ACHD: For Patients
Patients with all forms of congenital heart disease, from simple to complex, are seen in this practice.
There are more than 40 different types of structural congenital heart disease, including bicuspid aortic valve, atrial septal defects, ventricular septal defects and pulmonary valve stenosis. Patients with tetralogy of Fallot (repaired or unrepaired), transposition of the great arteries and coarctation of the aorta have more complex disease, but are reaching adulthood in greater numbers due to improved treatment options. Patients with single ventricles who have had palliative surgery such as the Fontan operation.
Adult Congenital Heart Disease
A New and Better Challenge
"The heart has to develop perfectly in order to function totally normally," said Dr. Ian Harris, director of the UCSF Adult Congenital Cardiology Program. "There is very little tolerance of error in the development process. If there is a severe error, the fetus does not survive, and even minor developmental errors may cause significant congenital heart disease."
Before the modern era of surgery, most children with complex heart defects died early. Fortunately, due to major advances in the last several decades, most babies with congenital heart defects — those present at birth — are now living into adulthood. "As of about 2002, there were more adults than children with congenital heart disease in the US," said Dr. Harris. This has led to the development of a large group of patients who require specialized care.
"A lot of patients are under the impression that since they had surgery as children, their problem was fixed," he said. "However, although many conditions can be improved through surgery, most patients are not cured. Today we have very effective treatments for patients, especially when we have an opportunity to intervene before they develop life-threatening problems."
The UCSF Adult Congenital Cardiology Program is helping lead the way in discovering how to best care for adults living with heart defects. The program receives about 10 new referrals a week, and follows about 5,000 patients who were born with structural heart defects, including holes in the heart, missing parts or inappropriate anatomical connections.
The program brings together a multidisciplinary team of experts to care for these complex patients, who may have one of more than 40 different conditions. "Rather than a collection of independent practitioners who have an interest in congenital defects, we have an unusually comprehensive and interdisciplinary program," said Dr. Harris. Many of the team's experts are also conducting cutting-edge research to learn more about how congenital heart disease develops, and are discovering better treatments that will help more patients live full, healthy lives.
The American Heart Association and the American College of Cardiology suggest that patients with congenital heart defects be seen at least once in a specialty center like UCSF's, and that those with moderately complex disease be seen on a regular basis. The Adult Congenital Cardiology Program provides a wide array of services, including a comprehensive medical evaluation, advanced medical investigations and treatments, and personalized recommendations about diet, exercise, psychosocial support, family planning and high-risk obstetrical services.
Because many congenital heart defects may run in families, the program also collaborates with the Cardiovascular Genetics Program to provide genetic counseling and testing to help identify other family members who may be affected. The team also works closely with referring physicians, particularly because many patients come from out of state and receive their routine care locally.
Lifelong Care of Complex Conditions
The interdisciplinary nature of the program is exemplified by the care provided to patients with the most common complex congenital condition: tetralogy of Fallot. This syndrome includes four defects of the heart and its major blood vessels: a hole between the right and left ventricles — the two lower chambers of the heart; a narrowing of the pulmonic valve and pulmonary artery, which connect the heart with the lungs; an aorta that is shifted over to the right ventricle and the hole between the two ventricles, instead of connecting with the left ventricle; and a thickened right ventricle wall.
"The most common problems we see are leakage of the pulmonic valve, arrhythmias (irregular heart rhythms) and heart failure, and they form a vicious cycle," said Dr. Harris. "The more leakage there is through the pulmonic valve, the greater the enlargement of the heart, which then leads to greater risk of arrhythmias and heart failure. These problems occur silently over time, and treatment usually involves replacing the pulmonic valve." The UCSF Adult Congenital Cardiology Program is leading a number of studies to better identify the ideal timing for intervention, when replacing the valve is truly needed, but not so late that the patient has developed irreversible heart damage.
With the recent recruitment of Dr. V.S. Mahadevan, UCSF now has the capacity to perform valve replacement using catheter-based procedures, in which cardiologists thread small devices through blood vessels up into the heart. This approach can spare appropriate adult congenital heart disease patients the need for an open-heart procedure, when most of them have already had two or three such operations by their 20s and are at higher risk for complications.
So far, the data have shown that often just replacing the pulmonic valve is not sufficient to optimize a patient's health. A collaborative effort at UCSF involving cardiologists, electrophysiologists, and congenital cardiac surgeons is investigating whether coupling the valve replacement with other treatments, such as treating their arrhythmias or implanting a defibrillator, can support better long-term outcomes. "As part of a research program spearheaded by one of our congenital cardiac surgeons, Dr. Tara Karamlou, we are standardizing our approach and evaluating whether each component results in an improvement," said Dr. Harris. "If it does, we continue it. If it doesn't, we modify it and test it again."
This type of careful tracking and evaluation is particularly important, since these conditions are relatively rare. "We will never have the opportunity to get 5,000 of these patients together and randomize them to one treatment or another, so we have to come up with a more innovative way to develop clinical evidence," said Dr. Harris.
Ultimately, some adult congenital heart disease patients may become transplant candidates, and the program collaborates closely with UCSF's outstanding heart and lung transplant programs.
Investigating Causes of Heart Defects
Another path of discovery is the laboratory research that many UCSF faculty members are conducting into the root causes of heart defects. For example, Dr. Harris is working with Dr. Brian Black in the Cardiovascular Research Institute on illuminating the complex genetic and molecular pathways that contribute to the formation of the human heart in utero. They are focusing on the cardiac outflow tract, a structure that eventually develops into the aorta, pulmonary artery and the outflow segments of the right and left ventricles. There are three different types of cardiac tissue that all converge in this one area during fetal development. "When you have three populations interacting, they all have to be on their game," said Dr. Harris. "If one of them is running a little bit late, it ends up not playing its part, and you end up with a defect that affects the other lineages."
Drs. Harris and Black have identified multiple genes that are expressed differently in these hearts than in normal hearts, and they hypothesize that these aberrant patterns of gene expression may play important and unanticipated roles beyond the abnormal cardiac development. For example, they found that problematic hearts have difficulty producing the correct proteins that regulate heart rhythm and electrical signaling, and these irregularities could contribute to problems later in life, even if the patient receives the best surgical interventions. "This is just a hypothesis at this point, but if it is true, a lot of these [molecular variations] could be drug targets in the future," said Dr. Harris.
Supporting Healthy Pregnancies
Along with Dr. Elyse Foster, the Araxe Vilensky Endowed Chair in Cardiology, and colleagues in the Department of Obstetrics, Dr. Harris also helped lead the formation of the Pregnancy and Cardiac Treatment (PACT) program, which brings together experts from maternal-fetal medicine, obstetrical anesthesiology, perinatal genetics, nursing and other disciplines to care for women with adult congenital heart disease who are pregnant or are thinking of starting a family. "Many heart defects are associated with much higher risks to a woman's own health and to a successful pregnancy, and there is a perception in the medical community that most of these defects are absolute contraindications to pregnancy," said Dr. Harris. "But what we have found here at UCSF is that most of these conditions can be managed successfully."
The PACT team offers preconception counseling, outlining possible risks of pregnancy and identifying defects that could be passed on to a child. The team can conduct a functional assessment of a woman's ability to exercise, demonstrating how her heart might respond to the extra demands of carrying a fetus. They may perform advanced imaging or cardiac catheterization to evaluate the heart and any repairs it has already undergone. In some cases, the team may recommend prophylactic surgery or intervention to improve the heart's ability to tolerate pregnancy.
During pregnancy, women are carefully monitored, and the fetus may also undergo echocardiography to assess for any congenital heart defects of its own. If there are problems with the fetus's heart, the family is connected with the UCSF Fetal Treatment Center. In collaboration with the high-risk obstetrics group, the team also develops a strategy to manage stress on the mother's heart during labor. Even after a successful delivery, the new mother is carefully monitored, since it takes about a month for hormonally related changes to the cardiovascular system to revert to a pre-pregnancy state.
A Growing Field
Not every heart defect is diagnosed in infancy or childhood. For example, the most common congenital heart defect is a bicuspid aortic valve, in which the valve between the left ventricle and the aorta has only two leaflets — flaps that open and close — instead of three. Often, this does not cause problems until middle age, when the valve begins to stiffen and develop what is called aortic stenosis. "The usual form of aortic stenosis — narrowing and calcification of the aortic valve — typically becomes noticeable when patients are 70 and 80, but when we see it in a 50-year-old, it's almost always because of an underlying bicuspid aortic valve," said Dr. Harris. The team monitors such patients, and can refer them for aortic valve replacement at the appropriate time.
In recognition of the complexity and growth of knowledge in the field of adult congenital heart disease, the American Board of Medical Specialties recently approved the creation of a new subspecialty in this area. The UCSF Division of Cardiology is among the first centers in the country to receive approval for a fellowship training program in adult congenital heart disease, and that program's first fellow, Dr. Anu Agarwal, started in July.
"What I like about this area of cardiology is that we almost never see the same thing twice, and I get to see a dizzying array of different problems," said Dr. Harris. It is not extraordinary for his group to see patients with combinations of anatomical defects which have never been reported in the medical literature, or where the underlying causes of defects are not clear.
"I encourage referring physicians to think of us if they have a patient with a cardiac problem that they can't quite identify," said Dr. Harris. "We enjoy the challenge of seeing these patients, and there are a lot of mysteries out there that we are interested in helping to solve."