Left bundle branch area pacing or conventional cardiac resynchronization therapy: an Electrophysiology-guided tailored approach.

BACKGROUND

Cardiac resynchronization therapy (CRT) with biventricular pacing (BiV-CRT) is the standard treatment for patients with dilated cardiomyopathy (DCM), severe left ventricular (LV) systolic dysfunction, and left bundle branch block (LBBB). However, up to 30% patients fail to respond. Left bundle branch area pacing (LBBAP) has emerged as an alternative, including as first-line therapy.

METHODS

We enrolled 84 patients with DCM, severe LV dysfunction, and LBBB between January 2022 and January 2024. Patients were assigned to either conventional CRT-D (control group) or electrophysiology (EP)-guided resynchronization (case group). Left sided septal mapping in addition to conventional His bundle mapping was done to identify the site of conduction block to guide therapy. Primary outcomes were QRS duration, LV ejection fraction (LVEF), and LV internal diastolic diameter (LVIDd) at 6 months. Statistical analysis was executed using SPSS.

RESULTS

Baseline characteristics and implantation success rates were comparable. Post-implant QRS duration was significantly shorter in the EP-guided group (116.18 ± 8.12 ms) than in the control group (128.26 ± 6.81 ms, p = 0.03). At 6 months, LVEF improved more in the EP-guided group (39.21 ± 2.07% vs. 34.20 ± 3.65%, p < 0.001), with a greater reduction in LVIDd. The responder rate was higher with EP-guided therapy (97.4% vs. 80%).

CONCLUSION

EP-guided tailored resynchronization provides superior electrical and mechanical outcomes with a higher responder rate compared to conventional CRT in patients with DCM, severe LV dysfunction, and LBBB.