Importance of quantitative analysis of ventricular arrhythmias for predicting the prognosis in low-risk postmyocardial infarction patients

In 378 placebo patients enrolled in the European Infarction Study (EIS), a secondary prevention study after acute myocardial infarction, 24-h baseline Holier monitoring was done 14 to 31 days after MI, and the relationship of electrical (ventricular arrhythmias) and mechanical (clinical signs of ventricular dysfunction ) risk factors was analysed on the basis of mortality during the subsequent 2 years of follow-up. There was a rather low overall 2-year mortality rate of 6.9%. Consecutive arrhythmias (ventricular pairs and runs of ventricular premature beats) and left-ventricular dysfunction alone were associated with a low mortality of 4.0% and 3.6%, respectively. However, the combination of both defined a high-risk group characterized by a 2-year mortality rate of 16.7%. Additionally, the risk of dying was dependent on the frequency of consecutive arrhythmias: 22.2% of the patients with > 10 ventricular pairs per day died during the follow-up period in contrast to 9.9% of those with only 1–10 ventricular pairs per day. Thus, only the combination of electrical and mechanical risk factors, and especially the frequency of consecutive VPB, is helpful in identifying a subgroup of post MI patients with poor clinical outcome. An intervention study should restrict itself to this risk population only.