Temporal Changes of Stable High‐Sensitivity Cardiac Troponin T Levels and Prognosis

Background The prognostic implications of temporal change of previously stable high‐sensitivity cardiac troponin concentrations are unknown. We investigated the prognosis associated with temporal changes of stable high‐sensitivity cardiac troponin T (hs‐cTnT) concentrations. Methods and Results All patients presenting with cardiac symptoms and ≥2 hs‐cTnT measurements at the time of their first visit to 7 different emergency departments in Sweden between December 9, 2009, and December 31, 2016, were identified (n=66 159). We included all patients with stable hs‐cTnT but no acute coronary syndrome diagnosis who had ≥1 hs‐cTnT measured also at a second visit >30 days from the first visit. Hazard ratios (HRs) with 95% CIs were calculated for all‐cause mortality and cardiovascular events according to temporal change of hs‐cTnT between the visits, using patients without myocardial injury (<15 ng/L) at the first visit and persistently stable hs‐cTnT at the second visit as the reference. Altogether, 12 869 patients were included, of whom 5191 (40%) had myocardial injury (hs‐cTnT ≥15 ng/L). During a median follow‐up of 2.3 (interquartile range, 1.4–3.7) years, 3271 (25%) patients died. In patients with myocardial injury and a temporal increase in hs‐cTnT, the adjusted all‐cause and cardiovascular mortality was 4‐ and 5‐fold elevated (HR, 4.21; 95% CI, 3.55–5.00; and HR, 5.08; 95% CI, 3.73–6.92), and the adjusted risk of heart failure hospitalization almost 3‐fold (HR, 2.77; 95% CI, 2.26–3.39). Conclusions Temporal change of previously stable hs‐cTnT is associated with the risk of death and cardiovascular outcomes, with highest risks observed in patients with myocardial injury and increasing hs‐cTnT.