Should We Anticoagulate Patients with CHA2DS2-VASc Scores of 1?

May 7, 2015

Should We Anticoagulate Patients with CHA2DS2-VASc Scores of 1?

  1. Kirsten E. Fleischmann, MD, MPH

Reported stroke rates vary widely.

  1. Kirsten E. Fleischmann, MD, MPH

The CHA2DS2-VASc score is used to stratify stroke risk in patients with atrial fibrillation (AF) based on seven features (Congestive heart failure, Hypertension, Age ≥75, Diabetes, prior Stroke or transient ischemic attack, Vascular disease, Age 65–74, and Sex). For patients with nonvalvular AF and scores of ≥2, U.S. guidelines recommend lowering stroke risk with anticoagulation (warfarin or novel anticoagulants; NEJM JW Cardiol Jun 2014 and Circulation 2014 Mar 28; [e-pub]), whereas patients with scores of 1 can be treated with aspirin, anticoagulants, or no agent at all. But are patients with scores of 1 likely to benefit from full anticoagulation? Several recent studies address aspects of this question.

In an analysis of >140,000 Swedish patients with AF but without anticoagulant exposure, researchers used both lenient and more stringent definitions of “stroke events” to determine risk for stroke in men and women with CHA2DS2-VASc scores of 1. Annual stroke rates were 0.1% to 0.2% in women and 0.5% to 1.3% in men, depending on the definition used. The authors concluded that patients in this risk group are unlikely to benefit substantially from anticoagulation.

Conversely, in a retrospective database analysis from Taiwan, annual risks for stroke in patients with a single risk factor other than sex (i.e., men with CHA2DS2-VASc scores of 1 and women with scores of 2) were 2.75% and 2.55%, respectively. Stroke risk was highest in people between ages 65 and 74, with annual stroke risks of 3.5% in men and 3.3% in women in this group.

Finally, in a Danish cohort, stroke rates at 1 year for untreated patients without additional risk factors (i.e., CHA2DS2-VASc scores of 0 for men and 1 for women) were very low (0.49 per 100 person-years), but this risk tripled (1.55 per 100 person-years) in those with one additional risk factor.


In the first study, stroke rates for patients with CHA2DS2-VASc scores of 1 who did not receive anticoagulation were lower than in the other two reports; therefore, the benefit of initiating anticoagulation was marginal. Editorialists point out the relatively wide variation in stroke rates seen in the literature, as demonstrated by the higher rates observed in the Danish and Taiwanese studies. Both the Swedish and Taiwanese studies show that not all factors worth 1 point in the CHA2DS2-VASc score convey equal risk. For example, age between 65 and 74 was associated with higher risk than other factors. Until we have randomized data in lower-risk patients, individualized decision making about antithrombotic therapy seems reasonable in patients with a single risk factor, with recognition of the strong effect of age on stroke risk.

Editor Disclosures at Time of Publication

  • Disclosures for Kirsten E. Fleischmann, MD, MPH at time of publication Grant / Research support NIH/NHLBI; Bluefield Project to Cure Frontotemporal Dementia Leadership positions in professional societies American College of Cardiology and American Heart Association (Vice Chair, Writing Committee for Guidance on Cardiovascular Evaluation and Care for Noncardiac Surgery)


Reader Comments (4)

eduard hernandez Physician, Cardiology

Even the anticoagulation reduces stroke incidence in that score, the risk of hemorragic complications is the same, so that must be the point in the choice risk-benefice.

kallinikos Tsakonas Physician, Cardiology, private

Guidelines for sure works as a ' dictionary" but we are living in the era of '' personalized, medicine'' I am trying to personalized the guidlines to the pt needs and not the opposite

Prem Physician, Cardiology, Patna india

Truly said. I agree with the study report

Bussey, Pharm D

Warfarin also reduces myocardial infarction, DVT/PE, and mortality such that risk for- and impact of treatment in these areas should be considered. Alternatively, patients with a TTR< 50% have higher rates of TE and bleeding than those on no treatment so that site-specific anti coagulation control should be considered

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