Survival prediction after cardiac resynchronization therapy: Clinical scores vs left ventricular ejection fraction

Left ventricular ejection fraction (LVEF) is commonly used to characterize remodeling and estimate prognosis after cardiac resynchronization therapy (CRT). Clinical scores assessed at follow-up may provide complementary prognostic information.

This study compared the predictive value of LVEF and clinical scores, measured at 6 months after CRT, for long-term survival.

This prospective cohort study enrolled 528 patients undergoing CRT between May 2016 and June 2022. Clinical scores, including the 6-minute walk distance, gait speed, the timed up-and-go test, the Study of Osteoporotic Fractures frailty index, and the 5-level EuroQol-5 dimension score, were evaluated at 6 months after CRT alongside LVEF. The primary end point was event-free survival, defined as survival without left ventricular assist device implantation, heart transplantation, or death. Using a nested model approach, Cox proportional hazards models assessed predictive accuracy using the concordance index (C-index).

Over a mean follow-up of 3.73 years, 127 patients (24%) reached the primary end point. In models adjusted for baseline covariates, LVEF at 6 months was associated with event-free survival (C-index 0.732), whereas several clinical scores showed higher discrimination (C-index: 6-minute walk distance 0.767; Study of Osteoporotic Fractures frailty index 0.754; timed up-and-go test 0.749; 5-level EuroQol-5-dimension score 0.740). Findings were consistent when using clinically relevant cut points. In LVEF-adjusted models, high-performing clinical measures provided incremental prognostic value beyond LVEF.

Although LVEF remains a valuable metric, a multidimensional approach incorporating clinical scores alongside LVEF may improve long-term survival prediction after CRT. Their integration into clinical practice could enhance personalized care and risk stratification for CRT recipients.