Outcomes of cardiac resynchronization therapy in patients with chemotherapy-induced cardiomyopathy

Background: Several chemotherapy agents are associated with the development of non-ischemic cardiomyopathy (NIC). When chemotherapy-induced cardiomyopathy (CHIC) is associated with left bundle branch block (LBBB) and a left ventricular ejection fraction (LVEF) 35% or lower, cardiac resynchronization therapy (CRT) is often utilized to improve cardiac function and relieve symptoms. Objective: To determine the echocardiographic and clinical outcomes of CRT in patients with CHIC. Methods: The study included 29 patients with CHIC (CHIC group) and 58 patients with other types of NIC (control group) who underwent CRT implantation between 2004 and 2017. The primary endpoints were changes in LVEF, left ventricular end-systolic diameter (LVESD), and left ventricular end-diastolic diameter (LVEDD) at 6–18 months after CRT. The secondary outcomes included changes in left ventricular global longitudinal strain (GLS), systolic strain rate (SRS), early diastolic strain rate (SRE), and overall survival. Results: Out of 29 patients with CHIC, 62.1% received chemotherapy for lymphoma, 13.7% for breast cancer, and 24.1% for sarcoma. The agent implicated in 93.1% of the patients was an anthracycline. Half of the patients had LBBB. The mean baseline LVEF was 28% ± 8%. The mean baseline QRS duration was 146 ± 26 ms. Twenty-eight patients had post-CRT follow-up data. CRT was associated with improvement in echocardiographic outcomes in the CHIC group and the control group. There was no difference in overall survival between the two groups (log-rank p =.148). Conclusion: CRT improves left ventricular function and reverses remodeling in patients with CHIC.