Influence of oral anticoagulation on stroke severity and outcomes: A propensity score matching case-control study

Background: Oral anticoagulants (OAC) such as vitamin K antagonists (VKA) and direct-acting OACs (DOAC) remain the mainstay for prevention of cardioembolic stroke. The influence of previous OAC treatment on stroke severity and outcomes is not well stablished. We compared patients with incident cardioembolic strokes according to pre-stroke treatment.

Methods: Retrospective observational study of patients with cardioembolic stroke. Demographic data, vascular risk factors, pre-stroke treatments, reperfusion therapies and outcomes were analyzed. Propensity score matching of baseline characteristics was used to compare case-control samples across different treatment groups: adequate OAC vs no OAC; inadequate VKA vs no OAC; adequate VKA vs inadequate VKA; adequate VKA vs DOAC.

Results: 462 patients (76 ± 11.6 years) included. 255 (55%) had a known major cardioembolic source, but only 151 (59%) of them were under OAC upon admission (127 VKA, 24 DOAC). Four patients received VKA for other reasons. Of those taking VKA, 91 (69%) had an inadequate anticoagulation. After propensity score matching, we found no significant differences in stroke severity across the different groups. Patients receiving DOAC had lower mortality at 3 months (8% vs 33%, p = .033) and higher successful recanalization rates after thrombectomy (100% vs 25%, p = .033) compared with adequate VKA anticoagulation.

Conclusions: DOAC treatment significantly reduced mortality at three months compared with adequate VKA anticoagulation. Further studies are needed to confirm its influence on endovascular thrombectomy outcomes.