Sex differences outcomes in conduction system pacing for patients with typical left bundle branch block

Area of Science:

• Cardiology
• Electrophysiology
• Medical Devices

Background:

• Biventricular pacing (BVP) shows advantages in women, but conduction system pacing (CSP) effects are less understood.
• Investigating sex-specific outcomes in left bundle branch block (LBBB) patients undergoing CSP is crucial.

Purpose of the Study:

• To evaluate sex-specific differences in clinical outcomes for patients with typical LBBB undergoing CSP.
• To identify factors contributing to observed sex disparities in CSP response.

Main Methods:

• Studied consecutive patients with nonischemic cardiomyopathy, LVEF ≤ 40%, and typical LBBB (Strauss criteria) who underwent CSP.
• Assessed improvements in LVEF and composite endpoint of mortality or heart failure hospitalization (HFH) through longitudinal monitoring.

Main Results:

• Women (n=84) had smaller heart size (LVEDd) and shorter baseline QRS duration (QRSd) than men (n=92).
• Super-response to CSP occurred more frequently in women (78.3%) than men (62.5%).
• Smaller LVEDd and pQRSd mediated the higher super-response in women, accounting for 26.07% and 27.98% respectively.

Conclusions:

• Women may experience greater benefits from CSP compared to men.
• Left ventricular diameter and paced QRS duration partially explain the enhanced efficacy of CSP in women.