A "PARADOXICAL" MINOCA

Abstract

Abstract Background The acronym MINOCA refers to myocardial infarction with normal or near–normal coronary arteries on invasive angiography. We report a case of MINOCA caused by paradoxical coronary embolism due to a right–to–left shunting through a patent fossa ovalis. Integrated multimodality imaging diagnostic work–up has been crucial for identifying the mechanism underlying MINOCA. Case Report A 48–year–old male was admitted to the Coronary Care Unit for sudden–onset oppressive chest pain lasting 1 hour, radiating to the left arm; no specific changes in ST–segment on a 12–lead ECG and elevated high–sensitive troponin I (peak value 1562 ng). Transthoracic echocardiography showed normal dimensions and function of the cardiac chambers and excluded valvular and pericardial diseases. Given the characteristics of the chest pain, we performed an urgent coronary angiography that showed normal epicardial coronary, including testing for epicardial coronary spasm and microvascular dysfunction. We also used Optical Coherence Tomography on LAD e RCA to rule out critical stenosis and sign of plaque instability. To investigate the etiology of myocardial damage the patient underwent a cardiac magnetic resonance (CMR) imaging that yielded the following findings: hypokinesis of the inferior–middle segment of the left ventricle associated myocardial edema and near transmural LGE. These features were consistent with a recent ischemic injury. Additionally, CMR showed an atrial septal aneurysm and a channel–like pattern of the interatrial septum, raising the suspicion of patent foramen ovale (PFO). The transesophageal echocardiography and transcranial Doppler with bubble test confirmed the presence of a PFO responsible for right–to–left shunting. Atrial fibrillation was excluded with ECG telemetry throughout the entire 7day hospitalization. Conclusions Based on the result of the overall clinical–instrumental evaluation, MINOCA caused by paradoxical coronary embolism due to a right–to–left shunting through a PFO was considered the most plausible diagnostic hypothesis. The patient underwent to interventional percutaneous closure of PFO and was discharged with no symptoms or complication at the follow–up.