PREVENTIVE CARDIOLOGY AS NEW SUBSPECIALTY OF CARDIOVASCULAR MEDICINE

Abstract

Although management of ischemic cardiovascular disease has improved by leaps and bounds and significantly reduced the risk of mortality from a heart attack relative to decades past, the life trajectory of the average person (with stress, poor diet, excess body weight, inactivity, smoking, exposure to pollutants, poor management of metabolic comorbidities, etc.) still leads straight to development of this disease. Therefore, we have an unprecedented opportunity to focus on prevention of atherosclerosis before cardiovascular events occur, an endeavor that needs expert intervention with cardiovascular risk assessment, risk factor management, lifestyle counseling, dietary interventions, use of natural supplements, and pharmacotherapy. It is time for the budding specialty of preventive cardiology to come to the fore, from the historic background of fragmented clinical services such as lipid, hypertension, diabetes, endocrine, and cardiology clinics. Many patients need this specialized service, which cannot be provided anywhere else but in a dedicated practice well integrated with all other hospital services. Here we discuss the origin of preventive cardiology, the organization and core competencies required for excellence in this medical art, and the structure for education and fellowship training for professional recognition and board certification.

INTRODUCTION

The value of preventing cardiovascular disease is intuitive; unfortunately, this very fact makes it difficult to implement. We all know the pillars of cardiovascular health: do not smoke, keep a healthy weight, exercise regularly, control your stress level, follow a prudent diet, and see your doctor for checkups on your blood sugar, cholesterol, and blood pressure. However, these deceivingly simple action items are often disregarded by the average person and not tackled or even addressed by most medical practices. A recent report found that only 112 out of 2000 patients having a BMI over 30 were defined as obese in an EMR search in a primary care setting (1). Similarly, the inherited form, familial hypercholesterolemia, is commonly unrecognized and undertreated (2). With such a cavalier approach to risk factor management, cardiovascular disease will continue to be the number one cause of death and disability worldwide (3). Several concerted efforts are required to significantly improve this forecast, the most important of which is the creation of a dedicated subspecialty aimed at preventing cardiovascular disease (4). As a matter of fact, fragments and specific aspects of the medical art we call preventive cardiology have a longstanding tradition as integrated components of internal medicine, endocrinology, cardiology, women's health services, cardiac rehabilitation centers, medical genetics, public policy, epidemiology, and most notably lipid clinics. However, a comprehensive, uniform definition and organization of preventive cardiology services has not been achieved; current efforts toward this goal are thinly dispersed, not standardized, and not recognized by certification bodies. Training of the next (and first) generation of true preventive cardiovascular providers will not be possible until the organization and standardization of a professional and educational structure takes place.

THE PIONEERING YEARS

In 1948, the National Heart, Lung, and Blood Institute funded the Framingham Heart Study (FHS) to determine the causes of atherosclerotic cardiovascular disease, or ASCVD (5). Indeed, FHS investigators were the first to coin the term “risk factor” for coronary heart disease in a 1957 publication (6). The knowledge that dyslipidemia, hypertension, diabetes, smoking, inheritance, and stress are linked to ASCVD contributed to the interest in studying risk factor management more in depth and to providing health care services geared at preventing the onset of ASCVD.

Beyond identifying the traditional ASCVD risk factors, the FHS clearly demonstrated that no single risk factor is responsible for ASCVD but rather multiple factors generally coexist and accelerate the path to its development (7). Finally, the main FHS findings have been recapitulated in numerous cohorts from around the world, suggesting that susceptibility to atherosclerosis is controlled largely by the same factors irrespective of race, ethnicity, and gender (8-10). Since many of these factors are in principle, modifiable, an initial impetus to study risk factor modification led to the goal of reducing the burden of ASCVD. Furthermore, one of the key FHS contributions was the derivation and validation of the Framingham Risk Score as method for ASCVD risk assessment (11).

The FHS also prompted the development of a network of lipid clinics in the United States and around the world. These were mostly research centers for clinical trials of lipid-lowering agents, for investigations of lipid metabolism, and for addressing extreme inherited conditions such as familial hypercholesterolemia (12). As a concept, they were far removed from the idea of global ASCVD risk assessment and management that currently permeates this budding field. However, out of well-designed clinical trials came one of the most important health care advances of the twentieth century: the discovery that statin drugs reduce the risk of heart attack. In 1994, the Scandinavian Simvastatin Survival Study (4S study) revolutionized our understanding of ASCVD risk management and convinced the cardiology field that elevated serum cholesterol levels are a low-hanging fruit for preventive intervention. A continuous stream of cardiovascular outcomes trials followed, which corroborated the efficacy of statins in essentially all high-risk groups (13). After the first wave of placebo-controlled statin trials, the study design evolved to avoid the use of a placebo; thus, studies of high-dose versus low-dose or high-potency versus low-potency statins were performed. The reduction in cardiovascular events observed across these trials was remarkably consistent. Importantly, cardiovascular benefits were also observed in people with average or low LDL-C levels, and there was no attenuation of cardiovascular benefits with reduction of plasma LDL-C beyond normal or even optimal levels. This realization transformed traditional thinking about the standard use of statins from only treating clearly elevated LDL-C to the contemporary standard of using statins for all individuals above specific risk thresholds. Since statin trials established that lowering LDL-C is safe and effective in reducing ASCVD risk, national and international guidelines emphasized the value of LDL-C lowering as an essential risk-reduction intervention. For a while, it seemed that the main tool of preventive cardiology was the aggressive management of LDL-C levels, though now we know that many interventions have risk-reduction power without exerting lipid modulation (Table 1).

TABLE 1.

Novel Interventions to Reduce Cardiovascular Risk

Comorbidity	Target	Medications
Dyslipidemia	LDL-C Triglycerides Lipoprotein(a)	Monoclonal antibodies (alirocumab, evolocumab) siRNA (inclisiran) Icosapent ethyl ApoCIII-Lrx IONIS-APO(a)Rx
Inflammation	IL-1β	Canakinumab
Diabetes	SGLT-2 GLP-1 receptor	Canagliflozin, dapagliflozin, empaglifolozin Albiglutide, dulaglutide, exenatide, liraglutide, lixisenatide, semaglutide
Obesity	Appetite Stomach capacity	Orlistat, locaserin, naltrexone-buproprion, phentermine-topiramate, liraglutide Gastric bypass, sleeve gastrectomy, adjustable gastric band, biliopancreatic diversion with duodenal switch
Hypertension	Vasopeptidase, Aldosterone synthase, Soluble epoxide hydrolase, natriuretic peptide A, vasoactive intestinal peptide receptor 2 Vaccines Catheter-based interventions	Vaccines against angiotensin II and  its receptor type I Renal denervation Baroreflex activation therapy
Antithrombotic therapy	Factor Xa	Rivaroxaban

PREVENTIVE CARDIOLOGY IN THE ACADEMIC SETTING

The practice of preventive cardiology requires specialized knowledge of metabolism, cardiovascular physiology, anatomy, imaging, functional stress testing, cardiac rehabilitation, pharmacology, and lifestyle management. Since most patients have, or are at risk of developing, ASCVD, the most appropriate setting for a preventive cardiology practice is in cardiovascular medicine, mostly for ease of coordination of additional cardiovascular care (diagnostic testing, curbside consultations, referrals to interventional cardiologists, etc.). However, cardiologists are not the only members of the preventive cardiology team. In contrast to other subspecialties of cardiovascular medicine, preventive cardiology should be open to other specialists; indeed, the best care is possible when a dedicated team is available to provide longitudinal care. This includes internists, endocrinologists, family physicians, clinical pharmacists, dietitians, nurses, and advanced practice providers.

Patient care teams that integrate clinical pharmacists and cardiologists yield improved health care measures in patients suffering from cardio-metabolic diseases, including hypertension, dyslipidemia, coronary artery disease (CAD), heart failure, and diabetes (14). The clinical pharmacist is an essential component of teams that improve safety and efficacy of therapeutic interventions (15), medication adherence (16), insurance coverage, and cost control of branded medications (17). The clinical pharmacist is also the most efficient operator of structured pharmacologic management protocols (PCSK9 inhibitor clinic, hypertension clinic, anticoagulation clinic, etc.) (18,19). The integration of clinical pharmacists in care teams is endorsed by several large national societies including the National Lipid Association, the American College of Cardiology (ACC), and the Heart Failure Society of America.

While it is well known that lifestyle counseling is of utmost importance in ASCVD risk management, very few practices are set up to provide specialized services that go beyond the ineffective verbal recommendations to improve diet, increase exercise, stop smoking, and manage stress. For the vast majority of our patients, ASCVD is the consequence of decades of suboptimal or harmful lifestyle habits. Devoting little time at the end of a patient encounter to provide generic advice across the spectrum of therapeutic lifestyle changes is not only ineffective but also sends a dangerous message to patients (i.e., pharmacologic therapy is more important than changes in behavior). Preventive cardiology programs must invest in the services of registered dieticians and lifestyle coaches for weight management, exercise prescription, smoking cessation, and stress reduction.

CORE COMPETENCIES

The emergence of preventive cardiology as a unique subspecialty of cardiovascular medicine is borne out of necessity, as we have reached a tipping point regarding scientific information and therapeutic options. There is simply too much for a general cardiologist, endocrinologist, or primary care provider to know regarding ASCVD risk evaluation and mitigation. And there is too much demand for expert management from the patient side to have a satisfying experience in a non--dedicated practice, such as a general endocrine or cardiology clinic, or even a focused lipid clinic or cardio-metabolic center. Table 2 lists the core competencies for a preventive cardiology practice.

TABLE 2.

Core Competencies in Preventive Cardiology

Lifestyle Management	Disease Management	Cardiovascular Risk Assessment
Exercise intervention	Lipid management	Lipid analyses
Dietary counseling	Inflammatory conditions	Monogenic analyses
Weight management	Diabetes	Noninvasive imaging
Treatment of obesity	Hypertension	Polygenic risk scoring
Tobacco cessation	Antiplatelet therapy	Biomarkers
Stress reduction	Antithrombotic therapy
Natural therapies	Drug aversion

REFERRALS TO PREVENTIVE CARDIOLOGY PROGRAMS

If ASCVD is so pervasive, we need to consider whether everyone should be evaluated by a preventive cardiologist. Even though the exposure to cardiovascular risk factors is ever present, not everyone needs to be evaluated by a preventive cardiologist. In general, young individuals ( < 40 years of age) from low-risk families and without comorbidities and past or current CVD risk exposures only need to keep following the mandates of a healthy lifestyle. Conversely, we envision a future when everyone above the age of 45 has at least one visit with a specialized center for cardiovascular risk assessment. Table 3 provides examples of patient types who may be referred to preventive cardiology and whose management in other settings may be less rigorous and of less value.

TABLE 3.

Examples of Patient Types Referred to Preventive Cardiology

An apparently healthy woman with no risk factors and a first attack at age 42 A young man with LDL of 270 who is skeptical about this being a problem A 62-year-old diabetic woman with well-controlled HbA1c levels and statin aversion A healthy 45-year-old man whose father died of sudden cardiac causes at age 45 A 60-year-old woman referred for evaluation of HDL>150 with normal LDL A 70-year-old man with hypertension, low HDL, and coronary artery calcium score (CACS) of 0 A healthy 58-year-old man requesting genetic assessment of cardiovascular risk

TRAINING AND CERTIFICATION

A practicing preventive cardiologist is often an internist, cardiologist, or endocrinologist with different degrees of competency who is driven by an interest in the topic and has had additional a la carte advanced exposure to the nuances of lipid metabolism as offered by organizations such as the National Lipid Association. The only existing certification is through the American Board of Clinical Lipidology, which is not under the American Board of Internal Medicine (ABIM) umbrella, does not require demonstration of specialized clinical training, and has awarded less than 800 diplomas since its inception in 2005. Preventive cardiology cannot thrive on this unstable ground and fragile trajectory. The COCATS4 standards (standards of training for cardiology fellows in American hospitals) only require minimal exposure to preventive services, such as one-month rotations in cardiac rehabilitation or lipid clinics, to satisfy criteria for taking the board examination (20). The many preventive cardiology “fellowships” currently available are not uniformly equipped to provide the necessary clinical competencies to produce trained experts, but rather represent a mélange of locally funded programs that mostly focus on clinical or basic research (21). What is needed is structure and uniformity of teaching, training, and preparation for a validated, comprehensive, and credible examination. The fellowship program should last at least one year, be performed in an accredited center of proven excellence, and provide repeated exposure to the outpatient management of cardiovascular risk. In addition, the certification exam should go well beyond knowledge of lipids. All this is currently in a construction phase and is being spearheaded by organizations such as the American Society for Preventive Cardiology (ASPC) and the ACC (22). In 2020, the ASPC launched The American Journal of Preventive Cardiology, which is devoted to the definition, expansion, and standardization of the medical art through editorials, opinion papers, teaching articles, and original investigations with high translational value.

CONCLUSIONS

The medical art of preventive cardiology has been hampered by false perceptions of its simplicity, intuitive value, and common-sense algorithms. Like other medical subspecialties have done, preventive cardiology must intelligently plan for a non-disruptive separation from the current main outlets of care (general cardiology and lipid clinic services) and for synergistic connection with all other services needed by cardiology patients (diabetes, hypertension, general cardiology, etc.). Until now, preventive cardiology has been provided with fragmented and non-uniform approaches. In the future, individual providers who want to have full competency in preventive cardiology should undergo proper training and achieve certification, and centers that specialize in preventive cardiology must have care team abilities in place to address the spectrum of needs of this ever-expanding category of patients.

DISCUSSION

Due to technical problems with the Grand Hotel audiovisual equipment, the questions by Drs. Konstam and Jordan associated with this paper and the responses by Dr. Fazio could not be transcribed.