Adequacy of anticoagulation in patients with nonvalvular atrial fibrillation

Fewer benefits are obtained from antithrombotic therapy in nonvalvular atrial fibrillation (NVAF) in routine practice than in clinical trials due to inadequate prescribing. This study aimed to assess the adequacy of anticoagulation therapy in clinical practice in patients with newly diagnosed NVAF.

A retrospective observational study was conducted to assess treatment adequacy in patients with newly diagnosed NVAF in Alava. The adequacy of direct-acting oral anticoagulant (DOAC) therapy was classified according to the dose specified in the summary of product characteristics. In patients treated with vitamin K antagonists (VKAs), anticoagulation therapy quality was considered good when the time in the therapeutic range (international normalised ratio: 2.0-3.0) was ≥60%. Univariate and multivariate logistic regression analyses were performed to analyse the probability of inadequacy.

Overall, 1446 patients with NVAF were included: 408 (28%) were treated with DOACs, and 856 (59%) with VKAs, while 182 (13%) received no anticoagulation therapy. The treatment was considered adequate in 75% of the DOAC group, 33% of the VKA group, and 57% of the no-anticoagulant group. The reason for inadequacy in treated patients was receiving an inappropriate dose of DOACs (25%) or VKAs (67%), while in the untreated group, 78 cases (43%) were classified as inadequate due to lack of anticoagulation with no clinical justification.

There is marked variability in the adequacy of anticoagulation in patients with NVAF. Guideline recommendations should be strictly followed to improve treatment adequacy, as it is unacceptable that half of these patients are inadequately anticoagulated.