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.
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