A 78-year-old woman suffers a transient ischemic attack. She is a type 2 diabetic, and has hypertension. There is no history of coronary artery disease. An ECG done in emerge demonstrates atrial fibrillation.
- Calculate her annual stroke risk.
The CHADS2 score can be used to evaluate a person’s annual risk of stroke with atrial fibrillation.
This woman’s annual risk of stroke (without anticoagulation) is 12.5%, corresponding to a CHADS2 score of 5. Points are allocated for the following factors:
- History of congestive heart failure +1
- History of hypertension +1
- Age ≥75 +1
- History of diabetes +1
- History of stroke or TIA +2
CHADS2 Score % Annual Stroke Risk 0 1.9 1 2.8 2 4.0 3 5.9 4 8.5 5 12.5 6 18.2
(Adapted from Gage BF, 2001.)
- What medications should she be on based on her risk, and for how long?
Because this patient is in the high-risk of annual stroke, she should be taking either warfarin or a novel oral anticoagulant (NOAC).
- If starting warfarin, she would require bridging anticoagulation with low molecular weight heparin until her warfarin dose is titrated to an INR of 2.0-3.0.
- Examples of NOACs include: dabigatran (anti-thrombin), rivaroxaban and apixaban (anti-Xa).
She should be taking this medication for life, or until the risk of complications outweighs the risk of stroke.
- Camm AJ et al. 2012 focused update of the ESC Guidelines for the management of atrial fibrillation: an update of the 2010 ESC Guidelines for the management of atrial fibrillation. Developed with the special contribution of the European Heart Rhythm Association. Eur Heart J. 2012, 33:2719-2747.
- Gage BF et al. Validation of Clinical Classification Schemes for Predicting Stroke. Results From the National Registry of Atrial Fibrillation. Jama. 2001, 285:2864-2870.
- Lip GY, Nieuwlaat R, Pisters R, Lane DA and Crijns HJ. Refining clinical risk stratification for predicting stroke and thromboembolism in atrial fibrillation using a novel risk factor-based approach: the euro heart survey on atrial fibrillation. Chest. 2010, 137:263-272.