Stroke Risk for Atrial Fibrillation Patients With a CHA2DS2-VASc Score of 1-2 | Journal Scan

Study Questions:

What is the risk of stroke in atrial fibrillation (AF) patients with a single CHA2DS2-VASc risk element?


Using the Taiwanese National Health Insurance Research Database, 186,570 AF patients not on antiplatelet or anticoagulant therapy were identified between 2006 and 2011. Men with a CHA2DS2-VASc risk of 1 and women with a CHA2DS2-VASc risk of 2 were selected and assessed for an ischemic stroke during a mean follow-up of 5.2 ± 4.3 years.


Among 12,935 men with AF and a CHA2DS2-VASc score of 1, 14.4% experience a stroke, with an annual stroke rate of 2.75%. For these men, ischemic stroke risk varied between 1.96%/year for young men with vascular disease to 3.50%/year for men ages 65-74 years. Of the 7,900 women with a CHA2DS2-VASc score of 2, 14.9% experienced a stroke with an annual stroke rate of 2.55%. Ischemic stroke risk varied between 1.91% for young women with hypertension to 3.34% for women ages 65-74 years.


The authors concluded that not all CHA2DS2-VASc risk factors carry the same risk of stroke. They also concluded that age 65-74 was the risk factor with the highest risk of stroke for both men and women. They suggested that oral anticoagulation should still be considered for all patients with a nongender CHA2DS2-VASc risk factor.


Using a national registry of AF patients, the authors demonstrated heterogeneity in the risk of stroke among Taiwanese patients categorized as low risk (CHA2DS2-VASc score of 1-2). This study avoided selection bias by assessing patients before the introduction of the CHA2DS2-VASc score in multiple guidelines as a means of determining the need for oral anticoagulation in AF patients. While there is heterogeneity in the absolute stroke risk associated with each CHA2DS2-VASc risk element, all elements contribute a risk of stroke between 2.0% and 3.5%/year. When warfarin is expertly managed or direct oral anticoagulants are appropriately selected, it is reasonable for all of these patients to be treated in accordance with American and European guidelines for the prevention of stroke and systemic embolism in AF.

Clinical Topics: Anticoagulation Management, Arrhythmias and Clinical EP, Prevention, Anticoagulation Management and Atrial Fibrillation, Atrial Fibrillation/Supraventricular Arrhythmias

Keywords: Anticoagulants, Atrial Fibrillation, Stroke, Warfarin, Risk, Risk Factors, Embolism, Primary Prevention

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