Abstract 2617: Comprehensive Cardiac Magnetic Resonance Imaging Protocol in the Emergency Department: T2W Imaging Improves Diagnostic Accuracy for Detection of Patients with Acute Coronary Syndrome
Background: Cardiac magnetic resonance imaging (MRI) permits evaluation and early tr iage of patients presenting to the Emergency Department (ED) with acute chest pain. The performance of MRI has been limited by the inability to differentiate a prior myocardial infarction (MI) from new acute coronary syndrome (ACS).
Objective: To evaluate the diagnostic performance of comprehensive cardiac MRI protocol that includes T2-weighted images in detecting patients with ACS.
Methods: In this cohort study we prospectively enrolled patients presenting to the ED with acute chest pain (within 12 hours of onset), negative cardiac biomarkers and no ECG changes indicative for acute myocardial ischemia. All patients were admitted to the hospital for a rule-out MI protocol. The cardiac MRI protocol consisted of T2W images, first-pass perfusion, cine left ventricular function and delayed-enhancement (De-MRI). The clinical outcome (ACS) was defined by review of clinical charts using AHA/ACC guidelines. Previous MI was defined if there was negative T2W images or LV wall thinning.
Results: Among 61 patients (43 men, mean age 58±14years), 13 (21%) developed ACS during index hospitalization. The mean MRI scan time was 32±8 minutes. Adding T2W imaging increased the specificity and positive predictive value from 81% to 96% and 55% to 85%; respectively as compared to the conventional MRI protocol (cine, perfusion and De-MRI) (Table 1⇓). The diagnostic accuracy of the new approach was significantly higher than the conventional approach (93% vs 82%, p<0.01). This improvement was achieved by the correct detection of patients with previous MI (7/9) who had no ACS at index hospitalization in the T2W group.
Conclusion: Our study indicates that addition of T2W imaging to the conventional imaging protocol improves the diagnostic performance of cardiac MRI for the detection of patients with ACS in the ED.