Troponin T identifies patients with unstable coronary artery disease who benefit from long-term antithrombotic protection. Fragmin in Unstable Coronary Artery Disease (FRISC) Study Group.

OBJECTIVES

We sought to evaluate whether troponin T might be used for identification of patients with unstable coronary artery disease in whom treatment with low molecular weight heparin is beneficial.

BACKGROUND

Early identification of subgroups with differences in response to a certain treatment is important to optimize the utilization of different therapeutic approaches.

METHODS

Nine-hundred seventy-one patients with unstable coronary artery disease who participated in a trial of the low molecular weight heparin dalteparin (Fragmin) and who provided blood samples were classified into subgroups according to troponin T level. In the short-term phase all patients received subcutaneous dalteparin/placebo twice daily for 6 days. During the long-term phase they continued with daltparin/placebo once daily for another 5 weeks.

RESULTS

In the short-term phase, dalteparin reduced the incidence of death or myocardial infarction from 2.4% to 0% (p = 0.12) and from 6.0% to 2.5% (p < 0.05) in 327 and 644 patients with troponin T levels < 0.1 and > or = 0.1 micrograms/liter, respectively. During long-term treatment there was an increasing difference between the placebo and dalteparin group in those with troponin T levels > or = 0.1 microgram/liter, in whom the incidences at 40 days were 14.2% and 7.4%, respectively (p < 0.01). In contrast, no beneficial effect of the long-term treatment could be demonstrated in those with troponin T levels < 0.1 microgram/liter (4.7% vs. 5.7%).

CONCLUSIONS

Elevation of troponin T identifies a subgroup of patients in whom prolonged antithrombotic treatment (e.g., with dalteparin) is beneficial.