Implantable cardioverter defibrillators in patients with valvular cardiomyopathy

Background: Implantable cardioverter-defibrillators (ICDs) are beneficial for preventing sudden cardiac death (SCD) in patients with previous SCD or left ventricular dysfunction. Objective: The objective was to investigate the outcomes of ICD implantation in patients who have surgery for valvular cardiomyopathy (VCM). Methods: We identified patients with VCM who had ICD implantation after valve surgery. Age-and sex-matched patients who received an ICD for ischemic cardiomyopathy (ICM) and dilated cardiomyopathy (DCM) served as controls. Patients with VCM who had valve surgery but did not receive an ICD served as an additional control group. We compared mortality and appropriate ICD discharges between the study group and control groups. Results: Mean (SD) age (31 patients with VCM with ICD, 30 with ICM, 26 with DCM, and 62 patients with VCM without ICD) was 60 (15) years, 73% were men. Ejection fraction at ICD implantation was 34%, 26%, and 23% for the VCM with ICD, ICM, and DCM groups, respectively (P= 0.03). After a median follow-up of 4.1 years, survival was not significantly different among ICD groups (P= 0.06). The annual appropriate shock rate was 5%, 10%, and 4% for the VCM with ICD, ICM, and DCM groups, respectively (P= 0.71). Compared to VCM without ICD, patients with VCM and ICD had comparable survival (P= 0.82) despite a reduced LVEF following valve surgery. Conclusion: Patients with VCM who undergo ICD implantation for SCD prevention have similar appropriate ICD discharge rates and mortality as do those with ICM and DCM. These data are hypothesis generating and deserve confirmation with large-scale prospective studies.