BACKGROUND AND PURPOSE:

• It is not clear whether warfarin or more recently developed direct oral anticoagulants (DOACs) are the better treatment option for extended VTE therapy
• Fang et al. (JAMA Network Open, 2023) compared DOACs vs warfarin for anticoagulant treatment beyond 6 months after acute VTE

METHODS:

• Cohort study
  • Data derived from Kaiser Permanente Virtual Data Warehouse 
  • Sampling time period: January 1, 2010, to December 31, 2018
• Population
  • ≥18 years
  • Received a diagnosis of incident VTE
  • Completed a 6-month initial treatment for VTE
• Exposures
  • DOACs
  • Warfarin
• Study design
  • Follow-up: End of the initial 6-month treatment period until discontinuation of anticoagulation | Occurrence of an outcome event | Health plan disenrollment | End of the study follow-up period
  • Comparison of DOAC and warfarin outcomes performed using multivariable Cox proportional hazards regression
• Primary outcomes
  • Recurrent VTE | Hospitalizations for hemorrhage | All-cause death

RESULTS:

• 18,495 patients
  • DOAC: 11.5% | Warfarin: 88.5%
  • Aged ≥75 years: 29.6% | Women: 48.5%
  • Predominant DOAC was dabigatran
• Unadjusted event rates were lower for patients receiving DOAC therapy than warfarin therapy for (per 100 person-years)
  • Recurrent VTE
    • DOACs: 2.92 (95% CI, 2.29 to 3.54)
    • Warfarin: 4.14 (95% CI, 3.90 to 4.38)
  • Hospitalizations for hemorrhage
    • DOACs: 1.02 (95% CI, 0.66 to 1.39]
    • Warfarin: 1.81 (95% CI, 1.66 to 1.97)
  • All-cause death
    • DOACs: 3.79 (95% CI, 3.09 to 4.49)
    • Warfarin: 5.40 (95% CI, 5.13 to 5.66)
• After adjustment, DOAC treatment was associated with a lower risk of recurrent VTE
  • Adjusted hazard ratio (aHR) 0.66 (95% CI, 0.52 to 0.82)
• There were no significant differences between the groups in the risk of
  • Hospitalization for hemorrhage: aHR 0.79 (95% CI, 0.54 to 1.17)
  • All-cause death: aHR 0.96 (95% CI, 0.78 to 1.19)

CONCLUSION:

• Patients who continued anticoagulation treatment beyond 6 months experienced a lower risk of recurrent VTE with DOACs vs warfarin
• The authors state

Our study contributes to the growing evidence supporting the use of DOACs for both initial and extended treatment of VTE in terms of clinical outcomes as well as treatment satisfaction

Learn More – Primary Sources:

Clinical Outcomes of Direct Oral Anticoagulants vs Warfarin for Extended Treatment of Venous Thromboembolism