Aims: The FRISC II trial demonstrated that, for patients with unstable coronary artery disease, an early invasive strategy following acute treatment with dalteparin and aspirin, was superior to a more conservative approach. We evaluated whether it is beneficial to extend treatment with dalteparin to patients eligible for revascularization but for whom these procedures are performed after the initial hospital stay.
Methods and results: As a subanalysis of FRISC II, the efficacy and clinical safety of extended dalteparin treatment (5000 or 7500 IU.12h(-1) to day 90) compared with placebo was assessed in 1601 patients randomized to a non-invasive group who underwent revascularization only when necessary because of recurring symptoms, (re)infarction, or severe ischaemia. By day 90, 440 patients had undergone revascularization: 267 of these procedures occurred during the double-blind period. All patients initially received acute treatment (5-7 days from day 1) with dalteparin (120 IU/kg(-1) 12h(-1)). The incidence of death and/or myocardial infarction was monitored until revascularization or day 45 and until revascularization or day 90. There was a significant difference in the estimated probability of death and/or myocardial infarction until revascularization or day 90 in favour of dalteparin (log-rank test, P=0.0415) and there was a significant reduction in death and/or myocardial infarction in favour of extended dalteparin treatment at day 45, with a 57% relative risk reduction (P=0.0004). At day 90 the relative risk reduction was 29%. The safety profile of extended dalteparin treatment was similar to that of acute usage.
Conclusion: Extended dalteparin treatment for up to 45 days is effective and safe as a bridging therapy for patients with unstable coronary artery disease awaiting revascularization.