Abstract Number: PB2071
Meeting: ISTH 2020 Congress
Background: Many elderly patients are confined to treatment with vitamin K antagonists (VKA) instead of direct oral anticoagulants (DOACs). However, quality of VKA treatment declines with age. At the same time, the average VKA dose requirement decreases with age. This increases the day-to-day variation in VKA dose.
Aims: To obtain information on the effect size for, and feasibility of a full scale trial to assess whether more precise dosing of acenocoumarol increases the quality of VKA treatment in elderly patients.
Methods: In this pilot study we randomized 80 patients aged 80 and above who used 0.5-2.0 mg acenocoumarol daily to either regular dosing in 1.0 mg acenocoumarol increments, or more precise dosing with 0.5 mg increments. We compared changes in time in therapeutic range (TTR) and International Normalised Ratio (INR) variability (VGR) between the two treatment groups, in the six month before and six months during study period. In addition changes in anticoagulation-related quality of life were assessed using PACT-Q.
Results: Patients were aged 84±3 years. Overall baseline TTR was 61% (± 19.2). TTR had improved in both groups, but somewhat more in the intervention group (3.4%, 9.0 vs 5.6; 95% CI -3.7 to 10.5). The INR variability also improved, slightly more in the 0.5 mg group. PACT-Q convenience remained constant in time and did not differ between groups. PACT-Q satisfaction decreased, almost equally, in both groups. Four dosing errors related to dose increments occurred, three in the intervention and one in the control group.
Conclusions: Although more precise dosing of acenocoumarol leads to a slightly better quality of anticoagulation, this effect is too small to convey a relevant clinical benefit. We will not proceed with a full scale RCT. Notably, the overall decrease in treatment satisfaction should be considered when performing future anticoagulation studies in this population.
To cite this abstract in AMA style:Piersma-Wichers M, van Miert J, Veeger N, Kooistra H, Meijer K. More Precise Dosing of Acenocoumarol for Better Control in Patients Aged above 80 Years, a Randomized Controlled Pilot Study [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/more-precise-dosing-of-acenocoumarol-for-better-control-in-patients-aged-above-80-years-a-randomized-controlled-pilot-study/. Accessed November 29, 2023.
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