Atrial Fibrillation — Written Clinical Reasoning

SAQ 1 — Integrated AF Management (20 marks, 30 minutes)

Prompt: Outline your integrated management plan for this patient, addressing stroke prevention, symptom/rhythm strategy, comorbidity optimisation, and medication changes. Justify each decision with reference to evidence and guidelines. [1]

Model Answer

Problem list (4 marks):

1. Persistent atrial fibrillation, symptomatic (palpitations, exertional dyspnoea) — newly diagnosed
2. High stroke risk — CHA₂DS₂-VASc requires calculation
3. Ischaemic heart disease (prior NSTEMI) — antiarrhythmic choice constrained
4. Type 2 diabetes (HbA1c 62) — suboptimal control
5. Hypertension — BP above target at 146/88
6. Stage 3A CKD (eGFR 52) — affects DOAC dosing and drug choices
7. Obesity (BMI 33) — modifiable AF risk factor
8. Dual antiplatelet/antithrombotic issue — currently on aspirin alone; needs anticoagulation [1]

Stroke prevention — anticoagulation (5 marks): [1]

CHA₂DS₂-VASc score: age 65–74 (1), hypertension (1), diabetes (1), vascular disease/prior MI (1) = 4 (male, so no sex point). A score of 2 or more in men warrants anticoagulation. He should be started on a DOAC. [1]

Apixaban is the preferred DOAC based on ARISTOTLE (PMID 21875359), which showed apixaban was superior to warfarin — 21% reduction in stroke/systemic embolism, 31% reduction in major bleeding, and 11% reduction in all-cause mortality. [1]

Dose check for apixaban: dose reduction to 2.5mg BID requires two of three criteria (age 80+, weight 60 kg or under, creatinine 133+ micromol/L). He meets none of these (age 72, weight 78 kg, creatinine 125), so apixaban 5mg BID is the correct dose. [1]

Stop aspirin: in a patient with AF requiring anticoagulation and a prior stent more than 12 months ago, anticoagulation alone (without aspirin) is recommended to reduce bleeding risk. Triple therapy or dual antithrombotic therapy is reserved for the first 1–12 months post-stent; beyond that, oral anticoagulation monotherapy is standard (ESC 2024, ACC/AHA 2023). [1]

HAS-BLED: hypertension uncontrolled (1), abnormal renal function (1), age over 65 (1), drugs (concomitant aspirin initially) (1) = approximately 3–4. This flags modifiable bleeding risk (control BP, stop aspirin), but does not contraindicate anticoagulation — the net benefit strongly favours treatment. [1]

Symptom and rhythm strategy (4 marks): [1]

He is symptomatic (palpitations, dyspnoea) with a resting HR of 98. Initial approach: rate control with a beta-blocker (dual benefit — rate control for AF and secondary prevention for his ischaemic heart disease). Add metoprolol or bisoprolol; titrate to target resting HR under 80 bpm given his symptoms. [1]

Consider rhythm control: given his symptoms, relatively recent diagnosis (within 1 year), and cardiovascular comorbidities, the EAST-AFNET 4 trial (PMID 32865375) supports early rhythm control — either pharmacological or ablation — in addition to rate control. Antiarrhythmic options are constrained by his ischaemic heart disease: flecainide (class IC) is contraindicated. Acceptable options are sotalol or amiodarone. If he remains symptomatic despite rate control and a trial of antiarrhythmic, refer for catheter ablation (pulmonary vein isolation). The CABANA heart failure subgroup and broader data support ablation for symptomatic AF refractory to medical therapy. [1]

Elective cardioversion can be considered after at least 3 weeks of therapeutic anticoagulation (or TOE-guided). After cardioversion, continue anticoagulation for at least 4 weeks regardless of baseline CHA₂DS₂-VASc. [1]

Comorbidity optimisation (4 marks): [1]

Communication and follow-up (3 marks): [1]

• Counselling on anticoagulation: explain stroke prevention rationale (AF increases stroke 4–5-fold), bleeding risk and what to do if bleeding occurs, medication adherence, and that DOACs require no INR monitoring.
• Shared decision-making on rate versus rhythm strategy: discuss the trade-offs of antiarrhythmic side effects versus ablation risks.
• Sleep apnoea screening: given BMI 33 and AF, screen for OSA (Epworth, sleep study); treat if present (reduces AF recurrence).
• Alcohol reduction counselling (alcohol is a potent AF trigger).
• Follow-up: review at 4–6 weeks for rate-control adequacy, renal function, bleeding, and symptom assessment. Annual review thereafter to reassess CHA₂DS₂-VASc, renal function, and medication interactions. [1]