Efficiencies and Complications of Dual Chamber versus Single Chamber Implantable Cardioverter Defibrillators in Secondary Sudden Cardiac Death Prevention: A Meta-analysis

BackgroundDual chamber implantable cardioverter defibrillators (ICDs) are considered to have better clinical outcomes than single chamber ICDs, however, an individual trial may not have sufficient power to prove it. This meta-analysis aimed to compare clinical outcomes of dual chamber ICDs (DC-ICDs) with single chamber ICDs (SC-ICDs) in secondary sudden cardiac death (SCD) prevention.MethodsWe searched Medline, the Cochrane Library, and other internet sources, without language or date restrictions for articles comparing clinical outcomes between DC-ICDs and SC-ICDs. Studies were selected for inclusion based on the following criteria: Randomised controlled trial.; Controlled design was used to compare SC-ICDs and DC-ICDs; Retrospective study if the survival analysis was performed. Efficacy endpoints were mortality, appropriate therapy, inappropriate detection of SVT, inappropriate therapy. Safety endpoints were lead-related complication and all complications. Relative risk (RR) or odds ratios (ORs) with 95% confidence intervals (CI) were calculated, and a χ2-based test of homogeneity was performed.ResultsWe identified nine trials (n=2594) with a weighted mean follow-up of 18.9 months. Compared with DC-ICDs, SC-ICDs were associated with a significant reduction in lead complications (RR:3.30; 95% CI: 1.17-9.30; p=0.02). However, both groups had similar rates of mortality (OR: 0.91; 95%CI: 0.91-1.51; p=0.73), appropriate therapy (RR: 0.90; 95%CI: 0.73-1.11; p=0.32), inappropriate detection of SVT (RR: 1.82; 95%CI: 0.71-4.62; p=0.21), inappropriate therapy (RR: 2.08; 95%CI: -0.22-0.19; p=0.86) and all complications (OR: 1.27; 95%CI: 0.19-8.67; p=0.81).ConclusionsBesides more lead-related complications, DC-ICDs had similar efficacy and all complications as SC-ICDs in secondary sudden cardiac death prevention.