Atrial fibrillation — structured viva

Stem

Practice viva. You are the cardiology registrar. The examiner shows you an ECG with an irregular narrow-complex rhythm in a 71-year-old woman referred from general practice, and follows her from diagnosis to stroke prevention, rhythm control and ablation.

Branch A — Diagnosis and framework

Examiner: How do you make the diagnosis, and how will you structure her care?

Strong answer:

• The ECG shows no discernible, regular P waves and irregular ventricular activation, with no specific RR pattern in the absence of atrioventricular block (ESC 2024).^[1]
• Confirmation by an ECG (12-lead, multiple or single leads) is recommended to establish the diagnosis of clinical AF and commence risk stratification and treatment (ESC 2024, Class I, level A).^[1]
• I structure care as the ESC 2024 AF-CARE pathway: comorbidity and risk factor management, avoiding stroke and thromboembolism, reducing symptoms by rate and rhythm control, and evaluation with dynamic reassessment.^[1]

Follow-up: What baseline tests?

• A 12-lead ECG; blood tests (full blood count, kidney function, serum electrolytes, liver function, glucose/HbA1c and thyroid function); and transthoracic echocardiography where this will guide AF-CARE management decisions (ESC 2024, Table 8: all patients).^[1]

Branch B — Stroke risk

Examiner: She has hypertension only. Does she need anticoagulation?

Strong answer:

• Her CHA2DS2-VA score is 2 (hypertension 1, age 65–74 years 1). ESC 2024 recommends a score of 2 or more as an indicator of elevated thromboembolic risk for decisions on initiating OAC (Class I, level C), and OAC in patients with clinical AF at elevated thromboembolic risk to prevent ischaemic stroke and thromboembolism (Class I, level A).^[1]
• Under the ACC/AHA her CHA2DS2-VASc score is 3, including female sex, and anticoagulation is recommended for an annual thromboembolic risk of 2% or more, e.g. a score of 3 or more in women, to prevent stroke and systemic thromboembolism (COR 1, LOE A).^[1][2]

Follow-up: Why did the ESC drop the sex criterion?

• The ESC regards female sex as an age-dependent stroke risk modifier rather than a risk factor per se, notes that it omits people who identify as non-binary or transgender or who are undergoing sex hormone therapy, and proposes CHA2DS2-VA in the absence of other locally validated alternatives.^[1]

Branch C — Bleeding

Examiner: A bleeding risk score puts her at high risk. Do you withhold anticoagulation?

Strong answer:

• No. Using bleeding risk scores to decide on starting or withdrawing OAC is not recommended in patients with AF, to avoid under-use of anticoagulation (ESC 2024, Class III, level B).^[1]
• The ACC/AHA says that in patients deemed at high stroke risk, bleeding risk scores should not be used in isolation to determine eligibility for OAC, but instead to identify and modify bleeding risk factors and to inform decision-making (COR 3: No Benefit, LOE B-NR).^[2]
• Assessment and management of modifiable bleeding risk factors is recommended in all patients eligible for OAC, as part of shared decision-making, to ensure safety and prevent bleeding (ESC 2024, Class I, level B).^[1]

Follow-up: What if she bleeds on apixaban?

• Interrupting anticoagulation and performing diagnostic or treatment interventions is recommended in AF patients with active bleeding until the cause of bleeding is identified and resolved (ESC 2024, Class I, level C); for a life-threatening bleed or a bleed into a critical site on a DOAC, specific antidotes should be considered to reverse the antithrombotic effect (Class IIa, level B).^[1]
• Andexanet alfa rapidly reverses the factor Xa inhibitors (apixaban, edoxaban, rivaroxaban).^[1]

Branch D — Rate or rhythm

Examiner: She remains symptomatic. Rate or rhythm control?

Strong answer:

• The ESC notes most patients need a combination approach, re-evaluated during follow-up.^[1]
• Implementation of a rhythm control strategy should be considered within 12 months of diagnosis in selected patients with AF at risk of thromboembolic events, to reduce the risk of cardiovascular death or hospitalisation (ESC 2024, Class IIa, level B); the ACC/AHA says that in recently diagnosed AF (under 1 year), rhythm control can be useful to reduce hospitalisations, stroke and mortality (COR 2a, LOE B-R).^[1][2]
• In EAST-AFNET 4 (early AF, diagnosed 1 year or less before enrolment, with cardiovascular conditions), the first primary outcome of cardiovascular death, stroke, or hospitalisation with worsening heart failure or acute coronary syndrome occurred at 3.9 per 100 person-years with early rhythm control (antiarrhythmic drugs or AF ablation after randomisation) vs 5.0 with usual care (rhythm control limited to managing AF-related symptoms) (HR 0.79; P = 0.005).^[5]
• The second primary outcome, nights spent in hospital per year, did not differ significantly between early rhythm control and usual care (P = 0.23), nor did the primary safety outcome of death, stroke, or serious adverse events related to rhythm-control therapy; serious adverse events related to rhythm-control therapy occurred in 4.9% of patients assigned to early rhythm control and 1.4% of those assigned to usual care; the trial was stopped for efficacy at the third interim analysis after a median 5.1 years of follow-up per patient.^[5]

Follow-up: Which first-line options for paroxysmal AF?

• Catheter ablation is recommended as a first-line option within a shared decision-making rhythm control strategy in paroxysmal AF, to reduce symptoms, recurrence and progression of AF (ESC 2024, Class I, level A); the ACC/AHA says catheter ablation is useful as first-line therapy in selected patients (generally younger with few comorbidities) with symptomatic paroxysmal AF in whom rhythm control is desired, to improve symptoms and reduce progression to persistent AF (COR 1, LOE A).^[1][2]
• Without impaired LV systolic function, severe LV hypertrophy or coronary artery disease, flecainide or propafenone is recommended in patients with AF requiring long-term rhythm control, to prevent recurrence and progression of AF (ESC 2024, Class I, level A), and concomitant use of a beta-blocker, diltiazem or verapamil should be considered in patients treated with flecainide or propafenone, to prevent 1:1 conduction if the rhythm transforms to atrial flutter (ESC 2024, Class IIa, level C).^[1]
• The ACC/AHA finds flecainide or propafenone reasonable for long-term maintenance of sinus rhythm in AF without previous MI, known or suspected significant structural heart disease, or ventricular scar or fibrosis (COR 2a, LOE A), and classes them as harmful with previous MI and/or significant structural heart disease, including HFrEF (LVEF 40% or less), because of the risk of worsening heart failure, potential proarrhythmia and increased mortality (COR 3: Harm, LOE B-R).^[2]

Branch E — Cardioversion

Examiner: A different patient presents with 3 days of AF and wants cardioversion today. She has not been anticoagulated.

Strong answer:

• Early cardioversion is not recommended without appropriate anticoagulation or transoesophageal echocardiography if AF duration is longer than 24 h, or there is scope to wait for spontaneous cardioversion (ESC 2024, Class III, level C); the ACC/AHA uses 48 h: with AF of 48 hours or more, 3 weeks of uninterrupted therapeutic anticoagulation or imaging to exclude intracardiac thrombus is recommended before elective cardioversion (COR 1, LOE B-R).^[1][2]
• Transoesophageal echocardiography is recommended if 3 weeks of therapeutic OAC has not been provided, for exclusion of cardiac thrombus to enable early cardioversion (ESC 2024, Class I, level B), and initiation of therapeutic anticoagulation should be considered as soon as possible in the setting of unscheduled cardioversion for AF or atrial flutter, to prevent procedure-related thromboembolism (Class IIa, level B).^[1]

Follow-up: And afterwards?

• OAC is recommended for at least 4 weeks in all patients after cardioversion, and long-term in patients with thromboembolic risk factor(s) irrespective of whether sinus rhythm is achieved, to prevent thromboembolism (ESC 2024, Class I, level B); the ACC/AHA likewise says that in patients with AF undergoing cardioversion, therapeutic anticoagulation should be established before cardioversion and continued for at least 4 weeks afterwards without interruption to prevent thromboembolism (COR 1, LOE B-NR).^[1][2]

Branch F — Appendage and device-detected AF

Examiner: A different patient cannot take any anticoagulant. Options?

Strong answer:

• Percutaneous LAA occlusion may be considered in patients with AF and contraindications for long-term anticoagulant treatment to prevent ischaemic stroke and thromboembolism (ESC 2024, Class IIb, level C); the ACC/AHA rates it as reasonable with a CHA2DS2-VASc score of 2 or more and a contraindication to long-term OAC due to a non-reversible cause (COR 2a, LOE B-NR).^[1][2]

Follow-up: And another patient whose AF is found only on a pacemaker?

• DOAC therapy may be considered in asymptomatic device-detected subclinical AF with elevated thromboembolic risk to prevent ischaemic stroke and thromboembolism, excluding patients at high risk of bleeding (ESC 2024, Class IIb, level B).^[1]
• The ACC/AHA tiers device-detected AHRE without previously diagnosed AF by duration: for 24 hours or more with a CHA2DS2-VASc score of 2 or more or equivalent stroke risk, it is reasonable to initiate OAC (COR 2a, LOE B-NR); for 5 minutes to 24 hours with a score of 3 or more or equivalent stroke risk, it may be reasonable (COR 2b, LOE B-NR), both within shared decision-making that considers episode duration and individual risk; and episodes under 5 minutes without another indication should not receive OAC (COR 3: No Benefit, LOE B-NR).^[2]
• In ARTESiA (subclinical AF lasting 6 minutes to 24 hours; apixaban 5 mg twice daily, 2.5 mg twice daily when indicated, vs aspirin 81 mg daily), apixaban lowered the primary efficacy outcome, stroke or systemic embolism, in the intention-to-treat population compared with aspirin (0.78% per patient-year with apixaban vs 1.24% with aspirin; HR 0.63; P = 0.007) but increased the primary safety outcome, major bleeding, in the on-treatment population (1.71% per patient-year with apixaban vs 0.94% with aspirin; HR 1.80; P = 0.001).^[6]

Branch G — The Australian guideline

Examiner: What does the Australian guideline say?

Strong answer:

• The 2018 NHFA/CSANZ Australian guideline, written to assist Australian practitioners in managing adult patients with AF, recommends the sexless CHA2DS2-VA score to assess stroke risk; anticoagulation is not recommended for a score of 0 and is recommended for a score of 2 or more, and non-vitamin K oral anticoagulants are recommended in preference to warfarin when anticoagulation is indicated.^[4]
• The 2018 NHFA/CSANZ guideline recommends opportunistic screening in the clinic or community for patients over 65 years of age.^[4]

Follow-up: And on rhythm control?

• The 2018 NHFA/CSANZ guideline states that flecainide is preferable to amiodarone for acute and chronic rhythm control, and that failure of rate or rhythm control should prompt consideration of percutaneous or surgical ablation.^[4]