Comparative Safety and Effectiveness of Reduced Doses of Direct Acting Oral Anticoagulants for Stroke Prevention in...

Area of Science:

• Cardiology
• Pharmacology
• Public Health

Background:

• Nonvalvular atrial fibrillation (NVAF) necessitates anticoagulation for stroke prevention.
• Warfarin has been the standard, but direct-acting oral anticoagulants (DOACs) offer alternatives.
• Optimizing DOAC dosing is crucial for balancing efficacy and safety.

Purpose of the Study:

• To evaluate the effectiveness and safety of reduced-dose DOACs (dabigatran, rivaroxaban, apixaban) versus standard warfarin.
• To compare stroke and systemic embolism prevention.
• To assess intracranial hemorrhage risk in NVAF patients.

Main Methods:

• Nordic observational cohort study using nationwide administrative databases (Denmark, Sweden, Norway, Finland).
• Inclusion of 26,883 patients on reduced-dose DOACs and 108,014 on warfarin.
• Primary effectiveness endpoint: ischemic stroke/systemic embolism; Safety endpoint: intracranial hemorrhage.

Main Results:

• Reduced-dose DOACs demonstrated similar or lower rates of ischemic stroke and systemic embolism compared to warfarin (HRs: rivaroxaban 0.93, dabigatran 0.88, apixaban 0.79).
• Intracranial hemorrhage rates were generally low and comparable or lower for DOACs versus warfarin (HRs: rivaroxaban 1.41, dabigatran 0.35, apixaban 0.72).
• Specific DOACs showed varying risk profiles, with apixaban and dabigatran indicating potential safety advantages.

Conclusions:

• Reduced-dose DOACs are effective and safe alternatives to warfarin for stroke prevention in NVAF.
• Apixaban and dabigatran, in particular, may offer improved safety profiles regarding intracranial hemorrhage.
• These findings support the use of carefully selected reduced-dose DOACs in specific patient populations.