Prognostic Implications of High-Sensitivity Cardiac Troponins in Patients With Acute Kidney Injury Without Myocardial Infarction

Elevated and dynamic high-sensitivity cardiac troponin T (hs-cTnT) concentrations are often observed in patients with acute kidney injury (AKI) without myocardial infarction (MI), yet their prognostic implications are unknown. This study investigated associations between hs-cTnT measurements and prognosis in patients with AKI in the emergency department (ED). All first visits to 7 EDs during 2010 to 2017 by patients without MI fulfilling AKI criteria and ≥1 hs-cTnT measured were included. Logistic and Cox regression analyses were applied to estimate short- and long-term risks of mortality and major adverse cardiovascular events (MACE) according to peak hs-cTnT and relative hs-cTnT change (Δhs-cTnT). A total of 12,136 patients were included. In-hospital- and long-term mortality was 15% and 49% (median follow-up: 3.8 years, IQR: 1.3 to 6.0). Adjusted in-hospital mortality risk increased with higher peak hs-cTnT, being >8-fold (aOR 8.68, 95% CI: 6.85 to 11.0) in the highest quintile of hs-cTnT, in whom long-term risk of cardiovascular mortality and MACE was 3-fold (HR: 3.01, 95% CI: 2.74 to 3.31) and 2-fold (HR: 2.12, 95% CI: 2.00 to 2.24). Associated risks were elevated already at intermediately elevated hs-cTnT and evident in patients with transient AKI and with normalized eGFR at discharge. Patients with the highest Δhs-cTnT experienced an increased short-term mortality risk, but Δhs-cTnT was not associated with long-term mortality and only weakly associated with the risk of MACE. In conclusion, in patients with AKI but without acute MI, peak hs-cTnT are associated with a worse prognosis in both the short and long term, whereas dynamic hs-cTnT changes may have less prognostic significance.