Abstract 18178: Cause-Specific Mortality in Patients with Prior Anterior Myocardial Infarction: Clinical Predictors Identified in the Home Automated External Defibrillator Trial
Introduction: Mortality risk in stable survivors of anterior wall myocardial infarction (MI) has been presumed to be about 4% per year after surviving the early post-infarct period. Contemporary rates are unknown. The Home Automated External Defibrillator (AED) Trial (HAT) examined cardiac arrest treatment in the home. Home AEDs had no effect on mortality; thus the study offers a unique opportunity to assess long-term predictors of mortality in a well-characterized cohort who did not receive implantable cardioverter-defibrillators.
Methods: Using Cox regression analysis, a multivariate risk factor model was constructed for prediction of all-cause and adjudicated arrhythmic mortality in the 7001 patients enrolled in HAT. The median age was 62 years; 83% were male. All patients had a previous anterior MI at a median interval of 1.7 years prior to randomization. Approximately two-thirds (64.4%) had Q-wave infarcts. Mean QRS duration was 94.8 ± 20.4 ms; 10.4% had QRS ≥ 120ms. The mean LVEF was 46.0 ± 13.6%; 25.6% had LVEF ≤ 35%.
Results: All-cause and arrhythmic mortality were 6.4% (n=450) and 2.4% (n=169), respectively, over a median follow-up of 37.3 months. Three-year mortality rates are shown in Table 1. On multivariate analysis, significant independent clinical predictors for all-cause mortality were: gender, age, NYHA class, history of revascularization, LVEF, atrial fibrillation and QRS duration. The independently significant risk factors for arrhythmic mortality were: gender, age, LVEF, NYHA class and atrial fibrillation.
Conclusions: Contemporary mortality rates in anterior MI survivors in the Home AED Trial were lower than in older published data. All-cause and arrhythmic mortality were very low especially in patients with QRS < 120 ms, even if LVEF values met conventional criteria for ICD implantation. New interventional trials should be more conservative in predicting subsequent mortality in survivors of anterior MI.
- © 2010 by American Heart Association, Inc.