5(th) generation vs 4(th) generation troponin T in predicting major adverse cardiovascular events and all-cause mortality in patients hospitalized for non-cardiac indications: A cohort study

OBJECTIVE: The frequency and implications of an elevated cardiac troponin (4(th) or 5(th) generation TnT) in patients outside of the emergency department or presenting with non-cardiac conditions is unclear. METHODS: Consecutive patients aged 18 years or older admitted for a primary non-cardiac condition who had the 4(th) generation TnT drawn had the 5(th) generation TnT run on the residual blood sample. Primary and secondary outcomes were all-cause mortality (ACM) and major adverse cardiovascular events (MACE) respectively at 1 year. RESULTS: 918 patients were included (mean age 59.8 years, 55% male) in the cohort. 69% had elevated 5(th) generation TnT while 46% had elevated 4(th) generation TnT. 5(th) generation TnT was more sensitive and less specific than 4(th) generation TnT in predicting both ACM and MACE. The sensitivities for the 5(th) generation TnT assay were 85% for ACM and 90% for MACE rates, compared to 65% and 70% respectively for the 4(th) generation assay. 5(th) generation TnT positive patients that were missed by 4(th) generation TnT had a higher risk of ACM (27.5%) than patients with both assays negative (27.5% vs 11.1%, p<0.001), but lower than patients who had both assay positive (42.1%). MACE rates were not better stratified using the 5(th) generation TnT assay. CONCLUSIONS: In patients admitted for a non-cardiac condition, 5(th) generation TnT is more sensitive although less specific in predicting MACE and ACM. 5(th) generation TnT identifies an intermediate risk group for ACM previously missed with the 4(th) generation assay.