A 72-year-old man attends his GP surgery for follow-up after atrial fibrillation was confirmed on a 12-lead ECG, having been detected as an irregular pulse at a routine appointment. He has type 2 diabetes managed with metformin and hypertension well controlled on amlodipine. He has no history of stroke, TIA, heart failure or vascular disease. He feels well, with a heart rate of 88 beats per minute, and his renal function is normal.
Which is the SINGLE MOST appropriate next step to reduce his risk of stroke?
- AStart aspirin 75 mg once daily
- BStart warfarin, target INR 2–3
- CStart apixabanCorrect
- DNo anticoagulation needed; reassess stroke risk in 12 months
- ERefer for direct current cardioversion
Understanding the Question
This question tests two steps: calculating a CHA₂DS₂-VASc score, then choosing the right agent. His score is 3 — hypertension (1), diabetes (1), age 65–74 (1). NICE recommends offering anticoagulation to men with a score of 2 or more, and a direct-acting oral anticoagulant (DOAC) such as apixaban, dabigatran, edoxaban or rivaroxaban is first line. Bleeding risk should be assessed (NICE recommends the ORBIT score), but a raised bleeding risk is a prompt to address modifiable factors, not usually a reason to withhold anticoagulation.
Key points
- CHA₂DS₂-VASc: Congestive heart failure (1), Hypertension (1), Age ≥75 (2), Diabetes (1), Stroke/TIA/thromboembolism (2), Vascular disease (1), Age 65–74 (1), Sex category female (1).
- Offer anticoagulation if the score is 2 or more; consider it for men with a score of 1.
- DOACs are first line; warfarin is reserved for when DOACs are unsuitable — and remains the choice in, for example, mechanical heart valves.
- Aspirin monotherapy is not recommended for stroke prevention in atrial fibrillation.
- Assess bleeding risk with ORBIT and address modifiable risk factors.
Why the other options are wrong
- A — Start aspirin 75 mg once daily: Antiplatelets are not recommended for stroke prevention in atrial fibrillation — aspirin offers inadequate protection with a comparable bleeding risk.
- B — Start warfarin, target INR 2–3: Effective, but no longer first line. NICE recommends a DOAC first, with warfarin reserved for when DOACs are contraindicated or not tolerated.
- D — No anticoagulation needed; reassess stroke risk in 12 months: His CHA₂DS₂-VASc score is 3, well above the threshold at which anticoagulation should be offered. Deferring leaves him exposed to a preventable stroke risk.
- E — Refer for direct current cardioversion: Cardioversion addresses rhythm, not stroke risk — and he is asymptomatic with acceptable rate control, so rate control plus anticoagulation is the priority in primary care.
For exam revision only. Always check NICE, CKS and the BNF.