Refining Residual Ischemic Stroke Risk in Anticoagulated Atrial Fibrillation Using Index Outpatient LA Diameter: The CHA2DS2-VALa Score.
TL;DR
The CHA2DS2-VALa score significantly improves stroke risk stratification in AF by integrating LA diameter into conventional scoring, as echocardiographic measurement is widely available and reproducible.
Abstract
Background
Atrial fibrillation (AF) increases ischemic stroke risk nearly fivefold. Although the CHA2DS2-VA score is widely used for risk stratification, its predictive performance is limited, particularly in intermediate-risk patients. Left atrial (LA) enlargement, a marker of structural remodeling, may improve risk prediction.
Aims
To evaluate whether adding LA diameter to CHA2DS2-VA (creating CHA2DS2-VALa) enhances ischemic stroke prediction in AF patients. We additionally derived a multivariable β-weighted model and benchmarked its performance against CHA2DS2-VA (and the simplified +1 LA rule).
Methods
This retrospective study included 1648 AF patients. LA diameter was measured by standardized echocardiography. A ROC-derived cut-off (> 4.7 cm) defined enlargement. Patients were followed for a mean of 4.18 ± 0.35 years. Imaging-confirmed ischemic stroke events were identified through institutional hospital records and the electronic health registry, and were validated using hospitalization documentation, neurology consultation notes, discharge summaries, and available brain CT/MRI findings. Predictors were assessed using multivariable logistic regression, and Kaplan-Meier/log-rank analyses compared CHA2DS2-VALa versus CHA2DS2-VA.
Results
Imaging-confirmed ischemic stroke events occurred more frequently in patients with LA > 4.7 cm (25 [3.8%] vs. 21 [2.1%], p < 0.001). Elevated CRP, NT-proBNP, diabetes, hypertension, CAD, and heart failure were also associated with stroke. LA > 4.7 cm independently predicted events (OR 1.97, 95% CI 1.36-2.86, p < 0.001). ROC analysis showed strong discrimination for LA diameter (AUC 0.872; sensitivity 82%, specificity 85%). Kaplan-Meier analysis demonstrated superior prediction with CHA2DS2-VALa compared to CHA2DS2-VA (log-rank p < 0.001).
Conclusion
The CHA2DS2-VALa score significantly improves stroke risk stratification in AF by integrating LA diameter into conventional scoring. As echocardiographic measurement is widely available and reproducible, this modification offers a simple, pragmatic approach to refine residual stroke-risk stratification and support closer evaluation and follow-up in anticoagulated AF patients. Prospective validation in diverse populations is warranted.