018 Acute coronary syndrome with normal coronary arteries. A prognostic study with cardiac magnetic resonance imaging at 3-Tesla

Abstract

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). However, CMRI can remain uninformative in many patients who have no detectable coronary lesion. Data are sparse regarding the prognosis of patients presenting an ACS with normal coronary arteries on CMRI. Seventy-nine consecutive patients (mean age 53 years, 39.2% male) presenting an ACS with tropinin elevation and normal coronary angiography were prospectively included. All patients underwent CMRI at 3-Tesla within 3 weeks of initial presentation. Adverse events were recorded with a follow-up of 6 months. An identifiable basis for ACS was established by CMRI in 69.6% of patients (27.8% MI, 29.1% acute myocarditis, 12.7% TTC). Only troponin level was significantly different between patients with normal vs abnormal CMRI (3.48 ± 4.3 vs 11.86 ± 11.99 mg/L, respectively, p = 0.0028). During the follow-up, 1 patient in the MI group suffered stroke (1.26%). In the myocarditis group, there was 1 episode of congestive heart failure (1.26%) and 7 patients had recurrent chest pain without troponin elevation (8.6%). Two patients in the TTC group initially presented with cardiogenic shock (2.53%), but there were no adverse events in this group during follow-up. In the remaining 30.2% patients, no clear diagnosis could be identified by CMRI, and no adverse events occurred during follow-up. CMRI is a useful tool for the management of ACS presenting with normal coronary angiography, as it helps to ascertain diagnosis and to adapt treatment in a large proportion of cases. Nonetheless, patients with no anomalies identified by CMRI have an excellent prognosis, without need for specific treatment.