Original Research
Sunday, November 12, 2023
12:45 PM–02:15 PM
Abstract
Introduction: Different dosing strategies exist to initiate warfarin, most commonly fixed warfarin dosing (FWD), clinical warfarin dosing (CWD) and genetic- guided warfarin dosing (GWD). Landmark trials have shown GWD to be superior when compared to FWD (EU-PACT trial) or CWD (GIFT trial). COAG trial did not show differences between GWD and CWD. This controversy raised the question on whether one of these control arms (CWD and FWD) is superior than the other. However, to date, no clinical trials exist to compare the outcomes of CWD to FWD.
Research Question or Hypothesis: To compare between the efficacy and safety of CWD and FWD.
Study Design: Prospective cohort with a retrospective comparator.
Methods: Recruited subjects in the prospective arm were started on warfarin according to the clinical dosing component of the algorithm published in www.warfarindosing.org for 3-5 days. The primary efficacy outcome was the percentage time in therapeutic INR range (PTTR) from day 4-30.
Results: The study enrolled 122 and 123 patients in the CWD and FWD, respectively. The PTTR did not differ statistically between CWD and FWD (62.2 ±26.2% Vs. 58± 25.4%, p=0.2). There was also no difference between both arms in the percentage of visits with extreme subtherapeutic INR (<1.5) [15 ± 18.3% Vs. 16.8 ± 19.1%, p=0.44] or extreme supratherapeutic INR (>4) [7.7 ±14.7 % Vs. 7.5 ±12.4 %, p=0.92]. Thromboembolic and major bleeding events did not differ between both arms (24.92 Vs. 16.42 cases/1000 person months p=0.64 and 33.05 Vs. 16.01 cases/1000 person months p=0.4, respectively).
Conclusion: CWD did not improve the anticoagulation quality parameters compared to the FWD which could infer that the results of the COAG trial maybe primarily due to the heterogenous population included, further supporting the use of GWD as a strategy superior to both CWD and FWD.
Presenting Author
Amr Fahmi MSc.ClinPharm, BCCPHamad Medical Corporation
Authors
Osama Abd El Samad B(Pharm)
Al Wakra Hospital-Hamad Medical Corporation
Eman Alhmoud MSc, BCPS, CPHQ
Hamad Medical Corporation
Christina L. Aquilante Pharm.D, FCCP
University of Colorado
Abdulrahman Arabi MD
Hamad Medical Corporation
Nidal Asaad MD
Hamad Medical Corporaion
Mohamed Kasem MSc Clinical Pharmacy
Hamad Medical Corporation
Ahmed Mahfouz BPharm, MSc(ClinPharm)
Hamad Medical Corporation
Mohamed Nabil Elshafei PharmD, BCPS, BCCCP
Hamad Medical Corporation/ Qatar University
Ahmed Elbardissy PharmD, BCPS
Hamad Medical Corporation
Hazem Elewa PhD, RPh, BCPS
Qatar University
Ihab Elmadhoun MD
Al-Wakra Hospital
Ezz Edin Elsoaly MD
Abdel-Naser Elzouki MD
Hamad Medical Corporation
Mohamed Saad PharmD, BCPS, BCCCP
Al-Wakra Hospital, Hamad Medical Corporation