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

Background Short-term treatment with subcutaneous low-molecular-mass hepari n 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 year s, 68% men) with unstable coronary-artery disease were randomly assigned to continue double blind subcutaneous dalteparin twice daily or placebo for 3 months, after at least 5 days' treatment with open-label dalteparin. The c omposite primacy 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-sig nificant decrease in the composite endpoint of death or myocardial infarcti on of 6.7% and 8.0% in the dalteparin and placebo groups, respectively (ris k ratio 0.8% [95% CI 0.60-1.10], p=0.17). At 30 days, this decrease was sig nificant (3.1 vs 5.9%, 0.53 [0.35-0.80]; p=0.002). In the total cohort ther e was at 3 months a decrease in death, myocardial infarction, or revascular isation (29.1 vs 33.4%, 0.87 [0.77-0.99]; p=0.031). The initial benefits we re not sustained at 6-month follow-up. Interpretation Long-term dalteparin lowers the risk of death, myocardial in farction, and revascularisation in unstable coronary-artery disease at leas t during the first month of therapy. These early protective effects could b e used to lower the risk of events in patients waiting for invasive procedu res.