Association of Novel Oral Antithrombotics With the Risk of Intraocular Bleeding

Novel oral anticoagulation and antiplatelet therapies have become a mainstay of treatment for thromboembolic disease. However, the safety profile of these medications has not been completely characterized.

To determine the risk of developing intraocular hemorrhages with novel oral antithrombotic therapy compared with that of traditional antithrombotic agents.

In this retrospective cohort study, a large national insurance claims database was used to generate 2 parallel analyses. All patients with incident use of dabigatran etexilate or rivaroxaban between January 1, 2010, and September 30, 2015, were compared with patients with incident use of warfarin sodium. Similarly, patients with new use of prasugrel hydrochloride were compared with those with new use of clopidogrel bisulfate. Both analyses required the patient to be in the insurance plan for at least 24 months prior to initiation of therapy and excluded patients with any previous diagnosis of intraocular hemorrhages or any prescription for the comparator medications. Furthermore, the antiplatelet analysis required a diagnosis of acute coronary syndrome or a myocardial infarction within 60 days of initiation of pharmacologic therapy. The anticoagulant analysis excluded patients with end-stage renal disease, renal transplants, and those with heart valve disease.

Incident intraocular hemorrhages at 90 and 365 days. Multivariate Cox proportional hazards regression models were used to compare the hazard ratio (HR) of developing an intraocular hemorrhage in individuals taking novel agents compared with those taking traditional medications.

A total of 146 137 patients taking warfarin (76 714 women and 69 423 men; mean [SD] age, 69.8 [11.8] years) were compared with 64 291 patients taking dabigatran or rivaroxaban (31 576 women and 32 715 men; mean [SD] age, 67.6 [11.7] years). Cox proportional hazards regression revealed a decreased hazard for developing an intraocular hemorrhage with dabigatran or rivaroxaban at 365 days (HR, 0.75; 95% CI, 0.58-0.97; P = .03), but not at 90 days (HR, 0.73; 95% CI, 0.22-2.63; P = .13). A total of 103 796 patients taking clopidogrel (37 578 women and 66 218 men; mean [SD] age, 68.0 [11.3] years) were compared with 8386 patients taking prasugrel (1988 women and 6380 men; mean [SD] age, 61.0 [9.6] years) and no increased hazard for developing an intraocular hemorrhage with prasugrel was seen at 90 days (HR, 0.75; 95% CI, 0.29-1.92; P = .55) or 365 days (HR, 1.19; 95% CI, 0.69-2.04; P = .53).

These results suggest a decreased risk of intraocular hemorrhage associated with novel direct thrombin inhibitors and direct factor Xa inhibitors, but no difference for P2Y12 inhibitors compared with traditional vitamin K anticoagulation and antiplatelet therapy, respectively.