Abstract Number: PB0619
Meeting: ISTH 2020 Congress
Background: Large inter-individual plasma level variability of the four direct oral anticoagulants (DOAC: apixaban, dabigatran, edoxaban and rivaroxaban), has been previously reported, showing a significant increase from phase II-III clinical trials up to post-marketing studies, both at standard and low dosages. At present poor data on intra-individual plasma level variability are available in real world.
Aims: To evaluate intra-individual variability, both at C-trough and C-peak, in patients with non valvular atrial fibrillation, treated with the four available DOAC, both at standard and low dosages.
Methods: After informed consent, 640 patients were enrolled and plasma samples were collected at C-trough and C-peak, after one month from starting DOAC (time 0) and each 3 months (time +3, +6). Three consecutive controls at C-trough and C-peak were considered for the analysis. Plasma DOAC concentrations were measured using Ecarin chromogenic assay for dabigatran and anti FXa activity, specifically calibrated for each anti-Xa drugs (Stago, France).
Results: From a total of 640 patients, 58 of them were excluded from the analysis: 40 had an incomplete collection of samples and 18 patients showed onset of new diseases or prescription of new potentially interfering drugs. 582 patients (73 dabigatran 150mgx2/die; 72 dabigatran 110mgx2/die; 76 rivaroxaban 20mg/die, 77 rivaroxaban 15mg/die; 75 apixaban 5mgx2/die, 78 apixaban 2.5mgx2/die, 68 edoxaban 60mg/die, 63 edoxaban 30mg/die) completed the study program and 3492 plasma samples were tested. DOAC mean CV% intra-individual variability at C-trough ranged from 23 to 31% while at C-peak from 22 to 30%. Details are showed in table 1.
Conclusions: The intra-individual variability was significantly lower in comparison with inter-individual variability, as shown in previous studies. Our data seems to suggest that DOAC levels are stable during the first six months of treatment. However, we can not exclude possible significant modifications of drug anticoagulant levels in case of new co-morbidities and/or changes in co-therapies.
To cite this abstract in AMA style:
Paoletti O, Dellanoce C, Legnani C, Cancelli V, Morandini R, Tala M, Cancellieri E, Zambelli S, Beati MC, Stramezzi M, Spotti E, Castellani V, Lambiase S, Testa S. DOAC Intra-individual Variability in Patients with Non Valvular Atrial Fibrillation [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/doac-intra-individual-variability-in-patients-with-non-valvular-atrial-fibrillation/. Accessed October 1, 2023.« Back to ISTH 2020 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/doac-intra-individual-variability-in-patients-with-non-valvular-atrial-fibrillation/