ACE inhibitors yield poorer cardiovascular outcomes in blacks than in whites

When treated with angiotensin-converting enzyme (ACE) inhibitors, black patients with hypertension had somewhat poorer cardiovascular outcomes—more strokes, myocardial infarctions, and heart failures—than hypertensive whites.

“The results of this study add to a growing consensus among physicians that treatment of hypertension in blacks should not be initiated with ACE inhibitors,” said the study’s lead author Gbenga Ogedegbe, MD, MPH, professor in the Department of Population Health at New York University (NYU) Langone Medical Center, in New York, NY. The study was published September 15, 2015 in the Journal of the American College of Cardiology.

Prior evidence from clinical trials has shown that ACE inhibitors may not provide the same benefits in blacks compared with whites, and may even cause harm. However, blacks have been underrepresented in the majority of these studies even though they have disproportionately higher rates of hypertension-related morbidity and mortality than other racial and ethnic groups, according to the study authors.

“We know what works in clinical trials. But when you go into the real-world clinical practice setting, physicians don’t often translate that evidence into practice,” Dr. Ogedegbe said. “This is the first study that looks at this issue in a real-world clinical practice setting.”

Dr. Ogedegbe and colleagues at NYU and other centers analyzed electronic health records of nearly 60,000 adult patients (47% of whom were black) who had hypertension and who received care between 2004 and 2009 in New York City’s Health and Hospital Corporation.

The investigators compared rates of all-cause mortality, acute myocardial infarction (AMI), stroke, and congestive heart failure between black and white patients who were prescribed 1 of 4 classes of antihypertensive drugs to treat high blood pressure: ACE inhibitors, beta blockers, calcium-channel blockers, or thiazide-type diuretics.

Results showed a small but statistically significant rate of poorer cardiovascular outcomes in blacks on ACE inhibitors (8.7%) compared with blacks not on ACE inhibitors (7.7%). Whites did not show the same disparity (6.4% vs 6.74%).

Likewise, black hypertensive patients on ACE inhibitors, compared with black hypertensives on other treatment, had slightly higher rates of AMI (0.46% vs 0.26%), stroke (2.43% vs 1.93%), and congestive heart failure (3.75% vs 2.25%).

“Using the number of events reported in the paper, 13 strokes, 3 heart attacks, and 25 cases of HF might be prevented over a period of about 5 years,” wrote Richard J. Kovacs, MD, of the Krannert Institute of Cardiology, Indiana University School of Medicine, Indianapolis, IN, in an accompanying editorial.

The reasons why ACE inhibitor-based regimens show disparities in clinical effectiveness between blacks and whites remain unclear, the authors noted. But the prevailing theory is that blacks are less responsive to ACE inhibitors compared with whites, particularly in regard to blood pressure reduction.

“Additional research is needed to understand the mechanisms underlying the disparate clinical effectiveness of ACE-inhibitor medication between blacks and whites,” the authors wrote.