Embolic MINOCA From Mechanical Aortic Valve Thrombosis: A Potential Role of Prosthesis-Patient Mismatch

Coronary embolism is a rare cause of MINOCA (myocardial infarction with nonobstructive coronary arteries), particularly in patients with mechanical aortic prosthesis.

A 64-year-old woman who underwent prior double mechanical valve replacement and had chronic aortic prosthesis-patient mismatch presented with myocardial infarction. Coronarography showed nonobstructive arteries. Multimodality imaging demonstrated a small transmural apical infarction and restricted leaflet motion along with a thrombus in the aortic prothesis. Despite therapeutic anticoagulation, a transient coronary embolic event from prosthetic thrombosis was considered the likely mechanism. The patient underwent redo aortic valve replacement with a larger prosthesis, resulting in favorable clinical and hemodynamic recovery.

Few studies suggest the role of prosthesis-related factors, including prosthesis-patient mismatch, in mechanical valve thrombosis and embolic MINOCA.

In MINOCA with mechanical valves, coronary embolism should be suspected. Prosthesis-patient mismatch may contribute to thrombotic risk beyond anticoagulation status.