CHADS₂ Score Calculation
The CHADS₂ score for this patient is 5 (Option D).
Component Breakdown
The CHADS₂ scoring system assigns points based on specific clinical criteria, and this patient accumulates points as follows 1, 2:
Congestive Heart Failure (C) = 1 point: The patient demonstrates clinical evidence of heart failure with elevated jugular venous pressure (high JVP), third heart sound (S3), and bibasal crackles on chest examination 2. These physical findings constitute objective evidence of cardiac dysfunction and satisfy the "C" criterion 2.
Hypertension (H) = 1 point: The patient has a documented history of hypertension and presents with blood pressure of 150/90 mmHg, which exceeds the 140/90 mmHg threshold 2. Either the history alone or the current elevated systolic pressure (≥140 mmHg) qualifies for this point 2.
Age (A) = 0 points: At 64 years old, this patient does not receive a point for age 1, 2. The CHADS₂ system awards 1 point only for age ≥75 years 1, 2. This is a common pitfall—ages 65-74 do not receive points in CHADS₂ (though they would in the newer CHA₂DS₂-VASc score) 2.
Diabetes Mellitus (D) = 1 point: The patient is a known case of diabetes mellitus, which adds 1 point 1, 2.
Prior Stroke or TIA (S₂) = 2 points: The patient has a documented history of stroke, which carries a doubled weight of 2 points in the CHADS₂ system 1, 2. This reflects the substantially elevated risk of recurrent thromboembolism 2.
Total Score and Clinical Significance
Total CHADS₂ Score: 1 + 1 + 0 + 1 + 2 = 5 points 2
A CHADS₂ score of 5 corresponds to a very high annual stroke risk of approximately 12.5% when no anticoagulation is used 1, 2.
This score mandates oral anticoagulation therapy according to ACC/AHA guidelines, either with warfarin (target INR 2-3) or a direct oral anticoagulant 2.
Common Pitfall to Avoid
The most frequent error in CHADS₂ calculation is misinterpreting the age criterion 2. Clinicians sometimes incorrectly assign a point for ages 65-74, but the CHADS₂ system only awards 1 point for age ≥75 years 1, 2. In this case, the patient's age of 64 years receives zero points, making the correct answer 5 rather than 6.