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CHADS-65 (Canadian Cardiovascular Society Algorithm)

Guides antithrombotic therapy selection in non-valvular atrial fibrillation.

CHADS-65 (Canadian Cardiovascular Society Algorithm)
Age
years
Prior stroke/TIA/systemic embolism, hypertension, heart failure (or reduced LVEF), or diabetes
Coronary artery disease or peripheral artery disease
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When to use

  • Selecting antithrombotic therapy (oral anticoagulant vs none) for stroke prevention in patients with non-valvular atrial fibrillation.

Formula

Decision algorithm: age >=65 years -> oral anticoagulant; else if a CHADS2 risk factor (prior stroke/TIA, hypertension, heart failure, diabetes) is present -> oral anticoagulant; else if coronary or peripheral artery disease is present -> oral anticoagulant alone; otherwise no antithrombotic therapy.

Pearls and pitfalls

  • Endorsed by the Canadian Cardiovascular Society as a simplified alternative to CHA2DS2-VASc for routine practice.

References

  1. Andrade JG, Aguilar M, Atzema C, et al. The 2020 Canadian Cardiovascular Society/Canadian Heart Rhythm Society Comprehensive Guidelines for the Management of Atrial Fibrillation. Can J Cardiol. 2020;36(12):1847-1948.