title: Detection of myocardial scar by contrast-enhanced cardiac magnetic resonance imaging in patients with troponin-positive chest pain and minimal angiographic coronary artery disease.
abstract: Patients who present with chest pain and elevated serum troponin levels may have minimal angiographic coronary artery disease, leading to diagnostic confusion. We investigated patients with troponin-positive acute coronary syndromes and minimal coronary artery disease (CAD) using contrast-enhanced cardiac magnetic resonance imaging to assess for myocardial scar. Twenty-three patients (54 +/- 8 years of age) who presented with chest pain, high troponin I level, and minimal angiographic CAD were included. Patients with a clinical pericarditis/myocarditis, tachyarrhythmia at presentation, previous myocardial infarction, or an alternative explanation for increased troponin I level were excluded. Myocardial scar was assessed with delayed-enhancement inversion-recovery imaging after administration of gadolinium. Hyperenhancement consistent with myocardial scar was seen in 7 of 23 patients (30%) and was located primarily in the right coronary artery distribution. Peak troponin level, clinical characteristics, and volumetric parameters were similar in patients with or without hyperenhancement. One patient had mid-myocardial enhancement that suggested undiagnosed myocarditis. There was a linear relation between the mass of myocardial scar and peak serum troponin level. In follow-up, subsequent cardiac events were more frequent in patients with hyperenhancement (43% vs 12.5%). In conclusion, patients with troponin-positive acute coronary syndromes may have significant myocardial scar even when minimal CAD is found on angiography.
authors.affiliation: Cardiovascular Division, North Shore Hospital, Waitemata Health, Auckland, New Zealand. jonathan.christiansen@waitematadhb.govt.nz
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Christiansen
authors.forename: Colin
authors.initials: C
authors.lastname: Edwards
authors.forename: Toni
authors.initials: T
authors.lastname: Sinclair
authors.forename: Guy
authors.initials: G
authors.lastname: Armstrong
authors.forename: Anthony
authors.initials: A
authors.lastname: Scott
authors.forename: Hitesh
authors.initials: H
authors.lastname: Patel
authors.forename: Hamish
authors.initials: H
authors.lastname: Hart
mesh_terms: D000328:Adult; D000368:Aged; D002637:Chest Pain / Q000097:blood*; D003287:Contrast Media; D017023:Coronary Angiography; D003327:Coronary Disease / Q000097:blood / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D014336:Troponin / Q000097:blood*
chemical_list: D003287:Contrast Media; D014336:Troponin