Hazards of antithrombotic therapy on hemodialysis patients with atrial fibrillation and high thromboembolic risk: a Taiwanese population-based cohort study

The benefit of antithrombotic therapy in hemodialysis (HD) patients with atrial fibrillation (AF) and high thromboembolic risk has not been proved. The purpose of this study was to examine the effects of antithrombotic therapy on HD patients with AF and high thromboembolic risk. We analysed the outcomes of 1,197 HD patients with AF having CHA(2)DS(2)-VASc scores >= 2 points by using data retrieved from the National Health Insurance Research Database between 1997 and 2008. Four groups of patients, namely aspirin, warfarin, aspirin combined with warfarin, and non-treatment groups, were compared. Between the treatment and non-treatment groups, multivariate Cox proportional analysis revealed no significant difference in the mortality. Among the treatment groups, the aspirin combined with warfarin group had a higher mortality than that of the aspirin group. No significant differences were observed among the four groups in the risks of haemorrhagic stroke, gastrointestinal bleeding, congestive heart failure, acute coronary syndrome, and peripheral arterial occlusive disease. However, the risk of ischemic stroke was significantly higher in the aspirin and the aspirin combined with warfarin groups than in the non-treatment group. In HD patients with AF and with high thromboembolic risks, the mortality rate was not significantly different between treatment groups and non-treatment group. However, the risk of ischemic stroke was significantly higher in aspirin and aspirin plus warfarin groups when compared with non-treatment group. Therefore, the usage of aspirin and warfarin in these patients should be meticulously evaluated.