Fatal early acute thrombosis of mechanical mitral prosthesis

OBJECTIVE: To report a rare case of fatal early acute thrombosis of mechanical mitral prosthesis. METHODS: A 62-year-old lady, who underwent closed mitral valvotomy for rheumatic heart disease 19 years ago, presented with Canadian Cardiovascular Society Class II angina and New York Heart Association Class III dyspnoea. Investigations including echocardiogram and cardiac catheterisation revealed mixed mitral valve disease. She had severe pulmonary artery hypertension with pulmonary artery wedge pressure of 35 mm of mercury. Significant stenosis in the midportion of dominant right coronary artery was also demonstrated. She underwent mitral valve replacement using mechanical tilting disc prosthesis, DeVega tricuspid annuloplasty and saphenous vein bypass graft to the distal right coronary artery. After having made satisfactory early postoperative progress, she suffered an asystolic cardiac arrest about 26 h postoperatively. RESULTS: The patient succumbed despite all resuscitative measures. Autopsy revealed an adherent thrombus occluding the atrial surface of the minor orifice of mechanical prosthesis, which prevented the valve from functioning. CONCLUSION: To the best of our knowledge, this is the first case of prosthetic valve thrombosis (PVT) occurring on the first postoperative day in a patient with a mechanical valve prosthesis, without any circulatory assist device.