Feasibility and implantation outcomes of left bundle branch area pacing versus right ventricular conventional pacing in patients previously submitted to valvular open-heart surgery

Introduction Left bundle branch area pacing (LBBAP) is emerging as the preferred physiological pacing strategy, with studies demonstrating better outcomes than conventional right ventricular (RV) pacing. Because LBBAP requires lead penetration through the interventricular septum, prior open-heart surgery may pose technical challenges due to septal fibrosis. Purpose To evaluate the feasibility of LBBAP in patients with a history of valvular open-heart surgery—including aortic, mitral, or tricuspid procedures—compared to RV pacing. Methods This single-center, retrospective observational study included patients who underwent LBBAP between September 2022 and December 2024. Data on pacing indications, prior valve surgery, and procedural characteristics were collected. The primary endpoint was a composite of emergency visits for acute heart failure and hospitalizations for heart failure. The median follow-up was 753 days (IQR=370 days). Results The analysis included 56 post–open-heart surgery patients who underwent permanent pacemaker implantation, 62.5% male, mean age 68.7 ± 1.66 years. Surgeries were 69.1% aortic, 21.8% mitral, and 8.9% mixed (p=0.159). Pacing indication was complete heart block in 30 (53.6%), bradycardia in 11 (19.6%), and the remainder second-degree block. Thirty-three patients (58.9%) received LBBAP and 23 (41.1%) RV pacing, with no differences in cardiovascular risk factors or surgery type. Median LVEF was 55% (IQR 13.5), slightly lower in LBBAP (52%, IQR 22.25; p=0.005). Procedure duration was similar (63.9 ± 2.5 min; p>0.05). Mean intrinsic QRS for the entire cohort was 145.4 ± 4.47ms; paced QRS was narrower with LBBAP (127.4 ± 3.6ms) versus RV (166.4 ± 6.0ms; p<0.001). Capture thresholds and sensed R waves were similar in the two groups (0.52 ± 0.04V and 13.7 ± 0.82mV). Median ventricular pacing was 90.7%, higher in LBBAP than in RV conventional pacing (98.4% vs 15.6%; p<0.001). Regarding primary composite endpoint, Kaplan-Meier analysis showed similar 2-year event-free survival for LBBAP and RV (91.2% vs 88.8%; p=0.802). Conclusion In patients with prior open-heart surgery and potentially altered septal anatomy, LBBAP was feasible and procedurally safe, having achieved narrower paced QRS durations, comparable to conventional RV pacing. Over a 2-year follow-up, clinical outcomes were comparable, supporting LBBAP as a viable and physiologically favorable pacing strategy even in patients with post-surgical septal distortion. The substantially higher ventricular pacing percentages in LBBAP group compared to RV may have an influence on the similar outcomes observed.Curves for survival of LBBAP vs RV