Study Links DOACs to Reduction in RVO, Intraocular Bleeding Risk

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A new investigation examined the effect of systemic anticoagulation with direct oral anticoagulants (DOACs) and warfarin on the risk of retinal vascular occlusion (RVO) and intraocular bleeding in a large national US cohort.

These data, presented at the American Society of Retina Specialists (ASRS) 42nd Annual Meeting, pointed to a significant protective correlation between the use of DOACs and the development of RVO, retinal artery occlusion (RAO), and intraocular bleeding risk, compared with warfarin use.

“These associations may be explained by reductions in subtherapeutic or supratherapeutic coagulation levels with DOAC use, compared to warfarin,” wrote the investigative team, led by Matthew Russell, MD, Cleveland Clinic Lerner College of Medicine.

Atrial fibrillation (AF) or venous thromboembolism (VTE) are risk factors for the development of RVO. Systemic anticoagulation serves as the standard of care for these conditions – novel DOACs are gaining favor over warfarin due to improved vascular outcomes and therapeutic reliability.

However, there has been no investigation into the risk of future RVO and intraocular bleed development with DOAC use in a large US cohort. In this retrospective study, Russell and colleagues evaluated RVO and intraocular bleeding risks among those requiring systemic anticoagulation with warfarin or DOACs across the TriNetX US Collaborative Network national database.

Among nearly 86 million patients in the database, those with a prescription for warfarin (n = 135, 605) or a DOAC (n = 164,229) for systemic antiocagulation were identified after exclusion. After propensity score matching, 108,895 patients managed with DOACs were matched to 108,895 patients managed with warfarin. Matching was performed based on age, sex, race, ethnicity, and vascular risk factors.

Outcomes of interest included the incident diagnoses of any RVO or RAO, branched RVO or RAO, and central RVO or RAO. Investigators also examined the incidence codes for intraocular bleeding, including vitreous, retinal, and choroidal hemorrhages, and hyphema.

At baseline, the matched cohorts were an average of 74 years old, 72% White, 5% Hispanic, and 52% female. Approximately 60% of patients had hypertension, 30% had type 2 diabetes (T2D), and 19% experienced heart failure.

Upon analysis, individuals treated with warfarin were at a significantly increased risk of a new diagnosis of all RVO (relative risk [RR], 1.49; 95% CI, 1.42 - 1.57), including central RVO (RR, 1.37; 95% CI, 1.26 - 1.49) and branch RVO (RR, 1.43; 95% CI, 1.32 - 1.55).

Those treated with warfarin were additionally at a higher risk of intraocular bleeding, including vitreous hemorrhage (RR, 1.84; 95% CI, 1.72 - 1.96), retinal hemorrhage (RR, 1.77; 95% CI, 1.66 - 1.89), choroidal hemorrhage (RR, 2.06; 95% CI, 1.53 - 2.79), and hyphema (RR, 1.76; 95% CI, 1.52 - 2.04), compared with patients managed with DOACs.

Overall, Russell and colleagues suggested these data indicate a significantly lower risk of RVO and intraocular bleeding with DOAC treatment compared with warfarin use.

“The associates herein suggest a need for further validation of these findings through investigation of large-scale clinical trials with more granular patient level ophthalmic data,” Russell and colleagues wrote.

Reference

1. _{Russell M. Comparison of Direct Oral Anticoagulants and Warfarin With Respect to Retinal Vein Occlusion and Intraocular Bleeding Risk Across a large US National Database. Poster presented at the American Society of Retina Specialists (ASRS) 42nd Annual Meeting. Stockholm, Sweden. July 17-20, 2024.}
2. _{Lucà F, Oliva F, Abrignani MG, et al. Management of Patients Treated with Direct Oral Anticoagulants in Clinical Practice and Challenging Scenarios. J Clin Med. 2023;12(18):5955. Published 2023 Sep 13. doi:10.3390/jcm12185955}