Racial Disparities in Cardiovascular Disease - Episode 2
Keith C. Ferdinand, MD, FACC, FAHA, FASH, FNLA: So when we look at these outcomes related to cardiovascular risk, they also translate based on income and real survival. The 1%, both from men and women, have a life expectancy in the United States, which is as much as 10 years or more for men and approximately 10 years for women, such that the lower class who have 1% of income versus the upper class with 1% of the highest income, have a real gap in life expectancy.
Now you often hear politicians say that in the United States, despite having one of the most expensive health care delivery systems in the world, we have a longevity that is just 16th among developed countries. This may be true, but the real reasons for that disparity in longevity are the racial, ethnic, and social determinants of health that I have described. In fact, a person who has means in the United States lives as long and as well as a person in Japan or Western Europe.
Let’s now look at hypertension. African Americans have a high rate of hypertension when compared with other ethnicities in the United States. If we use the lower cut point of 130/80 from the latest ACC/AHA [American College of Cardiology/American Heart Association] guidelines, as many as 60% to 65% of adult African American men and women will now be said to be hypertensive. This is not giving people disease. We know from the Sarah Lewington analysis that there is a direct, linear, and persistent relationship between elevated blood pressure and dying from ischemic heart disease and dying from stroke, such that the higher the blood pressure, starting at about a systolic of 115, the increased risk is seen such that by the time the person has a systolic blood pressure of 130, they have doubled their risk before the arbitrary cut point of 140/90. It’s important, therefore, to recognize the powerful impact of hypertension, which, again, is related to diet, stress, obesity, physical inactivity, and where you live, work, and play, and the outcomes related to cardiovascular disease.
We know African Americans are aware of hypertension and often will seek treatment. The control of blood pressure across various race ethnicities is less in African Americans, Hispanics of any race, and Asian Americans than for white Americans. This, again, is a marker for health-seeking behavior, culture, and the social determinants of health.
If we look across the landscape at various causes of disease, along with hypertension, diabetes is a powerful component of risk. In fact, persons who have diabetes, although not necessarily being a coronary heart disease risk equivalent, have a marked increased risk for premature heart disease, chronic kidney disease, stroke, and heart failure. Specific with African Americans, therefore, to control blood pressure, it may take 2 or more medications in most adults. And some data suggest if the blood pressure is 20 mm of mercury above the systolic goal, 2 medications in combination may be necessary. Unfortunately, some of the newest data suggest that the rates of blood pressure control may actually be decreasing in the United States. We certainly don’t see the marked increase in hypertension control as we saw in preceding decades. This, along with increasing obesity, increasing diabetes, and access to care may actually bake in some of the disparities that I previously mentioned on cardiovascular outcomes.
African Americans are clearly a high-risk population. When you look at the African American population, you see the downward trend in cardiovascular death. But the gap with African Americans having a higher rate of cardiovascular death versus white Americans is now baked in. Unless we do something to address these disparities they will persist for another decade or 2.
If we look across the population and you want to say what 1 thing really demonstrates these disparities, I think it’s longevity. The difference in survival of whites versus blacks is not driven by a drive-by shooting or the use of drugs; it’s mainly driven by poor control of cardiovascular risk factors—specifically, for African Americans, hypertension, more diabetes, the same level of lipids, perhaps less use of statins, and the appropriate use of antiplatelet agents.
If you look at life expectancy, therefore, black men have the shortest life expectancy. And the longevity of black women is more similar to white men than it is to white women, who have a higher life expectancy than black women and white men. Across the board, therefore, looking at some of these differences, the difference between hypertension related death rates is twice as high in African Americans versus whites.
Now 1 of the questions that come into play is: What about acute myocardial infarction? Is that driven by more lipids? The answer is no. Total cholesterol, LDL [low-density lipoprotein] cholesterol is similar in blacks and whites. In fact, in some population studies, blacks actually have higher HDL [high-density lipoprotein] cholesterols and lower triglycerides. Nevertheless, premature heart attacks occur more often in black Americans. Stroke, clearly related to blood pressure, is much higher in blacks. It starts earlier, and there’s an increase in mortality related to strokes in this population.
Even sudden cardiac death, which is multifactorial in its origin, appears to be higher in blacks versus whites. Diabetes, as I mentioned before, especially in earlier-onset diabetes, may not be a true coronary heart disease risk equivalent. But diabetes is higher in African Americans and in Hispanic Americans and may be another factor leading to these disparities.
Let’s look at chronic kidney disease [CKD]. We as cardiologists see lots of patients who have CKD. There is an increase in chronic kidney disease and a 3 to 4 times increase in end-stage renal disease in African Americans with higher rates of end-stage renal disease in Native Americans and in certain Latino populations. This is important because after a year or so with end-stage renal disease, these patients are declared disabled. And people who work and have income and do well for themselves pay $100 to $120,000 per year to take care of people with end-stage renal disease, much of which can be prevented by controlling diabetes and controlling hypertension.
Peripheral arterial disease is another factor that comes into play. It is higher in black men and black women with higher rates of amputation. Peripheral arterial disease to a large extent is a surrogate for poorly controlled risk factors.
Let’s visit heart failure. Heart failure across the general population, especially in African Americans, is more determined by poorly controlled hypertension, whereas in heart failure trials, which often enroll mainly whites, coronary disease is the underlying etiology. Nevertheless, if you look at the rates of heart failure with the aging of the population, poorly controlled hypertension, increase in diabetes, it’s expected that the rates for these populations will continue to increase. In order to control this increased risk of heart failure, we need to identify cardiac risk factors—specifically, uncontrolled hypertension—and treat it appropriately and treat it early.
Transcript edited for clarity.