ACHD general principles — structured viva

Stem

Practice viva. The examiner asks you to classify adult congenital heart disease, to say who should see an ACHD cardiologist and before which procedures, and to manage arrhythmia and heart failure in adults with congenital heart disease.^[2][1]

Branch A — Classification

Examiner: How do the American and European guidelines classify adult congenital heart disease?^[2][1]

Strong answer:

• ACC/AHA 2025 assigns an anatomic complexity, ranging from simple to complex (I–III), and a physiological stage that reflects clinical status (A–D); the AP classification was introduced in the 2018 AHA/ACC ACHD guidelines and aims to improve classification of disease severity given the potential for discordance between anatomic complexity and physiological stage.^[2]
• Patients are classified according to the “highest” relevant anatomic or physiological feature, and in patients with multiple lesions the most complex anatomic diagnosis determines the anatomic complexity.^[2]
• Physiological stage A requires “no anatomic sequelae”, so patients with certain conditions, such as Fontan circulation, a systemic right ventricle, or truncus arteriosus, can never be in physiological stage A.^[2]
• Biomarkers such as NT-proBNP, unplanned heart failure hospitalizations and recent endocarditis each identify patients with poorer prognosis and higher resource utilization and have been incorporated into the updated system: stage C includes a BNP or NT-proBNP level ≥2 times the upper limit of normal, and stage D includes hospitalization for heart failure in the past 12 months and endocarditis in the prior 1 year.^[2]
• ESC 2020 says CHD can be classified as mild, moderate, or severe in its Table 4: for example, repaired secundum ASD, sinus venosus defect, VSD, or PDA without residuae or sequellae is mild; coarctation of the aorta and repaired tetralogy of Fallot are moderate; and Fontan circulation and any cyanotic CHD (unoperated or palliated) are severe.^[1]

Follow-up: Where do the two systems place transposition, and how do you describe it?^[2][1]

• ACC/AHA 2025 places dextro-TGA after arterial switch operation in II: Moderate Complexity, and dextro-TGA after atrial switch (Mustard/Senning) operation, dextro-TGA after Rastelli operation and congenitally corrected TGA (CCTGA, levo-TGA) in III: Great Complexity.^[2]
• ESC 2020 lists transposition of the great arteries after arterial switch operation as moderate, and transposition of the great arteries (except for patients with arterial switch operation) as severe.^[1]
• Echocardiography provides information that includes situs, the connection of the atria and ventricles, and the connection of ventricles with the great arteries; TGA is characterized by AV concordance and ventriculo-arterial discordance, and ccTGA by discordant atrio-ventricular and ventriculo-arterial connections (ESC 2020).^[1]

Branch B — Who sees an ACHD cardiologist, and procedures

Examiner: Which patients should be under an ACHD cardiologist, and what changes when they need a noncardiac procedure?^[2]

• ACC/AHA 2025: patients in ACHD AP classes IB–D, IIA–D, and IIIA–D should be evaluated and managed by or in collaboration with an ACHD cardiologist and, when indicated and accessible, an ACHD program to improve outcomes (COR 1, LOE B-NR), and patients in AP class IA should have at least 1 evaluation by an ACHD cardiologist to develop a plan of care (COR 1, LOE B-NR).^[2]
• ESC 2020 recommends that all ACHD patients are seen once in a specialist centre, allowing ACHD specialists to determine the most appropriate level of care and follow-up intervals for each individual patient; it notes that patients with complex defects can easily be assigned to a high level of care, but even anatomically simple defects may require specialist care under certain circumstances, such as ASD with pulmonary arterial hypertension.^[1]
• Before noncardiac procedures, ACC/AHA 2025 recommends preprocedural involvement of an ACHD cardiologist in patients with ACHD to risk-stratify the patient, determine appropriate procedure location, guide periprocedural planning and support, and assist in preprocedural clinical optimization to improve outcomes (COR 1, LOE B-NR).^[2]
• In patients with ACHD AP classifications IC–D, IIB–D, and IIIA–D who undergo noncardiac procedures, postprocedural care should involve collaboration with an ACHD cardiologist to incorporate expert opinion, provide guideline-based therapy, and improve outcomes (COR 1, LOE B-NR); in AP classifications IC–D, IIC–D, and IIIA–D, anesthesia for noncardiac procedures should be administered by, or in collaboration or consultation with, an anesthesiologist with ACHD expertise to reduce the likelihood of perioperative complications (COR 1, LOE C-LD).^[2]
• ESC 2022 (non-cardiac surgery) recommends consultation with an ACHD specialist before intermediate- or high-risk surgery, and that intermediate- and high-risk elective surgery is performed in a centre with experience in the care of ACHD patients (both Class I, Level C).^[14]

Follow-up: And for invasive cardiac procedures?^[2]

• ACC/AHA 2025 recommends preprocedural involvement of an ACHD cardiologist in patients with ACHD who undergo invasive cardiac procedures, to risk-stratify the patient, determine appropriate procedure location, guide periprocedural planning and support, and assist in preprocedural clinical optimization to improve outcomes (COR 1, LOE B-NR); invasive cardiac procedures involving congenital lesions should be performed by operators with expertise in congenital heart disease procedures to ensure appropriate periprocedural care (COR 1, LOE B-NR).^[2]
• Postprocedural care should involve collaboration with an ACHD cardiologist to incorporate expert opinion, provide guideline-based therapy, and improve outcomes (COR 1, LOE C-LD), and in AP classifications IC–D, IIA–D, and IIIA–D anesthesia for invasive cardiac procedures should be administered by, or in collaboration or consultation with, an anesthesiologist who has congenital heart disease expertise to reduce the likelihood of perioperative complications (COR 1, LOE C-LD).^[2]
• ESC 2020: when ACHD patients are operated on by a congenital cardiac surgeon, outcome is proven to be superior, so its strict recommendation is that all ACHD patients are operated on by a congenital cardiac surgeon in a multidisciplinary environment with expertise in ACHD, except for surgery of uncomplicated bicuspid aortic valve, heritable thoracic aortic disease such as Marfan syndrome, and secundum-type ASD without anomalous pulmonary venous connection and/or absence of PVD (ESC 2020 text; no class or level given).^[1]

Branch C — Arrhythmia

Examiner: A patient with moderate congenital heart disease has a documented atrial arrhythmia. What do the guidelines advise?^[1][2]

• ESC 2020: in patients with moderate and severe CHD complexity and documented arrhythmias, referral to a centre with a multidisciplinary team and expertise in ACHD patients and ACHD-related arrhythmia is indicated (Class I, Level C).^[1]
• ESC 2020: in moderate and severe CHD, catheter ablation should be considered for symptomatic, sustained recurrent SVT (AVNRT, AVRT, AT, and IART), or if SVT is potentially related to SCD, provided that the procedure is performed in experienced centres (Class IIa, Level C); in mild CHD, catheter ablation is recommended over long-term medical therapy for symptomatic, sustained recurrent SVT (AVNRT, AVRT, AT, and IART), or if SVT is potentially related to SCD (Class I, Level C).^[1]
• ACC/AHA/ACCP/HRS 2023 (AF): in adults with congenital heart disease and AF, it is recommended to evaluate for and treat precipitating factors and reversible causes of AF, recognizing that residual hemodynamic sequelae may contribute to the occurrence of the arrhythmia (COR 1, LOE B-NR); with symptomatic or hemodynamically significant paroxysmal or persistent AF, an initial strategy of rhythm control is recommended regardless of lesion severity as AF in this population is often poorly tolerated (COR 1, LOE C-LD).^[6]
• In adults with AF and moderate or complex congenital heart disease, electrophysiological procedures should be performed by operators with expertise in ACHD procedures and in collaboration with an ACHD cardiologist, ideally in specialized centers, when available (ACC/AHA/ACCP/HRS 2023, COR 1, LOE C-LD).^[6]
• ESC 2024 (AF): oral anticoagulation should be considered in all adult congenital heart disease patients with AF/AFL and intracardiac repair, cyanosis, Fontan palliation, or systemic right ventricle to prevent ischaemic stroke and thromboembolism, regardless of other thromboembolic risk factors (Class IIa, Level C).^[5]
• ESC 2020 (ACHD, recommendations for intervention after Fontan operation): anticoagulation is indicated in the presence, or with a history, of atrial thrombus, atrial arrhythmias, or thromboembolic events (Class I, Level C).^[1]
• ACC/AHA/ACCP/HRS 2023: in adults with AF and moderate or severe forms of congenital heart disease, particularly those with low-flow states such as Fontan circulation, blind-ending cardiac chambers, and cyanosis, it may be reasonable to treat with anticoagulation independent of conventional risk score to reduce risk of thromboembolic events (COR 2b, LOE C-LD); newer ACC/AHA 2025 lesion rows for Fontan circulation, d-TGA after atrial switch, unrepaired cor triatriatum sinister and Eisenmenger syndrome sit beside it, each with its own conditions.^[6]
• ACC/AHA 2025 (Fontan): in adults with Fontan circulation and a known or suspected thrombus, atriopulmonary Fontan, a history of thromboembolism, or a history of sustained atrial flutter or fibrillation, anticoagulation is recommended to reduce the likelihood of thromboembolic disease (COR 1, LOE B-NR); in adults with Fontan circulation and the absence of high-risk features (history of thromboembolism, sustained atrial flutter/fibrillation, or atriopulmonary Fontan) or bleeding contraindications, treatment with either aspirin or anticoagulation is recommended to reduce the probability of thromboembolic disease (COR 1, LOE B-NR).^[2]
• ACC/AHA 2025 (d-TGA, cor triatriatum): in adults with d-TGA and atrial switch who have sustained intra-atrial reentrant arrhythmias or atrial fibrillation, oral anticoagulation can be useful to prevent embolic events (COR 2a, LOE C-LD); in adults with unrepaired cor triatriatum sinister and atrial fibrillation or atrial flutter, prior stroke, or left atrial thrombus, chronic anticoagulation is recommended to prevent embolic stroke, whether or not conventional thromboembolic risk factors are present (COR 1, LOE C-LD).^[2]
• ACC/AHA 2025 (Eisenmenger syndrome): anticoagulation therapy may be considered for patients with high-risk features (atrial arrhythmia, new or enlarging pulmonary arterial thrombosis, or prior thromboembolic event) and low bleeding risk to prevent thromboembolic complications (COR 2b, LOE C-EO), but adults with Eisenmenger syndrome should not be routinely prescribed oral anticoagulation given the high bleeding risk and lack of long-term survival benefit (COR 3: No Benefit, LOE B-NR).^[2]

Follow-up: When would you implant an ICD?^[3][1]

• ESC 2022 (ventricular arrhythmias): in adults with CHD with biventricular physiology and a left systemic ventricle presenting with symptomatic heart failure (NYHA II/III) and EF ≤35% despite ≥3 months of OMT, ICD implantation is indicated (Class I, Level C); in patients with advanced single ventricle or systemic RV dysfunction with additional risk factors, ICD implantation may be considered (Class IIb, Level C), and the table footnote says data are sparse and risk factors may be lesion-specific, including non-sustained VT, NYHA II/III, severe AV valve regurgitation, and wide QRS ≥140 ms (transposition of the great arteries).^[3]
• ACC/AHA 2025 sets a different class and different conditions for the heart failure population: in patients with ACHD and heart failure symptoms who have systemic LV dysfunction and biventricular circulation, who otherwise meet accepted criteria, a primary-prevention ICD is reasonable to prevent sudden cardiac death (COR 2a, LOE C-LD).^[2]
• ESC 2022: in patients with CHD with not tolerated VT/aborted CA due to VF, ICD implantation is indicated after exclusion of reversible causes (Class I, Level C).^[3]
• AHA/ACC/HRS 2017 (ventricular arrhythmias): in adult congenital heart disease with hemodynamically unstable VT, an ICD is recommended after evaluation and appropriate treatment for residual lesions/ventricular dysfunction if meaningful survival of greater than 1 year is expected, and with SCA due to VT or VF in the absence of reversible causes, an ICD is recommended if meaningful survival of greater than 1 year is expected (both COR I, LOE B-NR).^[8]

Branch D — Heart failure and transplantation

Examiner: How would you treat heart failure in an adult with congenital heart disease, and when would you think of transplantation?^[2]

• ACC/AHA 2025 notes that the randomized clinical trials showing that GDMT, CRT, and ICDs improve outcomes in heart failure exclude patients with ACHD; therefore, both the strength of recommendation and the level of evidence for GDMT and device therapy in ACHD with heart failure are lower than for patients without ACHD.^[2]
• In patients with ACHD and heart failure symptoms who have systemic LV systolic dysfunction and biventricular circulation, use of GDMT for heart failure is reasonable to improve heart failure symptoms (COR 2a, LOE C-LD); with heart failure symptoms, systemic LV dysfunction and biventricular circulation, CRT is reasonable to improve heart failure symptoms in those who otherwise meet accepted criteria for CRT (COR 2a, LOE B-NR), and a primary-prevention ICD is reasonable to prevent sudden cardiac death (SCD) in those who otherwise meet accepted criteria (COR 2a, LOE C-LD).^[2]
• ESC 2020 says that, as the pathophysiology of cardiorespiratory dysfunction is often different from the failing circulation in non-congenital (acquired) heart disease, extrapolation of results from published heart failure studies to ACHD patients is inappropriate, particularly in patients with a systemic RV, a failing subpulmonary ventricle, or a single ventricle physiology, and that any haemodynamic abnormalities, including arrhythmias, potentially causing heart failure that can be addressed by intervention or surgery must be excluded and, if possible, treated first.^[1]

Follow-up: And transplantation?^[2]

• ACC/AHA 2025: in patients with ACHD and heart failure, evaluation by specialists with medical and surgical experience in ACHD, as well as by specialists with expertise in advanced heart failure, is recommended to assess appropriateness for advanced heart failure therapies, such as heart transplantation or MCS (COR 1, LOE B-NR).^[2]
• Heart failure–related hospital admissions and the development of systemic ventricular dysfunction and protein-losing enteropathy are associated with worse outcomes and would be appropriate triggers for evaluation for advanced heart failure therapies, including transplantation.^[2]
• Multiorgan transplantation (heart–lung, heart–kidney, or heart–liver) is reasonable based on center-specific assessment of the degree of respective lung, kidney, or liver dysfunction in patients considered for heart transplantation (COR 2a, LOE B-NR), and with advanced heart failure refractory to optimal medical and device-based therapy, durable MCS devices are reasonable to improve quality of life or as a bridge to transplantation (COR 2a, LOE B-NR).^[2]
• Despite high early posttransplant mortality, patients with ACHD have equal or even superior long-term survival, particularly when cared for at high-volume centers with ACHD accreditation (ACC/AHA 2025); ESC 2020 text recommends timely evaluation for transplantation by ACHD heart failure specialists in a transplant centre with ACHD expertise (no class or level given).^[2][1]