PH and Congenital Heart Disease
- I have a congenital heart defect. How common is this?
- How is CHD connected to PH?
- Why is it important to recognize PH in CHD?
- What can be done for me?
I have a congenital heart defect. How common is this?
Congenital heart defects affect slightly less than 1 percent of the population. Because of the development of successful operative repairs and catheter-based corrections performed at an early age, the number of adults with congenital heart disease (CHD) has gradually increased. There are now estimated to be more than a million adults with CHD in the United States and, for the first time in medical history, more adults than children with this problem.
How is CHD connected to PH?
One of the most common and serious complications that CHD patients develop is pulmonary hypertension (PH). The patients most at risk for this complication are those with so-called “shunt lesions.” These result in blood flowing abnormally from the left side of the heart (the systemic circulation) to the right side of the heart (the pulmonary circulation).
Examples of shunts include holes between the upper heart chambers (atrial septal defects) and holes through the lower heart chambers (ventricular septal defects). Usually such shunts are present from birth, but in other cases they have been surgically created as a way to temporarily improve blood flow to the lungs. In either case the presence of excessive blood flow to the pulmonary arteries may trigger the development of increased resistance in the arterial vessels and thus PH. Repairing these lesions early, before they have the chance to cause PH, is important. However, many of these lesions are not detected until PH has already developed.
Up to 40 percent of CHD patients have structures in the heart that predispose them to the development of PH, and up to 10 percent of patients will actually develop PH. If PH is unrecognized and untreated, it can result in what has traditionally been recognized as “irreversible” damage to the pulmonary vessels and the shunt flow reverses (now traveling from the pulmonary to the systemic circulation). This results in cyanosis (low oxygen delivery to the tissues), a condition that is referred to as Eisenmenger Syndrome. It is now recognized that Eisenmenger Syndrome is not truly irreversible and that medical therapy may improve exercise capacity and possibly even increase survival.
Why is it important to recognize PH in CHD?
Fortunately the incidence of Eisenmenger Syndrome is now rare in the United States because of improved detection of CHD in children and the availability of simplified and perfected surgical and catheter-based corrections. However, in parts of the world with limited access to healthcare, only 2-15 percent undergo appropriate surgery and up to 30 percent of unrepaired patients develop Eisenmenger Syndrome. This makes CHD-PH a major public health concern.
Even in the absence of Eisenmenger, PH can have a substantial negative health impact. A recent study showed that PH more than doubled the risk of death and heart complications in CHD patients, including heart failure and arrhythmias. In addition, hospitalizations and length of stay in the hospital and in the intensive care unit were almost three times higher when PH was present.
The presence of PH can be detected by performing an echocardiogram. Because PH can be due to an intrinsic problem in the lung vessels (pulmonary arterial hypertension) or from backflow from problems on the systemic side of the heart (pulmonary venous hypertension), a heart catheterization is often required to differentiate these two very different problems, as therapy varies greatly depending on the diagnosis.
What can be done for me?
CHD-PH patients should be closely monitored at regular intervals by physicians experienced in the management of their condition. Although separate guidelines now exist for the treament of CHD patients and for patients with other forms of PH, treatment strategies are, for the most part, still based more on clinical experience than on study evidence.
Eisenmenger patients, in particular, should be managed in centers with experience in the treatment of this syndrome. In general, patients with CHD-PH benefit from a team-based approach to care with input from the CHD specialist and the PH specialist.
There are several facets of care that need to be addressed in the CHD-PH patient:
Oxygen supplementation:Many CHD patients, depending on the degree of shunting, have chronic hypoxia (low oxygen in the blood). Some also have varying degrees of lung disease. Oxygen therapy has not been demonstrated to improve exercise tolerance or survival in patients with CHD-PH, but may improve symptoms. Care should be taken not to over-oxygenate, as improvements in saturation are limited and administration can lead to problems such as nose bleeding when given by nasal cannula.
It is important to maintain good exercise tolerance, but strenuous exercise generally should be avoided.
Although many patients with PH are anticoagulated, this practice in the CHD patient is controversial. Patients with CHD are prone to bleeding, particular lung bleeding or hemoptysis (coughing up blood). When anticoagulation is used, levels of blood thinning should be monitored very carefully to prevent such complications.
Diuretics should be used sparingly in order to avoid dehydration, which can provoke hyperviscosity (abnormal denseness of the blood that can limit the blood flow) and can also lead to drops in systemic blood pressure.
Treatment of iron deficiency:
Despite having higher hematocrits (red blood cell counts) due to low blood oxygen levels (cyanosis), patients with Eisenmenger Syndrome are actually at higher risk for iron deficiency. The latter can increase their risk for hyperviscosity. Phlebotomy (the practice of removing blood to decrease the red blood cell count) should generally be avoided, as this can worsen iron deficiency. When phlebotomy is absolutely necessary, like when neurological problems result, fluid should always be administered whenever blood is removed.
Avoidance of pregnancy:
CHD-PH is associated with a substantially increased risk for both mother and child during pregnancy. With Eisenmenger Syndrome, there is up to a 50 percent risk of maternal death and 40 percent risk of spontaneous abortion. Patients should avoid pregnancy and discuss contaceptive options with their doctors.
Advanced medical therapy:
Randomized controlled trials demonstrating benefits of advanced medical therapy in PH patients have included a small number of patients with CHD-PH (most of whom had undergone a repair of the lesion). There are now reports of use of all three PH drug classes (endothelin antagonists, phosphodiesterase-5 inhibitors and prostanoids) in patients with CHD-PH. In the randomized BREATHE-5 study, bosentan (an endothelin antagonist) improved distance walked and did not appreciably change oxygen saturations in Eisenmenger patients. Recent studies suggest that advanced therapy in CHD-PH may significantly improve quality of life and may even improve survival.
When no other treatments are successful and quality of life is severely impaired, patients with CHD-PH can undergo heart and lung transplantation. Another option is repair of the heart defect along with lung transplantation. The latter, however, is rarely possible or successful. The early death rate after transplantation appears slightly higher than for patients without CHD; but after this early period, most patients experience dramatic improvements in symptoms and quality of life.
By Richard A Krasuski, MD, FACC, FA, HA;
Cleveland Clinic Foundation, Cleveland, Ohio
Robert Schilz, DO, PhD,
Case Western Reserve University School of Medicine,
This page last updated December 2013