背景:心肌缺血损伤指数(MI3)是一种用于早期诊断1型非ST段抬高型心肌梗死(NSTEMI)的新型机器学习算法。MI3的性能,无论是在使用早期连续抽血时(例如,在1小时或2小时),并与指南推荐的算法直接比较,仍然未知。我们的目标是外部验证MI3并将其性能与欧洲心脏病学会(ESC)0/1h算法进行比较。
方法:在对一项多中心国际诊断队列研究的二次分析中,从2006年4月21日至2019年2月27日,在来自五个欧洲国家(瑞士,西班牙,意大利,波兰,和捷克共和国)。如果患者出现ST段抬高型心肌梗死,则将其排除在外。没有至少两个连续的高灵敏度心肌肌钙蛋白I(hs-cTnI)测量,或者最终诊断仍不清楚。最终诊断由两名独立的心脏病专家使用所有可用的医疗记录进行集中裁决。包括连续的hs-cTnI测量和心脏成像。主要结果是1型NSTEMI。直接将MI3的性能与ESC0/1h算法的性能进行了比较。
结果:在6487名患者中,(平均年龄61·0岁[IQR49·0-73·0];2122[33%]女性和4365[67%]男性),882例(13·6%)患者患有1型NSTEMI。第一次和第二次hs-cTnI测量之间的中位时间差为60·0分钟(IQR57·0-70·0)。MI3性能非常好,接收器工作特性曲线下面积为0·961(95%CI0·957至0·965),总体校准良好(截距-0·09[-0·2至0·02];斜率1·02[0·97至1·08])。最初定义的小于1·6的MI3评分将4186(64·5%)患者确定为患有1型NSTEMI的概率较低(敏感性99·1%[95%CI98·2至99·5];阴性预测值[NPV]99·8%[95%CI99·6至99·9]);MI3评分为49·7或更高的MI3评分将95·5的概率确定为95·ESC0/1h算法的灵敏度和NPV均高于MI3(灵敏度差异为0·88%[0·19至1·60],p=0·0082;净现值为0·18%[0·05至0·32],p=0·016),MI3的排除效力更高(11%的差异,p<0·0001)。MI3的特异性和PPV优越(特异性差异为3·80%[3·24至4·36],p<0·0001;PPV差异为7·84%[5·86至9·97],p<0·0001),ESC0/1h算法的规则导入效率更高(差异为5·4%,p<0·0001)。
结论:MI3在诊断1型NSTEMI方面表现良好,在急诊科使用早期连续抽血时,证明与ESC0/1h算法具有可比性。
背景:瑞士国家科学基金会,瑞士心脏基金会,欧盟,巴塞尔大学医院,巴塞尔大学,雅培,BeckmanCoulter,罗氏,伊多尼亚,骨科临床诊断,Quidel,西门子,还有Singulex.
BACKGROUND: The myocardial-ischaemic-injury-index (MI3) is a novel machine learning algorithm for the early diagnosis of type 1 non-ST-segment elevation myocardial infarction (NSTEMI). The performance of MI3, both when using early serial blood draws (eg, at 1 h or 2 h) and in direct comparison with guideline-recommended algorithms, remains unknown. Our aim was to externally validate MI3 and compare its performance with that of the European Society of Cardiology (ESC) 0/1h-algorithm.
METHODS: In this secondary analysis of a multicentre international diagnostic cohort
study, adult patients (age >18 years) presenting to the emergency department with symptoms suggestive of myocardial infarction were prospectively enrolled from April 21, 2006, to Feb 27, 2019 in 12 centres from five European countries (Switzerland, Spain, Italy, Poland, and Czech Republic). Patients were excluded if they presented with ST-segment-elevation myocardial infarction, did not have at least two serial high-sensitivity cardiac troponin I (hs-cTnI) measurements, or if the final diagnosis remained unclear. The final diagnosis was centrally adjudicated by two independent cardiologists using all available medical records, including serial hs-cTnI measurements and cardiac imaging. The primary outcome was type 1 NSTEMI. The performance of MI3 was directly compared with that of the ESC 0/1h-algorithm.
RESULTS: Among 6487 patients, (median age 61·0 years [IQR 49·0-73·0]; 2122 [33%] female and 4365 [67%] male), 882 (13·6%) patients had type 1 NSTEMI. The median time difference between the first and second hs-cTnI measurement was 60·0 mins (IQR 57·0-70·0). MI3 performance was very good, with an area under the receiver-operating-characteristic curve of 0·961 (95% CI 0·957 to 0·965) and a good overall calibration (intercept -0·09 [-0·2 to 0·02]; slope 1·02 [0·97 to 1·08]). The originally defined MI3 score of less than 1·6 identified 4186 (64·5%) patients as low probability of having a type 1 NSTEMI (sensitivity 99·1% [95% CI 98·2 to 99·5]; negative predictive value [NPV] 99·8% [95% CI 99·6 to 99·9]) and an MI3 score of 49·7 or more identified 915 (14·1%) patients as high probability of having a type 1 NSTEMI (specificity 95·0% [94·3 to 95·5]; positive predictive value [PPV] 69·1% [66·0-72·0]). The sensitivity and NPV of the ESC 0/1h-algorithm were higher than that of MI3 (difference for sensitivity 0·88% [0·19 to 1·60], p=0·0082; difference for NPV 0·18% [0·05 to 0·32], p=0·016), and the rule-out efficacy was higher for MI3 (11% difference, p<0·0001). Specificity and PPV for MI3 were superior (difference for specificity 3·80% [3·24 to 4·36], p<0·0001; difference for PPV 7·84% [5·86 to 9·97], p<0·0001), and the rule-in efficacy was higher for the ESC 0/1h-algorithm (5·4% difference, p<0·0001).
CONCLUSIONS: MI3 performs very well in diagnosing type 1 NSTEMI, demonstrating comparability to the ESC 0/1h-algorithm in an emergency department setting when using early serial blood draws.
BACKGROUND: Swiss National Science Foundation, Swiss Heart Foundation, the EU, the University Hospital Basel, the University of Basel, Abbott, Beckman Coulter, Roche, Idorsia, Ortho Clinical Diagnostics, Quidel, Siemens, and Singulex.