Sensitive Cardiac Troponin T Assay and the Risk of Incident Cardiovascular Disease in Women With and Without Diabetes Mellitus

BACKGROUND: Very low levels of cardiac troponin T are associated with an increased risk of cardiovascular death in patients with stable chronic coronary disease. Whether high-sensitivity cardiac troponin T levels are associated with adverse cardiovascular outcomes in individuals without cardiovascular disease (CVD) has not been well studied. METHODS AND RESULTS: Using 2 complementary study designs, we evaluated the relationship between baseline cardiac troponin and incident CVD events among diabetic and nondiabetic participants in the Women's Health Study (median follow-up, 12.3 years). All diabetic women with blood specimens were included in a cohort study (n=512 diabetic women, n=65 events), and nondiabetic women were sampled for inclusion in a case-cohort analysis (n=564 comprising the subcohort, n=479 events). High-sensitivity cardiac troponin T was detectable (≥ 0.003 μg/L) in 45.5% of diabetic women and 30.3% of nondiabetic women (P<0.0001). In models adjusted for traditional risk factors and hemoglobin A(1c), detectable high-sensitivity cardiac troponin T was associated with subsequent CVD (myocardial infarction, stroke, cardiovascular death) in diabetic women (adjusted hazard ratio, 1.79; 95% confidence interval, 1.04 to 3.07, P=0.036) but not nondiabetic women (adjusted hazard ratio, 1.13; 95% confidence interval, 0.82 to 1.55; P=0.46). Further adjustment for amino-terminal pro-B-type natriuretic peptide and estimated renal function did not substantially alter this relationship among diabetic women (hazard ratio, 1.76; 95% confidence interval, 1.00 to 3.08; P=0.0499), which appeared to be driven by a 3-fold increase in CVD death that was not observed in nondiabetic women. CONCLUSIONS: Very low but detectable levels of cardiac troponin T are associated with total CVD and CVD death in women with diabetes mellitus. Among healthy nondiabetic women, detectable compared with undetectable troponin was not associated with CVD events.