Abstract
BACKGROUND: Coronary embolism is an uncommon cause of acute myocardial infarction, often related to atrial fibrillation or valvular heart disease. In such cases, concomitant valvular thrombosis requires additional diagnostic work-up and has major implications for subsequent management. Both conditions may represent significant diagnostic and therapeutic challenges. CASE SUMMARY: We report the case of a 71-year-old woman with double mechanical valve prostheses (aortic and mitral) under suboptimal anticoagulation therapy, who presented with chest pain and syncope. Initial workup revealed severe right ventricular dysfunction and dilation, with inconclusive electrocardiogram findings; pulmonary embolism was initially suspected. Emergent coronary angiography revealed a coronary embolism, successfully treated with thromboaspiration alone. The diagnosis of prosthetic valve thrombosis was delayed due to low cardiac output masking prosthetic dysfunction. Management of the valve thrombosis was unconventional, as therapeutic options were limited by a recent traumatic brain injury. DISCUSSION: This case illustrates the diagnostic and therapeutic challenges in patients with mechanical valve prostheses and high embolic risk. Atypical presentation and low-output conditions limited early identification of prosthetic valve thrombosis, highlighting the reduced sensitivity of transthoracic echocardiography in this context. Advanced imaging modalities, such as transoesophageal echocardiography or computed tomography, may improve diagnostic accuracy. Given absolute contraindications to both thrombolysis and surgery, the patient was managed with intensified anticoagulation, showing favourable clinical and echocardiographic evolution. This case emphasizes the need for individualized, context-driven decision-making in complex cardiovascular scenarios.