Abstract 15903: Gender Differences in the Mechanism of Death From the MADIT Trials
Background: Implantable cardioverter-defibrillators (ICD) reduce the risk of sudden cardiac death. Limited information is available assessing the mechanism of death following ICD or CRT-D implantation. We aimed to determine whether gender differences exist in the mechanism of death between men and women following ICD or CRT-D implantation enrolled in the MADIT trials (MADIT-II, MADIT-CRT, and MADIT-RIT).
Methods: The combined cohort consisted of 3038 men and 1000 women with either ischemic (ICM) or nonischemic cardiomyopathy (NICM), LVEF ≤ 30%; NYHA Class I-III heart failure who received either an ICD or CRT-D. Adjudication committees composed of individuals independent of all aspects of each trial reviewed the clinical data for all deaths. The mechanism of death was divided into cardiac and non-cardiac subgroups. Cox proportional regression models were used to evaluate the risk (hazard ratio) of death between men and women. Covariates adjusted for included: age, ejection fraction, NYHA class, diabetes, ischemic status, and gender.
Results: A total of 295 men and 66 women died (9.7% vs. 6.6%; p=0.003). All-cause mortality was highest in men with ICM (11.6%) and lowest in both men (n=48; 5.3%) and women (n=33; 5.3%) with NICM. The most common cause of death was non-arrhythmic cardiac death in men (n=124; 42%), and non-cardiac death in women (n=22; 33%). The frequency of arrhythmic death was similar between men and women with ICM (1.8% vs. 1.9%; p=NS) and NICM (0.9% vs. 0.8%, p=NS). A trend toward an increased risk of all-cause mortality and non-arrhythmic cardiac death was observed in men with ischemic heart disease when compared to women (Table).
Conclusion: The risk of arrhythmic death following ICD or CRT-D implantation is low and similar between men and women. Men with ischemic heart disease tend to be at greater risk of all-cause and non-arrhythmic cardiac death than women. However, mortality appears similar between men and women with nonischemic cardiomyopathy.
- © 2013 by American Heart Association, Inc.