Background The diagnosis of myocardial infarction (MI) in the presence of heart failure (HF) presents a clinical problem. While diagnostic algorithms using high-sensitivity cardiac troponin have been established for suspected MI, their accuracy in patients with HF remains uncertain. This study aims to assess the diagnostic accuracy of high-sensitivity troponin I (TnI) levels in identifying acute MI among patients with HF, focusing on baseline, absolute and relative TnI changes. Methods Data from 562 individuals admitted to the emergency department with suspected MI were retrospectively analysed. Two-point TnI and baseline brain natriuretic peptide (BNP) test results were available. HF status was determined based on clinical, laboratory and instrumental criteria. Results Among the 562 patients, 299 (53.2%) were confirmed having MI. Baseline TnI demonstrated predictive capability for MI in the overall population (area under the curve (AUC) 0.63), while TnI relative change exhibited superior performance (AUC 0.83). Baseline TnI accuracy varied significantly by group, notably decreasing in the third group (severe HF) (AUC 0.54) compared with the first and second groups (AUC 0.67 and AUC 0.71, respectively). TnI relative change demonstrated consistent accuracy across all groups, with AUCs of 0.79, 0.79 and 0.89 for the first, second and third groups, respectively, even after adjustment for age, sex and glomerular filtration rate. Discussion Troponin relative change is a reliable predictor of MI, even in patients with acute HF. Baseline TnI accuracy is influenced by HF severity. It is essential to consider HF status and BNP levels when employing high-sensitivity cardiac troponin testing to rule out suspected MIs. Data are available upon reasonable request. Available on reasonable request.

中文翻译：

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基线肌钙蛋白及肌钙蛋白变化对心肌梗死合并心力衰竭诊断的准确性

背景 在心力衰竭（HF）存在的情况下诊断心肌梗死（MI）是一个临床问题。虽然已经建立了使用高灵敏度心肌肌钙蛋白来诊断疑似心肌梗死的算法，但其在心力衰竭患者中的​​准确性仍不确定。本研究旨在评估高敏肌钙蛋白 I (TnI) 水平在识别心力衰竭患者急性心肌梗死方面的诊断准确性，重点关注基线、绝对和相对 TnI 变化。方法 回顾性分析急诊科收治的 562 名疑似心肌梗死患者的数据。两点 TnI 和基线脑钠肽 (BNP) 测试结果已可用。心力衰竭状态是根据临床、实验室和仪器标准确定的。结果 562例患者中，299例（53.2%）确诊为心梗。基线 TnI 表现出对总体人群 MI 的预测能力（曲线下面积 (AUC) 0.63），而 TnI 相对变化表现出优越的性能 (AUC 0.83)。各组的基线 TnI 准确度差异显着，与第一组和第二组（分别为 AUC 0.67 和 AUC 0.71）相比，第三组（严重心力衰竭）（AUC 0.54）显着下降。TnI 相对变化在所有组中表现出一致的准确性，即使在调整年龄、性别和肾小球滤过率后，第一组、第二组和第三组的 AUC 分别为 0.79、0.79 和 0.89。讨论 肌钙蛋白相对变化是 MI 的可靠预测因子，即使对于急性心力衰竭患者也是如此。基线 TnI 准确性受心力衰竭严重程度的影响。在采用高灵敏度心肌肌钙蛋白检测排除可疑心肌梗死时，必须考虑心力衰竭状态和 BNP 水平。数据可根据合理要求提供。可根据合理要求提供。