[Mishaps with anti-arrhythmic agents used to reduce mortality after infarction]

The presence of isolated and/or repetitive ventricular arrhythmias following myocardial infarction identifies a group of patients at increased risk of death. The availability of anti-arrhythmic drugs, noticeably drugs with class I activity, efficient at suppressing arrhythmias has led to the hope that their administration could reduce post-myocardial infarction mortality. However, this hypothesis has not been confirmed. The Cardiac Arrhythmia Suppression Trial, which was designed to have the power to test the hypothesis that suppression of ventricular arrhythmias is associated with a decrease in mortality following myocardial infarction, even showed an increase in mortality with two drugs with class I activity. Several meta-analyses have confirmed that administration of class I antiarrhythmic drugs is of no clinical benefit in patients with non sustained ventricular arrhythmias following myocardial infarction. Ongoings studies are testing the hypothesis that such benefit could exist with amiodarone. The clinical benefit of beta-blockers, in terms of reduction of both total and sudden death post-myocardial infarction, has been clearly documented and mandates their administration in this setting. Futures studies of anti-arrhythmic drugs will have to focus on groups of patients at increased risk of arrhythmic death.