American Heart Association - New Orleans

Verapamil Helps to Prevent Reinfarction


New Orleans - The Calcium Antagonist Reinfarction Italian Study (CRIS) shows that verapamil has a statistically significant effect in preventing reinfarction and also that, in patients taking the drug, heart rate is an accurate predictor of mortality. Dr. Nicola Ferrara, a CRIS investigator, presented these findings to participants at the 69th Scientific Sessions of the American Heart Association, held in November in New Orleans.

Dr. Ferrara began by noting that increased heart rate is a prognostic factor related to coronary events and mortality. In addition, a raised heart rate after acute myocardial infarction (MI) is an independent predictor of risk. Many large trials have shown the benefits of beta-blockade after acute MI: Decreasing the heart rate with beta-blockers is related to reduction in mortality. CRIS was initiated to determine if the same holds for calcium-channel blockers.

The CRIS trial

The CRIS trial looked at the effects of the calcium antagonist verapamil. This multicenter, double-blind, randomized, placebo-controlled trial involved 1,073 subjects, ages 35-70 years, who had experienced an acute MI between 1985 and 1987 and had no contraindications to verapamil nor a history of severe heart failure. Their MIs had no left bundle branch block. At baseline, the two cohorts had other similar characteristics: mean age was 55.5 years, and 91 percent were men.

Seven to twenty-one days after MI, verapamil (120mg t.i.d., slow release) was administered to 531 subjects. The remaining 542 subjects were given a placebo.

Benefits

After six months of follow-up, the verapamil group had acquired some clear benefits: a significant reduction in the number of patients having angina attacks; a drop in the use of antihypertensives; and a heart rate significantly lower than in those taking the placebo. In addition, there were no differences between the verapamil and placebo groups in discontinuation of therapy caused by adverse reactions.

More study is needed on other aspects of treatment, as the verapamil group experienced a nonsignificant reduction of reinfarction rates, and there was no significant difference between the effects of placebo, and verapamil treatments on death, heart failure, arrhythmias, gastrointestinal symptoms, rash, or hypotension.

Major events

Statistical analysis of the CRIS data confirm that a higher heart rate is associated with an increase in mortality and first major events in patients after MI. The risk of all-cause mortality and cardiac death associated with increased heart rate was significant in the placebo group but not in the group taking verapamil.

When the results of the CRIS study are combined with those of other trials, verapamil does have a statistically significant effect in preventing reinfarction. Unlike the dihydropyridine calcium-channel blockers, verapamil reduces major cardiac events after acute MI.

The CRIS trial thus provides additional evidence that verapamil is useful in preventing reinfarction and decreasing ischemic symptoms without causing serious adverse effects. However, more studies are needed to determine if verapamil significantly reduces mortality after acute MI.