to the control of hypertension in Latin America, the Caribbean, and other resource‐limited LMICs are complex and vast, going far beyond the BP value at which hypertension is diagnosed and treated. Some key barriers include the following.14, 15, 16

2.3.1. Patient barriers

• Poor awareness of hypertension status

• Limited education surrounding the importance of BP control

• Adoption of Westernized patterns of urbanization, high‐sodium and calorie‐rich diets, and sedentary lifestyles

• Low motivation to achieving BP control

2.3.2. Provider barriers

• Poor adherence to guidelines (as low as 40% in Brazil)17

• Clinical inertia to initiate and modify treatment regimens in a timely manner

2.3.3. Health system barriers

• Lack of and/or fragmented healthcare infrastructure to adequately diagnose and manage hypertension and its target organ complications

Of these barriers, the low awareness of hypertension status (approximately 63% in Southern Latin America and lower in other LMICs) is possibly most crippling to successfully increasing the control rates of hypertension and thereby decreasing the cardiovascular and renal complications from hypertension.12, 18, 19

2.4. Focus on Hypertension Screening in Latin America and the Caribbean

In resource‐limited settings such as Latin America and the Caribbean, the present healthcare infrastructure, as mentioned above, is a barrier to the widespread screening for hypertension. This has contributed to the high rates of undiagnosed and untreated hypertension, as well as to the poor control rates seen there.

Fueling this problem is the presence of significant gaps in the provision of effective primary care services across the region, as has been highlighted in studies conducted in Brazil, Colombia, El Salvador, Jamaica, Mexico, and Panama.20 Consequently, access to appropriate healthcare facilities, particularly in remote rural locations, is often meager. This results in inconsistent screening for hypertension and poor follow‐up.21, 22 This is the case with aboriginal communities across the Caribbean and Latin America region, which have reported hypertension control rates as low as 14%.23

To address this deficiency, the Pan American Health Organization (PAHO) developed and made available tools for population‐based screening for hypertension in resource‐limited settings; however, use of these resources has been poor.13

The release of the new hypertension guideline and its associated lower thresholds for diagnosing hypertension brings to the forefront the need for improved strategies to screen for hypertension, particularly in the Caribbean and Latin America. Continued exploration of population screening, including the utilization of creative means for nonphysician screening for hypertension, is urgently needed.24 One practical strategy is to enhance community‐based screening for hypertension by building on existing infrastructure, which has been successful in addressing tuberculosis and HIV.14, 25 This approach has been employed in some African countries with positive results.26

2.5. Success stories from the region

Some success has already been achieved, through the efforts of both governmental and nongovernmental agencies, in increasing the awareness of chronic noncommunicable diseases, including hypertension, through an increased focus on population screening. In the Caribbean, there is the “Declaration uniting to stop the endemic of chronic noncommunicable diseases” (frequently termed the “Port of Spain Declaration”), which was signed in 2007 by the 15 member countries of the Caribbean Community.27 This government‐level commitment to decreasing the burden of noncommunicable diseases has been deemed a success and acts as an essential background for governments to mobilize the resources needed to conduct screening for hypertension.

Regarding nongovernment organization–led screening programs, several successful examples exist across the Caribbean. One such example is the recently concluded screening initiative conducted by the Healthy Caribbean Coalition, in which widespread screening for hypertension in Haiti, Saint Vincent and the Grenadines, Dominica, Jamaica, and Saint Lucia was undertaken.28 In Guyana, a recently concluded pilot study demonstrated that the establishment of pharmacy and pharmacist‐based screening of hypertension is feasible.29 This emphasis on hypertension screening and surveillance in Latin America and the Caribbean will be essential to the successful application of the new ACC/AHA hypertension guideline, if adopted in whole or in part.

2.6. Surge in hypertension prevalence in Latin America and the Caribbean: absorbing the impact

Adopting the new hypertension guideline will logically result in a surge in the number of people diagnosed with hypertension and those requiring care. In the United States, for example, if the new 130/80‐mm Hg diagnostic threshold were applied, the prevalence of hypertension among adults would reach as high as 50%, an increase of approximately 15%.1 Similar increases should be expected in Latin America and the Caribbean. This would result in a significant strain on resources, not only in developed countries but especially in LMICs, which are home to three quarters of the world's hypertensive population.30

The financial burden associated with hypertension is massive. Current global estimates of the cost of hypertension (both direct and indirect) are staggering, in excess of US $370 billion per year.31 In 2015, conservative estimates for select countries in Latin America, including Brazil, Chile, Columbia, Ecuador, El Salvador, Panama, Peru, Mexico, and Venezuela, noted an economic impact attributable to hypertension of US $5.3 billion. This equates to 0.12% of Gross Domestic Product32 which is certain to rise with the application of the new hypertension guideline. This is of added concern in LMICs, where a significant proportion of the financial impact of hypertension is absorbed through out‐of‐pocket spending by individuals.33

In this context, a “call to action,” similar to that triggered by the PAHO and the Centers for Disease Control and Prevention in 2013 to help combat the soaring impact of hypertension in LMICs in Latin America and the Caribbean14 is of even greater relevance in the face of these new guidelines

To successfully cope with these increased financial demands, strategic planning by health officials will be paramount, with efforts focused on the prevention of hypertension, as well as reducing the cost of managing individuals diagnosed with hypertension. Such planning will need to include the development and implementation of well‐structured, standardized, and simple programs. For example, one such program is the Standardized Hypertension Treatment and Prevention Project, now called the HEARTS in the Americas Initiative, which was recently piloted in Barbados, with noteworthy results.28 This program, which focuses on strengthening the healthcare system through the partnership of governmental and nongovernmental organizations and communities, is one viable way to move forward.34

2.7. Lower BP targets: can they be achieved in LMICs?

Under the new ACC/AHA guideline recommendations, hypertension should be treated to a BP target of < 130/80 mm Hg in most adults starting with the use of aggressive lifestyle modification alone or together with pharmacologic intervention. This key step depends on the presence of cardiovascular risk and/or the stage of the hypertension.

This new recommendation comes on the backdrop of the observation that achieving BP control, even when using a BP target of < 140/90 mm Hg, has been difficult in both high‐income countries and LMICs.35 This is true in most countries in Latin America and the Caribbean, in which population control of hypertension falls as low as 19%.12 Indeed, even in Westernized, high‐income countries such as the United States, the rate of control as defined by < 140/90 mm Hg is only 50% to 60% among adults.36

To best achieve these lower BP targets, strategies should be implemented to develop hypertension registries and to formulate simple diagnostic, treatment algorithms and evidence‐based guided medication formularies. These formularies should include effective, affordable, and readily available antihypertensive drugs, including fixed‐dose combinations, an approach that has been proven to be effective in improving control rates.37 This comprehensive approach will require health authorities in Latin America and the Caribbean to focus on both the effectiveness and the efficiency of the programs, which are already putting pressure on their limited health budgets.34 With this approach, the region can meet its goal of increasing population control of hypertension to 35% by 2019,38 as well as achieve the lower BP targets, if adopted.

2.8. Downstream effects of greater pharmacologic treatment in LMICs

Given the theme of the ACC/AHA guideline of a more intensive approach to the management of hypertension, undoubtedly more individuals will require additional antihypertensive medications to reach BP targets. This will likely have significant downstream effects. Indeed, an increase of 15% to 20% in the prevalence of hypertension could further aggravate the current situation of poor availability and affordability of BP‐lowering medicines, particularly in Latin America and the Caribbean.

Two of the new recommendations are particularly relevant in this regard. First, in addition to lifestyle modification, pharmacologic treatment is now recommended for individuals with stage 1 hypertension and a cardiovascular risk > 10% (moderate risk) using the atherosclerotic cardiovascular disease (ASCVD) risk calculator. It is estimated that this will affect approximately 5% of individuals with stage 1 hypertension in the United States.1 For persons with stage 1 hypertension and a cardiovascular risk < 10%, the recommendation is to encourage lifestyle modification and follow up in the next 3 to 6 months. Importantly, no explicit recommendation is offered as to what to do if lifestyle modification fails to reach a goal BP of < 130/80 mm Hg within this time frame. If the goal BP is not achieved in this group, providers may opt to initiate drug therapy.

Second, in individuals with stage 2 hypertension, (defined as a BP ≥ 140/90 mm Hg), if the goal BP is > 20/10 mm Hg from the treatment target goal of 130/80 mm Hg, it is now recommended to start treatment with two BP‐lowering medications. While the use of fixed‐dose combination therapy may help this situation, the added need for medications may pose a major challenge unless special measures are put in place to ensure sustainable medication procurement and increase pharmacy capacity.

Fortunately, in Latin America and the Caribbean, PAHO has in place a strategic fund for the acquisition of a core set of affordable BP‐lowering drugs available to each member state.39 Such initiatives will be key in offsetting the astronomical cost increase for the procurement of antihypertensive medications that might occur with the adoption of the AHA/ACC hypertension guidelines in Latin America and the Caribbean.

At the patient level, this new recommendation translates to increased drug costs, increased pill burden, and polypharmacy, especially if concomitant diseases exist. While the use of complimentary pharmacologic classes of antihypertensive agents may reduce drug‐related side effects, if BPs are lowered too rapidly or too low or there is an aggressive use of diuretics, an increased likelihood of undesirable side effects, such as dizziness, syncope, and falls may occur, especially in the elderly.

Results from SPRINT demonstrated that intensive lowering of SBP was accompanied by an increase in dosage, as well as number of antihypertensive agents, used. This led to an increased incidence of adverse effects, including syncope, falls, electrolyte abnormalities, and acute kidney injury. However, unlike the intense monitoring of patients that was available during SPRINT, individuals in LMICs in Latin America and the Caribbean are unlikely to have the close follow‐up needed to address these complications in a timely manner in order to avert more serious consequences.

2.9. Other considerations of the ACC/AHA guideline

Interestingly, the ACC/AHA guideline uses the ASCVD risk calculation, mentioned above, to determine the need for pharmacologic treatment in stage 1 hypertension (Table 2). This recommendation has significant implications in LMICs, including those in Latin American and the Caribbean.

Table 2.

Treatment of stage 1 hypertension based on 10‐y ASCVD risk

10‐y ASCVD risk	Recommendation
> 10%	Aggressive lifestyle modification and introduction of blood pressure–lowering medication
< 10%	Trial of lifestyle modification for 3 to 6 mo

ASCVD, atherosclerotic cardiovascular disease.

Even though the cardiovascular disease risk can be estimated without laboratory tests,40 the use of the ASCVD risk calculator might prove challenging in LMICs, where obtaining key laboratory data (such as the lipid measurements needed to use the ASCVD risk calculator) are at times difficult and/or limited. Additionally, there are limited data to confirm whether the pooled cohort equations used by the ACC/AHA ASCVD risk calculator are accurate in predicting ASCVD risk in non‐US settings, particularly in LMICs, for which the risk factors for cardiovascular complications are likely different. Indeed, there are no validated risk tables for most LMICs, where more than three quarters of deaths from cardiovascular disease occur.41

The PAHO has attempted to address this issue of regionally relevant cardiovascular risk calculators with the development of the PAHO/WHO cardiovascular risk calculator. This mobile phone application, which has been used increasingly in the region, uses WHO tables to estimate risk and might serve as an alternate, region‐specific tool instead of the AHA/ACC ASCVD risk calculator, which uses American populations.42

2.10. Changes in BP measurement

The new hypertension guideline has increased the emphasis on the technique of measuring BP in the office setting, as well as the use of out‐of‐office BP measurements to augment in‐office readings when making treatment decisions. Unfortunately, some aspects of these methods of measuring BP are not practical in real‐world practice, including those similar to the robust in‐office measurement performed in SPRINT. Thus, incorporating these recommendations in LMICs will prove challenging, given the limited availability of the dedicated clinic space, staff numbers, and level of training needed to perform BP measurements using the methodology in the guideline. Other limiting factors include the large numbers of patients, short visit times, and the availability of validated BP monitors.

Within Latin America and the Caribbean, one approach would be to place emphasis on the affordable acquisition of both office and home BP monitors, and streamlining their use in certain populations, eg individuals for whom the diagnosis of hypertension is not certain and for those whose hypertension is difficult to control. Similarly, emphasis could be placed on achieving BP measurements using proper technique and validated devices in multiple community settings, such as at pharmacies, supermarkets, worksites, and churches. Recently, success was seen in a novel barbershop BP monitoring program conducted in black communities. With this approach, most participants in the intervention arm achieved BP < 130/80 mm Hg. Emulating such a program in Latin America and the Caribbean could reap dividends.43

2.11. Making the recommendations work

Even though the new ACC/AHA hypertension guideline raises many questions and concerns, attempting to apply their recommendations, totally or in part, in LMICs, including those in Latin America and the Caribbean, may have a positive impact on decreasing the cardiovascular disease burden. However, for this to be realized, a robust effort will be required (Table 3).

Table 3.

Summary of potential impact and solutions for application of the ACC/AHA guidelines in LMICs

Recommendation	Impact	Solutions
Diagnose hypertension at a BP ≥130/80 mm Hg	Increased hypertension prevalence/larger population requiring diagnostic workup and close initial follow‐up, leading to health system congestion	Allocate additional resources to meet increased demand
Increase detection and evaluation of individuals with BP ≥ 130/80 mm Hg, particularly persons at high risk or unaware of the condition		Consider utilizing nonphysician, team‐based approach and protocols for BP management in patients with low risk or stage 1 hypertension
Treat BP to a target < 130/80 mm Hg	More individuals who require BP‐lowering medications	Improve medication procurement and distribution
		Prescribe low‐cost, high‐quality, effective generic BP‐lowering medicines
	More medications needed per patient to meet BP targets	Consider fixed, single‐pill combinations to decrease pill burden, reduce side effects, and increase adherence
	Higher risk of side effects including syncope and falls	Stratify patients at increased risk of complications and utilize a more gradual approach to medication titration and addition
Treat stage 1 hypertension based on ASCVD risk	Need for additional laboratory testing	Negotiate affordable point‐of‐care lipid and glucose testing
		Utilize the PAHO/WHO risk calculator
Encourage out‐of‐office BP measurement	Increased cost of acquiring validated machines	Encourage BP check visits in clinic
		Facilitate BP measurement in pharmacies, supermarkets, barbershops, and other public spaces to help offset cost

ACC, American College of Cardiology; AHA, American Heart Association; ASCVD, atherosclerotic cardiovascular disease; BP, blood pressure; JNC 7, Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure; LMICs, low‐ and middle‐income countries; PAHO, Pan American Health Organization; WHO, World Health Organization.

2.12. Closing thoughts

Since the introduction of the ACC/AHA hypertension guideline is still relatively recent, when focusing on LMICs, including those in Latin America and the Caribbean, we recommend that the following additional questions be considered and discussed:

• How will the ACC/AHA guideline impact a health system/population approach to the management of hypertension, such as the GLOBAL HEARTS initiative, which even in their existing form are already costly, without the additional burden of risk stratifying and treating a greater hypertension pool?

• Given the higher percentage of persons in Latin America and the Caribbean who are unaware that they have hypertension, should there be a greater emphasis on public education and BP screening?

• Given that the ACC/AHA guidelines are national guidelines, what are the lessons that can be learned from the application of this guideline to underserved, resource‐limited communities within the United States?

Much more impactful than the novelty of the guidelines and the inherent challenge to being adopted in LMICs, such as those in Latin America and the Caribbean, is the continued need to examine and address the present deficiencies in the detection and management of hypertension in the developing world. Significant strengthening of the existing healthcare systems and infrastructure is critical, through the widespread screening for hypertension, use of registries, and ensuring the availability of affordable, reliable BP‐lowering medications and BP measurement devices. Until such systems are planned, and successfully implemented, and new evidence‐based studies are available that address the areas of expert opinion incorporated in the new guidelines, these new recommendations are likely to be impractical in many LMICs.

Finally, we recognize that the 2017 ACC/AHA new hypertension guideline poses an important ethical challenge. That challenge includes how the serious and thoughtful recommendations/guidelines of an expert panel can be adopted and followed in the real‐world practice, when resources present a significant barrier. In this instance, it is not a matter of turning one's head and ignoring recommendations, but of establishing a more strategic plan to improve resources and to place a greater emphasis on the primary prevention of hypertension and finding innovative, cost‐effective ways to improve the awareness, treatment, and control of hypertension.

DISCLAIMER

The content, findings, and conclusions in this report are solely the responsibility of the authors and do not necessarily represent the official position of the PAHO or any of the authors' affiliated institutions.