Cardiology  |  Atrial Fibrillation Pathway - Stroke Risk Calculation CHADS2 + HASBLED




Cardiology

Atrial Fibrillation Pathway - Stroke Risk Calculation CHADS2 + HASBLED

Tools to evaluate baseline stroke risk

The risk of stroke can be evaluated using a risk stratification tool such as CHADS2 or the updated version, CHA2DS2-VAS, which now includes additional stroke risk factors (see sidebar).6,18 CHADS2 is a simpler tool for use in general practice. These tools can be used to help decide whether to use warfarin in patients with non-valvular AF. However, they do not take into account bleeding risks, monitoring requirements and other factors that may make warfarin less suitable or potentially hazardous in a particular patient.

Stroke assessment tools for patients with AF6,18

The updated stroke assessment tool CHA2DS2-VAS puts greater emphasis on increasing age ( ≥ 75 years) and also incorporates additional risk factors for stroke - female gender, age group 65 - 75 years and a history of vascular disease e.g. myocardial infarction, peripheral arterial disease. Scores for each tool are calculated as follows:

CHADS2

Score

Congestive heart failure

1

Hypertension

1

Age 75 years or older

1

Diabetes mellitus

1

Previous Stroke or TIA

1

Maximum score

6

 

CHA2DS2-VAS

Score

Congestive heart failure/LV dysfunction

1

Hypertension

1

Age ≥ 75 years

2

Diabetes mellitus

1

Stroke/TIA

2

Vascular disease (prior MI, peripheral vascular disease)

1

Age 65-75 years

1

Sex category (i.e. female gender)

1

Maximum score

9


Note:  that using CHADS-VAS anti-coagulation is indicated for all females older than 65 and all males older than 75 with AF
.

CHADS2 Results

If the score is:

  • Greater than or equal to 2 - start warfarin (if no contraindicationslink here from below)
  • 0 - start aspirin
  • 1 - the annual risk of stroke is 2.8%.  The choice of either aspirin, warfarin or dabigatran will depend on patient preference, compliance, and bleeding risk.
  • Bleeding risk can be assessed using HAS-BLED score

Table 1: HAS-BLED Bleeding Risk Score (adapted from Pisters et al, 201015)

Letter

Clinical Characteristic

Points

H

Hypertension (systolic blood pressure > 160 mm Hg)

1

A

Abnormal renal and liver function

1 point each

S

Stroke (past history)

1

B

Bleeding (previous history of bleeding or predisposition to bleeding)

1

L

Labile INRs (unstable, high or insufficient time within therapeutic range)

1

E

Elderly (> 65 years)

1

D

Drugs or alcohol (including concomitant use of aspirin, other antiplatelet agents and NSAIDs)

1 point each

 

 

Max 9 points

 
A score of three or more indicates a patient who may be at high risk of bleeding complications and who therefore may benefit from more regular review of anti-coagulation therapy.



Last updated : Friday, August 21, 2015
Next review date : Saturday, August 20,2016


Disclaimer: This site is intended to be flexible and frequently updated. While every effort has been made to ensure accuracy, all information should be verified.