Comportamiento en vida real de los anticoagulantes orales de acción directa en pacientes con fibrilación auricular no valvularestudio en poblaciones especiales

Abstract

Atrial fibrillation is the most common cardiac arrhythmia. It is due to an asynchrony in atrial contraction, which favours blood stasis in the atria, and thus, increasing the risk of thromboembolism, mainly ischemic stroke. To reduce this risk, patients have been classically anticoagulated with vitamin K antagonist, and, more recently, with direct oral anticoagulants (dabigatran, rivaroxaban, apixaban and edoxaban), which have been shown in clinical trials to be at least as effective than vitamin K antagonist in preventing ischemic stroke and decreasing the risk of intracranial bleeding. However, this affirmation cannot be generalized to all risk groups, as subgroups such as elderly, chronic kidney disease and morbid obesity, were underrepresented in these trials. Therefore, these populations are the aim of this study. We designed a multicentric retrospective study in which three Spanish hospitals participated, which included patients with atrial fibrillation who started treatment with a direct oral anticoagulant from January 2013 to December 2016. Mean follow up was 1.6 years. Thromboembolic and hemorrhagic events and mortality were analyzed, showing the following results: 1. People who were ? 80 years represented the 42 % of the whole population. In this group, a higher rate of ischemic events and mortality were observed, and these rates were higher as age increases. Regarding haemorrhagic events, a trend towards a higher rate of bleeding was observed, although without reaching the statistical significance. 2. In the group with renal failure (renal clearance < 50 ml/min), which accounted the 21 % of the population, a higher rate of ischemic and haemorrhagic events was found. Furthermore, the worse the kidney function, the higher the death rate and a trend towards a higher ischemic stroke rate was observed. 3. The population with morbid obesity (BMI ? 40 or weight ? 120 kg) only represented 5 % of the whole cohort, where no significant differences were found in the main events studied. When analysing the correct or incorrect dosage of these drugs based on their respective technical sheets, we observed that 23 % of the population in our cohort was receiving an inappropriate dose, being mainly underdosed. The subgroup with the highest rate of wrong dosing was the elderly, followed by the morbidly obese population and finally patients with chronic kidney disease, with underdosing predominant in all cases. This underdosing resulted in a higher rate of mortality compared to the well dosed group. No differences were observed regarding thrombotic events in underdosed and haemorrhagic events in the overdosed ones.