Kidney function-specific cut-off values of high-sensitivity cardiac troponin T for the diagnosis of acute myocardial infarction.

Abstract

The diagnosis of acute myocardial infarction (AMI) using high-sensitivity cardiac troponin T (hs-cTnT) remains challenging in patients with kidney dysfunction. In this large, multicenter cohort study, a total of 20912 adults who underwent coronary angiography were included. Kidney function-specific cut-off values of hs-cTnT were determined to improve the specificity without sacrificing sensitivity, as compared with that using traditional cut-off value (14ng/L) in the normal kidney function group. The diagnostic accuracy of the novel cut-off values was validated in an independent validation cohort. In the derivation cohort (n=12900), 3247 patients had an estimated glomerular filtration rate (eGFR) <60mL/min/1.73 m2. Even in the absence of AMI, 50.2% of participants with eGFR <60mL/min/1.73 m2 had a hs-cTnT concentration ≥14ng/L. Using 14ng/L as the threshold of hs-cTnT for diagnosing AMI led to a significantly reduced specificity and positive predictive value in patients with kidney dysfunction, as compared with that in patients with normal kidney function. The kidney function-specific cut-off values were determined as 14, 18 and 48ng/L for patients with eGFR >60, 60-30 and <30mL/min/1.73 m2, respectively. Using the novel cut-off values, the specificities for diagnosing AMI in participants with different levels of kidney dysfunction were remarkably improved (from 9.1%-52.7% to 52.8-63.0%), without compromising sensitivity (96.6%-97.9%). Similar improvement of diagnostic accuracy was observed in the validation cohort (n=8012). The kidney function-specific cut-off values of hs-cTnT may help clinicians to accurately diagnose AMI in patients with kidney dysfunction and avoid the potential overtreatment in practice.