Young at Heart - Assessing Congenital Heart Disease in Adults
A congenital heart defect (CHD) is a problem with the heart’s structure due to an abnormal foetal development. The complex four-chamber configuration of a normal heart develops from a single tube in early foetal life. To complicate the developing anatomy, a temporary connection (ductus arteriosus) links the aorta and pulmonary artery in every foetal heart to allow oxygenated blood in from the placenta.
It is therefore not surprising that abnormalities can occur during foetal development or that CHDs are the most common type of birth defect in every country. Nearly 1 in 100 newborns has a congenital heart problem.1 More than one million babies are affected each year around the world.2
The population of adults with CHD is increasing. In the U.S. alone, an estimated 1 million adults live with congenital heart disease – partly due to better surgical correction techniques that have led to a steady decrease in CHD mortality. Today over 85% of babies born with a heart defect will survive into adulthood.3
Adults with CHD face difficulty with insurability. One study matched adults with CHD with similar controls and then compared their life insurance and mortgage experiences. Unsurprisingly, people with CHD had a higher incidence of premium loading or outright refusal. Severity didn’t appear to influence the decision – those with mild disease were just as likely to be refused – or to have premium loadings, as people with complex conditions do. Around 40% of applicants who were initially declined life insurance were subsequently offered cover, while 30% with complex CHD obtained life insurance at standard rates.4 While this may suggest difficulty in underwriting people with CHD, it also hints that current practice may have room for improvement.
CHD causes the heart structure to be compromised or miss essential parts, meaning that the chambers and valves don’t function properly. The two types of blood, oxygenated and deoxygenated, can be mixed or end up in the wrong place, causing problems with breathing, heart rhythm and functional capacity. In a normal heart, deoxygenated blood is collected in the right atrium. It passes through the tricuspid valve into the right ventricle and is then pumped via the pulmonary arteries to the lungs. Blood takes up oxygen in the lungs and is returned to the left atrium. It is then moved through the mitral valve to the left ventricle from where it is pumped through the aorta to be circulated around the body.
The heart is designed to keep the oxygenated blood and deoxygenated blood separate. CHD is labelled either acyanotic – where deoxygenated and oxygenated blood do not mix – or cyanotic where a connection between the right and left sides of the heart allows mixing to occur.
Different types of CHD have varying degrees of severity. The most common, which accounts for a third of all cases, is a ventricular septal defect – a hole between the two lower chambers of the heart, the right and left ventricles. A hole between the two upper chambers (atria) is called an atrial septal defect and is less common (7% of cases), about the same number as when the ductus arteriosus fails to close in newborns (patent ductus arteriosus).
More complex CHD includes narrowing (stenosis) of the pulmonary valve restricting blood flow from the heart to the lungs, transposition of the great arteries where the pulmonary and aortic valves positions are swapped and narrowing (coarctation) of the aorta that restricts blood flow away from the heart. Tetralogy of Fallot, the most common cyanotic CHD, is a complex abnormality including overriding of the aorta, ventricular septal defect, pulmonary valve stenosis and right ventricular enlargement (hypertrophy).
Long-term complications of CHD include arrhythmias, heart failure and infective endocarditis (infection of the heart’s valves or inner lining). In a study of people with complex disease, 20% required hospitalisation in a 12-month period, and 6% required two to four hospitalisations.5 In a heterogenous group of adults with congenital disease, 9.6% reported marked discomfort and physical limitation from fatigue, breathlessness and heart rhythm disturbance, even at rest.6 The incidence of neurodevelopmental impairment has increased, particularly in patients with CHD associated with other congenital syndromes.7
Underwriters require precise information about any heart defect, its severity and any surgical correction to make accurate and fair risk assessments. For instance, people with a simple defect, such as a small hole between heart chambers (septal defect) or a ductus arteriosus that has been surgically corrected, have near normal expected mortality. More complex CHD can have very high mortality, particularly if surgical correction isn’t an option.
- Green A., Outcomes of congenital heart disease: A review, Pediatr Nurs.2004;30(4).
- The Children’s Heart Foundation, http://www.childrensheartfoundation.org/about-chf/fact-sheets.
- Centers for Disease Control and Prevention, http://www.cdc.gov/ncbddd/heartdefects/data.html.
- Crossland D, et al., Life insurance and mortgage applications in adults with congenital heart disease, Eur J Cardiothorac Surg 2004;25:931-934.
- Simko LC, McGinnis KA, Quality of life experienced by adults with congenital heart disease, AACN Clin Issues 2003 Feb;14(1):42-53.
- New York Heart Association (NYHA) Functional Classification Class lll or lV., http://www.heart.org/HEARTORG/Conditions/HeartFailure/AboutHeartFailure/Classes-of-Heart-Failure_UCM_306328_Article.jsp.
- Marino BS, et al., Circulation 2012;125:1143-1172.