OC 48.2 - A TEN-YEAR REVIEW OF THE IMPACT OF TRANSITION FROM WARFARIN TO DIRECT ORAL ANTICOAGULANT– HAS VTE TREATMENT BECOME SAFER?

Monday, July 11, 2022

3:00 PM – 3:15 PM

Location: ExCel Center, ICC Capital Suite Room 17

Presentation Format: In-Person

Presenting Author(s)

BL

Brandon Lui

Medical Resident
Northern Clinical Pathology, Thrombosis and Radiology (NECTAR) Research Group
Epping, Victoria, Australia

Co-Author(s)

BW

Benjamin Jern Shern Wee, MBBS

Medical Resident
Northern Clinical Pathology, Thrombosis and Radiology (NECTAR) Research Group
Epping, Victoria, Australia
AK

Anna Kwok

Medical Resident
University of Melbourne
Melbourne, Victoria, Australia
JL

Jeffrey Lai

Medical Resident
University of Melbourne
Melbourne, Victoria, Australia
ZK

Zille Khattak

Medical Resident
Northern Health
Melbourne, Victoria, Australia
CD

Cynthia Donarelli

Pharmacist
Northern Health
Melbourne, Victoria, Australia
PH

Prahlad Ho, MBBS(Hons), BMedSc, PhD, FRACP, FRCPA

Haematologist
Northern Clinical Pathology, Thrombosis and Radiology (NECTAR) Research Group
Epping, Victoria, Australia
HL

Hui Yin Lim

Haematologist
Northern Clinical Pathology, Thrombosis and Radiology (NECTAR) Research Group
Epping, Victoria, Australia

Background: The introduction of direct oral anticoagulants (DOAC) has resulted in a paradigm shift in the management of venous thromboembolism (VTE) with DOAC the current agent of choice.

Aims: To evaluate the shift to DOAC in VTE management over the last decade on clinical outcomes, particularly in first unprovoked major VTEs.

Methods: A retrospective analysis of all VTE admissions in non-cancer patients from January 2010 to December 2020 at Northern Health, Victoria, Australia. “Warfarin era” included events that occurred between January 2011 and December 2014 and “DOAC era” from January 2015.

Results: There were 2687 cases involving 2508 patients (45.9% males; median age 63 years). 98% were symptomatic and 1261 events (47%) were unprovoked (Table 1). 1003 events occurred during the warfarin era (79% managed with warfarin and 6% DOAC) and 1684 during the DOAC era (22% warfarin 66% DOAC). While recurrent thrombosis within 12 months from index event was comparable, there were fewer events beyond 12 months in the DOAC era compared to warfarin era (HR 0.694, 95%CI 0.511-0.943, p=0.020) (Figure 1A). Clinically significant bleeding events were lower in the DOAC era (HR 0.633, 95%CI 0.410-0.978, p=0.039) (Figure 1B), despite having more patients on prolonged anticoagulation (29.3% vs 39.7%, p< 0.001).

A subanalysis of first unprovoked major VTE events (n=602) revealed longer therapeutic anticoagulation during the warfarin era (9 vs 6 months, p< 0.001) although more patients were continued on low dose thromboprophylaxis in the DOAC era (19% vs 1%, p< 0.001). There was a significant reduction in recurrent VTE beyond 12 months from the index event in the DOAC era (HR 0.315, 95% CI 0.132-0.750) with no difference in clinically significantly bleeding rates between the eras.

Conclusion(s): Treatment outcomes for VTE have improved over time with reduced rate of thrombotic and clinically significant bleeding complications in the DOAC era.