DIFFERENT REGIMENS FOR THROMBOLYSIS IN AC UTE MYOCARDIAL-INFARCTION

An early, complete, and sustained patency of the infarct related arter y achieved by thrombolytic therapy reduces mortality in patients with acute myocardial infartion. In the ISIS-3-study there was no differenc e in mortality between t-PA, APSAC, and streptokinase. In contrast, in the GUSTO-trial, a ''front-loaded'' regimen of t-PA (100 mg/90 min) l ead to a reduced inhospital mortality compared to streptokinase. This was most likely due to the higher early patency-rate of the infarct-re lated artery after the front-loaded t-PA. The search for new, more eff ective, thrombolytic regimens lead to a double-bolus injection of t-PA (2 x 50 mg) which revealed high early patency rates (> 80 % TIMI-3 af ter 90 min). R-PA, a new recombinant plasminogen activator with a prol onged half-life, given as double bolus (2 x 10 MU), also produced high patency rates after 90 min without an incresed incidence of reocclusi ons. Acetylsalicylic acid should be given routinely in every thromboly tic therapy. An anticoagulation with heparin seems to improve the effi cacy of the more fibrin-specific thrombolytics t-PA, r-PA: and pro-uro kinase. In dose-finding studies the specific thrombin inhibitor hirudi n has been shown to significantly reduce reocclusions and reinfarction s compared to heparin. An ''optimal thrombolysis'' most likely can onl y be achieved by a thrombolytic agent with a very high early patency c ombined with an effective adjunctive therapy with platelet aggregation - and thrombin-inhibition.