Investigating the association between QRS duration change under GDMT and cardiac structure/function alteration in...

This study investigates how change in QRS duration (QRSd) after guideline-directed medical therapy (GDMT) relate to left ventricular reverse remodeling (LVRR) and improvements in left ventricular ejection fraction (LVEF) in heart failure patients with reduced ejection fraction (HFrEF).

The study analyzed 520 HFrEF patients, all of whom received GDMT and had regular follow-ups. QRSd was measured at baseline and 6 months after GDMT initiation. Patients were categorized into three groups based on absolute QRSd change (ΔQRSd): narrow narrow (≤ -10 ms), stable (-10 to +10 ms), and wide (≥ +10 ms). The primary endpoint was left ventricular reverse remodeling (LVRR), and the secondary endpoint was LVEF improvement. Associations were assessed using multivariable Cox regression.

After a median follow-up of 40 months, the narrow group demonstrated the most significant improvements in cardiac structure and function (P < 0.001). In multivariable analysis, using the narrow group as reference, both the stable and wide groups showed significantly lower hazards of achieving LVRR (HR = 0.42, 95 % CI: 0.30-0.59 and HR = 0.21, 95 % CI: 0.12-0.37) and LVEF improvement(HR = 0.56, 95 % CI: 0.41-0.77 and HR = 0.26, 95 % CI: 0.15-0.43) (all P < 0.001). These findings were consistent in sensitivity analyses.

Dynamic QRSd change after 6 months of GDMT is a significant predictor of cardiac remodeling and functional improvement in HFrEF patients. Tracking QRSd dynamics can help clinicians stratify patients' responses to GDMT, identifying those who may need closer monitoring or earlier device therapy consideration.