The Pursuit of Ideal Cardiovascular Health: An Individual and Societal Challenge

In this issue of Mayo Clinic Proceedings, Artero et al¹ report the results of a comprehensive analysis of the Aerobics Center Longitudinal Study to determine the prevalence of ideal cardiovascular health, as recently defined by the American Heart Association (AHA)² (Table). They discovered that ideal cardiovascular health is extremely rare and that only a small percentage of the study participants met more than just a few measures of cardiovascular health. However, they also discovered that the AHA construct of cardiovascular health is valid because there is a clear association between the number of ideal metrics not met and the subsequent risk of cardiovascular death.

TABLE.

The Simple 7^a

1.Physical activity of at least 150 min of moderate intensity or 75 min of vigorous intensity each week

2.Body mass index <25 kg/m2

3.Never smoked or quit more than a year ago

4 Four to 5 key components of a healthy diet consistent with current AHA guidelines ▪ Fruits and vegetables: ≥4.5 cups per day ▪ Fish (preferably oily): two 3.5-oz servings per week ▪ Fiber-rich whole grains (1.1 g fiber per 10 g carbohydrate): ≥ three 1-oz equivalent servings per day ▪ Sodium: <1500 mg/d ▪ Sugar-sweetened beverages: ≤450 kcal (35 oz) per week

5.Total cholesterol <200 mg/dLb

6.Blood pressure <120/80 mm Hg

7.Fasting blood glucose <100 mg/dLb

Data from Circulation.²

^aAHA = American Heart Association.

^bSI conversion factors: To convert total cholesterol to mmol/L, multiply by 0.0259; to convert blood glucose to mmol/L, multiply by 0.0555.

In 2000, the AHA set a seemingly idealistic goal to reduce mortality due to coronary heart disease by 25% over the ensuing 10 years. Thanks in part to the well-orchestrated efforts by the AHA to promote effective primary prevention interventions, and in part to advances in the management of acute myocardial infarction, coronary heart disease deaths had decreased, in fact, by 35% in 2010, well exceeding the original goal. By 2010, however, it had also become very clear that several measures of cardiovascular health in the US population were showing disturbingly negative trends, including an alarming increase in the prevalence of obesity and diabetes, and stagnant trends in smoking cessation and blood pressure optimization. Objective projections of cardiovascular disease rates made it clear that unless the current trends in cardiovascular risk factor prevalence change, the incidence of cardiovascular events will probably increase again by 2020.³

Therefore, in 2010, the AHA published the 2020 goal that includes a new definition of cardiovascular health represented by an aggregate of 7 health behaviors and factors, with the goal of monitoring cardiovascular health trends in the population and assessing progress toward the goal of 20% reduction in cardiovascular mortality.² Those 7 factors were labeled The Simple 7 and have been promoted in the general population to enhance awareness of and promote heart-healthy behaviors.⁴ The new definition of cardiovascular health, based on input from various working groups within the AHA, has several strengths: it combines some of the most relevant health behaviors and factors known to decrease cardiovascular risk, and it provides specific goals for each metric in a relatively simple way. Although more than 50 cardiovascular risk factors have been identified to date, it would be impractical to set too many targets, especially for those that are not modifiable such as sex, age, or family history of premature coronary disease. Instead of a deterministic definition of cardiovascular health, the new AHA definition emphasizes the importance of modifiable risk factors for which patients can take ownership and control.

However, this new definition of cardiovascular health also has shortcomings. The details of each component of the new definition are not consistently evidence based, and some important factors are not addressed. For example, the 5 key components of a healthy diet do not include reduction in the intake of saturated and trans fats, arguably some of the most deleterious components of the American diet and a major risk factor for cardiovascular disease.⁵ Furthermore, the recommendation of an intake of less than 1500 mg of sodium a day in the sodium restriction component may be too strict for healthy individuals and is not evidence based. Recent studies have suggested that an extremely low-salt diet may increase, rather than decrease, cardiovascular mortality.^6,7 Other components of the main construct of cardiovascular health are oversimplified, such as the recommendation to achieve a body mass index (BMI) (calculated as the weight in kilograms divided by the height in meters squared) of less than 25 kg/m² and the definition of obesity as a BMI of more than 30 kg/m². This definition of obesity has been widely criticized, and many studies have shown the limitations of using BMI as the only factor to determine obesity-related risk.⁸ Individuals with a normal BMI but with a high fat percentage of the body composition or a high waist-to-hip ratio may be at increased risk for cardiovascular disease and death.⁹ Because obesity may become a major challenge to achieving the AHA 2020 goals, it will be desirable to expand the definition of ideal body composition to include body fat content and distribution.

The study by Artero et al¹ shows very troubling results, with an extremely low prevalence of ideal cardiovascular health in a sample of upper middle-class individuals attending a clinic that specializes in cardiovascular health. Among almost 12,000 patients, only 29 (0.2%) met all 7 ideal metrics, and 39% met fewer than 3 ideal metrics. Other studies have shown that the prevalence of ideal cardiovascular health is even worse in disadvantaged populations. Bambs et al¹⁰ demonstrated that blacks had an 82% lower likelihood of achieving more than 5 of the 7 ideal health factors than whites. The results from Artero and associates' analysis underscore the importance of increasing the efforts to improve the cardiovascular health of the US population.

The new definition of cardiovascular health and the related Simple 7 campaign are important steps to increase awareness about cardiovascular risk in the general population and to encourage people to set personal goals. However, increasing awareness by itself without implementing or providing proven strategies of intervention has failed to improve health behavior. As one example, most current smokers are generally aware that their smoking habits are unhealthy but find themselves unable to quit. Major improvements in cardiovascular health in the population will occur only if increased awareness and willingness to improve personal health coincide with changes in public policy, population-based interventions, and the implementation of universal health care.

Extensive research has demonstrated that changes in public policy impact the prevalence of cardiovascular risk factors more than any other strategy. The implementation of a smoking ban in public places has been a key factor in reducing the prevalence of smoking among adults, lowering both exposure to second-hand smoke and coronary event rates.¹¹ Results from the North Karelia project show that after taxing unhealthy foods and subsidizing fruits and vegetables, people changed their food choices and improved their diets, followed by an impressive reduction in cardiovascular mortality.¹² Humans have economic minds sensitive to prices and to the perception of value, proving that human behavior is many times driven by factors unrelated to risk perception or recognition of health benefits. Likewise, changes in the composition of school lunches, regulations to prevent direct marketing of food to children, and promoting more physical activity in schools will likely impact cardiovascular health in the long term. Urban designers should also include more spaces that facilitate regular exercise and physical activity associated with both individual and group sports. Redesigning roads to accommodate pedestrians and bicyclers would be another strategy to promote simple ways of incorporating regular physical activity in busy daily lives.

The role of universal access to health care cannot be overlooked when pursuing ideal cardiovascular health in the population. Before people become diabetic or hypertensive, they experience years of impaired fasting blood glucose or suboptimal blood pressure levels. The identification of “predisease stages” alerts patients and physicians about the need to take a more proactive approach implementing healthier lifestyles. Thus, access to health care where those factors can be identified and addressed in a timely manner will help to foster primordial prevention in the whole population.

During the past 30 years, there have been numerous advances and innovations to reduce cardiovascular disease risk and related deaths. It is widely accepted that if people follow the basic principles of cardiovascular disease prevention (no smoking, regular physical activity, healthy diet, and keeping hypertension, dyslipidemia, and diabetes under control), their risk for cardiovascular death can be reduced by more than 75%.¹³ However, currently available data are less instructive in identifying how to change human behavior in an effective and lasting way as a means to improve outcomes. More research is needed to better understand the factors that trigger and maintain healthy behaviors and improve compliance with medical treatments. We know we have a long way to go before achieving the 2020 goals when interventions for smoking cessation that have no more than a 20% quitting rate are considered “successful” and when the overwhelming majority of people with obesity who lose weight will regain all of the weight lost in less than a year.

The challenges ahead of us are immense, and the responsibility to prevent a reversal of the favorable trends in cardiovascular disease should be shared among individuals, scientists, leaders in public policy, and society as a whole. The ultimate victory against cardiovascular disease will come when personal accountability, effective primary care practices, public policy, population-based interventions, and universal health care work in concert. Are we there yet? We are certainly on our way, but we have not yet reached our destination.