DIGOXIN AND MORTALITY IN SURVIVORS OF ACUTE MYOCARDIAL-INFARCTION - OBSERVATIONS IN PATIENTS AT LOW AND INTERMEDIATE RISK

Controversy surrounds the safety of digoxin use in patients recovering from acute myocardial infarction. Previous observations yielded contr adictory conclusions. To determine whether digoxin therapy is associat ed with increased mortality in patients recovering from acute myocardi al infarction, we analyzed data from 1731 survivors of acute myocardia l infarction enrolled in the Secondary Prevention Reinfarction Israeli Nifedipine Trial (SPRINT), from which patients with severe heart fail ure were excluded. At the time of hospital discharge, 175 patients (10 %) were taking digoxin. Mortality over 1 year after infarction was sig nificantly higher in patients treated with digoxin than in patients wh o were not receiving digoxin 127 of 175 (15%) vs. 60 of 1556 (4%); p < 0.0001]. Digoxin administration was associated with increased mortali ty in several subsets of patients. Since patients treated with digoxin had baseline characteristics predictive of mortality more frequently than their counterparts, we adjusted for these differences. Multivaria te analysis performed by the Cox proportional hazards model identified treatment with digoxin as an independent determinant associated with increased death during the first year after myocardial infarction [rel ative risk (RR) 2.8; 90% confidence interval (CI) 1.8-4.2]. Subgroup m ultivariate analysis indicated digoxin as an independent predictor of first year death in 464 patients who developed heart failure during th eir hospital stay (RR 2.3; 90% CI 1.3-4.0), as well as among 1267 pati ents who did not (RR 3.4; 90% CI 1.7-6.9). The present study suggests a significant excess mortality associated with digoxin therapy after m yocardial infarction. The increased mortality risk may be related to u nidentified variables associated with the severity of disease in patie nts treated with digoxin. However, our findings raise concern that the administration of digoxin may contribute to increased mortality in su rvivors of acute myocardial infarction.