Abstract

Background Approximately 90% of patients presenting to the emergency department with suspected acute coronary syndrome have acute myocardial infarction excluded, but they remain at risk of major adverse cardiovascular events. This study assessed the long‐term outcomes of such patients, focusing on the incremental value of multiple biomarkers combined with clinical risk scores for risk stratification. Methods In this prospective observational study, 487 patients with suspected acute coronary syndrome but excluded acute myocardial infarction were recruited from a large urban hospital, with a median follow‐up of 5.8 years. The primary end point was major adverse cardiovascular events, including adjudicated type 1 myocardial infarction, unstable angina requiring urgent revascularization, and cardiovascular death. Biomarkers assessed were hs‐cTnT (high‐sensitivity cardiac troponin T), hs‐cTnI (high‐sensitivity cardiac troponin I), HFABP (heart‐type fatty acid binding protein), GDF‐15 (growth differentiation factor 15), NT‐proBNP (N‐terminal prohormone of brain naturetic peptide), galectin‐3, and hs‐CRP (high‐sensitivity C‐reactive protein (). Statistical methods included receiver operating characteristic analysis, Kaplan–Meier curves, net reclassification index, and Cox proportional hazards models to evaluate biomarker utility independently and combined with Thrombolysis in Myocardial Infarction and History, ECG, Age, Risk Factors, Troponin scores. Results Of the 487 patients (median age 56 years; 44% female), 9.9% experienced major adverse cardiovascular events. Annualized major adverse cardiovascular events rates for patients with troponin levels below the limit of detection were 0.5% (hs‐cTnT) and 0.7% (hs‐cTnI), with no cardiovascular deaths over 5 years. Both hs‐cTnT and hs‐cTnI levels modestly enhanced risk stratification when added to Thrombolysis in Myocardial Infarction or History, ECG, Age, Risk Factors, Troponinscores. Of the non‐necrosis biomarkers, only GDF‐15 demonstrated independent prognostic value in multivariable models. Conclusions Hs‐cTnT, hs‐cTnI, and GDF‐15 improve the long‐term risk stratification of the History, ECG, Age, Risk Factors, Troponinand Thrombolysis in Myocardial Infarction scores in patients with suspected acute coronary syndrome and acute myocardial infarction excluded. Hs‐cTn of either type at or below limit of detection was associated with excellent short‐ and long‐term outcomes. Registration URL: https://clinicaltrials.gov; Unique identifier: NCT03628586.