Recognition of Novel Anticoagulation and Antiplatelet Agents in Vitreoretinal Surgery

By Sruthi Arepalli, MD; and Aleksandra V. Rachitskaya, MD

Recently, Cole Eye Institute has become interested in the impact of anticoagulation on vitreoretinal surgery. Our interest stems from the increasing number of novel agents — direct oral anticoagulants (DOACs) and newer antiplatelets available on the market, and their limited reversibility. This can potentially lead to intraoperative and postoperative complications, such as intraocular hemorrhage. As the usage of DOACs and newer antiplatelet medications increases, surgeons are faced with the perioperative management of these agents. These medications include prasugrel, ticagrelor, dabigatran and others.

Retrospective review shows some lack of recognition

We undertook a study that analyzed how well the newer generation of blood thinners was recognized and managed before vitreoretinal surgery. The study, published in Ophthalmology Retina, showed that DOACs and novel antiplatelet agents were indeed not as well recognized in presurgical planning as older, more established agents such as clopidogrel and warfarin.

We retrospectively reviewed charts of patients on DOACs and newer antiplatelet medications undergoing vitreoretinal surgery between March 2011 and August 2016. The study compared the perioperative management of newer agents to that of warfarin and clopidogrel. The following medications were identified in the chart review: prasugrel, abciximab, ticagrelor, rivaroxaban, apixaban, dabigatran and cilastozol. We were most interested to see if the clinician performing the clinical examination or the practitioner performing the presurgical physical examination included the anticoagulation in the documentation and/or surgical planning, and if the medications were discontinued before surgery or not.

Noting and stopping medications

We identified 42 eyes in 34 patients who were on novel anticoagulant or antiplatelet agents in the preoperative period. Twenty-eight (66.7 percent) of these were on DOACs, and 14 (33.3 percent) were on novel antiplatelet agents. Of these 42, only 24 (57.1 percent) had the anticoagulation noted in either the clinical note or preoperative history and physical, and of these, 13 (54.2 percent) had their medication stopped within the two weeks leading up to surgery.

We found 39 eyes in 37 patients on older anticoagulation medications, with 20 (51.3 percent) on warfarin and 19 (48 percent) on clopidogrel. Compared to 57 percent documentation rate in the DOACs and novel antiplatelet agents, 34 of the older generation patients (87.2 percent) had their anticoagulation status noted. This difference was statistically significant (P = 0.0029). Of these, 17 (50 percent) were instructed to stop their anticoagulation, similar to the 54.2 percent cessation rate with newer agents (P = 0.75).

Both groups had two patients with postoperative hemorrhagic complications; the patients on warfarin had postoperative hemorrhage (one self-resolved, one required vitrectomy), and the patients on novel anticoagulation had postoperative hyphemas, both of which self-resolved.

Better recognition of new agents is needed

Our study was able to demonstrate that DOACs and novel antiplatelet agents might not be recognized or documented at the same frequency as more established anticoagulation and antiplatelet agents. To further support this lack of recognition, a patient who was on concurrent warfarin and a novel antiplatelet agent, cilastozol, was included in both groups. Only the warfarin was stopped preoperatively, suggesting that there is a lack of recognition of these newer agents.

What we found interesting as well is that once these drugs were recognized, the cessation rates were almost equal in both groups.

We believe this study brings to light the necessity for surgeons to increase recognition of these newer agents. There is a need for a larger scale study to fully assess the risks of these medications in general as well as the risk in the lack of recognition of these newer blood thinners.

Dr. Arepalli is a PGY-4 resident in ophthalmology at Cole Eye Institute.