Usefulness of Endothelin-1 Assessment in Acute Myocardial Infarction

Introduction and objectives: High endothelin-1 (ET-1) levels have been linked to poor clinical outcomes after ST-segment elevation myocardial infarction (STEMI). Vasoconstriction of the coronary microcirculation seems to be the underlying mechanism. The aim of the study was to assess the effect of ET-1 on microvascular integrity, infarct size, left ventricular ejection fraction (LVEF) and myocardial salvage in evolving myocardial infarction (MI). Methods: We measured ET-1 levels acutely (6-24 h) in 127 patients presenting with their first STEMI. Contrast-enhanced cardiac magnetic resonance (ce-CMR) was performed in 94 patients within 1 week to assess microvascular obstruction (MO), infarct size and LVEF. A myocardial salvage index (MSI) was defined as the percentage of at-risk angiographic area without necrosis on the ce-CMR. Results: Mean age was 60.9 (11.8) years and 98 (77%) were males. Median ET-1 level within the first 24 h was 6.8 pg/mL (25(th)-75(th) percentile range: 5.4-8.5 pg/mL). Patients with ET-1 concentrations over the median presented higher percentage of MO (77.7% for ET-1 > 6.8 pg/mL vs. 16.6% for ET-1 <= 6.8 pg/mL, P < .001) and lower MSI values (13.8 (26%) for ET-1 > 6.8 pg/mL vs. 37.4 (26%) for ET-1 <= 6.8 pg/mL, P = .02). ET-1 levels did not show a significant association with infarct size (P = .11) and LVEF (P = .16). Multivariate analysis found ET-1 to be a significant predictor of MO (OR = 2.78; CI 95% 1.16-6.66; P = .021) and MSI <= Percentile 25 (OR = 1.69, CI 95% 1.01-2.81; P = .04). Conclusions: High ET-1 levels after myocardial infarction are associated with the presence of microvascular obstruction and lower myocardial salvage index. (C) 2010 Sociedad Espanola de Cardiologia. Published by Elsevier Espana, S. L. All rights reserved.