Inappropriate Shocks in Patients with ICDs: Single Chamber versus Dual Chamber

Abstract

BackgroundDespite the technological evolution of the implantable defibrillator, one of the questions that remains is the possible benefit of the dual chamber versus single chamber implantable cardioverter defibrillator (ICD) in reducing inappropriate shocks.ObjectiveTo evaluate which type of device provides fewer inappropriate shocks (dual chamber versus single chamber) in patients with implantable cardioverter defibrillators (ICDs).MethodsMeta-analysis of randomized studies published in the literature comparing dual-chamber implantable cardioverter defibrillators to single chamber devices which have been known to cause, as an evaluated endpoint, inappropriate shocks. ResultsThe dual-chamber implantable cardioverter showed no benefit in reducing the number of inappropriate shocks. In fact, the opposite was shown. In the analysis of fixed effects, the association tended to favor single-chamber implantable cardioverter defibrillators (OR = 1.53, CI 95%: 0.91-2.57), despite the absence of statistical significance (p = 0.11). We highlight the heterogeneity observed in the results (I2 = 53%), which motivated a replication of the analysis using a model of random effects. However, significant differences remained in the occurrence of inappropriate shocks in both groups (OR = 1.1, 95% CI: 0.37-3.31; p = 0.86). To complement the analysis, we proceeded to perform sensitivity analysis, which showed that the exclusion of a study resulted in the lowest heterogeneity observed (I2=24%) and the association with inappropriate shocks significantly favored the single chamber cardiodefibrillator (OR = 1.91; 95% CI: 1.09-3.37; p = 0.27).ConclusionsIt was determined that there was no clear evidence of superiority of any of the devices evaluated.

2015 HRS/EHRA/APHRS/SOLAECE expert consensus statement on optimal implantable cardioverter-defibrillator programming and testing

“…Two meta-analyses found no superiority of dual-chamber ICDs in terms of mortality or inappropriate therapies [11,140]. Any benefit of dual-chamber discrimination is likely restricted to specific patient groups [103,138].…”

Inappropriate shocks in single-chamber and subcutaneous implantable cardioverter-defibrillators: a systematic review and meta-analysis

“… 6 Additionally, a recent systematic assessment of ISs comparing dual-chamber ICDs with single-chamber devices revealed no clear superiority of dual-chamber ICDs vs. single-chamber in reducing ISs. 7 Thus, an atrial lead is not recommended for a substantial proportion of ICD-indicated patients. 8 …”

2015 HRS/EHRA/APHRS/SOLAECE expert consensus statement on optimal implantable cardioverter‐defibrillator programming and testing

“…Clinical trials and simulated testing of induced arrhythmias that compared single- vs dual-chamber discriminators have reported inconsistent results [10] , [33] , [137] , [138] , [139] . Two meta-analyses found no superiority of dual-chamber ICDs in terms of mortality or inappropriate therapies [11] , [140] . Any benefit of dual-chamber discrimination is likely restricted to specific patient groups [103] , [138] .…”