Beta-thromboglobulin release within coronary circulation — a potential role of platelets in ergonovine-induced coronary vasospasm

Abstract

The role of platelets in the pathogenesis of acute myocardial ischemia is not yet agreed upon. In this study, the gradient of plasma beta-thromboglobulin concentration between coronary sinus and aorta was used as an indicator of platelet activation within the coronary circulation. Blood samples were drawn before and after injection of ergonovine maleate in patients without fixed coronary stenosis in whom significant coronary spasm was induced by ergonovine (n = 8, Group 1), patients with significant stenosis (≥ 75%) of the left anterior descending artery and positive ergonovine test (n = 7, Group 2) and patients with significant stenosis of left anterior descending coronary artery and negative ergonovine test (n = 11, Group 3). Fifteen patients with normal coronary arteries who were negative in the ergonovine test served as controls (Group 4). After the ergonovine test, all Group 1 patients revealed a significant increase of beta-thromboglobulin gradient (P < 0.001), while those in other groups did not. Additionally, the gradient after the ergonovine test of Group 1 patients was larger than those of the other groups (P < 0.01). All blood samples after the ergonovine test were collected before or at the onset of angina attacks. These results suggest that platelet activation within the cornary circulation has some pathogenic role, probablyas an aggravating factor, in coronary artery spasm.