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Beta-thromboglobulin release within coronary circulation--a potential role of platelets in ergonovine-induced
Insights
Platelet activation in coronary artery spasm was investigated. Increased beta-thromboglobulin levels in coronary sinus indicate platelet activation, suggesting a role in aggravating coronary artery spasm.
Area of Science:
- Cardiology
- Hematology
- Pathophysiology
Background:
- The precise role of platelets in acute myocardial ischemia remains debated.
- Platelet activation is a potential contributor to ischemic heart disease pathogenesis.
Purpose of the Study:
- To evaluate platelet activation within the coronary circulation during ergonovine-induced coronary artery spasm.
- To determine if platelet activation correlates with coronary artery spasm.
Main Methods:
- Measured plasma beta-thromboglobulin (a marker of platelet activation) gradients between the coronary sinus and aorta.
- Administered ergonovine maleate to induce coronary spasm in patients with and without significant coronary stenosis.
- Compared beta-thromboglobulin gradients in four groups: spasm without stenosis, spasm with stenosis, stenosis without spasm, and controls.
Main Results:
- Patients with ergonovine-induced coronary artery spasm (Group 1) showed a significant increase in beta-thromboglobulin gradient post-ergonovine (P < 0.001).
- The elevated beta-thromboglobulin gradient in Group 1 was significantly higher compared to other groups (P < 0.01).
- No significant increase in gradient was observed in patients without spasm or with stenosis alone.
Conclusions:
- Platelet activation occurs within the coronary circulation during coronary artery spasm.
- Platelet activation likely plays a role in the pathogenesis of coronary artery spasm, potentially as an aggravating factor.
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 (greater than or equal to 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 less than 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 less than 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 coronary circulation has some pathogenic role, probably as an aggravating factor, in coronary artery spasm.