The drugs are vasodilators, a class of medications that widen arteries and make blood flow easier. While official American Heart Association guidelines do not recommend their use for aortic regurgitation, some physicians still prescribe them for the condition.
In aortic regurgitation, the valve that controls the flow of blood from the heart to the rest of the body is so flabby that blood flows backward, causing the heart's pumping chamber, the ventricle, to enlarge dangerously.
The theory behind their use is that vasodilators could delay or prevent surgery to replace the faulty valve. But a study of 95 people with severe aortic regurgitation found that two widely used vasodilators, nifedipine and enalapril, did nothing of the sort.
Some of the 95 patients got nifedipine, some got enalapril, and some got no drug treatment, to serve as a control group.
"After a mean of seven years of follow-up, the rate of aortic valve replacement was similar among the groups: 39 percent in the control group, 50 percent in the enalapril group and 41 percent in the nifedipine group," the Spanish researchers wrote. In addition, there were no significant differences in a variety of measures of heart function, they said.
The findings, by doctors at the Hospital Universitari Vall d'Hebron in Barcelona, appear in the Sept. 29 issue of the New England Journal of Medicine.
Dr. Richard A. Stein, director of preventive cardiology at Beth Israel Medical Center in New York City, and a spokesman for the American Heart Association, said the study reinforces the heart association guidelines, which for seven years have advised against using enalapril. "And nobody uses nifedipine," he said.
"Your body sort of dilates itself in aortic regurgitation," Stein said. "It dilates the arteries as much as it can in response to this condition."
But Stein said it was "very important that this [study] be done" because "in my experience, some cardiologists and surgeons do prescribe vasodilators for the condition. Someone had to do a large, controlled study to show their lack of worth, and that's what this is."
In an accompanying editorial in the journal, Dr. Blase A. Carabello, a cardiologist at the Michael E. DeBakey Veterans Affairs Medical Center in Houston, took a different view of the study's value. It was just too small to settle the issue, Carabello said, and that is typically true of studies done of heart-valve conditions.
"Overall, there are probably more than 3,000 randomized trials in cardiologic subspecialties exploring outcomes in well over 150,000 patients," he wrote. "However, there are fewer than a dozen randomized trials involving patients with valvular heart disease, and most involve fewer than 200 patients."
Carabello listed several reasons for the neglect -- the relatively low incidence of valve conditions, the fact that drug companies are reluctant to support trials in the field, and the wide variation of treatments in different centers "making comparison of data difficult."
"Unfortunately, practitioners caring for patients with valvular heart disease will continue to grope for the best therapies until the evidence-based medicine so prevalent in the rest of cardiology becomes available," Carabello said.
More information
The American Heart Association has more about aortic regurgitation.
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