Predictors of Ischemic Stroke in Patients With Non-valvular Atrial Fibrillation: A Retrospective Study

Background Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and a major cause of ischemic stroke (IS). Although the Congestive heart failure (or left ventricular dysfunction), Hypertension, Age ≥ 75 years, Diabetes mellitus, prior Stroke, transient ischemic attack (TIA), or thromboembolism, Vascular disease (prior heart attack, peripheral artery disease, or aortic plaque), Age 65 to 74 years, and ​​​​​​​Sex category (Female) or CHA₂DS₂-VASc score is widely used for stroke risk stratification, additional clinical, treatment-related, and echocardiographic factors may influence stroke risk. This study aimed to determine the frequency of IS and identify its independent predictors among patients with non-valvular AF. Methods This retrospective study included 350 patients with non-valvular AF treated at a tertiary care hospital in Rawalpindi, Pakistan. Demographic, clinical, anticoagulation, CHA₂DS₂-VASc, and echocardiographic data were extracted from medical records. Statistical analyses were performed using IBM SPSS Statistics for Windows, Version 25 (Released 2017; IBM Corp., Armonk, New York, United States). Group comparisons were conducted using the independent-samples t-test and chi-square test, followed by multivariable logistic regression to identify independent predictors of IS. Results From the total study population, 71 (20.28%) experienced IS. Patients with stroke had a significantly higher mean CHA₂DS₂-VASc score than those without stroke (4.50 ± 1.40 vs. 3.20 ± 1.20, p<0.001). On initial analysis, age ≥65 years, previous stroke/TIA, vascular disease, smoking, chronic kidney disease, inadequate anticoagulation, left atrial enlargement, reduced left ventricular ejection fraction (LVEF<40%), left atrial appendage (LAA) thrombus/spontaneous echo contrast (SEC), and CHA₂DS₂-VASc score ≥4 were significantly associated with IS (all p<0.05). Multivariable logistic regression confirmed age ≥65 years (adjusted odds ratio (AOR)=2.59; p=0.003), previous stroke/TIA (AOR=2.37; p=0.012), vascular disease (AOR=1.88; p=0.045), smoking (AOR=1.93; p=0.039), chronic kidney disease (AOR=2.12; p=0.028), inadequate anticoagulation (AOR=2.90; p=0.001), left atrial enlargement (AOR=2.32; p=0.007), reduced LVEF (AOR=1.94; p=0.042), and LAA thrombus/SEC (AOR=3.07; p=0.004) as independent predictors of IS. Conclusion IS was observed in a considerable proportion of patients with non-valvular AF. IS was independently associated with advanced age, previous stroke/TIA, vascular disease, smoking, chronic kidney disease, inadequate anticoagulation, left atrial enlargement, reduced LVEF, and LAA thrombus/SEC. Assessment of these factors, in addition to the CHA₂DS₂-VASc score, may enhance risk stratification and facilitate timely implementation of preventive strategies.