EC Pharmacology and Toxicology

Introduction: Direct oral anticoagulants (DOACs) are the preferred therapy for prevention of thromboembolic events in patients with non-valvular atrial fibrillation (NVAF). Despite their proven efficacy, inappropriate DOAC dosing remains common and has been associated with increased risks of stroke and bleeding. Limited data exist evaluating the impact of interdisciplinary, pharmacist-involved care models on DOAC dosing accuracy. This study evaluated the effect of a multidisciplinary care model on achieving appropriate DOAC dosing in patients with NVAF.

Study Design: This retrospective cohort study compared the frequency of inappropriate DOAC dosing among patients managed under a multidisciplinary care model that included clinical pharmacist involvement versus those managed under a single-provider care model.

Methods: Adult patients (≥ 18 years) with NVAF treated at a university-affiliated ambulatory cardiology clinic and initiated on a DOAC for stroke prevention between June 2019 and June 2023 were included. Patients with valvular atrial fibrillation or a history of venous thromboembolism were excluded. The primary outcome was the occurrence of at least two consecutive inappropriate DOAC doses following treatment initiation. Binary logistic regression was used to assess the association between care model and inappropriate dosing, adjusting for age, body mass index, race, and stroke risk factors.

Results: Over a median follow-up of approximately one year, inappropriate DOAC dosing occurred in 3 patients (2%) in the pharmacist-involved group compared with 36 patients (24%) in the non-pharmacist group (p < 0.001). In adjusted analyses, pharmacist involvement was associated with a significantly lower likelihood of inappropriate dosing (adjusted odds ratio [aOR] 0.03; 95% CI, 0.004 - 0.14; p < 0.001). Unadjusted analysis demonstrated similar findings (OR 0.06; 95% CI, 0.02 - 0.22; p < 0.001).

Conclusion: Incorporation of pharmacists within a multidisciplinary care model was associated with significantly improved DOAC dosing appropriateness in patients with NVAF. These findings highlight the critical role of pharmacist involvement in optimizing anticoagulation therapy and support the integration of interdisciplinary care models in ambulatory cardiology practice.

 Keywords: Multidisciplinary Care Model; Clinical Pharmacist; Direct Oral Anticoagulants (DOACs)’ Non-Valvular Atrial Fibrillation (NVAF)

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