Troponin T (TnT) elevation above the 99th percentile upper reference limit (URL) is considered diagnostic of acute myocardial infarction (MI). Non-specific increases of TnT are frequent in acute stroke patients. However, in these patients, correct diagnosis of MI is crucial because the antithrombotic medications used to treat acute MI might be harmful and produce intracranial bleeding. In this study, we aimed to associate enhanced TnT levels defined by different cutoff values with occurrence of culprit lesion coronary artery disease (CAD) as well as 1-year major adverse cerebral and cardiovascular events (MACCEs). In this cohort study, we investigated 84 consecutive patients with acute ischemic stroke and concomitant MI. TnT levels were measured using a fourth-generation TnT assay. The incidence of culprit lesion CAD was determined by coronary angiography. MACCEs were recorded during 1-year follow-up. Culprit lesion CAD occurred in 55 % of patients, and 1-year MACCE in 37 %. TnT levels above the manufacturers' provided 99th URL (TnT > 0.01) were not associated with culprit lesion CAD (relative risk [RR], 1.3; 95 % confidence interval [CI] 0.96-1.8; P = 0.09). Slightly increased cutoff level (TnT > 0.03) increased specificity and was associated with culprit lesion CAD without decreasing sensitivity (RR, 1.5; 95 % CI 1.1-2.2; P = 0.021) and 1-year MACCE (RR, 1.7; 95 % CI 1.3-2.3; P < 0.001). Slightly increasement of the TnT cutoff level predicted MACCEs and is superior in prediction of culprit lesion CAD in stroke patients without being less sensitive. This finding has to be confirmed in large-scale clinical trials.
Keywords: MACCE; Myocardial infarction; ROC; Stroke; Troponin.