Clinical practice guidelines are not immutable laws carved in stone, but dynamic maps that are redrawn as we explore previously uncharted clinical territory. In adults with congenital heart disease (ACHD), that map is especially intricate. The patient we now see in clinic or in the operating room is, in reality, the product of the success of late-20th-century pediatric cardiac surgery: a survivor who forces us to confront hearts that, although repaired with remarkable skill, are far from cured.

The recent publication of the 2025 ACC/AHA guideline is not merely an update of the 2018 document. It represents, rather, a shift in perspective: it consolidates multidisciplinary care and explicitly incorporates multiorgan transplantation and new technological tools, including artificial intelligence, into everyday clinical practice.

• The Heart Team: a network of expertise and care

One of the cornerstones of the 2025 guideline is the formalization of care architecture. Individual experience alone, no matter how outstanding, is no longer enough. The evidence accumulated in recent years makes it clear that outcomes improve when patients are assessed and followed within a specialized Heart Team.

Compared with the 2018 guideline, the 2025 document upgrades to Class I the recommendation that every patient with moderately or highly complex anatomy or physiology should be assessed at least once at a referral center to define a long-term strategy. This team extends beyond surgeons and cardiologists: it includes anesthesiologists with expertise in congenital heart disease, hepatologists, pulmonary hypertension specialists, and, increasingly, palliative care clinicians.

A particularly relevant point is the emphasis on noncardiac procedures. Many adverse events in ACHD do not stem from surgical complexity itself, but from misinterpretation of the underlying physiology in settings that may appear unrelated. Coordination with the congenital heart disease team is no longer merely desirable; it has become a quality standard.

• A shift in focus: detecting decompensation earlier

Whereas the 2018 document placed greater weight on symptoms, the 2025 ACC/AHA guideline shifts the focus toward earlier and more refined surveillance of ventricular deterioration. We are moving from a reactive stance to proactive monitoring based on advanced imaging and biomarkers.

The clearest example is the right ventricle in tetralogy of Fallot. Traditionally, we were guided by end-diastolic volume, but there is now recognition of the prognostic value of indexed right ventricular end-systolic volume (RVESVi > 80 mL/m²) as a risk marker. In other words, the issue is not simply how much the ventricle dilates, but its inability to empty effectively.

In parallel, NT-proBNP has been formally incorporated into physiological staging. A value exceeding twice the upper limit of normal places the patient in stage C, allowing identification of myocardial deterioration before overt symptoms or clear declines in ejection fraction emerge.

• The transplant frontier: the challenge of the failing Fontan

Probably one of the most relevant sections of the guideline is the one devoted to Fontan circulation. “Fontan failure” is no longer understood as an exclusively cardiac problem, but is approached as a multisystem disorder.

In this context, the guideline more decisively introduces the role of simultaneous heart-liver transplantation in patients with advanced Fontan-associated liver disease (FALD). Annual liver screening is recommended, including laboratory testing with alpha-fetoprotein and close hepatology follow-up, with the aim of detecting complications such as hepatocellular carcinoma at an early stage.

From a surgical standpoint, the decision is far from trivial. Although isolated heart transplantation may be sufficient in earlier phases, the presence of cirrhosis with clinically significant portal hypertension, such as ascites or varices, clearly shifts the balance toward combined transplantation. This is an area in which collaboration with abdominal transplant teams is essential.

• Europe and the United States: nuances in surveillance

When these recommendations are compared with the 2020 ESC guideline, there is broad convergence, although subtle differences in clinical posture remain. In bicuspid aortic valve-associated aortopathy, the 2025 AHA document adopts a more vigilant approach, recommending lifelong surveillance once the diameter exceeds 4 cm or when risk factors are present.

The European approach, by contrast, maintains somewhat more conservative thresholds for prophylactic intervention in asymptomatic patients, usually in the 50–55 mm range depending on the clinical context.

Where there is clear agreement is in rhythm management. In patients with complex physiology, such as Fontan circulation or a systemic right ventricle, rhythm control is preferable to rate control. Loss of atrial contraction may carry major hemodynamic consequences, and therefore early cardioversion and catheter ablation assume a more active role, ideally before arrhythmic substrates become difficult to reverse.

• Artificial intelligence and new tools

The 2025 guideline also opens the door to the integration of emerging technologies. For the first time, it explicitly mentions the role of machine learning in image interpretation and advanced electrocardiographic analysis, with the potential to identify patterns associated with a higher risk of major events.

Techniques such as myocardial strain and 4D flow are moving from the research arena into clinically useful practice, particularly in complex anatomies. For the surgeon, this translates into improved planning: the possibility of anticipating the hemodynamic behavior of a repair before entering the operating room.

COMMENTARY:

The main lesson these new guidelines leave us is that the adult congenital heart is a structure in constant flux, shaped by its own history. Our role has evolved: we are no longer merely repairers of anatomic defects, but stewards of myocardial reserve.

As a final reflection, I would return to the metaphor of the heart as a palimpsest. For those unfamiliar with the term, a palimpsest is an ancient manuscript in which the original text was erased so that a new one could be written, yet traces of the initial writing still remain visible.

In our practice, the ACHD patient is exactly that: a canvas on which the original congenital anatomy was “erased” or altered by childhood operations, but where scars, patches, and prior adaptations remain “written” and continue to shape adult health today. Our mission in 2026 is to know how to read every layer of that writing so that the years gained in childhood may translate into an adult life that is functional, rhythmic, and full.

REFERENCE:

Gurvitz M, Krieger EV, Fuller S, Davis LL, Kittleson MM, Aboulhosn JA, Bradley EA, et al. 2025 ACC/AHA/HRS/ISACHD/SCAI Guideline for the Management of Adults With Congenital Heart Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. J Am Coll Cardiol. 2026 Feb 24;87(7):822-976. doi: 10.1016/j.jacc.2025.09.006. Epub 2025 Dec 18. PMID: 41411480.