Adult Congenital Heart Disease (ACHD)

Overview 

An increasing number of children with congenital heart disease are surviving into adulthood due to greatly improved surgical, medical, anaesthetic and intensive care over the last few decades. The survival of congenital patients into adulthood is now close to 85% in comparison to the 15% survival several decades ago. This new group of patients is now entering adulthood and will need regular monitoring and sometimes further surgical interventions may also be required. With the exception of a few conditions, ligation of isolated patent ductus arteriosus (PDA) and closure of isolated atrial and ventricular septal defects, surgical treatment of congenital heart disease is more often palliative than curative. Repeated procedures and interventions are the norms as conduits, baffles, shunts and grafts become stenosed, blocked and incompetent with time. In addition to the medical and surgical issues, this growing population may also face specific social, psychological and behavioral problems throughout their life.

It is timely that Adult Congenital Heart Disease (ACHD) is gaining recognition worldwide and in Singapore as an established sub-specialty of cardiology.

Size of the problem 

The incidence of congenital heart disease (CHD) in Singapore is 0.81% of total live births based on the birth defect registry from 1994-2000. In Singapore, with an estimated population of around 4.3 million, the estimated number of adults with CHD would be in the region of 12,000 adults with an extra 300-320 cases added annually, assuming an annual birth of 37,000 – 40,000 newborns. It is estimated that in the next decade, the number of adult patients with congenital heart disease worldwide will exceed their paediatric counterparts.

Challenges   

Despite their improved life expectancy, congenital patients stepping into adulthood face many issues:
· They have limited understanding of their underlying congenital defects
· Many believe that they are ‘cured’, unaware of possible sequel from their surgery and the need for further surgical procedures
· Medical and surgical issues which require life-long follow up, regular check up and repeated investigations and evaluation
· Issues related to pregnancy, contraception, risk to offspring need to be discussed
· Risk of endocarditis and the need for antibiotic prophylaxis
· Management of associated non-cardiac medical problems
· Social, emotional, financial, vocational, educational, psychological and lifestyle issues specific to each individual. As they enter adulthood, ACHD patients need to take charge of their lives, substituting parental overprotection in childhood with a sense of responsibility and maturity of their own
 
In the past, these adult patients were usually managed by paediatric cardiologists who, although excellent in interpreting and comprehending the underlying physiology and haemodynamics, were nonetheless ill-equipped in managing adult related problems like coronary artery disease, pregnancy and contraception, arrhythmias, hypertension. Research has shown that ACHD patients especially those of moderate to severe complexity do better when their care is centralised to a dedicated specialised ACHD unit.

NHCS Adult Congenital Heart Disease (ACHD) Programme 

This programme was first started in 2003 and has currently offers
· ACHD clinic once a week in which an average of 20 patients are seen each session, with plans to increase to 2 ACHD clinics a week. Besides offering care and follow up of ACHD patients, we also do screening of suspected Marfan patients, close monitoring of ACHD patients during pregnancy
· Monthly Transition Clinic in KK Hospital, run jointly with paediatric cardiologists from KKH for patients above the age of 16. The aim is to give paediatric patients a smooth transition from paediatric cardiology to adult cardiology services. It is anticipated that 150-200 patients per year will be transferred from the paediatric to the adult services
· Dedicated weekly congenital echo sessions, with an anticipated 800-1000 congenital echoes a year
· Dedicated weekly congenital cardiac catheterisation and intervention (particularly ASD and PFO device closure).
· Surgical interventions including extra-cardiac Fontan procedures for uni-ventricular hearts, pulmonary homograft replacements for Tetralogy of Fallot patients with severe pulmonary regurgitation, Rastalli conduit for patients with pulmonary atresia
· Expertise in nuclear imaging, Magnetic Resonance Imaging and Multislice CT imaging
· Expertise in pacing, arrhythmia treatment and ablation in congenital patients
· Expertise in cardiopulmonary and exercise testing
· Expertise in heart and lung transplantation for selected patients with end-stage congenital heart disease
· Dedicated ACHD nurse for education, support and care of ACHD patient and their families 

Conclusion 

Having survived into adulthood, ACHD patients are now facing a new set of challenges encompassing not only medical or surgical problems but extending to psychological, vocational and lifestyle issues. Congenital heart disease is a heterogenous condition with a wide spectrum of varying complexity and severity. Therefore, all ACHD patients (with the exception of those with mild isolated valvular heart disease or those with repaired Patent Ductus Arteriosus, Ventricular Septal Defect and Atrial Septal Defect) should be followed up in a specialised ACHD unit with a dedicated multidisciplinary team who can anticipate the various issues particular to each individual. Only then can we provide adequate care and work towards improving the clinical outcome of this special group of patients.