How lower doses of direct oral anticoagulants are interpreted in clinical practice: a national survey of the Italian Atherosclerosis, Thrombosis and Vascular Biology (ATVB) Study Group

AIM: To evaluate the current interpretation of the lower doses of direct oral anticoagulants (DOAC) dabigatran, apixaban, edoxaban and rivaroxaban in nonvalvular atrial fibrillation. METHODS: A questionnaire of 14 statements to which the possible answers were fully agree/partially agree/partially disagree/fully disagree or yes/no was prepared within the board of the Italian Atherosclerosis, Thrombosis and Vascular Biology Study Group and forwarded to individual Italian physicians. RESULTS: A total of 620 complete questionnaires were received from nearly all the Italian regions and physicians of various medical specialists, either enabled or not for the prescription of DOAC. A wide agreement was found as regards the pharmacological, as well as clinical consequences of the administration of the lower dose of factor-Xa inhibitors both in patients with and without clinical and/or laboratory criteria requiring dose reduction. Wide agreement was also found as regards the presence of moderate kidney insufficiency in selecting the dose of DOAC. Instead, more debated were issues regarding the proportionality between dabigatran dose and plasma concentration and selection of dabigatran dose, as well as the role of measuring drug plasma concentration and/or determine the anticoagulant activity of factor-Xa inhibitors when used at the lower dose. CONCLUSION: The interpretation of the lower doses of DOAC in current Italian clinical practice appears largely correct and shared. Because of the persistence of some residual uncertainties, essentially regarding dabigatran, however, continuous educational effort still appears warranted.