The role of peak troponin in patients with a working diagnosis of myocardial infarction with non-obstructive coronary arteries (MINOCA)

Abstract

Abstract Funding Acknowledgements Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Rosetrees Trust James Tudor Foundation Background 6-10% of patients who present with an acute coronary syndrome have a myocardial infarction with non-obstructive coronary arteries (MINOCA). Troponin T predicts infarct size and outcomes in patients with ST-elevation myocardial infarction. The value of peak troponin T in patients with a working diagnosis of MINOCA is not well understood. Purpose The aim of this study is to investigate the diagnostic and prognostic role of troponin in patients with MINOCA. Methods Consecutive patients with a working diagnosis of MINOCA (n = 719) from a single tertiary centre who underwent comprehensive cardiovascular magnetic resonance (CMR) imaging with late gadolinium enhancement (LGE) were followed prospectively. The primary endpoint was all-cause mortality. Results Peak troponin T ≥211 ng/L and time to CMR of ≤17 days have a positive predictive value of 94% for being able to make a diagnosis on CMR. If the scan was performed in ≤17 days the diagnostic yield was still 75% even in the lowest troponin decile, but this was 59% if performed after 17 days. Each increase in troponin decile increases the mean diagnostic yield of the CMR by 3.7% (p < 0.001, 95% CI 3.4 – 3.9; R2 0.84; Figure 1). There is no overall difference in median troponin in patients who died and those who survived (229 ng/l v. 424 ng/l; p = 0.157), however mortality is significantly lower in the highest two troponin quartiles (11.9% versus 6.9%; p = 0.009, figure 2). Conclusions Peak troponin T and time to CMR can be used by cardiologists to determine the likelihood of making a diagnosis using CMR. A higher troponin quartile is associated with lower mortality.