PLASMA-IMMUNOREACTIVE ENDOTHELIN CONCENTRATION CORRELATES WITH SEVERITY OF CORONARY-ARTERY DISEASE IN PATIENTS WITH STABLE ANGINA-PECTORIS AND NORMAL VENTRICULAR-FUNCTION

Objectives. The present study tested the hypothesis that plasma immuno reactive endothelin concentration correlates with the severity and ext ent of coronary atherosclerosis. Background. Plasma endothelin-1 conce ntration is increased in patients with unstable coronary syndromes and advanced atherosclerosis. This finding, together with other clinicopa thologic observations, suggests that endothelins may participate in th e atherogenic process. However, the relation between plasma immunoreac tive endothelin and coronary artery disease in patients with stable an gina pectoris remains controversial. Methods. Ninety consecutive patie nts undergoing coronary angiography for the investigation of exertiona l 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 arter y disease plus symptoms indicating atheroma in other vascular territor ies (group III). Computerized angiography was used to determine the ex tent, severity and morphology of coronary stenoses. Plasma immunoreact ive endothelin was measured by radioimmunoassay. Results. Mean (+/-SD) plasma endothelin concentration (pg/ml) was significantly higher in p atients 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, plasma endoth elin correlated with the maximal degree of stenosis in each patient (r = 0.25, p = 0.04) and with the number of stenoses with greater than o r equal to 70% diameter narrowing (r = 0.36, p = 0.002), The highest p lasma endothelin levels were found in patients with total occlusions ( 8.65 +/- 3.78 vs, 6.46 +/- 3.51, p = 0.02), Conclusions. Plasma immuno reactive endothelin concentration is increased in patients with chroni c stable angina. The highest levels occur in patients with severe sten oses and total coronary occlusion.