Assessment of Direct Oral Anticoagulant Plasma Concentrations Before Elective Electrical Cardioversion

Background and Objectives: Electrical cardioversion (ECV) restores sinus rhythm in patients with atrial fibrillation (AF) and requires uninterrupted anticoagulation to prevent thromboembolic events. Despite the predictable pharmacokinetic profile of direct oral anticoagulants (DOACs), variability in plasma concentrations and possible drug–drug interactions may have clinical implications. Therefore, this study aimed to describe DOAC plasma concentrations before elective ECV under routine clinical, using expected concentration ranges reported in the guidelines as descriptive reference points. Materials and Methods: A cross-sectional study included adult patients with AF receiving rivaroxaban, dabigatran, or edoxaban before elective ECV. Blood samples were collected before the procedure irrespective of the timing of DOAC administration, and plasma concentrations were measured using drug-specific chromogenic assays and compared with the expected peak and trough concentration ranges. Comparisons with expected peak and trough concentration distributions were descriptive only. Results: Thirty-seven patients were analysed, with polypharmacy observed in 83.8% of participants. Ten measurements (27.0%) exceeded the upper bounds of expected peak concentration distributions, while two measurements (5.4%) fell below the lower bounds of trough distributions. Two patients were receiving standard DOAC doses despite meeting renal criteria for dose reduction. Conclusions: Considerable variability in randomly timed DOAC concentrations was observed before ECV. Observed dosing discrepancies highlight the importance of periodically reassessing prescribed doses against current patient characteristics. Larger prospective studies with standardized sampling and clinical follow-up are needed to clarify the clinical significance of these findings.