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.................................................................................................................................................................. 4.15.4 Conservative management See sections 3.4.3 and 3.4.8 for haematological management and the role of targeted therapy in PVD.

4.15.5 Follow-up recommendations Regular evaluation is required in a specialized ACHD centre. Frequency is individualized, but at least yearly, with physical examination, measurement of oxygen saturation, laboratory tests (haematological indices, iron status, liver function, kidney function, etc.), ECG, X-ray, and echocardiography (see also section 3.4.8). CMR and an exercise test are required at least once at adult age and at further intervals timed according to baseline findings.

4.15.6 Additional considerations

• Exercise/sports: as a rule, patients do not have an elevated risk of death during exercise, but they do have a substantially reduced exercise capacity. Recreational sports can be considered at a symptom-limited level. • Pregnancy: contraindicated in patients with severely reduced pulmonary blood flow or with severe PVD, or if ventricular function is poor. Cyanosis poses a significant risk to the foetus, with a live birth unlikely (<12%) if oxygen saturation is <85%106 (see section 3.5.7). • For contraception, a combined oral contraceptive pill must be avoided because of the risk of thrombogenicity and thromboembolism. Progestogen-only pills and progestogen-eluting intrauterine devices or implantation systems provide safe contraception with a smaller cardiovascular risk. • IE prophylaxis: indicated in all patients (see section 3.4.6).

4.16 Patients after Fontan operation

4.16.1 Introduction and background The Fontan operation was introduced in 1968 and has become the definitive treatment for suitable patients with a range of cardiac malformations characterized by a single functional ventricle (see section 4.15). Surgery consists of the separation of the systemic and pulmonary venous returns without a subpulmonary ventricle and restores them to being ‘in series’. Since its introduction, a number of modifications have been made to the original procedure, designed to streamline the systemic venous return to the PAs. Currently, the total cavopulmonary connection has replaced the atriopulmonary connection (RA appendage to PA), with either an intracardiac or extracardiac conduit between the IVC and the PA, together with an SVC-to- PA anastomosis (bidirectional Glenn).301 This circulation is frequently established in two stages. Adults with HLHS remain a small but expanding group of patients. The first data in adulthood describe a considerable prevalence of major adverse cardiovascular events and it appears that HLHS patients are more prone to complications than general Fontan patients, warranting closer follow-up and assessment.302 The natural history and outcome of other palliations for hearts with a ‘single ventricle’ are poor, so that the Fontan is usually undertaken in all patients in whom the haemodynamics are suitable. It is now appreciated that the operative mortality and subsequent outcome depend on the suitability of the circulation and adherence to defined criteria. Strict selection gives the best early and late results, with operative mortality of <5% in modern series and includes low PVR and PAP (mean <15 mmHg), preserved ventricular function, adequate PA size, no relevant AV valve regurgitation, and normal rhythm. A ‘fenestration’ has been performed in selected or all cases by some centres to allow for shunting of deoxygenated blood to the systemic circulation at atrial level, aiming to improve the cardiac output at the expense of cyanosis.303 Fontan operation, when considered late in adults, is not always the palliation of choice because of the limited long-term outcome.

4.16.2 Clinical presentation and natural history The lack of a subpulmonary ventricle results in chronic systemic venous hypertension, markedly altered pulmonary haemodynamics, and a chronically ‘preload-deprived’ ventricle. A number of important problems have emerged during long-term follow-up. Although 10year survival may approach 90%, it should be appreciated that a premature decline in cardiovascular performance, with reduced survival, is inevitable even in the best Fontan patients.304 Important haemodynamic issues contributing to late Fontan failure include a progressive decline in systemic ventricular function, AV valve regurgitation, a rise in PVR, atrial enlargement, pulmonary venous obstruction, progressively restrictive subaortic VSD, and the consequences of chronic systemic venous hypertension including hepatic congestion and dysfunction.305 Further complications include atrial and PA thrombus formation, development of pulmonary arteriovenous malformations, systemic arterial-to-pulmonary venous or systemic arterial-topulmonary arterial connection, and systemic-to-pulmonary venous collaterals. After the Fontan operation, the majority of patients do well during childhood and adolescence, although exercise capacity is reduced when measured objectively. However, clinical complications may subsequently develop, with a progressive decline in exercise performance and heart failure, cyanosis, chronic venous insufficiency, and development of important arrhythmias, especially in patients with a classical Fontan operation.306 By 10 years after a Fontan operation, 20% of patients have supraventricular tachyarrhythmias (including typically IART and atrial flutter, but also AF and focal AT).307 Bradycardia due to SND may facilitate occurrence of AT. The incidence of AT is lower after total cavopulmonary connection than atriopulmonary connection, and lower after extracardiac conduit than intracardiac conduit.308 Atrial tachyarrythmias with rapid conduction are associated with SCD. The spectrum of Fontan-associated liver disease is wide and includes both hepatic congestion and severe fibrosis, with signs of portal hypertension and hyperenhancing nodules as well as hepatocellular carcinoma.309 Protein-losing enteropathy is a rare but important complication and results in peripheral oedema, pleural effusions, and ascites. It can be diagnosed by documentation of low serum albumin and elevated Downloaded from academic.oup.com/eurheartj/article/42/6/563/5898606 by guest on 07 October 2026