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.