Background Left bundle branch pacing (LBBP) and left ventricular septal pacing (LVSP) are referred to as left bundle branch area pacing (LBBAP). Objective This study investigated whether long-term clinical outcomes differ in patients undergoing LBBP, LVSP, and biventricular pacing (BiVP) for cardiac resynchronization therapy (CRT). Methods Consecutive patients with reduced left ventricular ejection fraction (LVEF<50%) undergoing CRT were prospectively enrolled if they underwent successful LBBP, LVSP, or BiVP. The primary composite endpoint was all-cause mortality or heart failure hospitalization (HFH). Secondary endpoints included all-cause mortality, HFH, and echocardiographic measures of reverse remodeling. Results A total of 259 patients (68 LBBP, 38 LVSP, and 153 BiVP) were followed for a mean duration of 28.8 ± 15.8 months. LBBP was associated with a significantly reduced risk of the primary endpoint by 78% compared to both BiVP 7.4% vs. 41.2%; adjusted hazard ratio (aHR) 0.22 (0.08, 0.57), p=0.002 and LVSP 7.4% vs. 47.4%; aHR 0.22 (0.08, 0.63), p=0.004. The adjusted risk of all-cause mortality was significantly higher in LVSP than BiVP 31.6% vs. 7.2%, aHR 3.19 (1.38, 7.39); p=0.007 but comparable between LBBP and BiVP 2.9% vs. 7.2%, aHR 0.33 (0.07, 1.52), p=0.155. Propensity score adjustment also obtained similar results. LBBP showed a higher rate of echocardiographic response (ΔLVEF ≥10%: 60.0% vs. 36.2% vs. 16.1%; p<0.001) than BiVP or LVSP. Conclusion LBBP yielded superior long-term clinical outcomes to BiVP and LVSP. The role of LVSP for CRT needs to be reevaluated due to its high mortality risk.
Zhu et al. (2024) studied this question.