New Atrial Fibrillation in a 72-Year-Old With Falls and a Low eGFR
A 72-year-old man is seen after an urgent care visit where an irregular pulse was noted and an ECG confirmed atrial fibrillation at 96 beats per minute. He feels well, with no chest pain, dyspnea, or palpitations. History: hypertension, type 2 diabetes for 12 years, no prior stroke or TIA, no heart failure. Medications: lisinopril, metformin, atorvastatin. eGFR 38 mL/min/1.73 m2, platelets 210,000, hemoglobin 13.4 g/dL, BP 138/82, weight 82 kg. He has had two mechanical falls in the past year, one in the yard and one in the bathroom, neither with head injury or fracture. He lives with his wife, walks with a cane, and drinks two beers most evenings. Echocardiogram: normal LVEF, mild left atrial enlargement.
1. Quantify his stroke and bleeding risk and make the anticoagulation decision.
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Stroke risk (CHA2DS2-VASc): age 65-74 = 1, hypertension = 1, diabetes = 1, no stroke/TIA, no heart failure, no vascular disease. Total = 3, roughly 3% annual stroke risk. In a man, a score of 2 or more is an indication for oral anticoagulation. The decision is not borderline.
Bleeding risk (HAS-BLED): age over 65 = 1, alcohol at eight or more drinks per week (he is at about 14) = 1. Hypertension is controlled and does not score; renal function does not meet the creatinine-based criterion; no labile INR, no prior bleed, no antiplatelet or NSAID. Total = 2, which is not a reason to withhold therapy.
Key reasoning point: a HAS-BLED score is used to identify and correct modifiable bleeding risks, not as a veto. Falls are not a validated reason to withhold anticoagulation - modeling studies consistently show that the stroke and intracranial hemorrhage risk averted outweighs fall-related bleeding unless falls are extremely frequent. Two falls without injury is not that threshold.
Document the shared decision, including that the alternative to anticoagulation is not 'no risk,' it is a stroke risk that climbs each year.
2. Which anticoagulant and dose, and how do you handle aspirin?
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Nonvalvular AF with eGFR 38: a direct oral anticoagulant is preferred over warfarin for stroke prevention, given lower intracranial hemorrhage and no need for INR monitoring.
- Apixaban 5 mg twice daily is appropriate here: his eGFR exceeds 25 and he does not meet two of the three dose-reduction criteria (age 80 or older, weight 60 kg or less, creatinine 1.5 mg/dL or higher). He is 72, weighs 82 kg, and his creatinine is not elevated. State that you verified all three criteria rather than reflexively reducing the dose - underdosing is a common and harmful error
- If apixaban were unavailable, a factor Xa inhibitor or dabigatran could be considered, but each has its own renal thresholds and interacting drugs; dabigatran is unattractive with crummy renal function and dyspepsia risk
- Warfarin remains acceptable if he prefers it or cost is prohibitive, but it requires INR monitoring and is the highest-risk option with his fall history
Aspirin: do not substitute aspirin for anticoagulation. Aspirin is not adequate stroke prophylaxis in AF and carries much of the bleeding risk without the benefit. He has no coronary stent or atherosclerotic disease that would justify adding an antiplatelet, and dual therapy without an indication would be a clear error.
Reasoning: the exam wants the dose justified by the three criteria, not guessed from the eGFR alone.
3. How do you address the falls and alcohol, and what is your follow-up plan?
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Treat the modifiable bleeding risks rather than the score.
- Alcohol: counsel reduction to fewer than eight drinks per week, with an honest conversation about why it matters here (both bleeding and fall risk). Document the advice
- Falls: assess gait and orthostatics, review vision and footwear, refer for physical therapy and a home safety evaluation, and check for hypoglycemia as a contributor given his metformin and diabetes
- Renal function: recheck eGFR and CBC at least annually, and more often if he becomes ill, since a decline crossing a dosing threshold changes the prescription
- Rate control: at 96 bpm and asymptomatic with normal LVEF, lenient rate control is reasonable; no rhythm control strategy is required based on this presentation
- Follow-up: office visit in two to four weeks to confirm he started the drug, check for bleeding, review adherence and cost, and revisit the alcohol plan; recheck CBC and renal function at three months, then annually
Counseling points: the reason for anticoagulation in plain language, what to do with a fall and head strike, signs of bleeding, and which over-the-counter drugs (NSAIDs) to avoid.
Reasoning: the case is testing whether you can hold two ideas at once - that falling is a real risk, and that withholding anticoagulation would be the larger harm.