Continuous multilead ST-monitoring identifies patients with unstable coronary artery disease who benefit from extended antithrombotic treatment.

Abstract

Prolongation of anticoagulant treatment might reduce subsequent cardiac events in patients with unstable coronary artery disease. Multilead ST-segment monitoring identifies patients with a high risk of adverse outcome. The aim was to assess the value of multilead ST-monitoring in prospectively identifying patients who respond to extended anticoagulant treatment with low-molecular weight heparin when treated by a primarily non-invasive strategy. In this substudy of the FRISC II trial, ST-monitoring with a continuous 12-lead ECG or vectorcardiography was performed for 24 h in 629 patients with unstable coronary artery disease randomized to receive either the low-molecular weight heparin dalteparin, or placebo for 3 months after at least 5 days' dalteparin treatment in all patients. Ischaemic episodes were detected in 34% during ST-monitoring. In the group with ischaemic episodes, the extended dalteparin treatment was associated with a lower rate of death, myocardial infarction, or revascularization (35.2% vs 53.4%, relative risk reduction: 34%, P=0.01). In patients without ischaemic episodes, long-term dalteparin treatment had no effect. In patients with unstable coronary artery disease treated primarily with a non-invasive strategy, ischaemic episodes revealed while on multilead ST-monitoring identifies patients who benefit most from extended treatment with anticoagulants.