Cardioversion and anticoagulation timing — structured written assessment

Abbreviations

Short-answer question 1 (10 marks)

Scenario

A 72-year-old woman with treated hypertension and type 2 diabetes has had palpitations for at least three days, possibly longer; she cannot say exactly when they began. A 12-lead ECG shows AF at 110 beats per minute. She is haemodynamically stable, takes no anticoagulant and has not had cardiac surgery. Her CHA2DS2-VASc score is 4. She would like her rhythm restored. (Practice scenario.)

Questions — question 1

1. Under the 2024 ESC guideline, what are her two routes to cardioversion, and why is early cardioversion without them not recommended? Give classes. (3)^[1]
2. Her AF has lasted at least three days. State the 2023 ACC/AHA row that applies to her before elective cardioversion. (2)^[2]
3. How long should anticoagulation continue after cardioversion under each guideline, and what decides the long-term plan? (2)^[1][2]
4. A TOE shows thrombus in the left atrial appendage. What does each guideline advise? (3)^[1][2]

Model answers — question 1

1. Route 1: therapeutic OAC for at least 3 weeks (adherence to DOACs or INR 2.0 or more for VKAs) before scheduled cardioversion, to prevent procedure-related thromboembolism (Class I, Level B); DOACs are recommended in preference to VKAs in eligible patients with AF undergoing cardioversion, for thromboembolic risk reduction (Class I, Level A).^[1] Route 2: TOE if 3 weeks of therapeutic OAC has not been provided, for exclusion of cardiac thrombus to enable early cardioversion (Class I, Level B); initiation of therapeutic anticoagulation should be considered as soon as possible in unscheduled cardioversion, to prevent procedure-related thromboembolism (Class IIa, Level B).^[1] Why: early cardioversion is not recommended without appropriate anticoagulation or TOE if AF has lasted longer than 24 h (Class III, Level C); the ESC adds that the definite onset of AF is often not known, as in her case, and that safety should come first.^[1]
2. ACC/AHA 2023: her AF has lasted 48 hours or more, so a 3-week duration of uninterrupted therapeutic anticoagulation or imaging evaluation to exclude intracardiac thrombus is recommended before elective cardioversion (COR 1, LOE B-R); with either route, therapeutic anticoagulation should be established before cardioversion, to prevent thromboembolism (COR 1, LOE B-NR; see answer 3).^[2] Also creditable, as a contrast that does not apply to her: the separate row for reported AF duration under 48 hours (not in the setting of cardiac surgery, not on anticoagulation) says pre-cardioversion imaging to exclude intracardiac thrombus may be considered in those at elevated thromboembolic risk (CHA2DS2-VASc 2 or more or equivalent) (COR 2b, LOE C-LD).^[2]
3. ESC 2024: 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 (Class I, Level B).^[1] ACC/AHA 2023: 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).^[2] For the long-term plan, ACC/AHA 2023 general AF rows: patients with AF should be evaluated for their annual risk of thromboembolic events using a validated clinical risk score, such as CHA2DS2-VASc (COR 1, LOE B-NR); with an estimated annual risk of stroke or thromboembolic events of 2% or more, selection of therapy to reduce the risk of stroke should be based on the risk of thromboembolism, regardless of whether the AF pattern is paroxysmal, persistent, long-standing persistent or permanent (COR 1, LOE B-R); for patients with AF and an estimated annual thromboembolic risk of 2% or more per year (eg, CHA2DS2-VASc score of 2 or more in men and 3 or more in women), anticoagulation is recommended to prevent stroke and systemic thromboembolism (COR 1, LOE A); and in patients with AF at risk for stroke, reevaluation of the need for and choice of stroke risk reduction therapy at periodic intervals is recommended to reassess stroke and bleeding risk, net clinical benefit and proper dosing (COR 1, LOE B-NR). Her CHA2DS2-VASc score is 4.^[2] She has hypertension and diabetes, both CHA2DS2-VA risk factors in ESC 2024 Table 10, so under the ESC text long-term OAC should be instituted irrespective of the rhythm outcome.^[1] ESC 2024 Recommendation Table 6: oral anticoagulation is recommended in patients with clinical AF at elevated thromboembolic risk, to prevent ischaemic stroke and thromboembolism (Class I, Level A); a CHA2DS2-VA score of 2 or more is recommended as an indicator of elevated thromboembolic risk for decisions on initiating oral anticoagulation (Class I, Level C), and hers is 3 (hypertension, diabetes and age 65–74 years); individualised reassessment of thromboembolic risk is recommended at periodic intervals in patients with AF, to ensure anticoagulation is started in appropriate patients (Class I, Level B); using the temporal pattern of clinical AF (paroxysmal, persistent or permanent) is not recommended to determine the need for oral anticoagulation (Class III, Level B); and antiplatelet therapy is not recommended as an alternative to anticoagulation in patients with AF to prevent ischaemic stroke and thromboembolism (Class III, Level A). ACC/AHA 2023 likewise says that in patients with AF who are candidates for anticoagulation and without an indication for antiplatelet therapy, aspirin either alone or in combination with clopidogrel as an alternative to anticoagulation is not recommended to reduce stroke risk (COR 3: Harm, LOE B-R).^[1][2] Bleeding risk scores should not decide it on their own. ESC 2024 Recommendation Table 12: assessment and management of modifiable bleeding risk factors is recommended in all patients eligible for oral anticoagulation, as part of shared decision-making, to ensure safety and prevent bleeding (Class I, Level B); use of bleeding risk scores to decide on starting or withdrawing oral anticoagulation is not recommended in patients with AF, to avoid under-use of anticoagulation (Class III, Level B). ACC/AHA 2023: patients with AF should be evaluated for factors that specifically indicate a higher risk of bleeding, such as previous bleeding and use of drugs that increase bleeding risk, in order to identify possible interventions to prevent bleeding on anticoagulation (COR 1, LOE B-NR); in patients deemed at high risk for stroke, bleeding risk scores should not be used in isolation to determine eligibility for oral anticoagulation but instead to identify and modify bleeding risk factors and to inform medical decision-making (COR 3: No Benefit, LOE B-NR).^[1][2]
4. ESC 2024 text: therapeutic anticoagulation for a minimum of 4 weeks, followed by repeat TOE to ensure thrombus resolution; repeat TOE should be considered before cardioversion if thrombus was identified, to ensure thrombus resolution and prevent peri-procedural thromboembolism (Class IIa, Level C).^[1] ACC/AHA 2023: cancel the planned cardioversion; therapeutic anticoagulation should be instituted for at least 3 to 6 weeks, after which imaging should be repeated before cardioversion (COR 1, LOE C-LD).^[2] Also creditable: the ACC/AHA notes cardiac computed tomography as an alternative imaging modality, and resolution rates of 61.2% on follow-up TEE 3 to 12 weeks after starting a VKA (CLOT-AF) and 41.5% after 6 weeks of rivaroxaban (X-TRA) in anticoagulant-naïve patients.^[2]

Short-answer question 2 (10 marks)

Scenario

A 49-year-old man attends the emergency department with palpitations that began 5 hours ago. The ECG shows AF without pre-excitation; his QTc is normal and there is no evidence of sinus node or AV conduction disease. Blood pressure is 132/80 mmHg and he is otherwise well. Echocardiography last year was normal (no LVH, normal LVEF), he has no coronary artery disease, no heart failure, no recent ACS, no aortic stenosis and normal kidney function. He has no hypertension, diabetes, previous stroke or TIA, or vascular disease, and his CHA2DS2-VASc score is 0. (Practice scenario.)

Questions — question 2

1. Outline the ESC 2024 wait-and-see option and the trial behind it. (3)^[1]
2. He prefers pharmacological cardioversion. Which intravenous drugs does ESC 2024 recommend for him, with doses from ESC Table 13, and what does ESC 2024 say about anticoagulation around it? (3)^[1]
3. If electrical cardioversion is chosen, give two ACC/AHA 2023 technique rows with their COR. (2)^[2]
4. He asks about treating future episodes himself. What do the guidelines require before a pill-in-the-pocket approach? (2)^[1][2]

Model answers — question 2

1. ESC 2024: a wait-and-see approach for spontaneous conversion to sinus rhythm within 48 h of AF onset should be considered in patients without haemodynamic compromise, as an alternative to immediate cardioversion (Class IIa, Level B).^[1] RACE 7 ACWAS randomised haemodynamically stable, recent-onset (under 36 hours), symptomatic AF in the emergency department to wait-and-see (rate-control medication only, delayed cardioversion if AF did not resolve within 48 hours) or early cardioversion.^[6][1] Sinus rhythm at 4 weeks was present in 193 of 212 (91%) vs 202 of 215 (94%), meeting non-inferiority (P = 0.005); in the wait-and-see group 69% converted spontaneously within 48 hours.^[6]
2. Intravenous flecainide or propafenone is recommended when pharmacological cardioversion of recent-onset AF is desired, excluding severe LVH, HFrEF or coronary artery disease (Class I, Level A); ESC Table 13 doses: flecainide 1–2 mg/kg over 10 min; propafenone 1.5–2 mg/kg over 10 min.^[1] Intravenous vernakalant is recommended when pharmacological cardioversion of recent-onset AF is desired, excluding recent ACS, HFrEF or severe aortic stenosis (Class I, Level A); Table 13 dose: 3 mg/kg over 10 min (maximum 339 mg), then 2 mg/kg over 10 min 10–15 min after the initial dose (maximum 226 mg); not in SBP under 100 mmHg, NYHA III or IV heart failure or QT prolongation.^[1] Also creditable: with flecainide, an AVN-blocking agent should be given to avoid 1:1 conduction if the rhythm transforms to atrial flutter, and the infusion stopped if QRS widens by more than 25% or bundle branch block occurs (Table 13); ESC 2024 Recommendation Table 18 says concomitant use of a beta-blocker, diltiazem or verapamil should be considered in AF patients treated with flecainide or propafenone, to prevent 1:1 conduction if their rhythm is transformed to atrial flutter (Class IIa, Level C).^[1] Anticoagulation: early cardioversion is not recommended without appropriate anticoagulation or TOE if AF duration is longer than 24 h, or there is scope to wait for spontaneous cardioversion (Class III, Level C); he is within the wait-and-see window from answer 1, so there is scope to wait.^[1] If cardioversion is not deferred, ESC 2024 text says anticoagulation should be started or continued according to a formal (re-)assessment of thromboembolic risk.^[1] ESC 2024 rows: initiation of therapeutic anticoagulation should be considered as soon as possible in unscheduled cardioversion, to prevent procedure-related thromboembolism (Class IIa, Level B); DOACs are recommended in preference to VKAs in eligible patients with AF undergoing cardioversion, for thromboembolic risk reduction (Class I, Level A).^[1] After cardioversion, OAC is recommended for at least 4 weeks in all patients and long-term in patients with thromboembolic risk factor(s), irrespective of whether sinus rhythm is achieved, to prevent thromboembolism (Class I, Level B); the ESC text makes it optional only without thromboembolic risk factors and with sinus rhythm restored within 24 h of AF onset, which could apply to him.^[1] Also creditable (ACC/AHA 2023): 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); with low thromboembolic risk (CHA2DS2-VASc 0–1 or equivalent) and AF under 12 hours, as in his case, the benefit of pre-cardioversion imaging or peri-cardioversion anticoagulation is uncertain, given the low incidence of peri-cardioversion thromboembolic events in this population (COR 2b, LOE C-LD).^[2]
3. Energy delivery should be confirmed to be synchronised to the QRS, to reduce the risk of inducing VF (COR 1, LOE C-LD).^[2] For elective electrical cardioversion, biphasic energy of at least 200 J as initial energy can be beneficial to improve success of the initial shock (COR 2a, LOE B-R).^[2] Also creditable: in elective cardioversion with longer AF or an unsuccessful initial shock, optimising the electrode vector, higher energy and antiarrhythmic pretreatment can facilitate success of electrical cardioversion (COR 2a, LOE B-NR).^[2]
4. ESC 2024: a single self-administered oral dose of flecainide or propafenone should be considered for patient-led cardioversion in selected patients with infrequent paroxysmal AF, after efficacy and safety assessment, excluding severe LVH, HFrEF or coronary artery disease (Class IIa, Level B); the ESC text requires screening to exclude sinus node dysfunction, atrioventricular conduction defects or Brugada syndrome, and prior in-hospital validation; and concomitant use of a beta-blocker, diltiazem or verapamil should be considered in AF patients treated with flecainide or propafenone, to prevent 1:1 conduction if their rhythm is transformed to atrial flutter (Class IIa, Level C).^[1] ACC/AHA 2023: for recurrent AF outside hospital, pill-in-the-pocket flecainide or propafenone with a concomitant AV nodal blocking agent is reasonable if previously tested in a monitored setting (COR 2a, LOE A), and it is reasonable to give the first dose in a facility with continuous ECG monitoring, given the potential for proarrhythmia (COR 2a, LOE B-NR).^[2]