Cryptogenic myocardial infarction in young patients: which is the optimal diagnostic and therapeutic management?

A 31-year-old athlete was admitted to our hospital for previous inferior myocardial infarction (MI), diagnosed by transthoracic echocardiography, myocardial scintigraphy, and cardiac magnetic resonance, while coronary angiography revealed normal coronary arteries. Laboratory investigations excluded acquired or inherited thrombophilia, immunologic disorders, cardiotropic agents infection, and drug abuse. Antiplatelet therapy was started but, after 15 days, he was rehospitalized with diagnosis of multiple left renal infarctions. A transesophageal echocardiography (TEE) was so performed which excluded a right-to-left shunt, suggestive of patent foramen ovale, or other cardioembolic sources in heart chambers and valve apparatus. Antiplatelet therapy was replaced with oral anticoagulants without any further embolic event at one-year follow-up. This case raises two important questions regarding young patients with cryptogenic MI. First, if TEE should be part of a complete diagnostic pathway; second, if oral anticoagulants should be preferred over antiplatelets for secondary prevention particularly when the cause of MI remains unknown.