Novel antithrombotic pose an equal or lower risk of intraocular hemorrhage than their traditional counterparts, according to this analysis of insurance claims.
Study design
This retrospective cohort study analyzed the safety profiles of novel anticoagulants and antiplatelet therapy. Investigators analyzed the incidence of intraocular hemorrhage between months 3 and 12 among new users of antithrombotic drugs.
Outcomes
A statistical comparison of 146,137 patients taking warfarin and 64,291 patients taking novel anticoagulants dabigatran (Pradaxa) or rivaroxaban (Xarelto) revealed a slightly lower risk of hemorrhage in the latter group at 365 days (HR 0.75; P=0.03).
However, a comparison of 103,796 patients taking clopidogrel with 8,386 patients taking novel antiplatelet therapy prasugrel revealed no differences (P=0.53).
Limitations
The study was unable to determine if patients temporarily stopped their medication at or around the time of eye surgery. Since the rate of intraocular hemorrhages was exceedingly low, the power of the study to detect subtle differences between antiplatelet cohorts was limited despite the large number of patients.
The authors defined intraocular hemorrhage as vitreous hemorrhage, non-traumatic intraocular hemorrhage, hyphema, choroidal hemorrhage, as well as retinal hemorrhage. While choroidal hemorrhage or vitreous hemorrhage and hyphema would be considered significant, retinal hemorrhage may be small and not clinically significant.
Additionally, there are other antithrombotic agents that were not examined in this study. Finally, there is no mention of other intraocular complications during surgery attributable to these drugs.
Clinical significance
There has been an increase in the use of novel anticoagulant and antiplatelet medications due to their ease of use, improved adverse effect profiles, less need for monitoring and superior efficacy. These real-world findings corroborate what has been observed in randomized controlled trials, and support the safety of these novel drugs.
This study suggests that there is not an increased risk of intraocular hemorrhage associated with the use of novel P2Y12 inhibitor Effient compared with Plavix. It also suggests that novel direct thrombin inhibitors and direct factor Xa inhibitors (Pradaxa and Xarelto, respectively) may actually decrease the risk of bleeding compared with traditional vitamin K anticoagulant warfarin.