Abstract 15753: High-Sensitivity Cardiac Troponin T and Secondary Events in Outpatients with Coronary Heart Disease: Data from the Heart and Soul Study

Abstract

Introduction: Elevated levels of high-sensitivity cardiac troponin T (hs-cTnT) predict secondary cardiovascular (CV) events in patients with stable coronary heart disease (CHD), but it is unclear whether this association is independent of structural and functional heart disease. We sought to evaluate the association of hs-cTnT with baseline measures of cardiac structure and function, and to determine whether the risk of secondary events associated with hs-cTnT was explained by baseline cardiac disease in outpatients with CHD.

Methods: We measured hs-cTnT and performed exercise treadmill testing with stress echocardiography in a prospective cohort study of 988 outpatients with CHD who were enrolled between 9/00 and 12/02. We used Cox proportional hazards models to evaluate the association between hs-cTnT and subsequent CV events (myocardial infarction, heart failure, or CV death).

Results: Of the 988 participants, 336 (34%) had undetectable hs-cTnT levels, 413 (42%) had intermediate hs-cTnT, and 239 (24%) had high hs-cTnT (above the sex-specific 99th percentile for a normal population). At baseline, hs-cTnT was associated with increased left ventricular mass index, diastolic dysfunction, and worse treadmill exercise capacity. During a median follow-up of 7.9 years, 295 participants (30%) experienced a CV event (Figure). Each doubling in hs-cTnT was associated with a 75% higher rate of CV events (HR 1.75, 95%CI 1.61, 1.89; P<.001). After adjustment for clinical risk factors, baseline cardiac structure and function, and other biomarkers, each doubling in hs-cTnT remained associated with a 31% higher rate of CV events (HR 1.31, 95%CI 1.14, 1.51; P<.001).

Conclusions: In outpatients with stable CHD, elevated hs-cTnT levels were associated with worse cardiac structure and function, but hs-cTnT remained independently associated with secondary events. These data suggest that hs-cTnT detects an element of risk that is not captured by existing measures.