Age and Gender Tailored Cutoff Value of hs-cTnT Contributes to Rapidly Diagnose Acute Myocardial Infarction in Chest Pain Patients.

BACKGROUND: Hs-cTnT concentrations are age and gender related, therefore establishment of age and gender optimized cutoff values for hs-cTnT might be essential. We aimed to define the age and gender specific hs-cTnT 99th percentile in reference population and assess its diagnostic and prognostic performance in patients with suspected AMI.

METHODS: In this prospective study, 1725 healthy individuals (18 - 97 years old) and 812 patients (15 - 98 years old) with chest pain with suspected AMI presenting to the emergency department were enrolled. The measurement of biomarkers was performed at presentation and at 3 - 4 hours according to clinical requirement. We stratified the reference population by age and gender through applying strict exclusion criteria. Clinical follow-up was obtained after 2 years.

RESULTS: The 99th percentile of hs-cTnT according to age and gender in adult Han population of Northern China is reported. The cutoff values of hs-cTnT in for subjects < 70 years, 70 - 79 years, and ≥ 80 years was 16 ng/L, 38 ng/L, and 57 ng/L, respectively. Among the 812 patients with chest pain, according to the age and gender tailored cutoff value, the specificity and positive predictive value of AMI diagnosis were increased from 53.9% to 72.2% and 48.6% to 60.8%, compared to 14 ng/L commonly recommended. Cumulative 2-year survival rate for patients with hs-cTnT levels above 14 ng/L was 93.3% compared to 99.5% in patients below that level (p < 0.001). The same was observed for the age and gender tailored cutoff value which was 92.5% compared to 98.5%, respectively (p < 0.001).

CONCLUSIONS: Age and gender tailored cutoff value for hs-cTnT provides better diagnostic information, but yields no additional prognostic performance for risk prediction of death or major adverse cardiovascular events.