Hald Niels Saaby, Riis Johannes, Riddersholm Signe, Pedersen Troels Yding, Andersen Mikkel Porsborg, Graff Claus, Torp-Pedersen Christian, Søgaard Peter, Kragholm Kristian, Polcwiartek Christoffer, Søndergaard Marc Meller
Department of Cardiology, Aalborg University Hospital, Aalborg, Denmark; Department of Clinical Medicin, Aalborg University, Denmark.
Department of Clinical Medicin, Aalborg University, Denmark; Department of Geriatrics, Aalborg University Hospital, Aalborg, Denmark.
J Electrocardiol. 2025 Jun 15;92:154049. doi: 10.1016/j.jelectrocard.2025.154049.
Left bundle branch block (LBBB) can be a marker of cardiovascular risk. This study investigates how electrocardiogram (ECG) measurements can be utilized in risk stratification of LBBB patients.
Using registry data from the Copenhagen General Practitioners Laboratory, first-time LBBB ECGs were identified from 2001 to 2015. Different ECG parameters were extracted including P-wave duration, PR interval, QRS duration, QRS area, QTc, JTc intervals and heart rate. Data were stratified according to the median values of these parameters (below vs above). The outcome was out-of-hospital cardiac arrest (OHCA), and the crude 5-year risk of OHCA was calculated for each subgroup. Multivariable Cox proportional hazards regression was employed to assess associations of ECG parameters with OHCA.
We identified 4644 patients with incident LBBB contributing to a combined 35,113 person-years follow-up (median age 75 [25th - 75th percentiles 66-83] years; male sex, 62 %). Over the study period, all-cause mortality was 50 % and 4 % reached the primary outcome. The crude 5-year risk of OHCA revealed significant associations for QRS duration >150 ms (p = 0.01) and JTc duration >317 ms (p = 0.03). Multivariable analysis showed a higher hazard ratio (HR) for OHCA associated with QRS duration >150 ms (HR 1.41 [95 % CI 1.06-1.88]), QTc duration >464 ms (HR 1.43 [95 % CI 1.08-1.90]), JTc duration >317 ms (HR 1.50 [95 % CI 1.13-2.00]) and heart rate > 72/min (HR 1.48 [95 % CI 1.12-1.97]).
This study provides insights into associations between specific ECG parameters and the risk of OHCA in patients with LBBB. This holds the potential for risk stratification and targeted intervention in this population, and individuals with LBBB and these specific ECG abnormalities might benefit from earlier referral to investigation by specialists.
左束支传导阻滞（LBBB）可能是心血管风险的一个标志。本研究调查了心电图（ECG）测量如何用于LBBB患者的风险分层。
利用哥本哈根全科医生实验室的登记数据，确定2001年至2015年首次出现LBBB的心电图。提取不同的ECG参数，包括P波持续时间、PR间期、QRS持续时间、QRS面积、QTc、JTc间期和心率。数据根据这些参数的中位数（低于或高于）进行分层。结局为院外心脏骤停（OHCA），计算每个亚组的5年OHCA粗风险。采用多变量Cox比例风险回归评估ECG参数与OHCA的关联。
我们确定了4644例新发LBBB患者，总计随访35113人年（中位年龄75岁[第25 - 75百分位数为66 - 83岁]；男性占62%）。在研究期间，全因死亡率为50%，4%达到主要结局。OHCA的5年粗风险显示，QRS持续时间>150毫秒（p = 0.01）和JTc持续时间>317毫秒（p = 0.03）存在显著关联。多变量分析显示，与OHCA相关的较高风险比（HR）为：QRS持续时间>150毫秒（HR 1.41[95%CI 1.06 - 1.88]）、QTc持续时间>464毫秒（HR 1.43[95%CI 1.08 - 1.90]））、JTc持续时间>317毫秒（HR 1.50[95%CI 1.13 - 2.00]）和心率>72次/分钟（HR 1.48[95%CI 1.12 - 1.97]）。
本研究深入探讨了特定ECG参数与LBBB患者OHCA风险之间的关联。这为该人群的风险分层和靶向干预提供了可能性，LBBB且有这些特定ECG异常的个体可能受益于更早转诊至专科医生进行检查。
