Decreased left ventricular systolic function during the late phase after response to cardiac resynchronization therapy

Abstract

Background

Cardiac resynchronization therapy (CRT) improves cardiac function in patients with heart failure (HF) and dyssynchrony. However, a subset of responders develops a delayed decline in left ventricular (LV) systolic function, referred to as “delayed negative reverse remodeling (DNRR).”

Objective

This study aimed to investigate the characteristics and prognosis of DNRR in CRT responders.

Methods

A total of 203 patients undergoing CRT device implantation were analyzed. Among them, 100 responders were identified on the basis of a ≥5% absolute LV ejection fraction (LVEF) increase and a ≥15% relative LV end-systolic volume reduction at 6 months after CRT device implantation. DNRR was defined as a ≥5% absolute decrease in LVEF at 1 year after treatment response determination.

ResultS

Of the responders, 22 (22.0%) exhibited DNRR, while 78 (78.0%) were classified as non-DNRR. The DNRR group showed a decline in LVEF from 41.2%±8.3% to 32.7%±9.6% (P<.001), while the non-DNRR group showed improvement from 42.8%±9.5% to 46.2%±10.5% (P<.001). Multivariate analysis identified LV end-systolic volume ≥ 100 mL (odds ratio [OR] 3.575; P=.041), paced QRS duration ≥ 150 ms (OR 4.427; P=.023), synchronized LV pacing rate < 85% (OR 5.753; P=.043) at 6 months after CRT device implantation, and intraventricular conduction disturbance (OR 5.593; P=.018) as independent predictors of DNRR. The DNRR group had significantly worse outcomes, including cardiac death and HF-related hospitalization, than did the non-DNRR group.

Conclusion

Despite an initial response to CRT, a subset of patients with HF developed DNRR, which correlated with worse clinical outcomes. Identifying risk factors associated with DNRR may help optimize CRT management and improve long-term patient care.