RESUMO
Background - Acute coronary syndrome with high level of troponin is a common pattern for emergency consultation. In 10% of cases, coronary angiography concluded that there were no significant coronary lesions. The contribution of cardiac magnetic resonance imaging (MRI) in the etiological investigation is increasing in these conditions. Aim - We analyzed the diagnostic value of cardiac MRI in case of acute coronary syndromes with elevated troponin and normal coronary angiography. Methods - It's a retrospective analytical study including 31 patients presenting with acute coronary syndrome with positive troponins and normal coronary angiography. All these patients underwent cardiac MRI. Results - The average age was 44.94 years. Cardiovascular risk factors were present in 38.70%. The average level of troponin was 4.85 ng/ml. Modification in the ST segment was noted in 87.1% of which 51.6% had ST elevated segment. Cardiac MRI was performed in the average of 8 days. MRI has contributed to the diagnosis in 77.4%: a myocardial infarction (MI) with no significant coronary lesions in 38.7% of cases, myocarditis in 29% of cases, Tako-Tsubo syndrome in 6.5% of cases and apical HCM in 3.2% of cases. MRI was normal in 22.6% of cases. Conclusions - The contribution of cardiac MRI is growing in the diagnostic management of patients with chest pain, elevated level of troponin and normal coronary angiography. The differential diagnoses have discriminating characteristics in MRI, allowing their identification with excellent diagnostic accuracy. The two main etiologies are myocardial necrosis and myocarditis.