Stable High-Sensitivity Cardiac Troponin T Levels and Outcomes in Patients With Chest Pain.

BACKGROUND: There is a paucity of data on the association between high-sensitivity cardiac troponin (hs-cTn) levels and outcomes in patients with chest pain but no myocardial infarction (MI), or any other condition that may lead to acutely elevated troponin levels.

OBJECTIVES: The authors hypothesized that any detectable high-sensitivity cardiac troponin T (hs-cTnT) level is associated with adverse outcomes.

METHODS: All patients (N = 22,589) >25 years of age with chest pain and hs-cTnT analyzed concurrently in the emergency department of Karolinska University Hospital, Stockholm, Sweden from 2011 to 2014 were eligible for inclusion. After excluding all patients with acute conditions that may have affected hs-cTnT, or MI associated with the visit, or insufficient information to determine whether troponin levels were stable, Cox regression was used to estimate risks for all-cause, cardiovascular, and noncardiovascular mortality, MI, and heart failure at different levels of troponins.

RESULTS: A total of 19,460 patients with a mean age of 54 ± 17 years were included. During a mean follow-up of 3.3 ± 1.2 years, 1,349 (6.9%) patients died. Adjusted hazard ratios (with 95% confidence intervals) for all-cause mortality were 2.00 (1.66 to 2.42), 2.92 (2.38 to 3.59), 4.07 (3.28 to 5.05), 6.77 (5.22 to 8.78), and 9.68 (7.18 to 13.00) in patients with hs-cTnT levels of 5 to 9, 10 to 14, 15 to 29, 30 to 49, and ≥50 ng/l, respectively, compared with patients with hs-cTnT levels <5 ng/l. There was a strong and graded association between all detectable levels of hs-cTnT and risk for MI, heart failure, and cardiovascular and noncardiovascular mortality.

CONCLUSIONS: Among patients with chest pain and stable troponin levels, any detectable level of hs-cTnT is associated with an increased risk of death and cardiovascular outcomes and should merit further attention.