title: Evidence of myocardial scarring and microvascular obstruction on cardiac magnetic resonance imaging in a series of patients presenting with myocardial infarction without obstructed coronary arteries.
abstract: Patients with acute chest pain, electrocardiographic ST-elevation and significant elevation of cardiac troponin but without obstructive coronary artery disease represent a diagnostic and therapeutic dilemma. Cardiac magnetic resonance imaging (CMR) can elucidate underlying alternative causes of troponin elevation including detection of (minor) myocardial infarction (MI) by identifying myocardial scarring as delayed enhancement. Of 77 patients, who were admitted between March 2009 and December 2012 with electrocardiographic (ECG) and biochemical evidence of acute MI without obstructive coronary artery disease, 45 patients underwent CMR that showed in 11/77 (14%) late gadolinium enhancement (LGE), compatible with myocardial scarring. We analyzed clinical, echocardiographic, and CMR data of these patients. Elevated troponin I levels were observed in all patients (median 1.3 ng/l, IQR 0.44-187) with median peak creatinine phosphokinase of 485 U/l (IQR 234-618). Echocardiographic wall motion abnormalities were detected in 8/11 (73%) patients; in 75% of these segments, ECG abnormalities were observed in corresponding leads. CMR detected LGE in the inferior (4/11), the inferolateral (5/11), the inferoseptal (2/11), the anterior (3/11), apical (3/11) and in the lateral segments (2/11). In addition, in all but two patients, these segments matched ECG abnormalities in corresponding leads. CMR identified microvascular obstruction in 4/11 (36%) patients. Patients with clinical, ECG, and biochemical signs of acute MI but unobstructed coronary arteries may have CMR-detectable myocardial scars. Information on myocardial scarring may help to make the diagnosis and draw therapeutic consequences. This case series underlines the value of contrast-enhanced CMR for myocardial tissue characterization.
authors.affiliation: Department of Cardiology, Thoraxcentrum Twente, Medisch Spectrum Twente, Haaksbergerstraat 55, 7513 ER, Enschede, The Netherlands, J.Hermens@mst.nl.
authors.forename: Jeannine A J M
authors.initials: JA
authors.lastname: Hermens
authors.forename: Jan
authors.initials: J
authors.lastname: van Es
authors.forename: Clemens
authors.initials: C
authors.lastname: von Birgelen
authors.forename: Jeroen W
authors.initials: JW
authors.lastname: Op den Akker
authors.forename: Lodewijk J
authors.initials: LJ
authors.lastname: Wagenaar
mesh_terms: D000328:Adult; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002921:Cicatrix / Q000097:blood / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D003287:Contrast Media; D003324:Coronary Artery Disease / Q000097:blood / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D003326:Coronary Circulation; D003402:Creatine Kinase / Q000097:blood; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008536:Meglumine; D008833:Microcirculation; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D009206:Myocardium / Q000378:metabolism / Q000473:pathology*; D009942:Organometallic Compounds; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D019210:Troponin I / Q000097:blood; D015854:Up-Regulation
chemical_list: D015415:Biomarkers; D003287:Contrast Media; D009942:Organometallic Compounds; D019210:Troponin I; D008536:Meglumine; D003402:Creatine Kinase; C072417:gadoterate meglumine