Department of Cardiology, Herlev-Gentofte Hospital, Hellerup, Denmark.
Laboratory for Molecular Cardiology, University Hospital Copenhagen, Rigshospitalet, Copenhagen, Denmark.
Heart. 2019 Aug;105(15):1160-1167. doi: 10.1136/heartjnl-2018-314295. Epub 2019 May 25.
Electrocardiographic bundle branch block (BBB) is common but the prognostic implications in primary care are unclear. We sought to investigate the relationship between electrocardiographic BBB subtypes and the risk of cardiovascular (CV) outcomes in a primary care population free of major CV disease.
Retrospective cohort study of primary care patients referred for electrocardiogram (ECG) recording between 2001 and 2011. Cox regression models were used to estimate hazard ratios (HR) as well as absolute risks of CV outcomes based on various BBB subtypes.
We included 202 268 individuals with a median follow-up period of 7.8 years (Inter-quartile range [IQR] 4.9-10.6). Left bundle branch block (LBBB) was associated with heart failure (HF) in both men (HR 3.96, 95% CI 3.30 to 4.76) and women (HR 2.51, 95% CI 2.15 to 2.94) and with CV death in men (HR 1.80, 95% CI 1.38 to 2.35). Right bundle branch block (RBBB) was associated with pacemaker implantation in both men (HR 3.26, 95% CI 2.74 to 3.89) and women (HR 3.69, 95% CI 2.91 to 4.67), HF in both sexes and weakly associated with CV death in men. Regarding LBBB, we found an increasing hazard of HF with increasing QRS-interval duration (HR 1.25, 95% CI 1.11 to 1.42 per 10 ms increase in men and HR 1.23, 95% CI 1.08 to 1.40 per 10 ms increase in women). Absolute 10-year risk predictions across age-specific and sex-specific subgroups revealed clinically relevant differences between having various BBB subtypes.
Opportunistic findings of BBB subtypes in primary care patients without major CV disease should be considered warnings of future HF and pacemaker implantation.
心电图束支传导阻滞（BBB）较为常见，但在初级保健中的预后意义尚不清楚。我们旨在研究初级保健人群中无主要心血管疾病（CV）的心电图 BBB 亚型与心血管（CV）结局风险之间的关系。
这是一项对 2001 年至 2011 年期间因心电图（ECG）记录而被转介的初级保健患者进行的回顾性队列研究。使用 Cox 回归模型来估计基于各种 BBB 亚型的 CV 结局的危险比（HR）和绝对风险。
我们纳入了 202268 名中位随访时间为 7.8 年（四分位距 [IQR] 4.9-10.6）的个体。左束支传导阻滞（LBBB）与男性（HR 3.96，95%CI 3.30 至 4.76）和女性（HR 2.51，95%CI 2.15 至 2.94）的心衰（HF）以及男性的 CV 死亡（HR 1.80，95%CI 1.38 至 2.35）相关。右束支传导阻滞（RBBB）与男性（HR 3.26，95%CI 2.74 至 3.89）和女性（HR 3.69，95%CI 2.91 至 4.67）的起搏器植入、两性的 HF 以及与男性的 CV 死亡弱相关。对于 LBBB，我们发现随着 QRS 间隔持续时间的增加，HF 的风险呈递增趋势（男性每增加 10 毫秒 HR 增加 1.25，95%CI 1.11 至 1.42；女性 HR 增加 1.23，95%CI 1.08 至 1.40）。按年龄和性别特定亚组划分的 10 年绝对风险预测显示，在各种 BBB 亚型之间存在有临床意义的差异。
在无主要 CV 疾病的初级保健患者中发现 BBB 亚型为偶发发现，应被视为未来 HF 和起搏器植入的警告。
