TUESDAY, Nov. 9, 2004 (HealthDayNews) -- Giving a hypertension drug to people with heart disease saves lives even if they have normal blood pressure, and a calcium channel blocker drug is more effective than an ACE inhibitor, a new study finds.
The researchers tested the calcium channel blocker amlodipine against the ACE inhibitor enalapril and a placebo in 1,991 patients with coronary artery disease whose blood pressure was normal by current standards. Over two years, the rate of adverse events such as a heart attack or death was 31 percent lower for those getting amlodipine and 15.3 percent lower for those getting enalapril, compared to patients getting the placebo, said a report in the Nov. 10 issue of the Journal of the American Medical Association.
"We don't think a single study is definitive, but this is a pretty solid finding," said study leader Dr. Steven E. Nissen, a cardiologist at the Cleveland Clinic Lerner School of Medicine. "What we consider a normal blood pressure may be too high if you are a patient with coronary artery disease."
The study was funded by Pfizer Inc., which markets amlodipine as Norvasc. But it will come off patent and be available in generic form next year, Nissen said. Enalapril is marketed as Vasotec and already is available as a generic. Both drugs are commonly prescribed to control high blood pressure.
Nissen said the better results achieved with amlodipine probably are related to its effects other than reducing blood pressure, such as preventing the chest pain called angina and reducing the incidence of blood clots. But the important point of the study is the lifesaving effect of treatment for high blood pressure even when it doesn't appear to exist, he said.
Participants in the study had average blood pressure of 129 over 78, generally regarded as normal. "It is a most incredible conclusion, very surprising, to find a 31 percent reduction in the composite endpoint in people well within the range of normal," Nissen said.
"For every 16 patients who receive amlodipine, there will be on average one adverse cardiovascular event avoided during the two-year period compared with patients who receive placebo," the report said. But the reduction in adverse effects achieved with enalapril was not statistically significant, it said.
More study is needed before cardiologists begin prescribing blood pressure medications to all patients with coronary artery disease, said Dr. Carl J. Pepine, a professor of medicine at the University of Florida College of Medicine, who wrote an accompanying editorial.
One reason is that doctors have to be concerned not only about systolic blood pressure -- the higher figure in 129 over 78 -- but also about diastolic pressure, the lower number, he said. Too-low diastolic pressure could produce adverse effects that would outweigh the benefits of systolic pressure reduction, Pepine said.
In his practice, Pepine said, he will make the decision about blood pressure drugs "one patient at a time, based on diastolic blood pressure. If it is above 75, I would consider trying to lower systolic pressure."
As to which kind of drug should be prescribed for such patients, Nissen noted that most people who need blood pressure medication take more than one drug, and that several families of medications are available -- not only ACE inhibitors and calcium channel blockers but also beta blockers and diuretics.
"It's not possible to get to your target without multiple drugs," he said. "I see nothing wrong with an ACE inhibitor combined with a calcium channel blocker."
A guide to blood pressure drugs and their use can be found at the American Heart Association.