Low molecular weight heparin (dalteparin) as adjuvant treatment to thrombolysis in acute myocardial infarction - A pilot study: Biochemical markers in acute coronary syndromes (BIOMACS II)

OBJECTIVES This randomized, double blind, placebo-controlled pilot trial ev aluated the effect of dalteparin as an adjuvant to thrombolysis in patients with acute myocardial infarction regarding early reperfusion, recurrent is chemia and patency at 24 h. BACKGROUND Low-molecular-weight heparin, given subcutaneously twice daily w ithout monitoring, might be an attractive alternative to conventional intra venous heparin in the treatment of acute myocardial infarction. METHODS In 101 patients dalteparin/placebo 100 IU/kg nas given just before streptokinase and a second injection 120 IU/kg after 12 h. Monitoring with continuous vector-EGG was done to obtain signs of early reperfusion and lat er ischemic episodes. Blood samples for myoglobin were obtained at start an d after 90 min to evaluate signs of reperfusion. Coronary angiography was p erformed after 20-28 h to evaluate TIMI-flow in the infarct-related artery. RESULTS Dalteparin added to streptokinase tended to provide a higher rate o f TIMI grade 3 flow in infarct-related artery compared to placebo, 68% vers us 51% (p = 0.10), Dalteparin had no effects on noninvasive signs of early reperfusion. In patients with signs of early reperfusion, there seemed to b e a 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. afte r 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 a spirin, there were tendencies for less ECG monitoring evidence of recurrent ischemia and better patency at 24 h, warranting further study. (C) 1999 by the American College of Cardiology.