Mechanical Mitral Valve Thrombosis: Management Complicated by Concomitant Large Left Atrial Appendage Thrombus and Systemic Thromboembolism

Abstract

Background: Mitral prosthetic valve thrombosis is a severe complication with high morbidity and thromboembolic risk. We present a rare case of a stuck mitral prosthetic valve with left atrial appendage (LAA) clot, leading to bilateral lower limb thromboembolism and ischemic stroke. Case: A 50-year-old female with a mechanical mitral valve replacement (MVR) presented with worsening dyspnea for 2–3 months. Transthoracic echocardiography (TTE) showed an elevated gradient (14 mmHg), suggesting mitral prosthetic valve thrombosis. Due to high surgical risk, systemic thrombolysis with carotid protection using filter wires was planned. However, she developed sudden bilateral lower extremity pain, and an aortogram revealed distal abdominal aorta occlusion. AngioJet thrombectomy restored bilateral limb perfusion. Transesophageal echocardiography (TEE) indicated LAA clot migration. The patient then developed stroke symptoms, and carotid angiography revealed thrombus in the distal left internal carotid artery. Carotid filter wires were placed, and thrombolysis was performed with tPA. The next day, CT revealed a left hemispheric infarction, and repeat carotid angiography showed middle cerebral artery occlusion. However, fluoroscopy demonstrated improved mitral leaflet mobility, and TTE showed a reduced mitral inflow gradient. Conclusion: This case highlights a complex scenario of severe mitral valve thrombosis and LAA clot with high surgical risk, requiring systemic thrombolysis. Carotid protection with filter wires is a novel technique that may help reduce stroke risk during thrombolysis.