Symptomatic mechanical heart valve thrombosis: high morbidity and mortality despite successful treatment options.

BACKGROUND Recommendations for treatment of mechanical prosthetic heart valve thrombosis (PVT) include systemic thrombolysis and/or reoperation. Data on complications and outcome are limited. METHODS Clinical and echocardiographic findings of 17 patients with mechanical PVT were reviewed. Complications and outcome of surgery and/or thrombolysis were analysed. Prospective follow-up was obtained. RESULTS Symptomatic PVT occurred 8.4 +/- 7.2 years after mechanical valve replacement at mean age 55 +/- 15 years. Thrombosis involved the mitral valve in 12 patients (71%), the aortic valve in 4 (24%) and the tricuspid valve in one (6%). The reason for PVT was inadequate anticoagulation in 11 patients (65%), endomyocardial fibrosis in 2 (12%) and unknown in 4 (24%). Prior to diagnosis, systemic emboli occurred in 6 patients (35%). Thirteen patients (76%) presented in functional class NYHA IV. Haemodynamic valve obstruction was documented by echocardiography in 15 patients (88%). Treatment included primary reoperation in 12 patients (71%), thrombolysis with urokinase in 3 (18%) (with reoperation in 1), reinstitution of adequate anticoagulation in one (6%); death occurred before treatment in one (6%). Intraoperatively, both pannus and thrombus were found in 5 of 13 patients (38%). Treatment-related emboli occurred in 5 patients (29%), to the brain in 3, to the legs in one and to a coronary artery in one. Five patients died (mortality 29%) within 30 days due to multiorgan failure/septicaemia (3 patients), congestive heart failure (1), or cerebral emboli (1). Follow-up after 28 +/- 28 months in the 12 surviving patients was unremarkable. CONCLUSIONS The most common aetiology for obstructive PVT is thrombus formation due to inadequate anticoagulation. PVT remains a serious complication with high morbidity and mortality despite aggressive treatment by thrombolysis and/or surgery. Surgery is often needed due to the frequent presence of pannus and/or large thrombi. However, long-term prognosis after successful treatment of PVT is excellent.