Background and Purpose- American Heart Association guidelines recommend obtaining baseline troponin in all patients with acute ischemic stroke. Yet, there is a paucity of data on the prevalence of baseline troponin elevation and specifically its diagnostic yield for acute myocardial infarction (AMI) in patients presenting within the time window for thrombolysis. Methods- We retrospectively analyzed 1072 consecutive patients admitted for acute ischemic stroke or transient ischemic attack, who presented within 4.5 hours of last known well (LKW). Patients who had baseline cardiac troponin I (bcTnI) obtained within 72 hours from LKW (n=525) were included in the study. Multivariable logistic regression was conducted to determine factors independently related to an elevated bcTnI (>0.04 ng/mL). We calculated the area under receiver operator curves, sensitivity, and specificity, to determine the diagnostic accuracy of (i) the bcTnI for AMI stratified by the time to assessment and (ii) the best time cutoff for obtaining bcTnI. Results- Among included subjects, the median time from LKW to the bcTnI was 3.8 hours and 113 (21.5%) subjects had an elevated bcTnI. Assessment of bcTnI within 4.5 hours from LKW was significantly more often associated with normal values as compared to assessment between 4.5 and 72 hours (61.7% versus 38.3%; P=0.001). Fifteen (2.9%) patients were diagnosed with AMI. After adjustment for pertinent confounders, time to bcTnI assessment was independently associated with AMI (odds ratio, 1.04 [95% CI, 1.02-1.07] P=0.001). When stratified by time, bcTnI assessed within 4.5 hours had a sensitivity of 25% and specificity of 83.7% for AMI, whereas bcTnI assessment between 4.5 and 72 hours was associated with a sensitivity of 90.9% and specificity of 74.8%. Conclusions- Assessment of bcTnI after 4.5 hours from LKW was associated with greater diagnostic accuracy than testing within 4.5 hours. This information may inform routine clinical practice.

中文翻译：

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4.5 小时内就诊的中风患者基线心肌肌钙蛋白与急性心肌梗塞的关联。


背景和目的 - 美国心脏协会指南建议所有急性缺血性中风患者获取基线肌钙蛋白。然而，关于基线肌钙蛋白升高的患病率，特别是在溶栓时间窗内就诊的患者中其对急性心肌梗死（AMI）的诊断率的数据很少。方法-我们回顾性分析了 1072 名因急性缺血性中风或短暂性脑缺血发作入院的连续患者，这些患者在最后一次已知良好 (LKW) 后 4.5 小时内就诊。该研究包括在 LKW 72 小时内获得基线心肌肌钙蛋白 I (bcTnI) 的患者 (n=525)。进行多变量逻辑回归以确定与 bcTnI 升高 (>0.04 ng/mL) 独立相关的因素。我们计算了受试者工作曲线下面积、敏感性和特异性，以确定 (i) 按评估时间分层的 AMI bcTnI 和 (ii) 获得 bcTnI 的最佳时间截止时间的诊断准确性。结果-在纳入的受试者中，从 LKW 到 bcTnI 的中位时间为 3.8 小时，113 名 (21.5%) 受试者的 bcTnI 升高。与 4.5 至 72 小时之间的评估相比，LKW 后 4.5 小时内的 bcTnI 评估更常与正常值相关（61.7% 对比 38.3%；P=0.001）。 15 名 (2.9%) 患者被诊断为 AMI。调整相关混杂因素后，进行 bcTnI 评估的时间与 AMI 独立相关（比值比，1.04 [95% CI，1.02-1.07] P=0.001）。按时间分层时，4.5 小时内评估的 bcTnI 对 AMI 的敏感性为 25%，特异性为 83.7%，而 4.5 至 72 小时之间评估的 bcTnI 则敏感性为 90.9%，特异性为 74.8%。 结论-LKW 4.5 小时后评估 bcTnI 比 4.5 小时内测试具有更高的诊断准确性。该信息可以为常规临床实践提供信息。