Prognostic implications of high sensitivity Troponin T levels among patients attending emergency departments and evaluated for an acute coronary syndrome.

BACKGROUND With increasing age, patients with suspected acute coronary syndromes (ACS) and elevated high sensitivity Troponin T (HsTnT) levels, type-1 myocardial infarction (MI) is diagnosed less often, though associations between these factors and gender, and prognosis is unclear. METHODS Patients presenting to the emergency department (ED) with potentially an ACS who underwent HsTnT testing were prospectively identified and followed. Diagnoses were adjudicated according to the 4th Universal Definition of MI as follows: type-1 MI, type-2 MI, acute myocardial injury, chronic myocardial injury and other diagnoses. Age in years was categorised: younger (<65); elderly (65-79) and very elderly (≥80). RESULTS Among 2738 patients with HsTnT measurements, 1611 were suitable for adjudication (42% aged <65 years). Type-2 MI and chronic myocardial injury diagnoses were more common in those aged ≥65 years whereas younger patients had more type-1 MI diagnoses. Late mortality rates at median 41 months [IQR 10-57] were 44% (223/506) in those aged ≥80 years, 22 % (92/423) in patients 65-79 years, and 7% (46/682) in those <65 years, irrespective of adjudicated diagnoses, log rank P ≤0.001. On multi-variable analyses the adjusted mortality hazard ratios for increasing HsTnT levels irrespective of diagnoses were attenuated in those aged ≥80 years, compared to younger patients. CONCLUSIONS Patients aged ≥65 years constituted ∼60% of ED attendances of patients with suspected ACS, and more had type 2 MI and chronic myocardial injury diagnoses compared to younger patients. The relative mortality impact of HsTnT levels was lower among elderly patients irrespective of adjudicated diagnoses.