The HIPOGAIA study: Monitoring of oral anticoagulation with vitamin K antagonists in the municipality of Gaia

Abstract

IntroductionAnticoagulant therapy is an effective measure in preventing thromboembolic adverse events. Of the diseases in which this treatment is indicated, atrial fibrillation (AF) has the highest incidence worldwide, with a prevalence of 1.5-2%. ObjectivesTo assess the quality of monitoring of patients with non-valvular AF under oral anticoagulation with vitamin K antagonists in Vila Nova de Gaia healthcare units. MethodsThis was a retrospective observational analytical study of the population registered at the 37 healthcare units of the Vila Nova de Gaia and Espinho health center area under oral anticoagulation with vitamin K antagonists during 2014. The data were collected using TAONet® software. The variables studied were health units, age, gender, INR value, time in therapeutic range (TTR) and medication. TTR was calculated for each patient using the Rosendaal linear interpolation method. It was stipulated that each patient should have undergone at least six INR measurements. Data were analyzed using Microsoft Excel® 2010 and SPSS® version 21, using descriptive and inferential statistical techniques. ResultsA total of 479 patients with non-valvular AF were studied, corresponding to 5883 INR tests. Mean TTR was 67.4±6.5%, and 35.3% of patients exhibited poor control (TTR <60%). DiscussionOur study showed moderate control of coagulation parameters, but better than in many international clinical trials and in another Portuguese observational study. Nevertheless, there is still room for improvement in anticoagulation monitoring in primary health care.