Placebo-controlled study of Iloprost (ZK 36374) in cardiopulmonary bypass surgery

Abstract

The effects of infusion of Iloprost (ZK 36374), a prostacyclin analogue, on platelet function, postoperative blood loss and microaggregate deposition on filters and oxygenators were studied in patients undergoing routine coronary operations. In this double-blind randomized study of 50 male patients, 25 received Iloprost and 25 a placebo. Platelet deposition was assessed using Indium-labelled platelets. Comparison of Iloprost and placebo groups showed the mean number of platelets to be significantly higher in the Iloprost group at the end of cardiopulmonary bypass and in early postoperative recovery. Similarly, spontaneous aggregation of platelets was higher in the placebo group. The mean percentages of platelets sequestrated in the extracorporeal circuit were significantly higher in the placebo group. There was no difference in either the amount or pattern of postbypass bleeding between Iloprost and the control patients. Infusion of the tested drug was responsible for significant hypotension, which was correctable with fluid administration alone. Thus, Iloprost diminishes the fall in circulatory platelet count during cardiopulmonary bypass, preserves platelet function, diminishes platelet deposition on filters and oxygenators, but also causes arterial hypotension.