Long-term low-molecular-mass heparin in unstable coronary-artery disease: FRISC II prospective randomised multicentre study Original Research Article

Background Short-term treatment with subcutaneous low-molecular-mass heparin in addition to aspirin is effective in unstable coronary-artery disease. We assessed the efficacy of long-term treatment with dalteparin in patients managed with a non-invasive treatment strategy. Methods 2267 patients from three Scandinavian countries (median age 67 years, 68% men) with unstable coronaryartery disease were randomly assigned to continue double-blind subcutaneous dalteparin twice daily or placebo for 3 months, after at least 5 daysʹ treatment with open-label dalteparin. The composite primary endpoint was death or myocardial infarction. Analysis was by intention to treat. Findings During the 3 months of double-blind treatment, there was a non-significant decrease in the composite endpoint of death or myocardial infarction of 6·7% and 8·0% in the dalteparin and placebo groups, respectively (risk ratio 0·81 [95% Cl 0·60–1·10], p=0·17). At 30 days, this decrease was significant (3·1 vs 5·9%, 0·53 [0·35–0·80]; p=0·002). In the total cohort there was at 3 months a decrease in death, myocardial infarction, or revascularisation (29·1 vs 33·4%, 0·87 [0·77–0·99]; p=0·031). The initial benefits were not sustained at 6-month follow-up. Interpretation Long-term dalteparin lowers the risk of death, myocardial infarction, and revascularisation in unstable coronary-artery disease at least during the first month of therapy. These early protective effects could be used to lower the risk of events in patients waiting for invasive procedures.