Syyli Nina, Hautamäki Markus, Antila Kari, Mahdiani Shadi, Eskola Markku, Lehtimäki Terho, Nikus Kjell, Lyytikäinen Leo-Pekka, Oksala Niku, Hernesniemi Jussi
Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.
VTT Technical Research Centre of Finland, Tampere, Finland.
Open Heart. 2019 Jun 27;6(1):e001007. doi: 10.1136/openhrt-2019-001007. eCollection 2019.
Reduced left ventricular ejection fraction (LVEF) is a risk marker for mortality after an acute coronary syndrome (ACS). Global Registry of Acute Coronary Events (GRACE) risk score, developed almost two decades ago, is the preferred scoring system for risk stratification in ACS. The aim of this study was to validate the GRACE score and evaluate whether LVEF has incremental predictive value over the GRACE in predicting 6-month mortality after ACS in a contemporary setting.
A retrospective analysis of all 1576 consecutive patients who were admitted to Tays Heart Hospital and underwent coronary angiography for a first episode of ACS (2015-2016). Clinical risk factors were extensively recorded. Adjusted Cox regression analysis was used to analyse the associations between LVEF and the GRACE score with 6-month all-cause mortality. The incremental predictive value was assessed by the change in C-statistic by Delong's method for paired samples and by index of discrimination improvement (IDI).
In univariable analysis, both LVEF and the GRACE were associated with 6-month mortality, and after applying both variables into the same model, the results remained significant (GRACE score: HR: 1.036, 95% CI 1.030 to 1.042; LVEF: HR: 0.965, 95% CI 0.948 to 0.982, both HRs corresponding to a one unit change in the exposure variable). The GRACE score demonstrated good discrimination for mortality (C-statistic: 0.833, 95% CI 0.795 to 0.871). Adding LVEF to the model with the GRACE score improved model performance significantly (C-statistic: 0.848, 95% CI 0.813 to 0.883, p=0.029 for the improvement and IDI 0.0171, 95% CI 0.0016 to 0.0327, p=0.031).
Adding LVEF to the GRACE score significantly improves risk prediction of 6-month mortality after ACS.
左心室射血分数（LVEF）降低是急性冠状动脉综合征（ACS）后死亡的风险标志物。大约二十年前开发的全球急性冠状动脉事件注册研究（GRACE）风险评分，是ACS风险分层的首选评分系统。本研究的目的是验证GRACE评分，并评估在当代环境下，LVEF在预测ACS后6个月死亡率方面是否比GRACE具有更高的预测价值。
对泰斯心脏医院收治的1576例因首次发作ACS（2015 - 2016年）而接受冠状动脉造影的连续患者进行回顾性分析。广泛记录临床风险因素。采用校正后的Cox回归分析来分析LVEF和GRACE评分与6个月全因死亡率之间的关联。通过配对样本的德龙方法计算C统计量的变化以及判别改善指数（IDI）来评估增量预测价值。
在单变量分析中，LVEF和GRACE评分均与6个月死亡率相关，将两个变量纳入同一模型后，结果仍然显著（GRACE评分：HR = 1.036，95% CI为1.030至1.042；LVEF：HR = 0.965，95% CI为0.948至0.982，两个HR均对应暴露变量的一个单位变化）。GRACE评分对死亡率具有良好的判别能力（C统计量：0.833，95% CI为0.795至0.871）。将LVEF添加到包含GRACE评分的模型中可显著改善模型性能（C统计量：0.848，95% CI为0.813至0.883，改善的p值 = 0.029，IDI为0.0171，95% CI为0.0016至0.0327，p值 = 0.031）。
将LVEF添加到GRACE评分中可显著改善ACS后6个月死亡率的风险预测。
