AF

Question 1

What is the risk reduction for embolic stroke in AF patients treated with warfarin?

Answer 1

2/3 irrespective of baseline risk

Question 2

What is the annual risk of ICH in patients on warfarin?

Answer 2

~0.4% (1 in 250)

Question 3

What is the baseline risk of ICH of non-anticaogulated patients?

Answer 3

0.2% - 1 in 500

Question 4

Outline the CHA2DS2-VASc.

Answer 4

• Calculates risk of stroke for patients in AF
• Categorizes risk as:
  
  • 0 points: Low risk - 0.2%/yr risk
  • 1 point: Moderate risk - 0.6%/yr risk
  • >=2 points: High risk - >=2.2%/yr risk (4pts = 5%; 9pts (max) = 12%)

CHA2DS-VASc:

• CHF = 1pt
• HTN = 1pt
• Age >75y = 2pt
• DM = 1pt
• Stroke (inc TIA and thromboembolism) = 2pts
• Vascular disease = 1pt
• Age 64-75y = 1pt
• Sex category - Female = 1pt

Question 5

Outline the HAS-BLED score.

Answer 5

• Estimates the 1-year risk of major haemorrhage (ICH, bleed requiring hospitalisation, drop in Hb > 20 or requiring transfusion) in patients taking warafrin for AF.
• Calculates a score from 0-9 which correlates to risk:
  
  • 0-1: Low risk - anticoagulation should be considered
  • 2pts: Moderate risk - anticoagulation can be considered
  • >=3pts: High risk - alternatives to anticoagulation should be explored

HASBLED

• Hypertension (SBP > 160) - 1pt
• Abnormal renal function (dialysis, transplant or Cr >200) - 1pt
• Abnormal liver function (cirrhosis, bilirubin >2x normal or AST/ALT/AP >3x normal) -1pt
• Stroke (any previous) - 1pt
• Bleeding (hx of major bleeding or predisposition to bleeding) - 1pt
• Labile INRs (Unstable/high INR, therapeutic INR range < 60% of time) - 1pt
• Elderley (>65yrs) - 1pt
• Drugs (NSAIDS or aspirin) - 1pt
• Drugs (ETOH excess) - 1pt

Question 6

Why is TIA important?

What is the risk of CVA post TIA and outline one tool to evaluate this risk.

Answer 6

1. TIA often closely precedes major CVA. As a result, urgent evaluation of modifiable causes is indicated, eg carotid endarterectomy, AF, structural cardiac causes
2. The ABCD2 score has questionable efficacy, but was designed to predict the risk of CVA in the 48h following TIA.

ABCD2

• Age: >60y = 1pt
• BP: >140/90 = 1pt
• Clinical features: Unilateral weakness = 2pts; Isolated speech disturbance = 1pt
• Duration of symptoms: >= 60mins = 2pts; 10-59mins = 1pt
• Diabetes: 1pt if present

Risk:

• Score 6 to 7: High two-day stroke risk (8 percent)
• Score 4 to 5: Moderate two-day stroke risk (4 percent)
• Score 0 to 3: Low two-day stroke risk (1 percent)