Clinical Outcomes of Complete Left Bundle Branch Block According to Strict or Conventional Definition Criteria in Patients with Normal Left Ventricular Function

Hui-Chun Huang ； Jui Wang ； Yen-Bin Liu ； Kuo-Liong Chien

《Acta Cardiologica Sinica》 36卷4期 (2020/07) Pp. 335-342

https://doi.org/10.6515/ACS.202007_36(4).20191230A

摘要

Background: Complete left bundle branch block (cLBBB) is associated with poor outcomes in patients with heart failure (HF) but appears to have minimal effects on cardiovascular (CV) mortality in relatively healthy adults. New criteria to define strict cLBBB have been proposed. Objectives: The aim of this study was to stratify the potential risk of cLBBB according to conventional or strict criteria in patients with normal ejection fraction (EF). Methods: Patients with cLBBB from 2010 to 2013 who underwent baseline echocardiography within 1 year and had a left ventricular ejection fraction (LVEF) ＞ 50% were enrolled. A control group of patients without intraventricular conduction abnormalities matched for age and sex was included. Primary outcomes including CV mortality, HF admission, EF reduction of 40%, and total mortality were compared. Results: A total of 137 patients with cLBBB were included, of whom 118 had strict cLBBB. The mean age was 72 ± 15 years and 56.2% were men. With a median follow-up of 4.3 years, normal LVEF patients with cLBBB but without a history of atrial fibrillation had a significantly higher risk of CV mortality (p ＜ 0.001), EF reduction to 40% (p ＜ 0.001), and admission for HF (p ＜ 0.001). A similar risk of CV events was noted for the patients with conventional and strict cLBBB. Conclusions: In patients with normal EF and without a history of atrial fibrillation, the presence of cLBBB led to a greater risk of CV mortality, HF admission and EF reduction to ＜ 40%. Strict cLBBB carries a similar risk of CV events to conventional cLBBB.

關鍵字

Ejection fraction ； Left bundle branch block ； Outcome