Background: Prosthetic valve thrombosis (PVT) is a potentially life-threatening complication of mechanical heart valves, particularly when affecting left-sided valves. Management requires rapid and precise assessment, balancing the risks and benefits of thrombolysis versus surgical intervention, especially in high-risk patients.

Case Summary: We report the case of a 64-year-old Iranian female with a history of mechanical aortic and mitral valve replacement (2019), chronic atrial fibrillation, and a recent cerebrovascular accident (October 2024), who presented with rapidly worsening dyspnea and pulmonary edema. Initial workup revealed atrial fibrillation with rapid ventricular response and signs of cardiogenic shock. Imaging confirmed mechanical aortic valve thrombosis with subtherapeutic INR levels. Echocardiography demonstrated a severely reduced ejection fraction (20–25%), left ventricular enlargement, and hemodynamic evidence of prosthetic valve obstruction. Given her New York Heart Association (NYHA) Class IV status and significant surgical risk due to low EF and recent stroke, a slow-infusion fibrinolytic therapy with alteplase was initiated as an alternative to surgery. The patient showed remarkable clinical and echocardiographic improvement, with resolution of pulmonary edema and restoration of normal valve leaflet motion. She was stabilized on anticoagulation therapy and discharged in good condition.

Conclusion: This case highlights the challenges in managing obstructive mechanical valve thrombosis in patients with high surgical risk and recent cerebrovascular events. Slow-infusion thrombolytic therapy may be a viable and effective alternative in carefully selected patients.