Factors Associated with Ischaemic Stroke Development Despite Oral Anticoagulant Therapy in Patients with Non-Valvular Atrial Fibrillation

Abstract

Objective: To evaluate the effectiveness of the most popular risk scores (CHADS2, CHA2DS2-VASc, and ATRIA scores) in predicting stroke events in patients with non-valvular atrial fibrillation (NVAF) who were already receiving oral anticoagulant therapy (OAT). Study Design: An observational study. Place and Duration of the Study: Department of Cardiology, Ataturk Research and Training Hospital, Izmir Katip Celebi University, Izmir, Turkiye, from January 2020 to December 2023. Methodology: Patients with NVAF who were on OAT were divided into two groups. Group 1 consisted of patients who had not experienced a stroke while on OAT, and Group 2 consisted of patients who had experienced at least one stroke while on OAT at the time of inclusion. Continuous variables were presented as mean or median values and were compared using Student's t-test or Mann-Whitney U test, depending on the type of data distribution. Results: There were 162 patients in Group 1 and 129 patients in Group 2, the majority being females. The median age of patients was 76 years (IQR: 71-82) in Group 1 and 75 years (IQR: 68-81) in Group 2. Comorbidities were statistically similar in both groups except for hyperlipidemia. Treatment for atrial fibrillation (AF) was also statistically similar in both groups. The CHA2DS2-VASc and ATRIA stroke scores showed statistically significant differences between the groups. In univariate analysis, hyperlipidemia and ATRIA stroke score were >8, and in multivariate analysis, only ATRIA stroke score was >8, which showed a correlation with estimating the risk of ischaemic stroke (IS) events under oral anticoagulation (OAC). The ATRIA stroke score showed a strong correlation Spearman's rho test and in the ROC curve. Conclusion: The CHA2DS2-VASc, CHADS, and ATRIA risk scores have proven effective in primary IS prophylaxis. The ATRIA stroke score system for secondary prevention appears to be more effective than the most popular score systems.