Increased serotonin release across the coronary bed during a nonischemic interval in patients with vasospastic angina

Background: Platelet activation and coagulation abnormality have been observed during coronary spasm. It is crucial whether platelet activation occurs even during a nonischemic period. Hypothesis: This study was designed to determine whether platelets might be activated across the coronary bed during a nonischemic interval in patients with vasospastic angina. Methods: Plasma levels of serotonin, 6‐keto‐prostaglandin F1 α, and catecholamines in the aorta and the coronary sinus were simultaneously measured in 16 patients with vasospastic angina and 13 control patients with nonischemic heart disease. Results: None of these patients showed myocardial ischemia during sampling. The difference in transcardiac plasma levels of serotonin in patients with vasospastic angina was significantly higher than that in controls (1.48 ± 1.08 ng/ml vs. 0.07 ± 0.12 ng/ml, respectively, p