Risk of Thromboembolism in Nonvalvular Atrial Fibrillation

Background: Atrial fibrillation is associated with atrial thrombus formation and peripheral embolization, which leads to ischemic stroke or systemic thromboembolism. The CHADS2, CHA2DS2-VASc scores are tool for estimating risk of stroke in nonvalvular atrial fibrillation (NVAF) patients. Data on scores variables, Body mass index (BMI) and chronic kidney disease (CKD) with reduced glomerular filtration rate on their implication in identify thromboembolic events (TE) in Saudi population with NVAF are quite limited.

Methods: The study consisted of 541 patients with AF seen in our institution from 2008 to 2013 were identified in database, 175 were NVAF. Thromboembolic end points were defined as ischemic stroke and systemic embolism. During follow - up period of 730 days. CHADS2, CHA2DS2-VASc scores components, BMI also CKD and association with TEs end points identified by Cox regression analysis.

Results: Of 175 patients with NVAF, 26 (14.9%) patients were identified to have TEs. Majority of them had stroke. Age (>or =75 years) and Peripheral vascular disease were significant factors for TEs. Thromboembolic risk in patients had previous stroke or TIA was 38.5% (P value =.000). Events rate of thromboembolism increased when CHADS2/ CHA2DS2-VASc score increased. No statistically significant associations were observed with BMI and TEs. Study has shown Despite only 35% of study population is suffering from CKD however level of estimated glomerular filtration rate were significant factor for TEs in patients with nonvalvular atrial fibrillation.

Conclusion: Study demonstrated CHADS2, CHA2DS2-VASc, CKD are predictor of TEs and should be included in risk stratification schemes among NVAF Saudi patient. While obesity was not predicator for TEs. So, keeping this association in consideration during thromboembolism risk assessment is recommended. Further study is needed to search for modifiable risk factors that are associated with increased risk thromboembolism in NVAF patient In addition to the conventional CHADS2/ CHA2DS2-VASc scheme.