Plasm immunoreactive endothelin concentration correlates with severity of coronary artery disease in patients with stable angin pectoris and normal ventricular function

Objectives. The present study tested the hypothesis that plasm immunoreactive endothelin concentration correlates with the severity and extent of coronary atherosclerosis. Background. Plasm endothelin-1 concentration is increased in patients with unstable coronary syndromes and advanced atherosclerosis. This finding, together with other clinicopathologic observations, suggests that endothelins may participate in the atherogenic process. However, the relation between plasm immunoreactive endothelin and coronary artery disease in patients with stable angin pectoris remains controversal. Methods. Ninety consecutive patients undergoing coronary angiography for the investigation of exertional chest pain and 49 normal control subjects were prospectively studied. Eleven patients had normal coronary angiographic findings (group I), 65 had coronary artery stenoses (group II), and 14 had coronary artery disease plus symptoms indicating atherom in other vascular territories (group III). Computerized angiography was used to determine the extent, severity and morphology of coronary stenoses. Plasm immunoreactive endothelin was measured by radioimmunoassay. Results. Mean (± SD) plasm endothelin concentration (pg/ml) was significantly higher in patients than in control subjects (7.29 ± 4.07 vs. 3.48 ± 1.29, p < 0.0001). Endothelin levels were higher in patients of group III than in those of groups II and I (9.43 ± 5.48, 7.20 ± 3.72 and 4.94 ± 2.89, respectively, P = 0.02). In patients of group II, plasm endothelin correlated with the maximal degree of stenosis in each patient (r = 0.25, P = 0.04) and with the number of stenoses with ≥70% diameter narrowing (r = 0.36, P = 0.002). The highest plasm endothelin levels were found in patients with total occlusions (8.65 ± 3.78 vs. 6.46 ± 3.51, P = 0.02). Conclusions. Plasm immunoreactive endothelin concentration is increased in patients with chronic stable angiuya. The highest levels occur in patients with severe stenoses and total coronary occlusion.