Refinement of Ischemic Stroke Risk in Patients with Atrial Fibrillation and CHA2DS2‐VASc Score of 1

Background Patients with atrial fibrillation (AF) with CHA2DS2‐VASc score of 1 (where CHA2DS2‐VASc is CHA2DS2‐Vascular disease, Age 65–74 years, Sex category) are recommended to receive antithrombotic therapy. Nonetheless, it remains unclear whether individual components that constitute CHA2DS2‐VASc score contribute equally to the ischemic stroke risk, particularly in patients with CHA2DS2‐VASc score of 1. The objective was to describe and compare the risk of ischemic stroke of the six individual components constituting CHA2DS2‐VASc among AF patients with CHA2DS2‐VASc score of 1.Methods and ResultsWe studied all patients with CHA2DS2‐VASc score of 1 and no antithrombotic therapy from our cohort of 9,727 Chinese AF patients. A total of 548 patients were studied: 190 patients with CHA2DS2‐VASc score of 0 and 358 patients with CHA2DS2‐VASc score of 1. Of those with a baseline CHA2DS2‐VASc score of 1, 51.1% patients aged 65–75; 29.3% patients were female; 12.0% had hypertension; 4.5% had heart failure; 2.5% had diabetes; and 0.6% had vascular disease. After 1,758 patient‐years of follow‐up, the annual incidence of stroke was 2.4% and 6.6% for patients with CHA2DS2‐VASc score of 0 and 1, respectively. Compared with patients with CHA2DS2‐VASc score of 0, patients with hypertension leading to CHA2DS2‐VASc score of 1 were at the highest risk of stroke (Hazard ratio [HR]: 9.8, 95% confidence interval [CI]: 2.7–35.6), followed by patients aged 65–74 (HR: 3.9, 95% CI: 2.3–6.6) and female gender (HR: 2.3, 95% CI: 1.1–4.8). Heart failure, diabetes mellitus, and vascular disease were not associated with stroke.ConclusionIn AF patients with CHA2DS2‐VASc score of 1, hypertension confers the highest risk for stroke among other risk factors comprising the score. A more aggressive thromboprophylaxis strategy may be justified among AF patients with CHA2DS2‐VASc score of 1 due to hypertension.