Heart disease, CVD, Preventive medicine, Cardiology, Coronary heart disease

What is Preventive Cardiology?

Lai Chim Chan, ND

Heart disease remains the leading cause of death in the United States (US). By heart disease we mean coronary heart disease (CHD), which accounts for 43.8% of deaths attributable to cardiovascular disease in the US.¹

Heart disease places a significant economic burden on the United States as well as globally. US annual direct and indirect costs of cardiovascular disease and stroke in 2013-2014 were an estimated $329.7 billion, which accounts for 14% of total health expenditures.¹ This is more than any major diagnostic group.

If coronary heart disease is the number one killer in this country, it certainly would be wise to focus our efforts on preventing this condition. So, the million-dollar question is how do we prevent heart disease?

We would think that cardiologists want to not only answer this million-dollar question but to make efforts to practice preventive cardiology. The title of a recent Medscape commentary by Melissa Walton-Shirley, MD, “Do Cardiologists Care About CV Prevention?” argues otherwise. Walton-Shirley states “unarguable data reveal that most of us do not offer our patients what will ultimately save them from myocardial infarction, stroke, heart failure, and death: prevention strategies.”²

At the European Society of Cardiology (ESC) 2018 session “Implementation of Cardiovascular Disease Prevention in Daily Practice – Insights From EUROASPIRE V,” the first talk centered on a survey assessing cardiovascular disease prevention. Greater than 8000 patients in 27 countries were surveyed after being hospitalized for acute coronary syndrome, elective coronary artery bypass grafting, or percutaneous coronary intervention more than six months prior and no longer than two years prior. In regard to smoking cessation, only 12% of smokers became abstinent, 4% were attending smoking cessation clinics, 8% were using nicotine replacement, and 4% were using smoking cessation drugs. 57% had reduced smoking. Walton-Shirley comments “Whatever smokers are being advised, it isn’t working.”²

At the end of this presentation of the ESC 2018 session, a German doctor, Stephan Jacob, stepped to the microphone and stated, “I came late and I thought I would not find a place to sit, but look. This is a shame,” he said, indicating a number of emptying seats.² He states, “We are not really focusing on what’s important. Yes, we need emergent care, but the follow-up is horrible.”²

David Allan Wood in his presentation “How to Improve Implementation of Guidelines in Daily Practice” concluded:

All over Europe, our patients receive the highest level of acute coronary care, but dilating a segment of a coronary artery and implanting a stent is not addressing the disease as a whole…and it is naïve the believe that interventional cardiology on its own can significantly impact the overall chances for survival without addressing lifestyle and risk factors that brought the patients into the hospital in the first place…We need to match high-quality intervention with high-quality preventative cardiology.²

Walton-Shirley concludes with “That is the crux of the matter, and there has been no truer statement in the entirety of the ESC 2018 meeting. It’s a pity there weren’t more attendees in the room to hear it.”²

Over and over again I see patients in the clinic, who despite pharmaceutical medications receive a second, third or a fourth stent due to recurrent symptoms of angina. It makes me wonder, if modern medicine is so great, why do people keep getting sick?

I realized the reason why people keep getting sick is because the treatments don’t directly address the underlying cause of heart disease. To prevent recurrent disease, we need to identify what the underlying cause of heart disease is and treat it.

The following excerpt from the classic cardiovascular textbook Braunwald’s Heart Disease A Textbook of Cardiovascular Medicine explains how we went from infectious disease as the major cause of death to cardiovascular disease being the major cause of death:

The overall increase in the global burden of CVD and the distinct regional patterns result in part from the epidemiologic transition, which includes four basic stages: pestilence and famine, receding pandemics, degenerative and manmade diseases, and delayed degenerative diseases. Progression through these stages has dramatically shifted the predominant causes of death over

the past two centuries, from infectious diseases and malnutrition in the first stage to CVD and cancer in the third and fourth stages.³

Before 1900, infectious diseases and malnutrition constituted the most common causes of death in every part of the world. The emergence of public health systems and improved food production and distribution reduced deaths from infectious disease and malnutrition. During the stage of degenerative and man-made diseases, urbanization led to dramatic changes in diet, activity levels, and behaviors such as smoking. The increased availability of foods high in calories, coupled with decreased physical activity, contributes to an increase in atherosclerosis. We may be advancing into a newer phase of epidemiologic transition, the age of Inactivity and Obesity with rising rates of type 2 diabetes, hypertension, and dyslipidemia.³

We are recognizing that behaviors increase the risk of heart disease and lifestyle modifications can reduce risk.⁴ Public health campaigns for smoking cessation and detection and treatment of hypertension have contributed to the reduction of mortality from heart disease.

Mortality from coronary heart disease have been declining since the 1960s due to improvements in risk factors and treatments.⁵ Advances in acute care has attributed much to the decline in mortality from heart disease with the development of emergency medical systems, coronary care units and the widespread use of diagnostic and therapeutic technologies such as echocardiography, cardiac catheterization, percutaneous coronary intervention, bypass surgery, and implantation of pacemakers and defibrillators.³ Advances in drug development has also improved acute care with beta blockers, aspirin, statins, and angiotensin-converting enzyme inhibitors being commonly prescribed medications in patients with heart disease as well as patients having risk factors for heart disease.³

Perhaps the reason for why preventive strategies are often dismissed in the medical community is because “both the glamour (and reimbursement) favored the diagnosis and management of acute illness over the more mundane (and poorly reimbursed) efforts required to maintain patients – particularly those who had no overt cardiovascular disease – on diet and other lifestyle measures….”⁴ Despite the development of guidelines that support prevention strategies, adherence and implementation is suboptimal. Too many of our health care dollars are spent on end-stage complications of heart disease such as stents, devices such as cardioverter-defibrillators, and coronary artery bypass surgeries rather than on prevention.

Secondary prevention, or the prevention of a myocardial infarction in those with documented heart disease, is of even more importance as these individuals have a much higher risk than those in whom we are carrying out primary prevention; or the prevention of a myocardial infarction in someone without known heart disease. It is estimated that in 2018, about 720,000 Americans will have a new coronary event (first hospitalized myocardial infarction or coronary heart disease death) and about 335,000 will have a recurrent event.¹ Rather than treating events when they occur when death is imminent, I would argue that we should focus more of our efforts on preventing these events in the first place.

What Are Risk Factors?

Unfortunately, heart disease is often clinically silent until one suffers from an acute coronary syndrome or sudden cardiac death.⁴ These events often strike otherwise healthy appearing individuals without warning. This then leads to the question of how we are to predict whether someone has a high or low risk of suffering from such an event? Risk factors, or factors that increase one’s risk for developing heart disease were identified by the prospective Framingham Heart Study.⁴ Identifying and managing risk factors then became the mainstay of preventive cardiology.

Classically, we have used the Framingham Risk Calculator to determine whether one is high risk for heart disease or not. More recently we have turned to using the 2013 ACC/AHA Atherosclerotic Cardiovascular Disease (ASCVD) Risk Estimator as it includes studies from pooled cohorts with nonwhite populations. This risk estimator has limitations, and there are efforts to improve risk stratification; but it is the best tool that we have by far, and the lipid and hypertension guidelines rely on it to determine whether an individual qualifies for lipid-lowering or blood pressure-lowering medication.

There are also biomarkers such as high-sensitivity C-reactive protein and imaging modalities such as CT coronary artery calcium being studied to improve risk stratification. The majority of these lab and imaging markers have weaker or limited evidence for widespread use in comparison to the ASCVD Risk Estimator; so, for the purposes of risk stratification, we shall focus our efforts on using the ASCVD Risk Estimator.

Preventive cardiology can be followed using the ABCDE framework.

A

ssessment of risk from a clinical and genetic perspective,

A

ntiplatelet therapy,

B

lood pressure management,

C

holesterol,

D

iet and lifestyle issues (

D

iabetes mellitus,

D

isparities in care,

D

iagnostic testing to improve risk prediction),

E

xercise prescriptions, and

E

motional aspects of preventive cardiology.⁴

Risk factors are modifiable or nonmodifiable. The nonmodifiable risk factors include age and family history. In 2011, the American Heart Association introduced a new concept of cardiovascular health that includes the modifiable risk factors.¹ Life’s Simple 7 includes core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health.¹ Each of these health behaviors and factors are independently associated with cardiovascular disease risk.¹ Poor levels of each of the seven health factors and behaviors resulted in substantial mortality and morbidity in the United States in 2010.¹

Ideal cardiovascular health is defined by the absence of clinically manifest cardiovascular disease together with the simultaneous presence of optimal levels of all seven metrics, in the absence of drug treatment.¹

Only 17% of US adults have ≥ 5 metrics at ideal levels.¹ Approximately 13% of US adults have five criteria, 5% have six criteria, and virtually 0% have seven criteria at ideal levels.¹ Arguably we are failing to meet the recommended guidelines, and “the medical community needs to promote guideline adherence and reduce the gap in use of proven medical and lifestyle therapies.”⁴ If we have a desire to practice preventive cardiology, our number one priority is to optimize these seven core behaviors and health factors.

For example, if we want to focus on blood pressure management (one of the health factors of Life’s Simple 7), nonpharmacological health behaviors should be recommended for every single patient, and pharmacologic management should be considered in high-risk patients.⁶

The metrics with the greatest potential for improvement in the United States are health behaviors including diet quality, physical activity, and body weight.¹ In addition to using pharmaceuticals as needed, naturopathic physicians are trained to use diet and exercise counseling as first-line approaches for risk reduction and management of disease. For this, I truly believe in integrative medicine, and there are numerous books titled “Integrative Cardiology” that champion a whole-person approach for the prevention and management of cardiovascular disease.

Inflammation

Experimental and clinical data have suggested that inflammation plays a role in atherosclerosis. This theory largely remained unproved until the Canakinumab Antiinflammatory Thrombosis Outcome Study (CANTOS) trial was published in 2017.⁷ The trial suggests that reducing inflammation independent of reducing lipid levels further reduced risk of nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death in patients with a previous myocardial infarction and elevated high-sensitivity C-reactive protein (defined as ≥ 2 mg/L).⁸ The intervention involved the use of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1-ß that was administered subcutaneously every three months compared to a placebo.

At 48 months, the intervention reduced high-sensitivity C-reactive protein from baseline compared to placebo.⁷ The hazard ratio was 0.83 for the 150-mg dose of canakinumab compared to placebo.⁷ The intervention was associated with a higher incidence of fatal infection than was placebo.⁷ This trial is important and will pave the way for future trials that will assess the effectiveness of interventions aimed at reducing inflammation. Indeed, one of the mechanisms that statins are believed to reduce the risk of heart disease is by reducing inflammation.

Physical Activity

An exercise prescription can be written according to the FITT mnemonic including the four dimensions of physical activity (Frequency, Intensity, Type, Time (duration)).¹ The American Heart Association guidelines recommends >150 minutes per week of moderate-intensity or 75 minutes per week of vigorous-intensity physical activity and muscle-strengthening activities at least two days per week.¹ Physical activity improves risk factors for cardiovascular disease (such as high blood pressure and high cholesterol) and reduces the likelihood of diseases related to cardiovascular disease including coronary heart disease, stroke, type 2 diabetes mellitus, and sudden heart attacks. Benefits from physical activity are seen for all ages and groups including older adults, pregnant females, and people with disabilities and chronic conditions.¹

Only 21.5% of adults met the 2008 federal physical activity guidelines for both aerobic and strengthening activity,¹ and 30.4% do not engage in any leisure-time physical activity. (“No leisure time physical activity/inactivity” refers to no sessions of light/moderate or vigorous physical activity of ≥10 minutes’ duration).¹

Community-level interventions have been shown to be effective at promoting increased physical activity as well as being cost effective.¹ Nearly $3 in medical cost savings is realized for every $1 invested in building bike and walking trails.¹ Worksites can also offer access to on-site exercise facilities or employer-subsidized off-site exercise facilities to encourage physical activity among employees.¹

Healthy Dietary Pattern

Patients frequently ask the elusive question of “What is the best diet for (fill in the blank with a medical condition)?” In this instance, we fill in the blank with heart disease or preventing heart disease. The American Heart Association’s dietary metric is targeted in the context of a healthy diet pattern consistent with a Dietary Approaches to Stop Hypertension (DASH)-type eating pattern.¹ This is defined by consuming ≥4.5 cups per day of fruits and vegetables, ≥2 servings per week of fish, ≥3 servings per day of whole grains and no more than 36 oz per week of sugar-sweetened beverages and 1500 mg per day of sodium.¹ The DASH-type eating pattern has been demonstrated to reduce blood pressure and LDL levels and may reduce risk of heart disease.⁸

A review of evidence-based healthy dietary patterns conclude that they are generally high in fruits, vegetables, whole grains and legumes with nuts consumed in moderation.⁸ Some may include limited quantities of lean meats in the form of poultry and seafood as well as low-fat dairy products and liquid vegetable oils.⁸ These dietary patterns tend to be low in saturated fats, trans fats, solid fats, refined grains, added sugars, and sodium.⁸

By far the dietary pattern with the most evidence for prevention of heart disease is the Mediterranean Diet as demonstrated by the Primary Prevention of Cardiovascular Disease with a Mediterranean Diet (PREDIMED) study.⁹ The Mediterranean Diet consists of high intakes of olive oil, fruit, nuts, vegetables, and cereals with moderate intake of fish and poultry.¹⁰ Intake of dairy products, meat, processed meats, and sweets are low with wine consumed with meals in moderation.⁹

The study was conducted in Spain with males and females at high cardiovascular risk randomized to a control, the Mediterranean Diet supplemented with extra-virgin olive oil, or the Mediterranean Diet supplemented with mixed nuts. Study subjects were followed up for a median of 4.8 years and the primary end point was the composite rate of cardiovascular events (myocardial infarction, stroke, and death from cardiovascular cause). The hazard ratio of the Mediterranean Diet with extra-virgin olive oil and of that with nuts were 0.70 and 0.72 respectively with a relative risk reduction of 30%.⁹

Epidemiological studies and randomized controlled trials indicate that plant-based diets are associated with improvement in heart disease risk factors and a decreased risk in heart disease.⁸ Of note is the Lifestyle Heart Trial conducted in 1986-1992 by Dean Ornish. Patients with moderate to severe coronary artery disease were randomized to either a control or the intervention. Subjects randomized to the intervention not only followed a 10% fat, whole foods vegetarian diet but participated in a comprehensive program including moderate aerobic exercise, stress management training, and group psychological support.¹⁰

The most impressive outcome of the study was that diameter stenosis was shown to be reduced; suggesting that heart disease was reversed.¹⁰ Additionally, the number of cardiac events defined as myocardial infarction, coronary angioplasty, coronary artery bypass surgery, cardiac-related hospitalizations, and cardiac-related deaths were reduced.¹⁰ There were 0.89 events per patient in the intervention compared to 2.25 events per patient in the control group.¹⁰ The Ornish program highlights the effectiveness of an integrative approach to secondary prevention of heart disease.

At the ESC 2018 session mentioned above, David Allan Wood gave a firm recommendation for preventive cardiology programs to integrate nurses, dietitians, physiotherapists, occupational therapists, pharmacists, and psychologists to work alongside cardiologists to address lifestyle and measure, monitor, and manage blood pressure, lipids, and glucose.² I would add that naturopathic physicians and other complementary care providers should be included in these programs. Equally important, these programs should monitor adherence.

When six of nine risk factors were addressed in a rehab and prevention setting (including smoking, diet, physical activity, blood pressure, cholesterol, glucose, cardiovascular drug use, and stress management), all-cause mortality decreased 37% compared with traditional programs.² Programs that measured, monitored, and managed risk factors by prescribing, up-titrating, and monitoring adherence to medications also reduced all-cause mortality.² If this is what is effective, why isn’t this type of program the standard of care and made widely available for patients? This type of program would presumably reduce healthcare costs.

This type of program wouldn’t necessarily need to be in a cardiology clinic and can be implemented in patient-centered primary care homes. “Prevention of cardiovascular disease is too important to leave to a relatively small group of experts, but instead must be carried out by all physicians, regardless of specialty, as well as by nurses and other health care professionals who care for patients with, or at risk of developing cardiovascular disease.”⁴

This is a brief review of preventive cardiology and entire textbooks have been written on this topic as well as the individual risk factors. Hopefully this brief review will help you get your patients on the first step to improved heart health.

References

1. Benjamin EJ, et al. Heart disease and stroke statistics – 2018 update: a report from the American Heart Association. Circulation. 2018;137:e67-e492.

2. Walton-Shirley M. Do Cardiologists Care About CV Prevention? Medscape. Available at: https://www.medscape.com/viewarticle/901327?src=soc_fb_180902_mscpedt_news_mdscp_esccongress&faf=1. Published August 2018. Accessed September 9, 2018.

3. Zipes DP, et al. Braunwald’s Heart Disease A Textbook of Cardiovascular Medicine. 11^th Edition. Philadelphia, PA: Elsevier; 2019.

4. Blumenthal RS, Foody JM, Wong ND. Preventive Cardiology A Companion to Braunwald’s Heart Disease. Philadelphia, PA: Elsevier Saunders; 2011.

5. Ford ES, Capewell S. Proportion of the Decline in Cardiovascular Mortality Disease due to Prevention Versus Treatment: Public Health Versus Clinical Care. Annu. Rev. Public Health. 2011;32:5-22.

6. Whelton PK, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Hypertension. 2017.

7. Ridker PM, et al. Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease. NEJM. 2017;377:1119-1131.

8. Freeman AM, et al. Trending Cardiovascular Nutrition Controversies. JACC. 2017;69(9):1172-1187.

9. Estruch R, et al. Primary Prevention of Cardiovascular Disease with a Mediterranean Diet. NEJM. 2013;368(14):1279-1290.

10. Ornish D, et al. Intensive Lifestyle Changes for Reversal of Coronary Heart Disease. JAMA. 1998;280(23):2001-2007.