PB0494 - Apixaban plasma levels at time of elective surgery: preliminary data from the DALI study

Monday, July 11, 2022

6:30 PM – 7:30 PM

Location: Exhibition

Presentation Format: In-Person

Presenting Author(s)

Eleonora Camilleri, MD

MD PhD student
Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands
Leiden, Zuid-Holland, Netherlands

Co-Author(s)

PS

Payam Shahbabai

Pharmacist
Department of Hospital Pharmacy, Haga Teaching Hospital, The Hague, The Netherlands
Den Haag, Zuid-Holland, Netherlands
MR

Mandana Rad

MD
Anaesthesiology, Haga Hospital Juliana Children's Hospital, Den Haag, The Netherlands
Den Haag, Zuid-Holland, Netherlands
Ev

Eveline L.A. van Dorp

MD PhD
Anaesthesiology, Leiden University Medical Center, Leiden, The Netherlands
Leiden, Zuid-Holland, Netherlands
LV

Loes E. Visser

PharmD PhD
Department of Hospital Pharmacy, Haga Teaching Hospital, The Hague, The Netherlands
Den Haag, Zuid-Holland, Netherlands
SC

Suzanne C. Cannegieter, MD PhD

Professor
Department of Clinical Epidemiology, Leiden University Medical Center
Leiden, Zuid-Holland, Netherlands
Nienke van Rein, PharmD PhD

Post doc, PhD PharmD
Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands
Leiden, Zuid-Holland, Netherlands

Background: Before elective surgery, direct oral anticoagulants (DOAC) are discontinued following a standardized protocol based on the average DOAC half-life and the patient’s kidney function. However, it is unclear whether this strategy is actually successful, since the average DOAC half-life may not be applicable to the individual patient, which could result in high DOAC levels and increased bleeding risk.

Aims: To investigate DOAC levels prior to elective surgery and the associated blood loss.

Methods: The DALI study is an ongoing cohort in which 300 adult patients (100 each for apixaban, rivaroxaban and dabigatran) who have to cease DOAC treatment due to an elective procedure are planned to be included. We report here the results of the complete apixaban cohort. Blood was drawn just before surgery to determine apixaban levels (by liquid chromatography-mass spectrometry), estimated glomerular filtration rate(eGFR) and activated partial thromboplastin and prothrombin time(aPTT, PT). Patients were split according to apixaban levels > or ≤30ng/ml as well as by bleeding risk of surgery and eGFR(as both influence ceasing period). Blood loss during surgery and bleeding events in the 30 days after were retrieved from patient files.

Results: Table 1 describes the characteristics of the 101 included apixaban patients. Apixaban levels were >30ng/ml in 13(13%) patients (Table 2), of whom two had eGFR < 30ml/min. Median aPTT was 29s (IQR 27-31) and median PT was 14s (IQR 12-15). aPTT and PT were above-range in 16(17%) and 30(33%) patients respectively, of whom 2(2%) and 4(4%) had apixaban levels >30ng/ml. Median blood loss during surgery was 0 ml (IQR 0-100). During the 30 days after, 3 patients (all with apixaban levels ≤30ng/ml) received a blood transfusion and 10 had a minor bleeding (1 with apixaban levels >30ng/ml).

Conclusion(s): With the current protocol,87% of the apixaban-treated patients achieved levels ≤30ng/ml and only one minor bleeding occurred in patients with levels>30ng/ml.