What are the common challenges in providing treatment for patients with congenital heart disease (CHD)?

Common Challenges in Providing Treatment for Congenital Heart Disease Patients

The most critical challenges in treating congenital heart disease (CHD) patients stem from the heterogeneity of anatomic variations, small patient subgroups limiting evidence-based care, high rates of late complications (dysrhythmias affecting up to 50% of patients), and fragmented care systems with inadequate access to specialized ACHD centers—all of which directly impact morbidity and mortality. 1

Structural and Systemic Barriers to Care

Fragmented Care Delivery and Access Issues

• Lack of specialized centers and expertise represents a fundamental barrier, as patients with moderate-to-complex CHD cared for in specialized ACHD centers demonstrate significantly lower mortality compared to those managed without specialized care 1
• Gaps in care during adolescence and young adulthood occur frequently, with common reasons including lack of knowledge regarding need for follow-up, inability to find specialized providers, insurance barriers, and patients feeling well despite underlying pathology 1
• Patients experiencing gaps in care are substantially more likely to develop medical problems requiring intervention than those receiving continuous care 1
• Insufficient availability of ACHD programs coupled with inadequate insurance coverage creates access barriers that regulatory agencies must address 1

Transition from Pediatric to Adult Care

• The transition from pediatric to adult providers represents a critical vulnerability period where many patients are lost to follow-up 1
• Patients and families often lack education about their specific cardiac anatomy, expected complications, and the importance of lifelong specialized surveillance 2
• Adult physicians frequently lack training in the complexity of CHD, creating a knowledge gap that can be fatal when complications arise 2

Clinical Complexity and Management Challenges

Heterogeneity of Disease and Limited Evidence Base

• Wide variations in anatomy, interposition of comorbidities, variability in diagnostic modalities, and differences in surgical experience have resulted in remarkably heterogeneous management strategies across centers 1
• The number of patients in each CHD subgroup is small at individual institutions, making carefully designed studies difficult and limiting evidence-based guidelines 1
• Management has evolved through trial and error over 60 years rather than through rigorous clinical trials, creating diverse approaches even for patients with the same underlying lesion 1
• Conventional medical therapies for acquired heart disease cannot be directly transferred to CHD patients, particularly those with systemic right ventricles or single-ventricle physiology 3, 4

High Burden of Late Complications

Dysrhythmias:

• Affect up to 50% of ACHD patients and include sudden death, ventricular tachycardia, intra-atrial muscle reentry tachycardia/atrial flutter, and bradycardia 1
• Represent the most common cause of unscheduled hospital visits, accounting for one-third of emergency admissions 4
• Long-term studies of cardiac pacing and cardiomyopathy in ACHD remain lacking despite advances in resynchronization therapy 1

Heart Failure:

• Decompensated heart failure is a leading cause of death in ACHD patients 4
• Conventional medical heart failure therapy for left ventricular dysfunction is not effective in patients at highest risk—those with right ventricular or single ventricular failure 4
• Careful hemodynamic assessment and structural interventions must be considered first in GUCH patients presenting with heart failure symptoms 4

Postoperative Residua:

• Long-term complications include ventricular outflow tract obstruction or aneurysm, valvular regurgitation, residual shunts, myocardial hypertrophy, chamber enlargement, ventricular dysfunction, and aortic complications 1
• The three most common late causes of death are arrhythmia, heart failure, and complications of reoperation 1

Superimposition of Acquired Adult Diseases

• Systemic hypertension and atherosclerotic vascular disease further modify underlying congenital cardiovascular defects 1
• Associated syndromes such as Down syndrome are associated with progressive medical problems requiring integrated management 1
• Non-cardiac events such as pregnancy or surgery on other body systems require special attention and management 1

Special Population Challenges

Pregnancy Management

• CHD is now the most common form of heart disease encountered during pregnancy in the United States 1
• Management of pregnant women with prosthetic heart valves placed to treat CHD is particularly difficult 1
• Ideal management strategies are difficult to delineate because each center has small numbers of patients and no collaborative multicenter studies have been performed 1
• Children of adults with CHD are several-fold more likely to have CHD than the general population, necessitating genetic evaluation for recurrence risk prediction 1
• Close interplay between obstetrician, adult congenital cardiologist, fetal medicine perinatologist, and neonatologist is essential but not widely available 2

Genetic and Risk Stratification Issues

• Specific genetic mutations (e.g., NkX2.5 transcription factor) not only cause structural cardiac malformations but may predispose individuals to arrhythmias, potentially increasing morbidity 1
• Knowledge of long-term outcomes for adults with complex CHD is necessary to provide optimal care and guide refinement of childhood interventions 1
• Many individuals with complex CHD are unaware of their prognosis and overestimate their life expectancy, resulting in requests or expectations at odds with clinical judgment 1

Diagnostic and Monitoring Limitations

Imaging Challenges

• 2D echocardiography has inherent technical limitations in adult CHD patients, including poor acoustic windows, difficulty imaging great vessels, and complex anatomic relationships 5
• The vast majority of CHD patients require lifelong periodic echocardiographic surveillance even when current studies appear normal, due to risk of residual defects and late postoperative complications 5
• Advanced imaging modalities (TEE, 3D echo, cardiac MRI) are often necessary but not universally available 5

Monitoring Complex Residuals

• Right-sided CHD residuals require monitoring for right ventricular dysfunction, arrhythmias, residual obstructive lesions, and pulmonary regurgitation—complications that can lead to sudden death and progressive cardiac deterioration 6
• Systematic follow-up every 1-2 years minimum is recommended, with more frequent evaluation for documented residual abnormalities 6
• Symptoms may appear late despite progressive hemodynamic abnormalities, requiring high clinical suspicion 5

Multidisciplinary Infrastructure Deficits

Lack of Comprehensive Support Services

• Inadequate resources for patients with cognitive or psychosocial impairment and lack of comprehensive case management compound medical complexity 1
• Multidisciplinary collaboration is required with congenital cardiac imaging, interventional catheterization, congenital cardiac surgery and anesthesia, heart failure, transplantation, electrophysiology, reproductive services, genetics, pulmonary hypertension, hepatology, nephrology, and hematology—services not easily available "off the rack" 2
• Cardiac surgery in GUCH patients should be performed by surgeons trained in CHD treatment who also operate on pediatric patients, but such expertise is limited 4, 2

Surgical and Procedural Expertise Requirements

• Cardiac surgery, catheter-based interventional procedures, and electrophysiological procedures involving congenital heart lesions should be performed by operators with expertise in CHD procedures and in collaboration with an ACHD cardiologist 1
• The nuances and complexities of congenital cardiac anatomy, coupled with high probability of previous childhood operations, make trained congenital cardiothoracic surgeons best suited for this population 2
• Specific ACHD training options are not generally available for cardiac anesthesiologists, though many develop expertise through pediatric anesthesiology training and mentoring 1

Resource-Limited Settings

Developing Country Challenges

• In developing countries, only a minority of children with CHD is detected and few benefit from surgical treatment, compared to prenatal diagnosis routinely used in developed countries 7
• A pattern of late presentation accompanied by high rates of complications is characteristic in resource-deprived settings 7
• The approach emphasizes treatment of "curable" malformations, with only a fraction of complex defects considered for surgery 7
• Surgery must be linked to early detection and a referral system where general practitioners, pediatricians, obstetricians, and cardiologists interact in protocols for diagnosis, management, and follow-up 7

Critical Knowledge Gaps

Unanswered Clinical Questions

The 2018 AHA/ACC guidelines identify multiple evidence gaps that create treatment challenges 1:

• Mechanisms of heart failure that can be prevented, reversed, or treated remain unclear
• Why the systemic right ventricle fails is not fully understood
• Whether all patients with Fontan physiology will develop clinically important cirrhosis and how to prevent it
• Which patients with ACHD benefit from standard heart failure therapies (beta blockers, ACE inhibitors/ARBs, aldosterone antagonists)
• What medical therapies benefit patients with failing Fontan physiology
• Criteria for transplantation eligibility and which patients benefit from primary prevention ICDs
• Optimal pacing and resynchronization strategies and timing of implementation

Prognostic Uncertainty

• Estimating prognoses in individuals with CHD remains challenging due to less predictable disease trajectories 1
• Certain CHD diagnoses have markedly reduced life expectancy (Fontan circulation, systemic right ventricle, cyanotic heart disease), with 5-year mortality of a 40-year-old with Fontan physiology comparable to a 75-year-old from the general population 1

Common Pitfalls to Avoid

• Never assume a "normal" 2D echocardiogram means no follow-up is needed, as periodic surveillance is indicated for virtually all CHD except repaired PDA and select repaired ASDs 5
• Do not apply treatment regimens from acquired heart disease directly to CHD without considering anatomic and physiologic differences 3, 4
• Avoid underestimating the complexity of "simple" postoperative heart defects, as even these can lead to age-related problems previously unexpected 3
• Do not delay referral to specialized ACHD centers for patients with moderate-to-complex disease, as survival benefit is clearly demonstrated 1, 4