Congenital cardiac anomalies are the most common birth defects in humans, affecting approximately 0.8 in 100 live births. While the incidence of congenital heart disease (CHD) is expected to decline as a consequence of improved prenatal diagnosis, the number of patients surviving with CHD, both in the United States and worldwide, has increased significantly over the past three decades. More than 85% of infants born with cardiovascular anomalies now can expect to reach adulthood. Reduced mortality rates can be attributed to improved diagnostic abilities, enhanced surgical and nonsurgical therapies, and improvements in intensive care. Once the province of pediatric cardiology, CHD is now largely an adult phenomenon. As of 2010, 66% of patients with CHD in North America are adults.
The increase in the number of adults with CHD requires that internists and adult cardiologists develop a more sophisticated knowledge of the anatomy and physiology of these defects. These patients fall into several broad categories: those surviving into adulthood without intervention and perhaps without clinical recognition, those surviving with curative surgical or nonsurgical intervention, and those surviving with palliative surgical or nonsurgical intervention. Nonsurgical interventions may include catheter-based valvuloplasty, stenting, coiling, or device occlusion. The patients who are today making the transition into the adult CHD population have hemodynamic and cardiac problems differing from those in previous eras. Surgical techniques have evolved, intervention occurs earlier and is often definitive rather than palliative, and a greater number of patients with complex single-ventricle physiology and various modifications of cavopulmonary anastomoses (Glenn shunt, Fontan procedure) will reach adulthood. Because of the unique clinical conditions and needs of these patients, the American College of Cardiology and the American Heart Association have recommended that all patients with moderate or complex CHD be evaluated at least once by a physician with specialized training and expertise in adult CHD. Furthermore, it is recommended that diagnostic and interventional cardiac catheterization and electrophysiologic and surgical procedures in these patients be performed in regional adult CHD centers.
ACHD AP (Anatomic and Physiologic) Classification
Acquired heart disease patients with heart failure have been classified based on the traditional staging system that doesn’t necessarily apply to the adult congenital heart disease (ACHD) population. Hence in the 2018 ACC/AHA Guidelines on ACHD, an anatomic and physiologic (AP) classification was described taking into account a patient’s specific anatomy (mild, moderate, severe), with their physiologic stage identified based on their current functional status (eg, NYHA classification) as well as aortic enlargement, end-organ involvement, degree of cyanosis or shunting, arrhythmias, and pulmonary hypertension (see Table 31–1). This allowed for the physiologic stage to be modified based on improvements after transcatheter or surgical intervention that provided better prognostication going forward. For example, a patient with repaired Tetralogy of Fallot (TOF), NYHA class II symptoms, and mild pulmonary regurgitation would be classified as II b based on the ACHD AP ...