Effect of ICD on patients with improved EF in idiopathic dilated cardiomyopathy

Abstract

Abstract Background The efficacy of implantable cardioverter defibrillator (ICD) therapy in patients who had heart failure with improved ejection fraction (HFimpEF) above guidelines indication for ICD (>35%) during generator change is still controversial. This meta-analysis assesses the impact of ICD therapy in patients with HFimpEF with EF >35% and patient with NICM. Methods Databases were searched for studies reporting the association between ICD in patients with NICM and HFimpEF and ventricular arrhythmias (VA) and sudden cardiac death (SCD); including Ovid MEDLINE, EMBASE, Web of Science, and Google Scholar. The search was not restricted to time or publication status. The minimal follow up duration was one year. Results A total of 38 studies and 13,538 patients (5,829 with improved EF vs 7,709 with EF <35% during follow up) were included; mean follow up was 43 months (ranging between 12 to 74 months). Mean age was 63.5 and 75% were males. Patients with HFimpEF with ICD, wither alone or as part of CRT therapy, was associated with lower risk of VA and SCD (OR 0.39, 95% CI 0.32-0.47; P<0.01; annual rate 4.1 vs. 8%). Sub-analysis for patients with ICD for patient with NICM was associated with lower risk of VA and SCD (OR 0.25, 95% CI 0.1-0.62; P<0.01; annual rate 2.9 vs. 10.2%). (Figure) Conclusion Improved EF is associated with reduced VA but with still elevated risk in HFimpEF especially in NICM.