Abstract 4137113: The Effectiveness of Cardiac Resynchronization Therapy in Patients with Cardiac Sarcoidosis: A Retrospective Analysis

Background: Cardiac sarcoidosis (CS) manifests in a wide range of clinical presentations, including conduction system abnormalities, ventricular arrhythmias, and systolic heart failure. Although cardiac resynchronization therapy (CRT) has shown efficacy in treating select nonischemic cardiomyopathy patients, its specific impact on CS patients remains less explored. This study aimed to evaluate the outcomes of CRT therapy in CS patients, focusing on implantable cardioverter defibrillator (ICD) therapies, heart failure (HF) hospitalizations and mortality. Methods: We retrospectively reviewed all patients with a clinical or histological diagnosis of CS who underwent device implantation (ICD or Permanent Pacemaker (PPM)) with or without CRT therapy at Johns Hopkins Hospital between 2004 and 2024. Baseline characteristics and echocardiographic parameters were assessed. Heart failure hospitalizations, the frequency of ATP (Anti-Tachycardia Pacing) or ICD shocks, and all-cause mortality were also evaluated as the outcomes. Results: The study included 212 patients (40.1% female, average age 52.8 ± 11.1 years). Eighty-five patients underwent CRT implantation (82 CRT-D and 3 CRT-P), whereas the rest received either an ICD or a PPM without CRT therapy. Most CRT devices (58.82%) were upgrades from an initial PPM or ICD. Over a follow-up of 6.15 ± 4.43 years, 27 (12.74%) patients were hospitalized for heart failure (HF), 86 (40.56%) experienced ATP or ICD shocks, and 17 (8.02%) died. The composite outcome was observed in 103 patients (48.5%), with no significant differences between CRT and non-CRT groups ( P = .51). Survival analysis indicated significantly reduced freedom from HF hospitalizations in the CRT group compared to non-CRT group ( P = .01). However, ATP/ICD shocks did not have a significant difference. CRT recipients showed an improvement in left ventricular ejection fraction (LVEF) from 35.3 ± 12.6% to 38.9 ± 13.6% at 6 months ( P = .01). Non-recipients showed no significant change in LVEF ( P = .43). Conclusions: Over an average six-year follow-up period, CRT upgrade does not appear to affect ATP/ICD shock and mortality in CS patients, although it is associated with significantly higher rates of heart failure (HF) hospitalizations compared to CS patients with an ICD or PPM alone. These findings underscore the complex response of CS patients to CRT, highlighting the need for further research to optimize treatment strategies within this subgroup.