Feasibility and efficacy of left bundle branch area pacing in patients indicated for cardiac resynchronization therapy

Abstract

Aims The present study was to evaluate the feasibility and clinical outcomes of left bundle branch area pacing (LBBAP) in cardiac resynchronization therapy (CRT)-indicated patients. Methods and results LBBAP was performed via transventricular septal approach in 25 patients as a rescue strategy in 5 patients with failed left ventricular (LV) lead placement and as a primary strategy in the remaining 20 patients. Pacing parameters, procedural characteristics, electrocardiographic, and echocardiographic data were assessed at implantation and follow-up. Of 25 enrolled CRT-indicated patients, 14 had left bundle branch block (LBBB, 56.0%), 3 right bundle branch block (RBBB, 12.0%), 4 intraventricular conduction delay (IVCD, 16.0%), and 4 ventricular pacing dependence (16.0%). The QRS duration (QRSd) was significantly shortened by LBBAP (intrinsic 163.6 ± 29.4 ms vs. LBBAP 123.0 ± 10.8 ms, P < 0.001). During the mean follow-up of 9.1 months, New York Heart Association functional class was improved to 1.4 ± 0.6 from baseline 2.6 ± 0.6 (P < 0.001), left ventricular ejection fraction (LVEF) increased to 46.9 ± 10.2% from baseline 35.2 ± 7.0% (P < 0.001), and LV end-diastolic dimensions (LVEDD) decreased to 56.8 ± 9.7 mm from baseline 64.1 ± 9.9 mm (P < 0.001). There was a significant improvement (34.1 ± 7.4% vs. 50.0 ± 12.2%, P < 0.001) in LVEF in patients with LBBB. Conclusion The present study demonstrates the clinical feasibility of LBBAP in CRT-indicated patients. Left bundle branch area pacing generated narrow QRSd and led to reversal remodelling of LV with improvement in cardiac function. LBBAP may be an alternative to CRT in patients with failure of LV lead placement and a first-line option in selected patients such as those with LBBB and heart failure.

Outcomes of Left Bundle Branch Area Pacing for Cardiac Resynchronization Therapy: An Updated Systematic Review and Meta-analysis

“…In our updated systematic review and meta-analysis of eight non-randomized studies, we examined the clinical outcomes of LBBAP from a pool of 527 patients with CRT indications. 9,11,[17][18][19][20][21][22] In contrast to Zhong et al, our study reported a detail analysis on the clinical outcomes of QRS duration, LVEDD, LVEF, and NYHA class from the four studies with comparison groups (between the LBBAP and BVP groups). 11,17,18,21 We also performed a pooled analysis from the eight studies on the clinical outcomes of LBBAP for CRT in patients with LBBB.…”

“… 21 Prospective, observational, single-centre LBBAP vs BVP LBBB defined according to Strauss criteria, NYHA functional class II-IV with LVEF ≤ 35% 45 Primary LBBAP, * n = 24 Implant success, n = 21 (87.5%) Primary BVP, n = 21 6 Li et al. 22 Prospective, observational, single-centre LBBAP only NYHA functional class II-IV with LVEF < 50% (LBBB, n = 14; RBBB, n = 3; IVCD, n = 4; RVP, n = 4) 25 Primary LBBAP, * n = 20 Rescue LBBAP, † n = 5 Implant success, not reported NA Mean 9.1 ± 5.1 Vijayaraman et al 20 Retrospective, observational, multicentre LBBAP only NYHA functional class II-IV, baseline LVEFs ≤ 50%, and indications for ventricular pacing and/or CRT (LBBB, n = 126; RBBB, n = 54; IVCD, n = 49; RVP, n = 48, narrow, n = 48) 325 A mix of primary LBBAP * and rescue LBBAP † , and LBBAP § , n = 325 Implant success, n = 277 (85.2%) NA Mean 6 ± 5 Huang et al. 9 Prospective, observational, multicentre LBBAP only Complete LBBB, nonischemic cardiomyopathy, symptomatic heart failure with LVEF < 50% 63 Rescue LBBAP, § n = 63 Implant success, n = 61 (96.8%) NA Mean 18 (range, 15 to 20) Zhang et al.…”

“…As shown in Table 1, seven studies specified the number of subjects who underwent primary LBBAP and rescue LBBAP procedures due to failed HBP lead or coronary sinus (CS) lead placement. 9,11,[17][18][19]21,22 Table 2 reports the overall baseline clinical characteristics of the total population with LBBAP. 9,11,[17][18][19][20][21][22] The mean age was 68-years.…”

“…9,11,17 Procedure duration and success Table 4 displays the overall procedure, echocardiographic and pacing characteristics of studies with LBBAP (all patients). 9,11,[17][18][19]21,22 The average procedural time was 105.70 ± 51.13 minutes.…”

“…Figure 3 displays the clinical outcomes of LBBAP as CRT in patients with LBBB. 9,11,[17][18][19][20][21][22] In patients with LBBB, pooled analysis showed that LBBAP significantly improved their QRS…”