Influence of age and renal function on high-sensitivity cardiac troponin T diagnostic accuracy for the diagnosis of acute myocardial infarction.

Concerns have been raised about the performance of highly sensitive cardiac troponin assays to accurately detect acute myocardial infarction (AMI), particularly in non-ST segment elevation (NSTEMI), in elderly patients, and in patients with renal failure. We evaluated whether increased age and low estimated glomerular filtration rate (eGFR) alter diagnostic performance of high-sensitivity cardiac troponin T (HScTnT). In a prospective multicentric study, HScTnT levels were measured blindly at presentation in patients with acute chest pain. Three hundred and sixty-seven patients were enrolled, including 84 patients ≥70 years. Final diagnosis was AMI for 57 patients (16%) and NSTEMI for 43 patients (12%). NSTEMI was more frequent in elderly patients (p = 0.008). Sensitivity and specificity of HScTnT >14 ng/L at admission for AMI were 96% and 51% in patients ≥70 years versus 91% (NS) and 88% (p <0.0001) in younger patients; the same observations were done for the diagnosis of NSTEMI. Given an HScTnT >53.5 ng/L for the diagnosis of AMI and NSTEMI, respective sensitivities were 87% and 84% and respective specificities were 87% and 87% in elderly patients. Using a cutoff at 35.8 ng/L (for AMI) or 43.2 ng/L (for NSTEMI), sensitivities were 94% and 92%, and specificities were 86% and 88% in patients with low eGFR. Older age, but not low eGFR, was an independent predictive factor of an elevated HScTnT at admission (odds ratio 2.2 [1.2-3.9], p = 0.007). In conclusion, adapted thresholds of HScTnT are required for an accurate diagnosis of AMI/NSTEMI in patients aged ≥70 and in those with low eGFR.