Implantable cardioverter defibrillators in left ventricular assist device patients: Α systematic review and meta-analysis

Implantable cardioverter-defibrillators (ICDs) remain the standard of care in advanced heart failure with reduced ejection fraction patients for the prevention of sudden cardiac death. However, current guidelines remain conflicting with respect to the use of ICDs in patients supported with a continuous flow left ventricular assist device (CF-LVAD). The current review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies comparing the use of ICD in patients with CF-LVADs were included. The 2 primary outcomes studied were all-cause mortality, and a successful bridge to heart transplantation. We calculated pooled odds ratios (ORs) with 95% confidence intervals (CIs). We also compared baseline characteristics between US and European studies, for CF-LVAD patients with an ICD. Among all studies, the use of an ICD was not associated with all-cause mortality in patients with CF-LVADs (OR: 0.85, 95% CIs: 0.64-1.12, p = 0.24). The presence of an ICD was associated with a trend towards increased likelihood of successful bridge to heart transplantation (OR: 1.12, 95% CI: 1.0-1.3, p = 0.06). A subgroup analysis of studies published by European centers revealed a significant decrease in pooled mortality (OR: 0.58, 95% CI: 0.4-0.83, p = 0.003) with the use of ICD, contrary to an increase in pooled mortality among studies published by US centers (OR: 1.2, 95% CI 1.02-1.33, p = 0.025). Moreover, we identified significant differences in baseline characteristics such as bridge to transplantation rate, Interagency Registry for Mechanically Assisted Circulatory Support profiles, and use of an intra-aortic balloon pump or extracorporeal membrane oxygenation preoperatively, between the US and European populations. While this meta-analysis did not show an overall survival benefit with the use of an ICD in CF-LVAD patients, it revealed significant differences in the derived benefit, in distinct patient populations. This might reflect differences in baseline patient characteristics and warrants further investigation.