Head-to-head comparison of cardiac troponin T and troponin I in patients without acute coronary syndrome: a systematic review.

BACKGROUND: Cardiac-specific troponin T (cTnT) and troponin I (cTnI) are considered diagnostically equal in patients with acute coronary syndrome (ACS). The aim of this systematic review was to compare the prevalence and prognostic strength of elevations of cTnT and cTnI in patients with other conditions than ACS.

METHODS: A systemic review was conducted in concordance with the PRISMA guidelines. The studies were identified by searching PubMed, EMBASE and Cochrane Central Register, from May to August 2016. Studies measuring both cTnT and cTnI in populations without ACS were eligible.

RESULTS: Twenty-nine studies were included (n = 25,859). Seventeen studies reported on prognostic information with follow-up time ranging for 30 d-5 years. Elevation above the 99th percentile (reference value for a healthy population) in non-ACS population was reported to be 0-39% for cTnI and 40-100% for cTnT. Elevation of cTnT tends to be a superior predictor for all-cause mortality and elevation of cTnI tends to be a superior predictor for cardiovascular related mortality.

DISCUSSION: In the absence of ACS, elevation of cTnT is more frequent than elevation of cTnI.

CONCLUSION: Both cTnT and cTnI elevations have important prognostic information regarding morbidity, cardiac mortality and all-cause mortality.