Long-term follow-up of morbidity and mortality after aortic valve replacement with a mechanical valve prosthesis

Aims The aim of this study was to determine the incidence of valve-related complications in patients with a mechanical aortic valve prosthesis and to identify risk factors for an adverse outcome. Methods and Results In the 424 patients, event-free survival rates 5 and 10 years after aortic valve replacement were 62% and 37%, respectively. The l inearized incidence of thromboembolic events was 4.4% per patient-year, and of anticoagulant-related haemorrhage 8.5% per patient-year. Advanced NYHA functional class? atrial fibrillation, pure aortic regurgitation and thromb oembolism prior to surgery decreased event-free survival. A history of pre- operative thromboembolism increased the risk for a first embolic event afte r aortic valve replacement (relative hazard [RH] 3.2), but was even more st rongly associated with the risk for repeated events (22 events, RH 5.4). Af ter each thromboembolic episode that occurred, the risk for a subsequent on e was increased. The risk for at least one, and up to three or more haemorr hages was increased in patients with a pre-operative history of bleeding (R H 33-55.1) and of atrial fibrillation (RH 1.8-39). The risk for a subsequen t event was increased by a history of repeated haemorrhages, a short interv al since previous bleeding, and high age. Conclusions There were few factors strongly related to valve related morbid ity. However, previous bleedings and previous thromboembolism were powerful risk factors for repeated events. (C) 2000 The European Society of Cardiol ogy.