Evolution of acute coronary syndrome with normal coronary arteries and normal cardiac magnetic resonance imaging

Background. - Acute coronary syndrome (ACS) with normal coronary angiography is a frequent clinical situation with an uncertain prognosis. Cardiac magnetic resonance imaging (CMRI) is a powerful tool for differential diagnosis between myocardial infarction (MI), acute myocarditis and Tako-tsubo cardiomyopathy (TTC). Data are sparse regarding the evolution of patients presenting an ACS with normal coronary arteries and normal CMRI. Aims. - To evaluate the evolution of patients presenting an ACS with normal coronary arteries and normal CMRI, with a 1-year follow-up. Methods. - Eighty-seven consecutive patients (mean age, 53 years; 40.2% men) presenting an ACS with troponin elevation and normal coronary arteries by angiography were prospectively included. All patients underwent CMRI at 3-Tesla. Adverse events were recorded with 1-year follow-up. Results. - A likely aetiology for the acute clinical presentation was established by CMRI in 63.2% of patients (22.7% MI, 26.4% acute myocarditis, 11.5% TTC). During follow-up, one patient in the MI group had a stroke (1.2%). In the myocarditis group, there was one initial cardiogenic shock, one episode of congestive heart failure (1.2%) and nine patients had recurrent chest pain without troponin elevation (10.3%). Two TTC group patients initially presented with cardiogenic shock (2.4%); there were no other adverse events in this group during follow-up. In the remaining 36.7% patients, no clear diagnosis could be identified by CMRI, and no adverse events occurred during follow-up. Conclusion. - CMRI is a useful tool for the management of ACS presenting with normal coronary angiography, as it helps to ascertain the diagnosis and adapt treatment in a large proportion of cases. Nonetheless, patients with no abnormalities identified by CMRI have an excellent evolution. (C) 2011 Published by Elsevier Masson SAS.