Impact of Implantable Cardioverter-Defibrillator Interventions on All-Cause Mortality in Heart Failure Patients: A Meta-Analysis

Implantable cardioverter-defibrillators (ICDs) have a unique role in the primary and secondary prevention of sudden cardiac death. However, appropriate and inappropriate ICD interventions [antitachycardia pacing (ATP) or shocks] can result in deleterious effects. The aim of our study was to systematically review the existing data about the impact of ICD interventions on all-cause mortality in heart failure patients with reduced ejection fraction (HFrEF). We systematically searched MEDLINE (by using PubMed Web-based search engine) without any limits until September 30, 2017. After screening 17,752 records, a total of 17 studies met our inclusion criteria and were included in our meta-analysis. Our data showed that in patients with HFrEF, appropriate [hazard ratio (HR), 2.00; 95% confidence interval (CI), 1.52-2.63; P < 0.01; I² 88%] and inappropriate [HR, 1.30; 95% CI, 1.07-1.58; P < 0.01; I² 26%] ICD interventions were significantly associated with increased all-cause mortality. However, neither appropriate ATP [HR, 1.27; 95% CI, 0.80-2.02; P = 0.30; I² 62%] nor inappropriate ATP [HR, 1.01; 95% CI, 0.49-2.07; P = 0.98; I² 46%] were significantly associated with all-cause mortality in this patient population. In conclusion, ICD shocks are associated with a worse prognosis in HFrEF.