Diagnostic value of contrast-enhanced cardiac magnetic resonance in patients with acute coronary syndrome with normal coronary arteries

Purpose: To evaluate retrospectively the diagnostic value of cardiac magnetic resonance (CMR) in patients with acute coronary syndromes (ACS) with normal coronary arteries, without pre-existing comorbidities. Materials and methods: We retrospectively reviewed the contrast-enhanced (CE) CMR images of 143 patients (70 males and 73 females, mean age 63 years, age range 37–87), within a server of 1590 patients, between January 2012 and January 2014. Only patients with ACS (anginal episode lasting at least 30 min) with normal coronary arteries were included, as well as patients with serologic assay of positive troponin I (TnI) and possible changes in ECG, particularly ST elevation. All patients with a history of ACS, or chronic troponin elevation, dyslipidemia, smoking, patients with cardiomyopathies or preexisting comorbidities such as diabetes, hereditary collagenopathies, amyloidosis, sarcoidosis, hemosiderosis or other infiltrative diseases were excluded to avoid possible bias. Results: The CMR LGE pattern attributable to AMI occurred in 40/143 cases (28 %) and in particular involved only a myocardial segment (60 %). The MR pattern of acute myocarditis occurred in 16/143 (11.2 %); in 6/143 cases, Tako-Tsubo cardiomyopathy was present. Eighty-one cases out of 143 presented a CMR with no LGE, parietal edema or morphological alterations (56.6 %). Conclusion: In patients with a first episode of ACS with normal coronary arteries, in the absence of pre-existing comorbidities, CMR has a high negative predictive value, often without significant alterations. In particular, the CMR LGE for AMI is infrequent and has predominantly focal distribution. However, further multidisciplinary studies are needed to define the prognostic value of CMR.