Effect of recombinant hirudin (LU 52369) on reocclusion rates after thrombolysis in rabbits.

The effect of recombinant hirudin (r-hirudin, LU 52369) and unfractionated heparin on recombinant tissue-type plasminogen activator (rt-PA; LU 50232) thrombolysis and reocclusion rates after successful thrombolysis was studied in a copper-coil-induced thrombus model in the iliac artery of anesthetized rabbits. Simultaneous administration of rt-PA and recombinant hirudin (r-hirudin) at a dose not affecting the partial thromboplastin time (PTT) increased the number of recanalized arteries significantly. The incidence of reocclusion was drastically reduced from 100% to less than 25%. At a dose increasing PTT twofold, unfractionated heparin had no effect on the incidence of reperfusion and reocclusion. These experimental data indicate that the combination of rt-PA with low-dose r-hirudin may be useful for the prevention of early reocclusion in thrombolytic therapy.