Single vs Dual Antiplatelet Therapy Following Transcatheter Aortic Valve Implantation: A Systematic Review

There is wide variability in prescribing of antiplatelet regimens following transcatheter aortic valve implantation (TAVI). The objective of this review was to evaluate published and unpublished reports regarding the efficacy and safety of dual antiplatelet therapy (DAPT) compared with a single antiplatelet agent in patients undergoing TAVI. We searched MEDLINE, CENTRAL, Embase, and unpublished sources of literature from inception to December 2014 using terms synonymous with TAVI and DAPT. We included randomized controlled trials (RCTs) and cohort or case-control studies that compared DAPT with a single antiplatelet agent post-TAVI. Four articles met the inclusion criteria (2 RCTs, 2 cohort studies), of which all were deemed to be at high risk of bias, for a total of 662 patients. Compared with a single antiplatelet agent, DAPT did not significantly reduce all-cause mortality (risk ratio: 1.22, 95% confidence interval: 0.72-2.09, I(2) = 0%). Due to selective outcome reporting and variable follow-up, other outcomes of interest could not be meta-analyzed; however, evaluation of individual studies demonstrated no significant reduction in thrombotic events with DAPT and a similar or higher risk of bleeding. Current evidence, though limited by low methodological quality, suggests a lack of benefit and potential harm with DAPT compared with a single antiplatelet agent in patients post-TAVI. Therefore, clinicians should evaluate the use of DAPT in patients post-TAVI on a case-by-case basis until more robust evidence is available to guide practice.