P612Multimodal cardiac imaging in patients with suspected ST-elevation myocardial infarction and no obstructive coronary arteries

Abstract Background Patients with suspected ST-elevation myocardial infarction (STEMI) and normal coronary arteries comprise a heterogeneous group with various underlying causes of disease. Purpose To study pathophysiology and underlying diagnoses in patients with suspected STEMI and normal coronary arteries using multimodal cardiac imaging. Methods We consecutively included patients with suspected STEMI, normal coronary arteries on acute coronary angiography, and elevated troponin T levels at a tertiary heart center (2012–14). Patients were examined with echocardiography, cardiac magnetic resonance imaging, and 13NH3/82Rb and 18F-FDG positron emission tomography within one week from symptom onset. Results We included 42 patients (60% male, median age 58 (IQR 50–65) years. Median troponin T levels were 783 (IQR 566–1208) ng/l. Multimodal cardiac imaging findings are presented in Table 1. Multimodal cardiac imaging showed signs of cardiac involvement in all but one patient (98%). Underlying diagnoses were acute myocardial infarction (36%), Takotsubo cardiomyopathy (29%), perimyocarditis (10%), and cardiomyopathy (7%). The diagnosis was unclear in 19% of patients. Echocardiography Left ventricular ejection fraction <40%, n (%) 12 (29) Moderate to severe left ventricular hypertrophy, n (%) 3 (7) Moderate to severe valvular disease, n (%) 3 (7) Pericardial effusion, n (%) 5 (12) Apical thrombus, n (%) 1 (2) Magnetic resonance imaging Left ventricular end diastolic volume, ml (IQR) 157 (125–185) Left ventricular end systolic volume, ml (IQR) 75 (63–88) Left ventricular stroke volume, ml (IQR) 73 (57–93) Edema, n (%) 38 (91) Late gadolinium enhancement, n (%) 22 (52) 13NH3/82Rb and 18F-FDG positron emission computer tomography Myocardial perfusion defect, n (%) 29 (69) Myocardial perfusion-metabolism mismatch, n (%) 12/30 (40) Reduced myocardial viability, n (%) 6/30 (20) Conclusion The majority of patients with suspected STEMI and normal coronary arteries had signs of cardiac involvement by multimodal cardiac imaging and were diagnosed with cardiac disease. Acknowledgement/Funding The Danish Heart Foundation, the A.P. Møller Foundation, the Foundation of Reinholdt W. Jorck and Wife, Rigshospitalet's Research Foundation