TREATEMENT OF PULMONARY EMBOLISM BY A VERY LOW MOLECULAR WEIGHT HEPARIN FRAGMENT (CY 222), A DOSE RANGE STUDY

Experimental studies showed that CY 222 (MW 2500 - 250 U AXAIC/ mg - 25 Ul/mg) kept the profibrinolytic properties of heparin with a considerable reduction of bleeding risk and that the optimal dose was about 1 000 U AXAIC/kg/day in rabbits. We have tested the dose related effectiveness and tolerance of this drug in 47 patients (pts) with acute pulmonary embolism (PE) less than 5 days. Pts were divided into 3 groups receiving : Group I : 500 (n = 16), Group II : 750 (n = 17), Group III : 1 000 (n = 14) U AXAIC/kg/day by continuous intravenous infusion for ten days. Effectiveness was appreciated by Miller’ s index with pulmonary angiography (PA) performed before, on the 5th day and on the 10 th day of treatment. The decrease of Miller’ s index mean value was comparable in the 3 groups. But the improvement was faster in the group IIIWe noticed 5 recurrent PE (2 in Group I, 1 in Group II and 2 in Group III) of which one was fatal (Group I), and 2 hematoma at the venous punction site in Group III.In conclusion, CY 222 is a safe treatment of PE and the most effective dose seems to be 1 000 U AXA IC/kg/day in spite of minor bleeding.