Local experience of cardiac resynchronisation therapy in cancer patients

Abstract

Background: International guidelines recommend cardiac resynchronization therapy (CRT) in heart failure (HF) patients with left ventricular ejection fraction (LVEF) <35% and prolonged QRS duration, despite optimal medical therapy (1); where CRT significantly improves symptoms and reduces morbidity and mortality (2-4). Heart failure is common in cancer patients due to shared oncological and cardiovascular risk factors and cardiotoxic cancer therapies. The safety and efficacy of CRT in this growing cohort of potentially eligible cancer patients with heart failure remains uncertain. Purpose(s): To investigate the outcomes of cancer patients who underwent CRT at our local institution. Method(s): Multicentre retrospective cohort study of cancer patients referred for CRT following CO-MDT review. Patient characteristics, including cancer and cardiac status, as well as procedural complications and longer-term outcomes (from CO-MDT referral to latest follow up) were extracted from electronic health records. Result(s): Between January 2022 and December 2024, 11 patients were referred for CRT following CO-MDT review (total 417 individual cases reviewed). The patients were predominately older men, undergoing active cancer therapy (median age 76, 65% male, 73% current systemic cancer therapy, 82% solid tumours, 67% metastatic disease) (table 1). Mean QRS duration was 156ms (+/-30), and mean LVEF 29% (+/-11) prior to CRT. Indication for CRT was symptomatic severe HF in 91% (n=10) of patients. One referred patient had CRT despite moderate LV dysfunction, given concerns for decline in LVEF with reintroduction of breast cancer therapy. CRT implantation occurred in 55% (n=6) without complication, remainder were awaiting implantation (n=2) or no longer eligible due to later improvements in LVEF/HF symptoms (n=3). One patient underwent CRT with defibrillator, she was the youngest patient at age 55 and had LVEF of 18%. Following CRT implantation, t-mean biventricular pacing percentage was 94% (+/-6); there was a meaningful reduction in QRS duration (mean 38ms +/- 25, p=0.008) and increase in LVEF (mean LVEF pre-CRT 29%, mean LVEF post-CRT 42%, p=0.09) at a follow up of 12 months. One patient was hospitalised with heart failure (unrelated to CRT implantation) and all patients remained alive at 12 months follow up. Conclusion(s): Cancer patients underwent successful CRT following CO-MDT review, without procedural or long-term complications. CRT resulted in satisfactory biventricular pacing percentage, plus meaningful improvements in QRS duration and left ventricular function, and can help facilitate ongoing cancer therapies. Cancer patients should not be excluded from the potential benefits of CRT and CO-MDTs can aid in ensuring cancer patients with heart failure receive equitable, guideline directed care.