ATENOLOL REDUCES ADVERSE CARDIOVASCULAR OUTCOMES BY OVER 50% IN ASIST TRIAL,
Executive Summary
ATENOLOL REDUCES ADVERSE CARDIOVASCULAR OUTCOMES BY OVER 50% IN ASIST TRIAL, study director Carl Pepine, MD, University of Florida, reported March 16 at the American College of Cardiology annual meeting in Anaheim. The Atenolol Silent Ischemia Trial (ASIST), which used ICI's Tenormin, marks the "first time" that treatment of asymptomatic or mildly symptomatic coronary artery disease patients has been shown to "result in significant benefit," Pepine said. "Prior to this [study], we treated ischemia but we never demonstrated that actual reduction in ischemia reduces adverse outcome," Pepine remarked. "That is important because that lends credibility to the fact that ischemia can be a surrogate for adverse outcome down the road." It is also "the first time that treatment of silent ischemia has been shown to have some benefit," he said. Pepine added, however, that "the risk reduction has to be repeated in other trials." The ASIST trial screened a population of 2,037 patients with coronary artery disease for transient ischemia, enrolling 306 largely asymptomatic and minimally symptomatic patients. Study participants were treated with 100 mg atenolol or placebo for four weeks. Pepine reported that atenolol reduced ambulatory ischemia from 3.2 episodes per 38 hours to 1.4 episodes. In addition, there was a significant reduction in the duration of ischemia from 3.5 minutes in the placebo group to 2.8 minutes in the atenolol- treated patients. All cardiovascular outcomes, such as death, myocardial infarction, unstable angina and revascularization, were reduced by 56%, from 39 events in the placebo group to 17 events in the atenolol-treated patients. The major side effect associated with atenolol was a 6% incidence of bradycardia defined as less than 50 heart beats per minute. Pepine noted that physicians are already treating patients who have ischemia with beta blockers like atenolol. The study "provides some clarity or some reason for what is already going on out there," he said. The message from the trial might be that "patients who appear to be clinically stable can be at high risk," Pepine suggested, noting that 91% of the patients in the trial had silent ischemia.