Congenital Heart Disease in Adults

Synonyms: Adult congenital heart disease, ACDH, ACHD, grown up congenital heart disease, GUCH

The topic covers a very wide range of diseases:

• Fallot's tetralogy
• Transposition of the great arteries
• Atrial septal defect
• Ventricular septal defect
• Coarctation of the aorta
• Valvular defects (usually aortic valve disease or mitral valve disease as right heart valve disease including pulmonary valve disease is very much rarer)
• Patent ductus arteriosus
• Cardiomyopathies
• Primary pulmonary hypertension

Some of these are not strictly diseases of the heart but they are certainly the domain of the cardiologist. As more patients with congenital heart disease survive into adult life, paediatric cardiologists have to pass over their patients to adult cardiologists but the role of the general practitioner or primary care physician becomes more important.

The British Heart Foundation recommends that:

• Management of adults with congenital heart disease is complex and requires close liaison between primary and secondary care.
• Secondary care should be provided at the level of an adult Cardiology Department for most patients but complex cases should be seen by specialist Adult Congenital Heart Disease units.
• The main medical issues are the risk of infective endocarditis, the management of contraception, pregnancy, the occurrence of arrhythmias and the complications of hypoxaemia.

This is echoed by the Department of Health (DOH) but in a much more circuitous fashion.¹

Congenital heart disease (CHD) is the commonest inborn defect with a worldwide incidence of 1%. Some have lesions that permit survival into adult life (indeed 10% are first diagnosed in adulthood) but others would have died in childhood without the advent of cardiothoracic surgery. Around 4,600 babies are born in the UK every year with congenital heart disease, representing about 1 in 145 births. About half of these will not need any treatment. About 90% of those born with congenital heart disease now survive into adult life, compared with 20% in the 1950s.

The Department of Health says that there are around 135,000 young people and adults currently living in England with congenital heart disease.¹ However, only about 11,500 have the more complex forms of the disease, requiring life-long expert supervision and intervention.²

There are a number of recurring and particular medical issues in patients with ACDH highlighted by the British Heart Foundation and the DOH.¹
Even patients who have had surgery may have significant haemodynamic impediment but there are specific areas of danger. These include haemodynamic decompensation, an example of which is Eisenmenger's syndrome, infective endocarditis. There are also specific problems regarding contraception and cardiac disease in pregnancy.

Eisenmenger syndrome

• This occurs when a left to right shunt is converted into a right to left shunt due to pulmonary hypertension.
• Typical causes of shunts include: large VSD (as originally described), patent ductus (PD), and less commonly other abnormalities.
• Compensating polycythaemia, associated with a high haematocrit, can cause problems such as deep vein thrombosis. This may cause not only pulmonary embolism but systemic emboli via the shunt. The result will depend upon where the embolus lodges but if it goes to the brain a stroke will result.
• Hypoxia, caused by haemodynamic decompensation, can lead to a Hb of 18 g/dL with a haematocrit of 60%. Venesection may be required if there are symptoms such as headache, faintness, blurred vision, amaurosis fugax, fatigue, myalgia or paraesthesia. In this group a high Hb is not a risk factor for arterial thrombosis but it may increase risk of venous thrombosis. However, anticoagulation gives many problems.³

This group may also have raised uric acid and require allopurinol to protect from gout.

Infective endocarditis

There have been important changes in the recommendations on the prevention of endocarditis.⁴ Routine prophylaxis is now no longer recommended and antibiotics would only be given to treat active infection (of whatever type) whilst awaiting (or with) microbiological advice.This is covered in the articles entitled Prevention of Endocarditis and Infective Endocarditis.

Identification of at-risk patients is still clinically relevant. Patients at high, moderate and low risk of infective endocarditis can be identified:

• Highest risk patients include:
  • Those with all types of prosthetic valve
  • Previous infective endocarditis
  • Surgically produced systemic or pulmonary shunts
  • Congenital cyanotic heart disease
• Moderate risk patients are:
  • Congenital cardiac conditions (other than cyanotic) but excluding isolated atrial septal defects (ASD) and surgical repairs of ASD or patent ductus arteriosus over 6 months ago
  • Bicuspid aortic valves
  • Acquired valve disease including rheumatic heart disease, mitral stenosis and calcific aortic stenosis
  • Hypertrophic cardiomyopathy
  • Mitral valve prolapse with regurgitation and with or without thickened leaflets
• Low risk patients include:
  • Mitral valve prolapse without significant regurgitation
  • Implanted pacemakers, defibrillators and coronary stents
  • Innocent murmurs (except elderly patients where this may represent an at risk calcified leaflet)

Contraception

• In some conditions the combined oral contraceptive is contraindicated but the risks of pregnancy are even greater and so an alternative but reliable form of contraception must be used.
• The Eisenmenger syndrome, polycythaemia and primary pulmonary hypertension are important risk factors and exogenous oestrogens in the COC or HRT should be avoided.
• Emergency contraception is still permissible as is the progestogen only pill.
• The IUCD and IUS are also acceptable although they are more difficult to fit in a nulliparous uterus and it is important to give appropriate antibiotic cover for a GU procedure.
• Depot and implant contraception is also permissible and antibiotic cover my also be wise.
• Barrier contraceptives are not a problem although when contraception methods are compared they tend to have a higher failure rate than others. They can be good when used meticulously.
• If there is no chance that the woman will wish to have a baby in the foreseeable future then sterilisation is a rational option although the failure rate can be no better than reversible forms of contraception and it requires the dangers of a general anaesthetic. For this reason vasectomy of the husband may seem an attractive alternative but if the life expectancy of the wife is limited, they may wish to consider the possibility of the husband remarrying.

Pregnancy

As more people with congenital heart disease survive into adult life, grown up congenital heart disease and pregnancy becomes more common and it affects more pregnancies.

• The risk is dependent upon the nature of the lesion and complications such as Eisenmenger syndrome or cardiomegaly where mortality may be as high as 25 to 50%. Primary pulmonary hypertension and cyanotic disease can also have a maternal mortality of 50%.⁵
• Pregnancy is contra-indicated in pulmonary hypertension, Marfan's syndrome with a dilated aortic root, severe aortic or mitral valve stenosis, and any patient with poor ventricular function.⁶
• Peripartum cardiomyopathy and Marfan's syndrome may be less dangerous than once thought.
• There may be a genetic element in some forms of heart disease in that the chance of the fetus having congenital heart disease is increased between 2 and 20 fold.⁵
• Physiological changes in pregnancy include a 30% increase in resting cardiac output as well as further demands that may occur with such complications as hypertension in pregnancy. Normal labour with an active management of the 3rd stage sees a boost to the circulation as the uterus contracts.
• Any delay is usually managed by intervention with forceps to prevent exhaustion.
• It is essential that any woman who has heart disease undergoes pre-pregnancy counselling not just to assess her risk but to review medication.
• If she takes warfarin this should be converted to heparin as the former crosses the placenta causing fetal loss or abnormalities. The rate of pregnancy loss in women with prosthetic or biomechanical valves is very high if they take warfarin but conversion to heparin gives a very favourable outcome except that the risk of thromboembolic events is increased.⁷
• ACE inhibitors and angiotensin receptor antagonists are both severely teratogenic.

Figures about maternal mortality need to be treated with caution. The nature and severity of the lesion is important. Management is improving all the time and some statistics are from countries with less well developed health services and perhaps still a significant volume of rheumatic heart disease.

Coarctation of the aorta

Coarctation of the aorta is a narrowing of the aorta most commonly found just distal to the origin of the left subclavian artery.

• It represents 5 to 10% of all congenital cardiac lesions and 7% of critically ill infants with heart disease.
• Surgical treatment is usually with a patch graft but morbidity remains.
• There is increased risk of berry aneurysm that can cause subarachnoid haemorrhage.
• If coarctation is not repaired, fewer than 20% reach the age of 50.
• If it is repaired before the age of 14 that figure is just over 90% but if it is repaired after the age of 14 it is just under 80%.
• After operation an increased pressure gradient at the site of the lesion persists but quality of life is good with nearly all patients being classified as NYHA (New York Heart Association) grade I (no symptoms on ordinary physical activity).
• After repair of coarctation blood pressure remains elevated and there is risk of re-stenosis or rupture.⁸
• As with all disease of the aorta and aortic valve, strenuous and prolonged isometric activities are dangerous. The risk of dissection remains significant even after repair and may be increased with isometric activity.
• Pregnancy represents a significant risk to both mother and fetus if it has not been repaired.
  • After repair there is an increased risk of dissection of the aorta and rupture of a cerebral aneurysm in the third trimester and peripartum period due to haemodynamic and hormonal changes.
  • There is a significant risk of hypertensive disease of pregnancy or pre-eclampsia.⁹
  • A Dutch study found an excess of miscarriages and a 4% rate of congenital heart disease in the offspring.⁹ An American study found similar results, including a high incidence of hypertension in pregnancy.¹⁰
  • All pregnant women with a history of coarctation, whether repaired or not, should be considered high risk.
  • Significant stenosis, whether unrepaired, residual or recurrent, is a contraindication to pregnancy.
  • Unrepaired coarctation of the aorta has significant maternal mortality.

Palpitations and arrhythmias

Palpitations and arrhythmias are very common in the general population but with congenital heart disease they can have sinister significance.

• Palpitations may indicate atrial fibrillation or ventricular extrasystoles or a tachyarrhythmia.
• Atrial tachyarrhythmias may occur in those who have had ASD, even if it was repaired.
• Ventricular dysrhythmias are likely after repair of Fallot's Tetralogy or in the patient in their 3rd or 4th decade with ventricular dysfunction.
• The onset of arrhythmias often heralds haemodynamic deterioration and requires full assessment.
• Atrial tachyarrhythmias can be poorly tolerated and are potentially life threatening in those with a Fontan circulation or repair for transposition of the great vessels, a single ventricle or with ventricular dysfunction.
• Bradycardia may require a pacemaker.
• Arrhythmias are the commonest cardiological reason for admission to the hospital, and atrial flutter is the most frequent disorder of rhythm, usually related to haemodynamic disturbances.¹¹

Patients with congenital heart disease generally have impaired exercise tolerance but they should be encouraged to exercise within the limits of their abilities.¹² Even after surgery, serious problems remain.¹³

• Exercise should only be discouraged in those with pulmonary hypertension or severe obstructive lesions of the left side of the heart.
• Commercial air travel is usually safe, even with cyanosis.¹⁴
• Few patients will have a normal life expectancy.
• Pregnancy may be troublesome or dangerous but adoption agencies do not look favourably on a potential mother who may die young.
• The demands for management vary considerably according to the complexity of the problem and the degree of surgical correction. About 20 to 25% are complex or rare and require lifelong expert supervision. About 35 to 40% require access to expert supervision and the other 40% require little or no expert supervision.¹⁴
• The organisation of care currently requires a more rational basis but the British Cardiac Society is keen to foster a more rational structure. Transition from paediatric to adult care can be a problem for adolescents.