Utility of C-terminal Proendothelin in the Early Diagnosis and Risk Stratification of Patients With Suspected Acute Myocardial Infarction

Abstract Background Endothelial dysfunction plays a major role in cardiovascular diseases, including acute myocardial infarction (AMI). However, its quantification has not been available as a clinical tool. Methods In a prospective international multicentre study, we analyzed the diagnostic and prognostic utility of endothelial dysfunction as quantified by C-terminal proendothelin-1 (CT-proET-1) in 658 consecutive patients presenting with suspected AMI. The final diagnosis was adjudicated by 2 independent cardiologists. Patients were followed long-term for mortality. Results The adjudicated final diagnosis was AMI in 145 patients (22%). The diagnostic performance of CT-proET-1 for AMI was moderate; its area under the receiver operating characteristic (ROC) curve amounted to 0.66 (95% confidence interval [CI], 0.61-0.72; P 82 pmol/L). The prognostic accuracy of CT-proET-1 regarding mortality was tantamount to that of N-terminal pro–B-type natriuretic peptide (NT-proBNP) and outperformed cTnT and hs-cTnT both in patients with AMI and in patients without acute coronary syndrome. CT-proET-1 at presentation yielded high prognostic accuracy that was similar to that of the Thrombolysis in Myocardial Infarction (TIMI) and Global Registry of Acute Coronary Events (GRACE) risk scores. The TIMI risk score could be significantly improved by adding CT-proET-1 (integrated discriminatory improvement [IDI] of 0.074 P  = 0.004). Conclusions Use of CT-proET-1 improves risk stratification of unselected patients with suspected AMI. CT-proET-1 did not provide additional diagnostic value.