Diagnosis of acute myocardial infarction in patients with renal insufficiency using high-sensitivity troponin T

Background: The objective of this study was to examine the diagnostic accuracy of high-sensitivity cardiac troponin T (hs-cTnT) for acute myocardial infarction (AMI) in patients with renal insufficiency, since this population has a high incidence of non-AMI elevations of hs-cTnT. Methods: In this prospective study, we enrolled 2249 consecutive patients presenting with chest pain in the emergency department (ED), of whom 19.5% had an estimated glomerular filtration rate (eGFR)(cys) of < 60 mL.min(-1) (1.73 m(2))(-1). Hs-cTnT levels were measured blindly at presentation. Results: Of the patients, 1108 (49.3%) were diagnosed as having AMI [321 with non-ST segment elevation myocardial infarction (NSTEMI)]. In patients whose final diagnosis was not AMI, there was a low but significant correlation between hs-cTnT and renal function [eGFR(cys), r = -0.43 (-0.48, -0.38), p < 0.001; eGFR(creat), r = -0.33 (-0.38, -0.27), p < 0.001]. The area under the curve of the receiver operating characteristic (AUC) for hs-cTnT to diagnose AMI was 0.93 in patients with eGFR(cys) levels of < 30 mL.min(-1) (1.73 m(2))(-1), and AUCs did not vary significantly according to eGFR categories. On the basis of the ROC curve, the optimal threshold value for hs-cTnT was 143.6 ng.L-1 to diagnose AMI in patients with eGFR cys of < 30 mL.min(-1) (1.73 m(2))(-1), with a sensitivity of 83% and a specificity of 91%; 54.1 ng.L-1 in patients with eGFR(cys) between 30 and 59 mL.min(-1), with a sensitivity of 90% and a specificity of 87%; 30.0 ng.L-1 in patients with eGFR(cys) between 60 and 89 mL.min(-1), with a sensitivity of 89% and a specificity of 85%; and 20.3 ng.L-1 in patients with eGFR(cys) = 90 mL.min(-1) (1.73 m(2))(-1), with a sensitivity of 92% and a specificity of 88%. The same observations were done for the diagnosis of NSTEMI. Conclusions: Using a higher hs-cTnT cut-off value based on eGFR level is necessary for accurate diagnosis of AMI or NSTEMI in patients with renal insufficiency.