Are dual-chamber implantable cardioverter-defibrillators really better than single-chamber ones? A systematic review and meta-analysis

Although dual-chamber (DC) cardioverter defibrillators (ICDs) offer theoretical advantage over single-chamber (SC) ICDs, clinical studies showed conflicting results. The aim of this systematic review and meta-analysis was to compare DC and SC ICDs. A systematic search of publications in PubMed, Embase, and the Cochrane Library without language restriction was performed. Randomized or nonrandomized controlled studies that compared DC and SC ICDs were included. Six randomized studies including 2,388 patients and 14 nonrandomized studies including 113,931 patients were identified. No difference in mortality was observed between DC and SC ICDs recipients in randomized studies. In nonrandomized studies, higher mortality was shown in DC group. There was no difference in the rate of inappropriate therapy between the DC and SC group after pooling the results from randomized studies as well as nonrandomized studies. More complications were observed with DC ICDs recipients. DC ICDs showed no conclusive superiority over SC ICDs. Without indications for antibradycardia therapy, SC ICDs seem to be the preferred selection.