Changes in CHA2DS2-VASc score and risk of ischemic stroke among patients with atrial fibrillation

AimsThe CHA(2)DS(2)-VASc score is fundamental to stroke risk assessment in atrial fibrillation. However, stroke-related risk factors can be modified later in life. This study aimed to assess the association of changes in CHA(2)DS(2)-VASc score over time (Delta CHA(2)DS(2)-VASc score) with the risk of ischemic stroke.Materials and methodsThis is an observational analysis of 1127 atrial fibrillation patients previously enrolled in the MISOAC-AF trial. After a median 2.6-year follow-up period, baseline and follow-up CHA(2)DS(2)-VASc scores were used to extract the Delta CHA(2)DS(2)-VASc score. The stroke predicting accuracies of the baseline, follow-up, and Delta CHA(2)DS(2)-VASc scores were assessed through regression analyses.ResultsThe mean baseline, follow-up, and Delta CHA(2)DS(2)-VASc scores were 4.2, 4.8, and 0.6 respectively. Ischemic stroke occurred in 54 (4.4%) patients, of which 83.3% had a Delta CHA(2)DS(2)-VASc score >= 1, contrary to 40.1% of the stroke-free group. The stroke risk per 1-point increase of the CHA(2)DS(2)-VASc score was not significantly associated with the baseline score (aHR=1.14; 95%CI: 0.93-1.41; p=0.201), whereas a significant association was observed with the follow-up (aHR=2.58; 95% CI: 2.07-3.21; p<0.001) and Delta (aHR=4.56; 95%CI: 3.50-5.94; p<0.001) scores. C-index assessment indicated that follow-up and Delta CHA(2)DS(2)-VASc scores were more potent predictors of ischemic stroke compared to baseline.ConclusionIn atrial fibrillation patients, changes in CHA(2)DS(2)-VASc score over time were associated with the incidence of stroke. The improved predictability of follow-up and Delta CHA(2)DS(2)-VASc scores indicates that stroke risk is not a static parameter.