High-Sensitivity Cardiac Troponin T is Associated with Acute Kidney Injury in Emergency Department Patients

Structured Abstract:Introduction Chronic high-sensitivity cardiac troponin T (hs-cTnT) elevations are common in chronic kidney disease, but whether hs-cTnT predicts subsequent acute kidney injury (AKI) is unclear.Methods We examined the association between maximum hs-cTnT and subsequent AKI in 23,292 Emergency Department encounters. AKI was defined as serum creatinine (sCr) increase ≥0.3 mg/dL within 48 hours or ≥1.5x the presenting value; secondary endpoints were time to AKI and peak sCr.Results AKI occurred in 8.9% of encounters. Maximum hs-cTnT was independently associated with AKI (adjusted OR 1.58 [95% CI 1.53-1.63] per 1-unit increase in ln[hs-cTnT]), with similar associations among encounters with and without reduced kidney function at presentation. The median interval from maximum hs-cTnT to AKI was 43 hours (IQR, 21-97). A data-derived hs-cTnT cutoff of 148 ng/L yielded an AUC of 0.82, 80% sensitivity, 70% specificity, and 97% negative predictive value for AKI. Among encounters with AKI, maximum ln(hs-cTnT) was modestly associated with ln(sCr) at AKI in univariable analysis (R2=0.10) and with subsequent maximum ln(sCr) after multivariable adjustment (incremental R2=0.04; both P < 0.0001).Conclusion Maximum hs-cTnT identified patients at increased risk for subsequent AKI, including those with normal renal function at presentation, and may help identify patients warranting closer kidney-function monitoring.