Cardiac Myosin-Binding Protein C for Diagnosis of Myocardial Infarction in Patients With Prior Coronary Artery Bypass Grafting

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• Picked for Cardiology and Cardiovascular Medicine (paper of the day, 14 October 2026): cMyC vs hs‑cTn for MI diagnosis in CABG patients

Abstract

BACKGROUND: Diagnosing myocardial infarction in patients with prior coronary artery bypass grafting (CABG) remains challenging, primarily because of lower diagnostic accuracy of high-sensitivity cardiac troponin (hs-cTn). cMyC (cardiac myosin-binding protein C), because of its faster release kinetics and greater abundance, may offer improved diagnostic performance in this population. METHODS: The diagnostic accuracy of cMyC was directly compared with that of hs-cTnT and hs-cTnI in a prospective, international, multicenter, diagnostic study enrolling adult patients presenting to the emergency department with acute chest discomfort. Final diagnoses were centrally adjudicated by 2 independent cardiologists using all available clinical and study-specific data, including imaging and serial hs-cTnT measurements. Patients were stratified according to the presence or absence of prior CABG. RESULTS: Among 4752 patients, 387 (8%) had prior CABG (median age, 75 years; 86% men). The incidence of myocardial infarction was significantly higher in patients with prior CABG (38% versus 16%; P<0.001). In the CABG group, the diagnostic accuracy of cMyC as quantified by the area under the curve was 0.88 (95% CI, 0.85-0.92), which was comparable but not superior to that of hs-cTnT (0.89 [95% CI, 0.86-0.92]) and hs-cTnI (0.88 [95% CI, 0.84-0.91]). These findings were consistent across alternative high-sensitivity cMyC assays. CONCLUSIONS: In patients with prior CABG, cMyC demonstrated high diagnostic accuracy for myocardial infarction, but not superior to established hs-cTnT and hs-cTnI assays. REGISTRATION: URL: clinicaltrials.gov; Unique Identifier: NCT00470587.

Abstract as published, via PubMed.