Randomized controlled trials of aprotinin in cardiac surgery: could clinical equipoise have stopped the bleeding?

Aprotinin is a serine protease inhibitor used to limit perioperative bleeding and reduce the need for donated blood transfusions during cardiac surgery. Randomized controlled trials of aprotinin evaluating its effect on the outcome of perioperative transfusion have been published since 1987, and systematic reviews were conducted in 1992 and 1997.