# Building evidence on safety of endovascular thrombectomy for patients under anticoagulation with vitamin K antagonists

## TL;DR

This study examines the safety of endovascular thrombectomy in patients using vitamin K antagonists and finds that recent use with high INR increases the risk of bleeding.

## Contribution

The study identifies that VKA use with an INR >1.7 increases the risk of sICH after endovascular thrombectomy.

## Key findings

- Prior VKA use did not increase overall sICH risk.
- VKA use with INR >1.7 significantly increased sICH risk.
- INR ≤1.7 showed no significant difference in sICH risk between VKA and non-VKA users.

## Abstract

A recent study by Brian Mac Grory and colleagues investigated the safety of endovascular thrombectomy (EVT) among patients under vitamin K antagonists (VKAs) use within 7 days prior to hospital admission. Through this retrospective, observational cohort study, they found prior VKA use did not increase the risk of symptomatic intracranial hemorrhage (sICH) overall. However, recent VKA use with a presenting international normalized ratio (INR) > 1.7 was associated with a significantly increased risk of sICH. Future large‐scale randomized controlled trials should be conducted to further clarify the effects and feasibility of EVT therapy in ischemic stroke patients under anticoagulation.

In this study, a total of 32,715 patients with acute ischemic stroke undergoing endovascular thrombectomy (EVT) were included. In total, 29,628 patients (90.6%) were not taking a vitamin K antagonist (VKA) prior to stroke, and 3087 patients (9.4%) were taking a VKA. The incidence of symptomatic intracranial hemorrhage (sICH) among the VKA group is 6.8%, which is comparable to those non‐VKA users with an incidence of 6.4%. Then, the international normalized ratio (INR) was dichotomized as ≤1.7 and >1.7 to assess the risk of sICH in each subgroup. Among 830 patients taking a VKA with an INR greater than 1.7, the incidence of sICH was 8.3%, which is significantly higher than those not taking a VKA (6.4%). Meanwhile, those with an INR of 1.7 or lower (n = 1585) had no significant difference of the risk of sICH (6.7%).