Blood thinning with bioprosthetic valves
Clinical question: Does anticoagulation prevent thromboembolic events in patients undergoing bioprosthetic valve implantation?
Background: The main advantage of bioprosthetic valves, compared with mechanical valves, is the avoidance of long-term anticoagulation. Current guidelines recommend the use of vitamin K antagonist (VKA) during the first 3 months after surgery, which remains controversial. Two randomized controlled trials (RCTs) showed no benefit of using VKA in the first 3 months; however, other studies have reported conflicting results.
Study design: Meta-analysis and systematic review.
Setting: Multicenter.
Synopsis: This meta-analysis included two RCTs and 12 observational studies that compared the outcomes in group I (VKA) versus group II (antiplatelet therapy/no treatment). There was no difference in thromboembolic events between group I (1%) and group II (1.5%), but there were more bleeding events in group I (2.6%) versus group II (1.1%). In addition, no differences in all-cause of mortality rate and need for redo surgery were found between the two groups.
Bottom line: The use of VKA in the first 3 months after a bioprosthetic valve implantation does not decrease the rate of thromboembolic events or mortality, but it is associated with increased risk of major bleeding.
Citation: Masri A, Gillinov M, Johnston DM, et al. Anticoagulation versus antiplatelet or no therapy in patients undergoing bioprosthetic valve implantation: a systematic review and meta-analysis [published online ahead of print Aug. 3, 2016]. Heart. doi: 10.1136/heartjnl-2016-309630
Dr. Florindez is an assistant professor at the University of Miami Miller School of Medicine and a hospitalist at University of Miami Hospital and Jackson Memorial Hospital.
