Risk factors for ischemic stroke in patients with non-valvular atrial fibrillation and therapeutic international normalized ratio range

INTRODUCTION: Atrial fibrillation (AF) is the most common cause of ischemic stroke (IS). Atrial fibrillation patients are recommended to use oral anticoagulants (OACs) as part of prevention against IS. However, despite having a therapeutic intensity of OAC therapy, IS can still occur in such patients. The aim of our study was to examine the configuration of IS risk factors in patients with non-valvular atrial fibrillation (NVAF) and within the therapeutic INR range (TINR). MATERIAL AND METHODS: Our retrospective study involved 1835 patients with a recent IS. The experimental group consisted of 154 patients with acute IS, NVAF and TINR. The control group consisted of 1681 patients with acute IS but without AF. RESULTS: Patients with IS, NVAF and TINR were significantly older and more often female than patients with IS without NVAF (p < 0.001 and p < 0.001, respectively). In these patients, diabetes mellitus, dyslipidemia, hypertension, coronary heart disease, smoking and previous IS were significantly more frequent than in the patients with IS without NVAF (p = 0.036, p = 0.002, p < 0.001, p < 0.001, p < 0.001, p = 0.003). Based on a univariable and multivariable logistic regression model, we found that in the group of patients who suffered a stroke despite TINR compared to patients with IS without AF there were more smokers (OR = 20.337; OR = 147.589) and patients with previous stroke (OR = 6.556; OR = 11.094), hypertension (OR = 3.75; OR = 2.75) and dyslipidemia (OR = 2.318; OR = 2.294). CONCLUSIONS: The group of patients with NVAF and TINR is significantly more burdened by other independent common risk factors for stroke.