Endothelin-1 in patients with coronary heart disease undergoing cardiac catheterization

Objectives. This study examined the possible association between endothelin and coronary atherosclerosis and evaluated the synthesis and release of endothelin in the presence of various stimuli that occur during cardiac catheterization. Background. Circulating endothelin has been reported to be increased in diffuse atherosclerosis and acute myocardial infarction. However, the relation between coronary artery disease and endothelin release remains unclear. Methods. We measured the plasma and urinary concentrations of endothelin immunoreactivity in 45 patients and 10 healthy control subjects. Results. In group IA (n = 9), simultaneous blood sampling in the coronary sinus and femoral artery during coronary angioplasty of the left anterior descending coronary artery demonstrated no immediate changes in plasma immunoreactive endothelin-1 (ir-ET-1) levels. In 11 patients in group IB undergoing coronary angioplasty of a major artery, we did not detect changes in peripheral plasma concentrations of ir-ET-1 within 24 h, but urinary ir-ET-1 levels increased from 9.2 ± 2.3 to 18.6 ± 4.9 pg/mg of creatinine a few hours after coronary angioplasty (mean ± SEM, p < 0.05). This increase in urinary endothelin excretion persisted 24 h later. Group II patients (n = 12) had coronary angiography without coronary angioplasty. Levels of both plasma and urinary ir-ET-1 did not change during the 24-h follow-up period. There was no relation between the severity of coronary atherosclerosis and the plasma or urinary concentrations of ir-ET-1. Systolic aortic pressure correlated with basal urinary excretion of endothelin (r = 0.54, p = 0.03, n = 15). In group III (n = 13), levels of ir-ET-1 in patients undergoing right heart catheterization without angiography did not differ from those in the control group. Conclusions. The presence or the severity, or both, of coronary atherosclerosis is not associated with a detectable increase in endothelin release. The diagnostic procedures of Catheterization do not modify endothelin concentrations in plasma and urine. Vascular stretch or injury, or both, during coronary angioplasty increases urinary ir-ET-1 levels a few hours after the procedure. This increase persists for at least 24 h but is not detectable by brief sampling of peripheral or coronary sinus blood.