Left bundle branch-optimized cardiac resynchronization therapy (LOT-CRT): results from an international LBBAP collaborative study group
Abstract
BACKGROUND: Cardiac resynchronization therapy (CRT) based on the conventional biventricular pacing (BiV-CRT) technique sometimes results in broad QRS and suboptimal response. OBJECTIVE: We aimed to assess the feasibility and outcomes of CRT based on left bundle branch area pacing (LBBAP, in lieu of right ventricular lead) combined with coronary venous (CV) left ventricular pacing in an international multicenter study.
METHODS: LBBAP-optimized CRT (LOT-CRT) was attempted in non-consecutive patients with CRT indications. Addition of LBBA (or CV) lead was at the discretion of the implanting physician, guided by suboptimal paced QRS and/or on clinical grounds.
RESULTS: LOT-CRT was successful in 91/112 (81%) patients. Baseline characteristics: age 70+-11 years, female 20%, LVEF 28.7+-9.8%, LVEDD 62+-9 mm, NT-pro-BNP 5821+-8193 pg/ml, LBBB 42%, NIVCD 22%, RVP 23%, RBBB 12%.
Procedure characteristics: mean fluoroscopy 27.3+-22 min, LBBAP capture threshold 0.8+-0.5V @0.5ms, R-wave amplitude 10 mV. LOT-CRT resulted in significantly greater narrowing of QRS from 182+-25 ms at baseline to 144+-22 ms (p= 3 months, EF improved to 37+-12%, LVEDD decreased to 59+-9 mm, NT-pro-BNP decreased to 2514+-3537 pg/ml, pacing parameters were stable, and clinical improvement was noted in 76% of patients (NYHA class 2.9 vs 1.9).
CONCLUSION: LOT-CRT is feasible, safe and provides greater electrical resynchronization compared to BiV-CRT and could be an alternative option, especially when only suboptimal electrical resynchronization is obtained with BiV-CRT. Randomized, controlled trials comparing LOT-CRT and BiV-CRT are needed.