Shengjie Wu1, Lan Su1, Pugazhendhi Vijayaraman2, Rujie Zheng1, Mengxing Cai1, Lei Xu1, Ruiyu Shi1, Zhouqing Huang1, Zachary I Whinnett3, Weijian Huang4. 1. Department of Cardiology, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China; The Key Lab of Cardiovascular Disease of Wenzhou, Wenzhou, China. 2. Geisinger Heart Institute, Wilkes Barre, Pennsylvania, USA. 3. National Heart and Lung Institute, Imperial College London, London, United Kingdom. 4. Department of Cardiology, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China; The Key Lab of Cardiovascular Disease of Wenzhou, Wenzhou, China. Electronic address: weijianhuang69@126.com.
Abstract
BACKGROUND: Left bundle branch pacing (LBBP) is a novel method for delivering cardiac resynchronization therapy (CRT). We compared on-treatment outcomes with His bundle pacing (HBP) and biventricular pacing (BVP) in this nonrandomized observational study. METHODS: Consecutive patients with left-ventricular ejection fraction (LVEF) ≤ 40% and typical left bundle branch block (LBBB) referred for CRT received BVP, HBP, or LBBP. QRS duration, pacing threshold, LVEF, and New York Heart Association (NYHA) class were assessed. RESULTS: One hundred thirty-seven patients were recruited: 49 HBP, 32 LBBP, and 54 BVP; 2 did not receive CRT. The majority of patients had nonischemic cardiomyopathy. Mean paced QRS duration was 100.7 ± 15.3 ms, 110.8 ± 11.1 ms, and 135.4 ± 20.2 ms during HBP, LBBP, and BVP, respectively. HBP and LBBP demonstrated a similar absolute increase (Δ) in LVEF (+23.9% vs +24%, P = 0.977) and rate of normalized final LVEF (74.4% vs 70.0%, P = 0.881) at 1-year follow-up. This was significantly higher than in the BVP group (Δ LVEF +16.7% and 44.9% rate of normalized final LVEF, P < 0.005). HBP and LBBP also demonstrated greater improvements in NYHA class compared with BVP. LBBP was associated with higher R-wave amplitude (11.2 ± 5.1 mV vs 3.8 ± 1.9 mV, P < 0.001) and lower pacing threshold (0.49 ± 0.13 V/0.5 ms vs 1.35 ± 0.73 V/0.5 ms, P < 0.001) compared with HBP. CONCLUSION: LBBP appears to be a promising method for delivering CRT. We observed similar improvements in symptoms and LV function with LBBP and HBP. These improvements were significantly greater than those seen in patients treated with BVP in this nonrandomized study. These promising findings justify further investigation with randomized trials.
BACKGROUND:Left bundle branch pacing (LBBP) is a novel method for delivering cardiac resynchronization therapy (CRT). We compared on-treatment outcomes with His bundle pacing (HBP) and biventricular pacing (BVP) in this nonrandomized observational study. METHODS: Consecutive patients with left-ventricular ejection fraction (LVEF) ≤ 40% and typical left bundle branch block (LBBB) referred for CRT received BVP, HBP, or LBBP. QRS duration, pacing threshold, LVEF, and New York Heart Association (NYHA) class were assessed. RESULTS: One hundred thirty-seven patients were recruited: 49 HBP, 32 LBBP, and 54 BVP; 2 did not receive CRT. The majority of patients had nonischemic cardiomyopathy. Mean paced QRS duration was 100.7 ± 15.3 ms, 110.8 ± 11.1 ms, and 135.4 ± 20.2 ms during HBP, LBBP, and BVP, respectively. HBP and LBBP demonstrated a similar absolute increase (Δ) in LVEF (+23.9% vs +24%, P = 0.977) and rate of normalized final LVEF (74.4% vs 70.0%, P = 0.881) at 1-year follow-up. This was significantly higher than in the BVP group (Δ LVEF +16.7% and 44.9% rate of normalized final LVEF, P < 0.005). HBP and LBBP also demonstrated greater improvements in NYHA class compared with BVP. LBBP was associated with higher R-wave amplitude (11.2 ± 5.1 mV vs 3.8 ± 1.9 mV, P < 0.001) and lower pacing threshold (0.49 ± 0.13 V/0.5 ms vs 1.35 ± 0.73 V/0.5 ms, P < 0.001) compared with HBP. CONCLUSION: LBBP appears to be a promising method for delivering CRT. We observed similar improvements in symptoms and LV function with LBBP and HBP. These improvements were significantly greater than those seen in patients treated with BVP in this nonrandomized study. These promising findings justify further investigation with randomized trials.