CHADS₂ Score Calculation
This patient has a CHADS₂ score of 4 points.
Score Breakdown
The CHADS₂ scoring system assigns points as follows 1, 2:
- C (Congestive Heart Failure): 0 points — No heart failure mentioned 1, 2
- H (Hypertension): 1 point — Blood pressure 150/90 mmHg confirms hypertension 2
- A (Age ≥75 years): 0 points — Patient is 64 years old, which does not meet the ≥75 threshold 1, 2
- D (Diabetes Mellitus): 1 point — Known diabetic 1, 2
- S₂ (Prior Stroke/TIA): 2 points — History of stroke carries doubled weight 1, 2
Total CHADS₂ Score: 0 + 1 + 0 + 1 + 2 = 4 points
Clinical Significance
A CHADS₂ score of 4 indicates very high stroke risk with an annual stroke rate of approximately 12.5% without anticoagulation 2. This score places the patient in the highest risk category, where the absolute benefit of anticoagulation substantially outweighs bleeding risk 1.
Critical Management Implications
Oral anticoagulation is strongly indicated for this patient 1, 2:
- Either warfarin (target INR 2.0-3.0) or a direct oral anticoagulant (DOAC) should be initiated 2
- DOACs are generally preferred over warfarin as first-line therapy given their superior safety profile 3
- The prior stroke history alone (2 points) warrants anticoagulation regardless of other risk factors 1
Important Clinical Caveat
Do not confuse CHADS₂ with CHA₂DS₂-VASc: The CHADS₂ system awards 1 point only for age ≥75 years 2. Ages 65-74 do not receive a point in CHADS₂ (though they would in the newer CHA₂DS₂-VASc score) 4, 2. This is a common pitfall in clinical practice 2.
Blood pressure control is critically important in this patient receiving anticoagulation, as intracerebral hemorrhage risk is exquisitely sensitive to blood pressure management 1.