Adult Congenital Heart Disease Guidelines Get Major Overhaul

Patrice Wendling

August 20, 2018

The American Heart Association (AHA)/American College of Cardiology (ACC) have released a major update to the first US guidelines on the management of adult congenital heart disease, published a decade ago.

"Since 2008 a lot of work has been done on trying to risk stratify adult congenital patients and has identified a lot of physiologic factors that are independent of their anatomy to some degree," said guideline writing committee chair, Karen K. Stout, MD, University of Washington, Seattle. "We used that to articulate a classification system that should allow providers to think a little bit more clearly about their patients individually and then do follow-up based on that classification and may guide thinking around therapies as well."

The new classification system for adult congenital heart disease (ACHD) retains the three previous anatomic categories of "simple," "moderate," or "great" complexity in the 2008 guideline but adds the physiologic classification of A through D — fairly similar to the AHA heart failure stages.

For example, a patient with tetralogy of Fallot who is extremely functional, who has no arrhythmias, and whose heart looks good on imaging would be classified as IIA, she said. A second patient with the same diagnosis who has several arrhythmias, some degree of heart failure, limited exercise capacity, and some kidney and liver dysfunction would be class IID.

"Those are such clearly different patients and should be followed differently, but the old system only used the fact that they had tetralogy of Fallot," said Stout. "The new classification system gives everyone that comes in contact with an ACHD patient a different way of thinking about them and a different way of engaging an ACHD cardiologist."

"I think it's the biggest change but also the most practical change."

The updated guideline was published online August 16 in the Journal of the American College of Cardiology and copublished in Circulation.

It was developed in collaboration with the American Association for Thoracic Surgery, American Society of Echocardiography, Heart Rhythm Society, International Society for Adult Congenital Heart Disease, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons.

Improved survival in children diagnosed with CHD has swelled the population of patients with ACHD in the United States to about 1.4 million. A national accreditation program for the subspecialty was launched last year at 11 US centers, but the sticky wicket is that there are now only about 300 board-certified adult congenital cardiologists.  

Nonetheless, the new guidelines recommend that patients with moderate to complex disease — ACHD AP classification IB-D, IIA-D, and IIIA-D — should be managed in collaboration with an ACHD cardiologist. This need for specialized care is noted throughout the guidelines and is something Stout suggests may prompt the most pushback.

"We actually did get pushback in the review of the guidelines on that because whether you agree with the need for an ACHD cardiologist or not, there's a general concept that guidelines shouldn't recommend who sees patients, but rather recommend what should be done," she said. "But in this particular patient population, which is so new and isn't something that all adult cardiologists are familiar with, there really is some evidence that expertise can be really helpful in the care of these patients."

Writing committee vice chair, Curt J. Daniels, from the Ohio State University Heart Center and Nationwide Children's Hospital, Columbus, agreed the recommendation may be controversial.

"I hope that the message is that we need to work closely with general cardiology; that these patients are going to be seen by them and the guidelines are a guide to how to follow and how to treat ACHD patients from general cardiology," he said. "But also that they are so unique, there are so many nuances that you can't put within the guidelines, that ACHD consultation is necessary."

Another potentially controversial aspect of the guidelines is the suggestion that closure of atrial septal defects (ASDs) is reasonable for some patients but not necessary for all ASDs. That is a shift from the long-standing idea, Stout said, that once you find an ASD big enough to enlarge the right heart, you should just close it.  

"It's not so much that we say you shouldn't, that's totally reasonable, but there's just not enough data to say we are clearly benefiting patients in the long run by closing their ASDs, besides the [reduction in] arrhythmia risk, which is not inconsequential," she said. "It's a class IIA indication but a couple of our class II indications people practice as if they're class I. So I think that's going to catch people's eye."

The guidelines task force also examined the question of whether patients with ACHD with systemic right ventricles benefit from medical therapy, such as β-blockers, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, and aldosterone antagonists.

Ultimately, the guideline committee balked at making a recommendation, citing a lack of sufficient data. Although small studies have suggested a benefit, part of the problem in evaluating drugs is the tremendous variability in anatomy and physiology, even within a diagnostic category.

"It's not that they don't work, but more that we haven't drilled down to which patient population really is going benefit," Stout said. "Because we all have a sense there is one; we just haven't studied it and been able to prove it."

The 2018 guidelines feature a variety of charts and tables as well as lesion-specific sections, all designed to be easy to use.

"We also created treatment algorithms, which weren't in the first guidelines but are consistent with more recent guidelines," Daniels said. "So you can have a patient with tetralogy of Fallot, for instance, and go to the algorithm and find out how best, and more visually, to treat the patient to pulmonary valve replacement."

While the guideline committee made a point of making the report more accessible as a point-of-care document, Stout said what she really appreciates is that it will allow for more real-time updates.

"One good example of that is one of our recommendations says closing an ASD in someone with severe pulmonary hypertension is a class 3 because it can cause harm, but there are groups out there that are using the pulmonary vasodilator therapies to treat patients, bring their pulmonary pressures down, and then close their atrial septal defect," she said. "As soon as that data gets published, then there'll be an opportunity to update the guideline just for that one thing."

"It's not really interactive, but in that 'What's different now than 10 years ago,' that's huge. It's actually the main reason the whole guideline was redone, to allow that real-time updating."

Finally, the 2018 guidelines highlight the need for more data, particularly the importance of long-term data. Both Stout and Daniels note that the Canadians and Europeans are further ahead in this area, in part because of the ability to track patients through universal healthcare.

There have been conferences with the Centers for Disease Control and Prevention and National Institutes of Health to create a unique identifier to track patients with CHD through the lifespan, but this costs money and requires organizational infrastructure, Daniels said.

"There are many, many datasets out there for congenital heart disease, such as surgical datasets, interventional, but there are no prospective datasets that we are collecting," he said. "It is an important area that we are still missing if we are ever going to get to the point of preventive care, improving care on a wider scale."

Stout reports no relevant conflict of interest. Daniels reports a relationship between his institution and Actelion. Disclosure information for other committee members is listed in the paper.

J Am Coll Cardiol. Published online August 16, 2018. Full text

Circulation. Published online August 16, 2018. Full text

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