A Practical Guide to Haemostasis

Atrial Fibrillation and Ischaemic Stroke:
Risk Assessment Algorithms


Atrial Fibrillation is a major risk factor for acute ischaemic stroke and whilst anticoagulation therapy significantly reduces this risk, it is associated with an increased bleeding risk. A number of algorithms have been developed to stratify the risk of stoke in patients with AF and a number of these are summarised below with links to the relevant algorithm.

The ATRIA Score

The ATRIA score was developed to establish the risk of a stroke in individuals with Atrial Fibrillation [AF]

Click HERE to access the ATRIA Score.

CHADS2 Score

The CHADS2 is a stroke-risk grading system that estimates the risk of stroke in patients with atrial fibrillation. A high CHADS2 score corresponds to a greater risk of stroke, whilst a low CHADS2 score corresponds to a lower risk of stroke. The CHADS2 score is simple and has been validated by many studies.

Click HERE for more information on the CHADS2 algorithm.

CHA2D2-VASc Score

The CHADS2 score has been superseded by the CHA2DS2VASc score and which is designed to improve the stratification of low-risk patients. It uses the same 5 risk factors but assigns a score of ‘2’ for patients ≥75 years and in addition, includes 3 new risk factors:
    1. A history of vascular disease,
    2. Age 65-74 years
    3. Female sex

Click HERE for more information on the CHA2DS2VASc algorithm.



The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation - GARFIELD-AF tool, is a clinical prediction algorithm that stratifies patients with Atrial Fibrillation to facilitate decisions on the potential benefits & risks of anticoagulation, based on mortality, stroke and bleeding.

Click HERE for additional information on the GARFIELD-AF tool.