December 19, 2012
Higher BMI Means Fewer Cardiac Events for Diuretic Combination UsersBrooklyn, NY—For patients taking a single-pill combination of benazepril and hydrochlorothiazide, higher body mass index (BMI) was associated with fewer cardiac events, according to a new study.
Reporting online in Lancet earlier this month, researchers lead by Michael A. Weber, MD, of the State University of New York, Downstate College of Medicine, in Brooklyn, noted that BMI had no influence, however, on efficacy in patients taking benazepril plus amlodipine.
In a subanalysis of the Avoiding Cardiovascular Events in Combination Therapy in Patients Living with Systolic Hypertension (ACCOMPLISH) trial, researchers divided the 5,709 member cohort into three categories—obese, overweight, and normal weight—and tracked event rates for the primary endpoint, defined as cardiovascular death or nonfatal myocardial infarction or stroke.
“In patients allocated benazepril and hydrochlorothiazide, the primary endpoint (per 1000 patient-years) was 30.7 in normal weight, 21.9 in overweight, and 18.2 in obese patients (overall P = 0.0034),” the authors write. “However, in those allocated benazepril and amlodipine, the primary endpoint did not differ between the three BMI groups (18.2, 16.9, and 16.5, respectively; overall P = 0.9721).”
The research was conducted, they note, because “paradoxically higher cardiovascular event rates have been reported in patients of normal weight compared with obese individuals” in previous clinical trials.
The results raised questions about whether diuretics could be safe and effective for obese patients but increase the risk of cardiovascular events in those who aren’t obese, according to the authors.
A commentary accompanying the article suggests that the obese subjects may have responded well to diuretic treatment because many of them may have been at risk for heart failure. The commentary also notes that metabolic differences in obese and nonobese patients should be taken into consideration.
“Obesity is known to lead to hypertension and, conversely, hypertension to result in obesity; therefore, both disorders commonly coexist. However, obesity profoundly affects hemodynamic, neuroendocrine, and metabolic processes, in addition to target organ disease in hypertension. Since excess adipose tissue needs a higher cardiac output to meet metabolic demands, for any level of arterial pressure, vascular resistance will be lower in an obese than in a lean patient,” writes Franz H. Messerli, MD, of St. Luke's Roosevelt Hospital in New York City, and Sripal Bangalore, MD, of New York University School of Medicine, in the editorial.
“This strategy relegates diuretics to third-line agents for treatment of hypertension, except in patients at risk of heart failure,” Messerli and Bangalore conclude.
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