Division of Cardiology, Department of Internal Medicine, College of Medicine, Seoul National University and Cardiovascular Center, Seoul National University Bundang Hospital, Seongnam, South Korea; Cardiovascular Center and Department of Internal Medicine, Seoul National University Hospital, Seoul, South Korea.
Division of Cardiology, Department of Internal Medicine, College of Medicine, Seoul National University and Cardiovascular Center, Seoul National University Bundang Hospital, Seongnam, South Korea.
J Am Soc Echocardiogr. 2018 Jan;31(1):52-63.e6. doi: 10.1016/j.echo.2017.08.016. Epub 2017 Nov 2.
The prognostic value of left ventricular (LV) global strain and twist in patients with left bundle branch block (LBBB) is not fully investigated. The aim of this study was to investigate the association between myocardial strain and twist and cardiovascular events in patients with LBBB, as assessed using two-dimensional speckle-tracking echocardiography.
A total of 269 patients with LBBB (mean age, 69.5 ± 10.9 years; 46.8% men) were retrospectively identified. Using speckle-tracking, LV global longitudinal strain (GLS), global circumferential strain, and twist were measured. Association between LV global function and a composite of cardiovascular mortality and hospitalization for heart failure was compared with clinical risk factors, LV ejection fraction (LVEF), and other echocardiographic parameters.
During a median of 27.5 months (interquartile range, 12.8-43.9 months), the composite end point occurred in 55 patients (20.4%). In univariate analyses, diabetes mellitus, chronic kidney disease, ischemic etiology of LBBB, dilated left atrium, reduced LVEF, dilated left ventricle, and impaired LV global strain (GLS > -12.2%, global circumferential strain > -11.8%, and twist < 6.5°) showed associations with the composite end point. In multivariate analyses, GLS was significantly associated with the composite end point (adjusted hazard ratio, 4.697; 95% CI, 1.344-16.413; P = .015), whereas global circumferential strain, twist, and LVEF were not. GLS showed an additive association with poor prognosis over clinical risk factors and other echocardiographic parameters, including LVEF. Patients with preserved LVEFs (≥40%) but impaired GLS (>-12.2%) had a larger number of clinical events than those with impaired LVEFs but preserved GLS.
Among patients with LBBB, GLS can provide better risk stratification than LVEF or other echocardiographic parameters.
左束支传导阻滞（LBBB）患者左心室（LV）整体应变和扭转的预后价值尚未得到充分研究。本研究旨在通过二维斑点追踪超声心动图评估心肌应变和扭转与 LBBB 患者心血管事件的相关性。
共回顾性分析了 269 例 LBBB 患者（平均年龄 69.5±10.9 岁，46.8%为男性）。使用斑点追踪技术测量 LV 整体纵向应变（GLS）、整体圆周应变和扭转。比较 LV 整体功能与心血管死亡率和心力衰竭住院的复合终点与临床危险因素、左室射血分数（LVEF）和其他超声心动图参数的相关性。
在中位数为 27.5 个月（四分位间距 12.8-43.9 个月）的随访期间，55 例患者（20.4%）发生了复合终点事件。单因素分析显示，糖尿病、慢性肾脏病、LBBB 的缺血性病因、左心房扩大、LVEF 降低、左心室扩大和 LV 整体应变受损（GLS>-12.2%，整体圆周应变>-11.8%，扭转<6.5°）与复合终点相关。多因素分析显示，GLS 与复合终点显著相关（调整后的危险比 4.697；95%置信区间 1.344-16.413；P=0.015），而整体圆周应变、扭转和 LVEF 与复合终点无关。GLS 与临床危险因素和包括 LVEF 在内的其他超声心动图参数相比，对预后不良具有附加的相关性。与 LVEF 受损但 GLS 正常的患者相比，具有正常 LVEF 但 GLS 受损的患者发生临床事件的数量更多。
在 LBBB 患者中，GLS 比 LVEF 或其他超声心动图参数能提供更好的风险分层。
