Behavior of circulating endothelin-1 in a group of patients with acute myocardial infarction

The aim of this study was to investigate the behavior of plasma endothelin- 1 (ET-1) in 23 patients with acute myocardial infarction, complicated and u ncomplicated by left ventricular failure, and treated with and without thro mbolytic agents. ET-1 was measured on admission; on days 2, 3, and 5; and a gain on discharge. In addition, on discharge, ET-1 was correlated with left ventricular systolic function. Left ventricular failure was present, on ad mission, in 14 patients, whereas the other nine did not have any hemodynami c impairment. On discharge, no patients had left ventricular failure, but 1 1 had moderate to severe left ventricular systolic dysfunction, defined as left ventricular ejection fraction (LVEF) < 40%. Fourteen subjects, matched for age and sex, served as a control group. Compared with the control rang e, ET-1 was highly elevated on the first day, in both uncomplicated (p < 0. 01) and complicated patients (p < 0.001). Then it decreased rapidly in the uncomplicated group, reaching the control range within day 5, whereas in th e complicated group it remained significantly elevated in comparison with b oth the control subjects and the uncomplicated patients, until discharge. E T-1 was not correlated with the peak of creatine-kinase MB isoenzyme in any group. In seven patients submitted to thrombolytic treatment ET-1 was alwa ys significantly lower than in the nonthrombolyzed patients (p < 0.05), but the pattern of variation across time was no different. On discharge, the d ifference in plasma ET-1 between patients with LVEF < 40% and the control g roup was significant (p < 0.001), as was the difference between patients wi th and without moderate to severe systolic dysfunction (p < 0.01). ET-1 was closely and inversely correlated with LVEF when patients were considered a s a whole (p < 0.001). These results suggest that the ET-1 increase in the early phase of myocardial infarction could be due to an ischemic process, t o stress reaction, and to cardiac hemodynamic impairment, and therefore, ET -1 may be a good marker of disease. In the following phase the ET-1, being correlated with LVEF, could be a reliable index of systolic function.