Role of protease inhibition in myocardial preservation following ischemia and reperfusion.

Aprotinin, a naturally occurring protease inhibitor, in concentrations of 10(6) KIU/L was found to have no effect on myocardial performance in normally perfused isolated rat hearts, before ischemia. Given during the preischemic period, the drug had a significant protective effect on the reperfused hearts, following cardioplegic ischemia: better contractility upon reperfusion (p < 0.011), faster decline of the ischemic contracture, higher coronary flow (p < 0.025), lower AV-difference (p < 0.05), and lower CPK levels (p < 0.01).