Department of Cardiology, Aalborg University Hospital, Aalborg, Denmark.
Washington University, St. Louis, Missouri.
J Am Coll Cardiol. 2018 Mar 27;71(12):1325-1333. doi: 10.1016/j.jacc.2018.01.042.
Cross correlation analysis (CCA) using tissue Doppler imaging has been shown to be associated with outcome after cardiac resynchronization therapy (CRT) in patients with heart failure (HF) with wide QRS. However, its significance in patients with narrow QRS treated with CRT is unknown.
The aim of the current study was to investigate the association of mechanical activation delay by CCA with study outcome in patients with HF enrolled in the EchoCRT trial.
Baseline CCA could be performed from tissue Doppler imaging in the apical views in 807 of 809 (99.7%) enrolled patients, and 6-month follow-up could be performed in 610 of 635 (96%) patients with available echocardiograms. Patients with a pre-specified maximal activation delay ≥35 ms were considered to have significant delay. The study outcome was HF hospitalization or death.
Of 807 patients, 375 (46%) did not have delayed mechanical activation at baseline by CCA. Patients without delayed mechanical activation who were randomized to CRT-On compared with CRT-Off had an increased risk of poor outcome (hazard ratio: 1.70; 95% confidence interval: 1.13 to 2.55; p = 0.01) with a significant interaction term (p = 0.04) between delayed mechanical activation and device randomization for the endpoint. Among patients with paired baseline and follow-up data with no events before 6-month follow-up (n = 541), new-onset delayed mechanical activation in the CRT-On group showed a significant increase in unfavorable events (hazard ratio: 3.73; 95% confidence interval: 1.15 to 12.14; p = 0.03).
In the EchoCRT population, absence of delayed mechanical activation by CCA was significantly associated with poor outcomes, possibly due to the onset of new delayed mechanical activation with CRT pacing. (Echocardiography Guided Cardiac Resynchronization Therapy [EchoCRT] Trial; NCT00683696).
组织多普勒成像的互相关分析（CCA）已被证明与心力衰竭（HF）伴宽 QRS 患者心脏再同步治疗（CRT）后的结局相关。然而，其在接受 CRT 治疗的窄 QRS 患者中的意义尚不清楚。
本研究旨在探讨 EchoCRT 试验中 HF 患者的 CCA 机械激活延迟与研究结局的相关性。
在 809 名入选患者中，807 名（99.7%）可在心尖切面进行组织多普勒成像的基线 CCA，610 名（96%）有可用超声心动图的患者可进行 6 个月随访。被认为存在显著延迟的患者的最大激活延迟≥35ms。研究结局为 HF 住院或死亡。
在 807 名患者中，375 名（46%）基线时 CCA 无机械激活延迟。与 CRT-Off 相比，随机接受 CRT-On 的无机械激活延迟患者不良结局风险增加（风险比：1.70；95%置信区间：1.13 至 2.55；p=0.01），且终点的机械激活延迟和设备随机分组之间存在显著交互作用（p=0.04）。在无 6 个月随访前事件的配对基线和随访数据的 541 名患者中，CRT-On 组新发机械激活延迟显著增加不良事件（风险比：3.73；95%置信区间：1.15 至 12.14；p=0.03）。
在 EchoCRT 人群中，CCA 无机械激活延迟与不良结局显著相关，可能是由于 CRT 起搏导致新的机械激活延迟。（EchoCRT 试验；NCT00683696）
