Release of Prostaglandins and Thromboxane into the Coronary Circulation in Patients with Ischemic Heart Disease

Abstract

Endogenous modulators of platelet aggregability and vascular tone may play a part in coronary-artery disease. We therefore measured the release of prostaglandins and thromboxane into the coronary circulation in patients with various kinds of cardiac disease. Simultaneous coronary-sinus (CS) and ascending-aortic (AO) blood samples were obtained from 60 patients for measurement of 6-keto-prostaglandin F_1α (6-keto-PGF_1α, a prostaglandin l₂ metabolite) and of thromboxane B₂ (T×B₂). Samples from 45 of these patients were also tested for prostaglandin E₂ (PGE₂) and lactate. Patients with unstable angina pectoris who reported chest pain within 24 hours of study had higher T×B₂ CS/AO ratios (5.8±2.8, mean ±S.D.) than patients whose most recent anginal pain was more than 96 hours before study (1.3±0.6; P2 CS/AO ratios (range, 0.5 to 2.1) like the patients in the three aforementioned groups, whereas a few had markedly elevated values (range, 10.5 to 46.6). The 6-keto-PGF_1α and PGE₂ CS/AO ratios and myocardial lactate extraction were not significantly different among the five groups. These data suggest that local thromboxane release is associated with recent episodes of angina in patients with unstable angina pectoris, but whether this release is a cause or an effect is not yet known. (N Engl J Med. 1981; 304:685–91.)