Association Between Inappropriately Dosed Anticoagulation Therapy With Stroke Severity and Outcomes in Patients With...

Area of Science:

• Cardiology
• Neurology
• Pharmacology

Background:

• Oral anticoagulation (OAC) is crucial for preventing stroke in atrial fibrillation (AF) patients.
• However, strokes can occur despite OAC, and the impact of prior treatment quality is not well understood.

Purpose of the Study:

• To evaluate the association between OAC treatment quality and stroke severity and mortality in AF patients.
• To compare outcomes between vitamin K antagonist (VKA) and direct OAC (DOAC) therapies.

Main Methods:

• Retrospective analysis of 2319 AF patients with ischemic stroke from the Danish Stroke Registry (2005-2018).
• Patients were categorized by OAC type (VKA or DOAC) and dosing adequacy (subtherapeutic, therapeutic, supratherapeutic for VKA; underdosed, appropriately dosed, overdosed for DOAC).
• Stroke severity assessed using Scandinavia Stroke Scale; 1-year mortality analyzed using logistic and Cox regression models.

Main Results:

• Nearly half (46% VKA, 23% DOAC) of patients received suboptimal OAC therapy.
• Subtherapeutic VKA therapy was linked to significantly increased stroke severity (OR 2.06) and 1-year mortality (HR 1.66) compared to therapeutic VKA.
• Neither underdosed nor overdosed DOAC therapy showed significant associations with worse stroke severity or 1-year mortality compared to appropriate DOAC dosing.

Conclusions:

• Inappropriate OAC therapy is common in AF patients experiencing stroke.
• Suboptimal VKA dosing is associated with poorer outcomes, while DOAC dosing variations did not significantly impact outcomes in this study.
• Findings suggest DOACs may offer a more predictable safety and efficacy profile compared to VKAs in AF stroke prevention.