Mechanical heart valve prostheses and persistent lupus anticoagulant: Is the thrombotic risk increased?

Abstract

The risk of thrombosis in patients with mechanical heart valve prostheses in spite of life-long adequate anticoagulation is 1–2% per year. Current recommendations for anticoagulation take into account the prosthesis itself and the co-morbid conditions that enhance the thrombotic risk. Lupus anticoagulant is diagnosed in many thrombotic recurrences. We designed an ambispective case–control study to evaluate thrombotic events in patients with mechanical heart valve prostheses and persistent lupus anticoagulant. Our objectives were to determine whether persistent lupus anticoagulant increased the risk of embolism in that population and thus, if a more intense anticoagulation would be recommended, even at the risk of increasing bleeding episodes. We included 16 patients and 16 controls with more than 80 patient-years of follow-up and with other risk factors for embolism. We observed no increased rate of thromboembolic events in patients than in controls, even during high-risk situations (i.e. bacterial endocarditis). Our population spent most of the time within the intended anticoagulation range. We conclude that adequate anticoagulation is the most important issue to prevent events, protecting against thrombosis without increasing the bleeding risk.