JAMA. 2005;293:427-435. The CREATE Trial Group Investigators Context： Although reperfusion therapy， aspirin， -blockers， and angiotensin-converting enzyme inhibitors reduce mortality when used early in patients with acute myocardial infarction (MI)， mortality and morbidity remain high. No antithrombotic or newer antiplatelet drug has been shown to reduce mortality in acute MI.

Objective： To evaluate the effects of reviparin， a low-molecular-weight heparin， when initiated early and given for 7 days in addition to usual therapy on the primary composite outcome of death， myocardial reinfarction， or strokes at 7 and 30 days.

Design， Setting， and Patients： A randomized， double-blind， placebo-controlled trial (Clinical Trial of Reviparin and Metabolic Modulation in Acute Myocardial Infarction Treatment Evaluation [CREATE]) of 15 570 patients with ST-segment elevation or new left bundle-branch block， presenting within 12 hours of symptom onset at 341 hospitals in India and China from July 2001 through July 2004.

Intervention： Reviparin or placebo subcutaneously twice daily for 7 days.

Main Outcome Measure： Primary composite outcome of death， myocardial reinfarction， or stroke at 7 and 30 days.

Results： The primary composite outcome was significantly reduced from 854 (11.0%) of 7790 patients in the placebo group to 745 (9.6%) of 7780 in the reviparin group (hazard ratio [HR]， 0.87; 95% CI， 0.79-0.96; P = .005). These benefits persisted at 30 days (1056 [13.6%] vs 921 [11.8%] patients; HR， 0.87; 95% CI， 0.79-0.95; P = .001) with significant reductions in 30-day mortality (877 [11.3%] vs 766 [9.8%]; HR， 0.87; 95% CI， 0.79-0.96; P = .005) and reinfarction (199 [2.6%] vs 154 [2.0%]; HR， 0.77; 95% CI， 0.62-0.95; P = .01)， and no significant differences in strokes (64 [0.8%] vs 80 [1.0%]; P = .19). Reviparin treatment was significantly better when it was initiated very early after symptom onset at 7 days (<2 hours: HR， 0.70; 95% CI， 0.52-0.96; P = .03; 30/1000 events prevented; 2 to <4 hours: HR， 0.81; 95% CI， 0.67-0.98; P = .03; 21/1000 events prevented; 4 to <8 hours: HR， 0.85; 95% CI， 0.73-0.99; P = .05; 16/1000 events prevented; and 8 hours: HR， 1.06; 95% CI， 0.86-1.30; P = .58; P = .04 for trend). There was an increase in life-threatening bleeding at 7 days with reviparin and placebo (17 [0.2%] vs 7 [0.1%]， respectively; P = .07)， but the absolute excess was small (1 more per 1000) vs reductions in the primary outcome (18 fewer per 1000) or mortality (15 fewer per 1000).

Conclusions： In patients with acute ST-segment elevation or new left bundle-branch block MI， reviparin reduces mortality and reinfarction， without a substantive increase in overall stroke rates. There is a small absolute excess of life-threatening bleeding but the benefits outweigh the risks.