Peak Troponin Level and Revascularisation Rate in Type 2 MI

Background: Peak troponin level has been shown to predict benefit from early invasive management in type 1 MI (T1MI), but this relationship has not been established for type 2 MI (T2MI). The aim of this study was to investigate whether peak cardiac troponin T (cTnT) level in the first 24 hours of presentation is associated with rate of revascularisation in patients with T2MI. Methods: A statewide, multicentre, prospective cohort study with enrolment between 1 February 2020 and February 2021 was performed, with follow-up extending for 12 months. Those presenting to emergency departments with any form of myocardial injury (defined as troponin T above the upper limit of normal, >14 ng/l) in the first 24 hours of presentation were considered. Those under 18 years of age, those who had a previous emergency department assessment with troponin T and/or who had undergone coronary angiography in the 6 months prior to identification, were excluded. Results: T2MI or acute myocardial injury was associated with higher 12-month mortality (HR 1.87; 95% CI [1.43–2.43]; p<0.001) but a lower rate of subsequent T1MI (HR 0.46; 95% CI [0.31–0.68]; p<0.001) compared with patients presenting with T1MI. Peak cTnT was significantly associated with higher overall mortality on multivariable analysis (HR 1.01 per 100 ng/l cTnT; 95% CI [1.01–1.02]; p<0.001). Troponin level was not associated with a higher rate of revascularisation in patients with T2MI/acute myocardial injury who underwent a coronary angiogram. Conclusion: Patients with T2MI or acute myocardial injury have increased cardiovascular risk. Peak cTnT level appears to be a poor predictor for revascularisation requirement in patients with T2MI/acute myocardial injury who undergo coronary angiography.