Low molecular weight heparin (dalteparin) as adjuvant treatment to thrombolysis in acute myocardial infarction— pilot study: Biochemical Markers in Acute Coronary Syndromes (BIOMACS II)

OBJECTIVES This randomized, double blind, placebo-controlled pilot trial evaluated the effect of dalteparin as an adjuvant to thrombolysis in patients with acute myocardial infarction regarding early reperfusion, recurrent ischemi and patency at 24 h. BACKGROUND Low-molecular-weight heparin, given subcutaneously twice daily without monitoring, might be an attractive alternative to conventional intravenous heparin in the treatment of acute myocardial infarction. METHODS In 101 patients dalteparin/placebo 100 IU/kg was given just before streptokinase and second injection 120 IU/kg after 12 h. Monitoring with continuous vector-ECG was done to obtain signs of early reperfusion and later ischemic episodes. Blood samples for myoglobin were obtained at start and after 90 min to evaluate signs of reperfusion. Coronary angiography was performed after 20–28 h to evaluate TIMI-flow in the infarct-related artery. RESULTS Dalteparin added to streptokinase tended to provide higher rate of TIMI grade 3 flow in infarct-related artery compared to placebo, 68% versus 51% (p = 0.10). Dalteparin had no effects on noninvasive signs of early reperfusion. In patients with signs of early reperfusion, there seemed to be higher rate of TIMI grade 3 flow, 74% versus 46% (myoglobin) (p = 0.04) and 73% versus 52% (vector-ECG) (p = 0.11). Ischemic episodes 6–24 h. after start of treatment were fewer in the dalteparin group, 16% versus 38% (p = 0.04). CONCLUSIONS When dalteparin was added as an adjuvant to streptokinase and aspirin, there were tendencies for less ECG monitoring evidence of recurrent ischemi and better patency at 24 h, warranting further study.