Atrial fibrillation management strategies and early mortality after myocardial infarction: results from the Valsartan in Acute Myocardial Infarction (VALIANT) Trial.

Abstract

The management of patients with atrial fibrillation (AF) following a myocardial infarction (MI) remains uncertain. This study compared a rate control strategy to an anti-arrhythmic-based rhythm control strategy for the treatment of AF following myocardial infarction. We studied 1131 patients with AF after MI who were enrolled in the Valsartan in Acute Myocardial Infarction Trial (VALIANT). We classified patients into those treated with a rhythm control strategy (n=371) and those treated with a rate control strategy (n=760). Using Cox models, we compared the two groups with respect to both death and stroke during two different time periods after randomisation for which data collection had been pre-specified: 0-45 days and 45-1096 days. After adjustment, a rhythm control strategy was found to be associated with increased early mortality (0-45 days: HR: 1.9, 95% CI 1.2 to 3.0, p=0.004) but not late mortality (45-1096 days: HR 1.1, 95% CI 0.9 to 1.4, p=0.45). No difference was observed in the incidence of stroke (0-45 days: HR 1.2, 95% CI 0.4 to 3.7, p=0.73; 45-1096 days: HR 0.6, 95% CI 0.3 to 1.3, p=0.21). In patients with AF after an MI, an anti-arrhythmic drug-based rhythm control strategy is associated with excess 45-day mortality compared with a rate control strategy, but is not associated with increased mortality outside of the immediate peri-infarct period. These results potentially identify a patient population in whom the use of anti-arrhythmic drug therapy may portend an increased risk of death.