Abstract 17491: Long-term Mortality of Patients With Single-Chamber versus Dual-Chamber Implantable Cardioverter-Defibrillators
Nationwide, dual-chamber ICDs comprise the majority of defibrillator implantations. Although dual-chamber ICDs are associated with increased periprocedural complications including death, the relationship between single-chamber versus dual-chamber ICDs and long-term mortality remains unclear. We sought to determine possible differences in long-term mortality among patients receiving single-chamber versus dual-chamber ICDs. Records and device interrogations of patients who underwent primary ICD implantation between July 1, 1997 and March 23, 2001 at one academic medical center were reviewed. Patient status was determined as of December 31, 2010. Mean follow-up time was 11.6 years. During the study period, 513 patients underwent primary ICD implantation (65% singe-chamber, 35% dual-chamber). Of patients with a dual-chamber ICD, 18% had an indication for antibradycardia pacing, 22% had conduction disease, and 19% had asymptomatic sinus bradycardia. Univariable analysis suggested that dual-chamber ICD device selection is associated with increased long-term mortality (HR 1.41, 95% CI 1.09-1.92, p=0.008). However, after adjusting for numerous possible confounders, no significant difference in long-term mortality between patients who received single-chamber versus dual-chamber ICDs was identified (HR 1.19, 95% CI 0.91-1.56; p=0.21, see figure). Patients implanted with dual-chamber ICDs were older (66.5 years versus 62.1 years, p=0.002) and had more coronary artery disease (76% versus 68%, p=0.03) than those implanted with single-chamber ICDs. Secondary analysis, which included percentage of right ventricular pacing as a covariate, revealed an independent association between long-term mortality and greater than 50% ventricular pacing (HR 1.72, 95% CI 1.18-2.52).
- © 2013 by American Heart Association, Inc.