Change in Risk Score Strong Predictor of Stroke in Atrial Fibrillation
Patients with atrial fibrillation (AF) are at increased risk of stroke, however, this risk can vary depending on the presence or absence of various factors.1 The CHA2DS2-VASc score is recommended in relevant guidelines to support physicians in assessing stroke risk in patients with AF.2,3 The CHA2DS2-VASc score calculation is performed at baseline to determine whether anticoagulation therapy should be initiated in a patient. In a recent study published in the Journal of the American College of Cardiology, Chao et al. investigated three ways of using the CHA2DS2-VASc score to predict stroke risk in a Taiwanese AF population. The research team calculated: (1) the baseline score; (2) a time-dependent score, called the follow-up CHA2DS2-VAScscore; and (3) the change in score, called the delta CHA2DS2-VASc score. The accuracies of these three scores in predicting ischaemic stroke were analysed and compared.4 This was a retrospective study of 31,039 low-risk AF patients who were not receiving antiplatelet or anticoagulation therapy.
During the 171,956 person-years of follow-up, the mean baseline CHA2DS2-VASc score was 1.29, the mean follow-up CHA2DS2-VASc score was 2.31, and the mean delta CHA2DS2-VASc score was 1.02. CHA2DS2-VASc score did not change in 40.8% of patients. The researchers found that, of the 4,103 patients who experienced ischaemic stroke, 89.4% had a delta CHA2DS2-VASc score of at least 1, compared with only 54.6% of patients who did not experience an ischaemic stroke. Furthermore, of those patients who experienced ischaemic stroke, 64.4% (2,643) acquired at least one new comorbidity, with hypertension being the most common. The net reclassification index and c-index demonstrated that the delta CHA2DS2-VASc score was a better indicator of ischaemic stroke than either the baseline or follow-up scores.
The researchers concluded that the CHA2DS2-VASc score is not static. Stoke risk is dynamic since patients age with time and accumulate additional comorbidities, further increasing their risk. More research is needed to validate the delta CHA2DS2-VASc score.
Disclosure: Emma East is an employee of Touch Medical Media.
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2. Kirchhof P, Benussi S, Kotecha D, et al. 2016 ESC Guidelines for the management of atrial fibrillation developed in collaboration with EACTS. Eur Heart J. 2016;37: 2893–962.
3. January CT, Wann LS, Alpert JS et al. 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the Heart Rhythm Society. J Am Coll Cardiol. 2014;64:e1–76.
4. Chao T-F, Lip GYH, Liu C-J, et al. Relationship of aging and incident comorbidities to stroke risk in patients with atrial fibrillation. J Am Coll Cardiol. 2018;71(2):122–32.