Anticoagulation, falls and competing risks in an 84-year-old
An 84-year-old woman with permanent atrial fibrillation has a CHA2DS2-VASc score of 5 and a HAS-BLED score of 4. She fell at home and sustained a 3 cm scalp haematoma; CT showed no intracranial injury. She lives alone, has mild cognitive impairment (MMSE 22), an eGFR of 38, and weighs 48 kg. She takes ibuprofen bought over the counter for knee pain. The stroke physician wants to start apixaban 5 mg twice daily. The pharmacist flags the dose, and the falls team says anticoagulation is 'too risky'. The patient says she does not want another stroke but does not want to bleed. The MDT must reach a recommendation today.
1. Is 5 mg twice daily the correct dose? How should the MDT handle the disagreement about dosing?
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The dose is wrong. Apixaban is reduced to 2.5 mg twice daily when two of three criteria are present: age 80 or over, weight 60 kg or less, and creatinine 133 micromol/L or more. She meets two - age 84 and weight 48 kg. The pharmacist was right to flag it, and the renal function supports apixaban (eGFR 38 is well above the threshold at which it should be avoided), so the drug is appropriate and the strength is not.
The governance point matters more than the arithmetic. Dosing should not be settled by a show of hands in a meeting. The prescriber must review the two criteria explicitly, calculate renal function with the correct formula for the drug, and document the reasoning and the dose. The MDT's role is to surface the discrepancy and direct it back to the prescriber with the facts, not to outvote the physician or the pharmacist.
2. How should the team weigh fall risk against stroke risk, and what modifiable factors should be addressed?
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The two risks are not symmetrical, and the team should say so with numbers rather than adjectives. Untreated atrial fibrillation at this stroke risk carries a high annual risk of disabling stroke; anticoagulation reduces that risk by roughly two-thirds in trial populations. Anticoagulation does increase intracranial bleeding, but the absolute excess is far smaller than the stroke burden prevented at this score. A single fall with soft tissue injury and a normal CT is not a contraindication.
A HAS-BLED score of 4 is a prompt to fix what can be fixed, not a reason to withhold:
- stop the over-the-counter ibuprofen, which is a major bleeding risk combined with an anticoagulant, and treat the knee pain another way;
- falls assessment, home hazard review, vision and footwear, and a strength and balance programme;
- blood pressure control, alcohol review, and a medication review for other antiplatelets or sedatives;
- agree a clear plan for what to do if she falls again, written down before it happens.
Documenting the reasoning matters as much as the conclusion, because the next clinician will meet the same disagreement.
3. How would you structure the conversation with the patient and record it?
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Explore before explaining. Ask what she has seen or heard about anticoagulants, what she fears most, and what a stroke would mean for her living alone. Her statement already contains the trade-off; the job is to make it concrete rather than resolve it for her.
Explain with absolute numbers in plain language, using a validated tool to generate her own figures: 'Over the next year, out of 100 people like you, about X would have a stroke without treatment and about Y with it; about Z would have a serious bleed.' Acknowledge uncertainty honestly.
Include the practical conditions: the ibuprofen must stop, the dose is 2.5 mg twice daily, and there is a plan if she falls.
Record: that capacity was assessed and she had it; what was discussed and with whom; her stated priorities; the decision and who made it; the treatment plan and the follow-up date; and that the decision will be reviewed if her circumstances change. A shared decision that is not documented will be re-litigated by the next team.