Comparative outcomes of LBBAP-CRT versus BIV-CRT in a real-world cohort
M J Primo, I Cruz, A L Silva, D Martinez, D Fernandes, C Saleiro, P Alves, P A Sousa, J A Ferreira, N Antonio, L GoncalvesAbstract
Background
Cardiac resynchronization therapy (CRT) delivered through conduction system pacing—particularly left bundle branch area pacing (LBBAP- CRT)—is emerging as a promising alternative to conventional biventricular pacing (BiV- CRT). However, comparative evidence on CRT response between these pacing modalities remains limited.
Objective
To compare the response rate and improvement in left ventricular ejection fraction (LVEF) of LBBAP-CRT versus BiV-CRT patients.
Methods
We conducted a retrospective observational study of 217 patients who underwent CRT implantation between 2022 and 2024. Patients were categorized into LBBAP-CRT (n = 117) or BiV-CRT (n = 100). CRT response was defined as an improvement in left ventricular ejection fraction (LVEF) superior or equal to 5%. Patients were considered super-responders if they achieved a left ventricular ejection fraction >50% or improvement of more than 14.5% in LVEF after 6 months of cardiac resynchronization therapy. Statistical comparisons were performed using chi-square, t-tests and Mann-Whitney U tests where applicable.
Results
A total of 217 patients were included. Baseline demographic characteristics were similar between groups (mean age 73.0 ± 10.5 vs 70.9 ± 11.2 years, p = 0.155) and there was no statistically significant differences observed across gender, NYHA class, MCD, atrial fibrillation, or pre-procedural BCRD. Follow-up duration differed between groups: patients with LBBAP-CRT had a median follow-up of 15.0 months (IQR 12.7), while those with BiV-CRT had a longer follow-up of 28.6 months (IQR 23.2). Although not statistically significant on two-tailed testing (p = 0.056), the LBBAP group demonstrated a numerically greater improvement in LVEF compared with the BIV group (ΔLVEF 11.4% vs. 6.7%). The proportion of responders (variation in LVEF > 5%) was significantly higher in the LBBAP group compared to the BIV group (83.8% vs. 56.6%, p = 0.007). The proportion of super-responders (variation LVEF > 14.5%) was similar between the LBBAP and BIV groups (24.3% vs. 22.6%, p = 0.853).
Conclusion
In this real-world cohort, LBBAP-CRT was associated with a significantly higher responder rate and greater improvement in LVEF compared with conventional BiV-CRT. These findings support conduction system pacing as a promising alternative for achieving superior reverse remodelling, warranting confirmation in prospective randomized studies.% variation in LVEF in BIV and LBBAP CRTrate of responders in BIV and LBBAP CRT