Relationship of Aging and Comorbidities to Stroke Risk in AF

Study Questions:

What is the impact of a change in the CHA2DS2-VASc score over time and the risk of ischemic stroke in patients with atrial fibrillation (AF)?


The authors studied 31,039 AF patients from the Taiwan National Health Insurance system who were not treated with antiplatelet agents or oral anticoagulants and without any CHA2DS2-VASc risk elements other than age or sex. These patients were followed for the development of any new CHA2DS2-VASc risk factors (e.g., hypertension, diabetes). A change in the CHA2DS2-VASc scores was assessed for the risk of subsequent ischemic stroke. Predictive ability for ischemic stroke was compared using the C-statistic and net reclassification index.


Mean CHA2DS2-VASc scores were 1.29 at baseline, which increased to 2.31 over the 171,956 person-years of follow-up (mean change in CHA2DS2-VASc score of 1.02). Among the 4,103 patients who experienced an ischemic stroke, 89.4% had an increase in CHA2DS2-VASc of ≥1, compared to only 54.6% of patients without an ischemic stroke (p < 0.001). The most common new comorbidity was hypertension. A change in CHA2DS2-VASc score was a better predictor of ischemic stroke than baseline or follow-up CHA2DS2-VASc score.


The authors concluded that the CHA2DS2-VASc score is not static and that most patients develop ≥1 new CHA2DS2-VASc comorbidities. The authors also concluded that an increase in CHA2DS2-VASc score is associated with an increased risk of ischemic stroke, perhaps as a better predictor of stroke than the CHA2DS2-VASc score itself.


This study leverages a large, national health data set to explore the impact of stroke risk factors on subsequent ischemic stroke risk in patients with AF. Important findings for practicing clinicians are that the CHA2DS2-VASc score does not remain static and should be periodically re-calculated. Additionally, patients who develop new risk factors (e.g., hypertension) may be at increased risk for ischemic stroke, highlighting the importance of prophylactic anticoagulation.

Clinical Topics: Anticoagulation Management, Arrhythmias and Clinical EP, Prevention, Anticoagulation Management and Atrial Fibrillation, Implantable Devices, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Hypertension

Keywords: Aging, Anticoagulants, Arrhythmias, Cardiac, Atrial Fibrillation, Comorbidity, Diabetes Mellitus, Hypertension, Platelet Aggregation Inhibitors, Primary Prevention, Risk Factors, Stroke, Vascular Diseases

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