Prostaglandin E1 infusion in unstable angina: effects on anginal frequency and cardiac function.

Intermittent vasospasm and/or platelet aggregation may play an important role in producing transient coronary artery obstruction leading to an unstable ischemic syndrome. To determine whether intravenous infusion of prostaglandin E1 (PGE1) a known coronary vasodilator and inhibitor of platelet aggregation, produces salutary effects in unstable angina, we evaluated its effects in 19 patients with an unstable acute ischemic syndrome. PGE1 produced a significant decrease in the number of episodes of rest angina (p less than 0.001) and eliminated the need for intravenous nitroglycerin and morphine in 10 patients. These salutary clinical effects were associated with a significant (p less than 0.05) reduction in mean arterial pressure, mean pulmonary artery pressure, mean pulmonary capillary wedge pressure, and the double product, without a reduction in the endocardial perfusion gradient (aortic diastolic blood pressure--mean pulmonary capillary wedge pressure). Adverse effects were generally minor and easily controlled. Thus PGE1 infusion may be of value in the treatment of acute unstable ischemic syndromes.