A Stepwise Diagnostic Approach to Transmural Myocardial Infarction With Non-obstructive Coronary Arteries With Microvascular Obstruction Highlighting the Role of Cardiac MRI in Suspected Thrombolysis

Myocardial infarction with non-obstructive coronary arteries (MINOCA) presents a diagnostic challenge due to its heterogeneous etiologies and the absence of obstructive coronary lesions. We report the case of a 74-year-old male with hypertension, prior deep vein thrombosis, and a history suggestive of thrombophilia under evaluation, on chronic warfarin therapy, who presented with chest pain, ST elevation, and elevated troponins. Coronary angiography revealed no obstructive coronary artery disease. Cardiac magnetic resonance imaging (MRI) demonstrated an acute transmural myocardial infarction with microvascular obstruction in the left anterior descending artery region. Alternative cardiac and extracardiac causes were excluded, and the diagnosis was revised to MINOCA. This case underscores the diagnostic power of cardiac MRI and suggests spontaneous thrombolysis as a plausible mechanism, based on the transmural infarction pattern, presence of microvascular obstruction, and absence of angiographic obstruction.