Comparison of the benefit of primary prevention implantable
cardioverter-defibrillator therapy in ischemic versus nonischemic
dilated cardiomyopathy
Abstract
Introduction: Ischemic cardiomyopathy (ICM) and idiopathic dilated
cardiomyopathy (DCM) share common structural alterations with a high
mortality from sudden cardiac death (SCD) and pump failure. Implantable
cardioverter-defibrillator (ICD) has, since inclusion in international
guidelines, been confirmed beneficial and cost-effective for primary
prevention of SCD in patients with ICM, while huge debates in
non-ischemic heart disease. This study was to compare the primary
prophylactic value of ICD therapy in patients with ICM or DCM to
identify a subgroup with greater advantage specially. Methods: We
conducted a retrospective, single-center study, which enrolled 82
patients with ICM or DCM and guideline indications for primary
prophylactic ICD or cardiac resynchronization therapy-defibrillator
(CRT-D). Primary end-point was all-cause mortality and secondary
outcomes included SCD and cardiovascular death. Results: During a median
follow-up of 38.5 months, 78 patients baseline data were analyzable. The
primary outcome occurred in 8 patients in ICM group and 5 patients in
DCM group (p = 0.012). Cardiovascular death occurred in 5 patients in
ICM group and 3 patients in DCM group [hazard ratio (HR) 0.119, 95%
confidence interval (CI) 0.016-0.860, P = 0.035]. Resuscitated cardiac
arrest or sustained ventricular tachycardia occurred in 4 patients in
ICM group and 8 patients in DCM group (HR 0.294, 95% CI 0.040-2.144, P
= 0.227). Conclusions: DCM patients with ICD implantation could gain
more benefit with a reduction in the risk of all-cause mortality and
cardiovascular disease compared with ICM patients, while the occurrence
of SCD had no difference in two groups.