Approximately 1.4 million adults have congenital heart disease (CHD) in the United States (US), but few percutaneous devices have been specifically developed for these patients. As a result, interventionalists must often find creative tools and techniques to treat complex lesions and structural defects in the heart. “We’re the MacGyvers of the cath lab,” explained Richard A. Krasuski, MD, of Duke.
Krasuski shared his insights into new and emerging treatments for adult CHD at the American Heart Association’s Scientific Sessions held November 11 to 15, 2017, in Anaheim, CA.
Coarctation of the aorta, a narrowing in the descending aorta, is a common CHD lesion that affects about 8% of patients. It often presents with difficult-to-control, elevated blood pressure in young adults. Treating coarctation can be challenging, particularly with very tight narrowing, wherein damage to the aortic wall can result in aneurysms and dissection.
The Covered Cheatham Platinum Stent, a 0.013” platinum/iridium “zigged” structure that has been blazed in 24K gold and covered by an expanded sleeve, can be extended from 12.0 mm to 24.0 mm. The stent received US Food and Drug Administration approval in April 2016 to treat coarctation of the aorta based on results from the COAST trial (N = 105), which demonstrated that the stent improved blood pressure and reduced the number of antihypertensive medications needed. COAST II (N = 158) then evaluated the Covered Cheatham Platinum Stent for the treatment or prevention of aortic wall injury in patients with coarctation of the aorta. COAST II showed that the stent improved hemodynamics and that 93% of aortic wall injuries could be covered by a single covered stent.
“The Covered Cheatham Platinum Stent has the potential to be used in the management of a variety of different congenital defects, as well as rapidly stabilize procedural complications such as perforation,” said Krasuski, an investigator in both trials. “It has become a very important part in our congenital interventional toolkit and is rapidly expanding the number of challenges we are able to safely approach.”
Krasuski also discussed percutaneous treatments in tetralogy of Fallot, the most common form of cyanotic CHD. Tetralogy of Fallot composes up to 15% of new referrals to adult CHD departments. Surgical repairs often eventually result in either narrowing or leaking of the pulmonic valve. The ability to implant transcatheter valves into the sites of prior surgeries has greatly expanded the role of catheter-based interventions in these patients. Occasionally, treatment for these patients results in disruption of surgical material and leaking of blood into the chest. In the past, this necessitated urgent or emergent surgical repair. The PARCS trial is examining the use of the Covered Cheatham Platinum Stent to repair these leaks in patients undergoing implantation of the Melody transcatheter pulmonary valve.
A percutaneous approach that incorporates a covered stent could also be used to repair select sinus venosus atrial septal defects and treat advanced pulmonary hypertension. Sinus venosus atrial septal defect is a defect in the roof of the atrium that is accompanied by abnormal inflow of the pulmonary veins into the heart. This is traditionally repaired with highly complicated surgery. For the treatment of advanced pulmonary hypertension, a Potts Shunt—a connection from the left pulmonary artery to the descending aorta—is created to decompress the right side of the heart.
Expanding the number of less-invasive treatment options for adults with CHD is timely, given the progressively aging population. “We have a rapidly growing population of adults with CHD, many of whom have highly complicated heart lesions. Some have been operated upon multiple times previously and have lots of scar tissue and distorted anatomy,” Krasuski explained. “We often have to decide between surgical or percutaneous repair options. We’re increasingly able to offer patients a transcatheter approach, which is particularly important, as many patients have excessive surgical risk and are best suited to percutaneous treatments.”
Source: Krasuski RA. The next big hit in congenital interventions. Presented at: American Heart Association Scientific Sessions 2017; November 11-15, 2017; Anaheim, CA. Abstract IN.HALL.04.