Department of Cardiothoracic Surgery and Anesthesiology, Karolinska University Hospital, Stockholm, Sweden; Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
Cardiology Department, Kyorin University, Tokyo, Japan.
Am Heart J. 2014 Sep;168(3):325-31. doi: 10.1016/j.ahj.2014.03.025. Epub 2014 Jun 9.
The Seattle Heart Failure Model (SHFM) predicts survival in heart failure but may underestimate risk in severe heart failure, and the performance has not been evaluated explicitly in patients with cardiac resynchronization therapy (CRT) and/or implantable cardioverter defibrillator (ICD) referred for heart transplantation. We aimed to assess the utility of the SHFM by validation in patients with CRT and/or ICD referred for heart transplantation.
We assessed the SHFM performance in 382 patients with CRT and/or ICD referred for heart transplantation. Outcome was survival free from urgent transplantation or left ventricular assist device. Model discrimination and calibration were assessed graphically and by formal tests.
During a mean follow-up of 2.3 years, 195 events occurred. One-, 2-, and 3-year observed event-free survival was 77%, 62%, and 52%, and the observed to predicted event-free survival ratio was 0.89, 0.80, and 0.76. Calibration plots demonstrated results deviating from the ideal calibration line at 1, 2, and 3 years. The SHFM score adequately assigned patients in discrete risk strata, according to Kaplan-Meier estimated survival. Time-dependent receiver operating characteristic curve analyses demonstrated good discrimination overall, which was slightly better for 1-year (area under the curve [AUC] 0.774) compared with 2-year (AUC 0.742) and 3-year (AUC 0.728) event-free survival.
The SHFM has good discrimination but underestimates risk of adverse outcomes in patients with CRT and/or ICD referred for heart transplantation. The SHFM may be used to assess relative risk and changes over time, but when assessing absolute percentage of event-free survival, the overestimation of event-free survival should be accounted for.
西雅图心力衰竭模型（SHFM）可预测心力衰竭患者的生存率，但在因心脏移植而接受心脏再同步治疗（CRT）和/或植入式心脏复律除颤器（ICD）治疗的重度心力衰竭患者中，其风险预测可能存在低估。我们旨在通过对因心脏移植而接受 CRT 和/或 ICD 治疗的患者进行验证，评估 SHFM 的实用性。
我们评估了 382 例因心脏移植而接受 CRT 和/或 ICD 治疗的患者的 SHFM 表现。结局是无紧急移植或左心室辅助装置的生存情况。通过图形和正式检验评估模型的区分度和校准度。
在平均 2.3 年的随访期间，发生了 195 例事件。1、2 和 3 年的观察无事件生存率分别为 77%、62%和 52%，观察到的与预测的无事件生存率之比分别为 0.89、0.80 和 0.76。校准图显示，1、2 和 3 年时，结果偏离理想校准线。根据 Kaplan-Meier 估计的生存率，SHFM 评分可充分将患者分配到离散风险分层中。时间依赖性接受者操作特征曲线分析显示总体上具有良好的区分度，与 2 年（曲线下面积[AUC]为 0.742）和 3 年（AUC 为 0.728）无事件生存率相比，1 年（AUC 为 0.774）时的区分度略好。
SHFM 具有良好的区分度，但对因心脏移植而接受 CRT 和/或 ICD 治疗的患者的不良结局风险预测存在低估。SHFM 可用于评估相对风险和随时间的变化，但在评估无事件生存率的绝对百分比时，应考虑到对无事件生存率的高估。
