Neurology Perspectives (Jul 2024)
Frequency of and factors associated with underdosing of direct oral anticoagulants in patients with ischaemic stroke and atrial fibrillation
Abstract
Introduction: Direct oral anticoagulants (DOACs) are the first line of stroke prevention treatment in patients with non-valvular atrial fibrillation (NVAF). However, their inappropriate use is associated with increased risk of stroke, haemorrhagic complications, and mortality. The aim of this study is to analyse the factors associated with the non-prescription of anticoagulants and the underdosing of DOACs. Methods: We conducted a descriptive study of a prospective registry of patients admitted to a stroke unit due to ischaemic stroke or transient ischaemic attack (TIA) during an 1-year period. We included consecutive patients with history of NVAF with indication for anticoagulant therapy (ACT), according to the CHA2DS2-VASc scale. We analysed demographic factors, exposure to vascular risk factors, kidney function, polymedication, and short- and medium-term stroke progression. Results: Data were obtained from 60 patients admitted due to TIA or ischaemic stroke, with a previous diagnosis of NVAF, of whom 13 (21.7%) were not receiving ACT. Of the remaining 47, 25 (53.2%) were under treatment with DOACs, 21 (44.7%) with vitamin K antagonists, and 1 (2.1%) with heparin. Among patients on DOACs, 8 (32%) were receiving inappropriately low doses, with no differences between drugs.Age (80.8 vs 74.9 years, p=.05) and female sex (75% vs 35.3%, p=.05) were associated with underdosing of DOACs. Paroxysmal atrial fibrillation (46.2% vs 14.9%, p<.005) and antiplatelet therapy (61.5% vs 8.5%, p<.005) were associated with non-prescription of ACT. Conclusions: Inappropriate use of ACT, including underdosing, is frequent in our setting, occurring in up to one-third of patients admitted due to ischaemic stroke. Resumen: Introducción: Los anticoagulantes orales de acción directa (ACOD) son la primera línea de tratamiento preventivo del ictus en pacientes con fibrilación auricular no valvular (FANv) sin embargo, su uso inapropiado se asocia a mayor riesgo de ictus, complicaciones hemorrágicas y mortalidad. Nuestro objetivo es analizar los factores asociados a la no prescripción de anticoagulación y al uso de dosis baja inapropiada (DBI) en ACOD. Métodos: Estudio descriptivo de un registro prospectivo de pacientes ingresados por AIT o ictus isquémico en una Unidad de Ictus durante un año. Se incluyeron pacientes consecutivos con antecedentes de FANv con indicación, según escala CHADS-Vasc2, para tratamiento anticoagulante (ACO). Analizamos factores demográficos, exposición a factores de riesgo vascular, función renal, polifarmacia y evolución del ictus a corto y medio plazo. Resultados: Obtuvimos datos de 60 pacientes ingresados por AIT o ictus isquémico, con diagnóstico previo de FANv, de los cuales 13 (21,7%) no recibían ACO. Del resto (47): 25 (53,2%) tomaban ACOD, 21 (44,7%) con antivitamina K y 1 (2,1%) heparina. Entre los pacientes con ACOD, 8 (32%) recibían DBI, sin diferencias según clase de ACOD.La edad (80,8 vs 74,9, p = 0,05) y el sexo femenino (75% vs 35,3%, p = 0,05) se asociaron con la prescripción de DBI. La FA paroxística (46,2% vs 14,9%, p < 0,005) y el tratamiento antiagregante (61,5% vs 8,5%, p < 0,005) se asociaron con la no prescripción de ACO. Conclusiones: El uso inadecuado de la ACO, incluyendo el uso de DBI, es frecuente en nuestro medio pudiendo alcanzar hasta un tercio de los pacientes ingresados por ictus isquémico.
