Abstract Body (Do not enter title and authors here): BACKGROUND: Patient-reported outcomes, such as quality of life (QoL) scores, provide a comprehensive measure of health status from the patient's perspective, which may be relevant for predicting survival after cardiac resynchronization therapy (CRT).

HYPOTHESIS: We hypothesize that a healthier QoL score at 6 months post-CRT is associated with better long-term survival.

AIM: To evaluate the association between a validated QoL at 6 months post-CRT and two-year survival in CRT patients.

METHODS: A prospective cohort study recruited 524 patients who received CRT at the Cleveland Clinic between May 2016 and June 2022. The 5-level EuroQol-5 Dimension (EQ-5D-5L) was used to assess QoL at 6 months post-CRT (higher scores indicating worse QoL) and patients were divided into two strata (EQ-5D-5L ≤ or > 10). Our primary endpoint was Event-Free Survival (EFS) – defined by the absence of both significant cardiac interventions (LVAD implantation or heart transplant) and mortality.

RESULTS: The population had a median (IQR) age of 71 years (IQR: 62-78), with 343 (65.5%) men and 419 (80%) received a defibrillator. Median EQ-5D-5L was 7 (IQR: 5-9). The response rate at 6 months post-CRT was 321 (68.2%), and the 2-year EFS rate was 397 (75.8%). Univariate analysis re revealed that EQ-5D-5L>10 was significantly associated with increased EFS. The Cox proportional hazard model showed it to be an independent predictor of EFS (HR: 2.33, 95% CI [1.53-3.56], p<0.001), after adjusting for potential confounders, including age, gender, diabetes mellitus, ischemic cardiomyopathy, AFib/flutter, history of TIA/CVA, NYHA Class, and COPD. The Kaplan-Meier survival curves demonstrated a significantly lower EFS probability for patients with EQ-5D-5L>10 (log-rank test: p<0.001).

CONCLUSIONS: QoL assessed at 6 months post-CRT is a significant predictor of two-year survival in CRT patients. The EQ-5D-5L score can be a valuable tool to enhance patient risk stratification and management.