Initial Experience, Safety, and Feasibility of Left Bundle Branch Area Pacing: A Multicenter Prospective Study.

OBJECTIVES

This study sought to evaluate the safety and feasibility of conduction system pacing by performing left bundle branch area pacing (LBBAP).

BACKGROUND

There are limited data from single centers showing that LBBAP may circumvent the technical and electrophysiological challenges encountered with His bundle pacing.

METHODS

Patients referred for pacemaker implantation at 2 centers between February 1, 2019, and March 31, 2020, were considered for LBBAP. LBBAP was performed by implanting a lumen-less, exposed helix lead approximately 2 cm distal to the His bundle and deep into the septum using a specialized delivery sheath. Implant success rates, complications, and electrophysiological parameters were assessed.

RESULTS

LBBAP was successful in 305 of 341 patients (89%). Mean age was 72 ± 12 years; 45% were women; and 39% had QRS duration (QRSd) >130 ms, 22% right bundle branch block, 11% left bundle branch block, and 6% intraventricular conduction defect. Pacing indications were sinus node dysfunction in 28.7%, atrioventricular block in 52.5%, cardiac resynchronization therapy in 8.8%, and refractory atrial fibrillation in 10% of patients. Procedural duration was 74.7 ± 34 min and fluoroscopic time was 10.4 ± 8.1 min. The mean baseline QRSd and paced QRSd in the overall cohort was 114 ± 29.8 ms versus 112 ± 11.7 ms (p < 0.001) and in patients with infra-Hisian disease was 144.5 ± 19 ms versus 115 ± 12 ms (p < 0.001), respectively. Mean left ventricular activation time was 71.7 ± 11 ms at high output and 74.7 ± 11 ms at low output. LBB potentials were noted in 41% patients. Pacing threshold and R waves were 0.74 ± 0.3 V at 0.4 ms and 10.7 ± 4.9 mV at time of implantation and were stable at 1-, 3-, 6-, and 12-month follow-ups. The only major complications were 3 LBBAP lead dislodgements, 2 within 24 h and 1 at 2 weeks.

CONCLUSIONS

LBBA pacing is safe, feasible, and a reliable alternative to His bundle pacing for providing physiological pacing. Randomized controlled studies are needed to confirm the safety, feasibility, and clinical outcomes of LBBAP.