Myocardial Infarction Revealing Thrombosis of Mechanical Prosthesis in Mitral Position

Aims: This case demonstrates that coronary embolism secondary to prosthetic valve thrombosis, although rare, can occur in patients years after mitro-aortic valve replacement despite adequate anticoagulation.

Presentation of Case: We report the case of a 52-year-old man with a mechanical prosthesis in mitral and aortic position who presented to the emergency department with a recent anterior post-myocardial infarction complicated by reccurent angina. Coronary angiography revealed a complete occlusion of the middle segment of the anterior interventricular artery by a fresh thrombus, despite an INR within the recommended target for mechanical prostheses in the mitral position. The etiological workup was in favor of a thrombosis of the mitral prosthesis. He was successfully treated with antiglycoprotein IIb-IIIa in combination with unfractionated heparin.

Discussion: Myocardial infarction by coronary embolism secondary to prosthetic valve thrombosis is a rare event. A few authors have reported patients with mechanical valve prostheses whose thrombosis caused myocardial infarction in the contexte of inadequate anticoagulation. Case reports in the setting of optimal anticoagulation are even more rare. To date, there is no consensus on the treatment of coronary embolism, although there are many therapeutic options. In this case, 72 hours of intravenous anticoagulation with glycoprotein IIb-III a inhibitors and unfractionated heparin were sufficient to recanalize the anterior interventricular artery with a satisfactory control coronary angiography.

Conclusion: Coronary embolism in mechanical prosthesis wearers in the context of adequate anticoagulation is possible and need to be rapported and explored.