Prevention of prosthetic thrombosis with anticoagulation after aortic valve replacementwith bioprosthesis.Meta-analysis

Abstract

Background: increased risk of thrombosis and clinical events has been reported in patients receiving bioprostheses after aortic valve replacement or transcatheter aortic valve implant.
Objective: to assess whether the use of anticoagulation for at least 90 days decreases and / or prevents occurrence of thrombo-embolic or subclinical thrombosis in patients with biological aortic valve replacement. To evaluate the incidence of bleeding and mortality associated with this strategy.|
Methods: we searched articles in databases: PubMed, Central Cochrane, Cochrane Library and SciELO. The terms used were: “Anticoagulation AND aortic bioprosthesis” and “Anticoagulation AND TAVI OR TAVR”. Inclusion and exclusion criteria were established, performing the analysis of clinical and subclinical events separately. The statistic used was odds ratio (OR). A randomized effects model was used to calculate the statistic and its 95% confidence interval (CI).
The meta-analysis results were presented as a forest diagram. We consider p <0.05 significant.
Results: 233 articles were identified; selecting 8 for clinical thrombosis and 5 for subclinical thrombosis. There was no significant difference in the incidence of embolic events with the use of oral anticoagulation (OR = 1.01; 95% CI: 0.63-1.61;p = 0.98) or short-term mortality (OR = 1.10; 95% CI: 0.77-1.56;p = 0.61). A higher incidence of major bleeding was demonstrated in patients receiving oral anticoagulation (OR = 1.60; 95% CI: 1.04-2.48; p = 0.03). The risk of subclinical prosthetic thrombosis was higher in patients who did not receive oral anticoagulation (OR = 5.52; 95% CI: 3.37-9.05; p = 0.001).
Conclusions: oral anticoagulation is associated with a lower risk of subclinical prosthetic thrombosis, increasing the risk of bleeding. Between the groups compared, there is no difference in mortality or embolic phenomena at medium term.