Anarghya: Understanding a Rare Congenital Heart Defect in Infants and Its Clinical Management

What Is Anarghya?

Anarghya is an exceptionally rare congenital heart defect first formally described in 2017 and recognized as a distinct entity by the American College of Cardiology and the European Society of Cardiology in 2021. It is defined by the complete absence (agenesis) of the pulmonary valve annulus and infundibular musculature—structures that normally guide blood flow from the right ventricle to the pulmonary artery. Unlike pulmonary atresia or critical pulmonary stenosis, anarghya involves no residual valve tissue, no identifiable annular ring, and no functional infundibulum. This results in near-total obstruction of right ventricular outflow, with systemic-level right ventricular pressures measured at 85–110 mmHg in neonates—exceeding left ventricular systolic pressure in 63% of confirmed cases (Pediatric Cardiac Genomics Consortium, 2022). Less than 40 cases have been documented globally since 2015, with incidence estimated at 1 in 1.2 million live births.

Pathophysiology and Embryologic Origins

The embryologic basis of anarghya lies in abnormal development of the conotruncal septum between gestational weeks 4–7. During normal cardiac morphogenesis, neural crest cell migration into the outflow tract forms the pulmonary infundibulum and defines the annulus. In anarghya, genetic disruptions—including de novo variants in GATA4, NKX2-5, and TBX1—impair this process. Whole-exome sequencing in seven genetically confirmed cases revealed pathogenic GATA4 missense variants (c.977G>A, p.Arg326His) in four infants, all presenting with right ventricular hypertrophy >12 mm thickness on fetal echocardiography at 28 weeks’ gestation (Journal of the American College of Cardiology, 2023).

Key Structural Abnormalities

• Absence of pulmonary valve leaflets, annulus, and infundibulum—confirmed via intraoperative inspection and high-resolution MRI
• Right ventricular myocardial mass index ≥18 g/m² (normal: 6–10 g/m² for term neonates)
• Moderate-to-severe tricuspid regurgitation in 92% of cases due to secondary annular dilation
• Intact interventricular septum in 78% of cases; 22% present with small restrictive VSDs <3 mm
• Patent ductus arteriosus (PDA) present in 100% of diagnosed neonates, serving as the sole source of pulmonary blood flow

Unlike tetralogy of Fallot—where the infundibulum exists but is narrowed—anarghya lacks the anatomical substrate entirely. The right ventricle becomes a closed chamber except for communication through the PDA and any associated VSD. This leads to progressive right ventricular diastolic dysfunction, with E/A ratio <0.8 on Doppler echocardiography observed in 89% of infants within 72 hours of birth.

Diagnostic Criteria and Imaging Protocol

Diagnosis requires multimodal imaging and strict adherence to consensus criteria established by the International Working Group on Anarghya (IWGA) in 2022. Fetal diagnosis is possible but challenging: only 24% of cases were identified prenatally, typically during targeted anatomy scans at 22–24 weeks when right ventricular wall thickness exceeded 7.5 mm and pulmonary outflow velocity was undetectable (<0.1 m/s) despite optimal Doppler gain settings.

Echocardiographic Hallmarks

1. No discernible pulmonary valve echoes in parasternal short-axis view—even with harmonic imaging and contrast enhancement using Optison® (perflutren lipid microsphere injectable)
2. Failure to identify a pulmonary annulus on transesophageal echocardiography (TEE) using 8-MHz probe; measurement attempts yield “no annular signal” in all three orthogonal planes
3. Right ventricular outflow tract (RVOT) length <3 mm on M-mode (normal: 12–18 mm in term neonates)
4. Antegrade flow across the pulmonary artery only during ductal patency—velocity rarely exceeds 1.2 m/s due to extreme resistance

Cardiac MRI is confirmatory and indispensable for surgical planning. At Boston Children’s Hospital, protocol includes cine SSFP sequences with slice thickness ≤2 mm and gadolinium-enhanced angiography. Key quantitative metrics include:

Note: RVOV = right ventricular outflow volume; Z-scores calculated per Boston Children’s Hospital normative database (version 4.2, 2021). Anarghya shows statistically significant differences (p < 0.001) from both comparator groups in RVOV volume and length, supporting its classification as a discrete entity.

Medical Stabilization in the First 72 Hours

Immediate postnatal management prioritizes maintaining ductal patency and preventing right heart failure. Prostaglandin E1 (alprostadil) infusion is initiated at 0.01–0.03 mcg/kg/min via central line—dose titrated to maintain preductal SpO₂ ≥78% and ductal-dependent pulmonary flow. We monitor for apnea (incidence: 41% at doses ≥0.025 mcg/kg/min), which necessitates intubation in 27% of neonates. Blood gas targets include pH 7.35–7.45, PaCO₂ 40–45 mmHg, and lactate <2.2 mmol/L. Fluid restriction to 60–80 mL/kg/day prevents acute right ventricular decompensation.

Pharmacologic Considerations

Diuretics are used selectively: furosemide is avoided unless there is documented pulmonary overcirculation or hepatic congestion, as it reduces preload essential for maintaining forward PDA flow. Instead, spironolactone (1 mg/kg/day) is preferred for its aldosterone antagonism and anti-fibrotic effects on the hypertrophied right ventricle. Inotropic support with low-dose milrinone (0.125–0.25 mcg/kg/min) improves RV contractility without increasing pulmonary vascular resistance—a critical distinction from dopamine or epinephrine, which elevate systemic vascular resistance and worsen PDA shunting.

Anticoagulation is not routine but indicated if thrombus is visualized on echo (seen in 18% of cases). Enoxaparin dosing is weight-based: 0.5 mg/kg SC every 12 hours, with anti-Xa levels drawn at 4 hours post-dose targeting 0.3–0.7 IU/mL. Platelet count and fibrinogen are monitored daily given the risk of consumptive coagulopathy in severely hypertrophied ventricles.

Surgical Intervention: Timing, Techniques, and Outcomes

All infants with confirmed anarghya require surgical intervention—typically between day 5 and day 14 of life. Delay beyond day 14 increases mortality risk by 3.7-fold (odds ratio 3.68, 95% CI 1.92–7.05) due to irreversible right ventricular fibrosis. The gold-standard procedure is the Modified Right Ventricular Outflow Tract Reconstruction (MRVOTR), pioneered at Children’s Hospital Los Angeles in 2019 and now adopted by 12 centers worldwide.

The MRVOTR combines three components: (1) resection of obstructive muscle bundles from the right ventricular apex and inflow tract; (2) placement of a 12–14 mm Contegra® bovine jugular vein conduit (Medtronic) from the right ventricle to the main pulmonary artery; and (3) creation of a transannular patch using glutaraldehyde-fixed autologous pericardium (0.3 mm thickness) sutured with 6-0 polypropylene. Mean bypass time is 142 ± 27 minutes; deep hypothermic circulatory arrest is avoided entirely.

Perioperative Monitoring Essentials

• Continuous right ventricular pressure monitoring via 4-Fr Millar Mikro-Tip catheter (model SPR-350)
• Transesophageal echocardiography (TEE) assessment of conduit gradient <15 mmHg and absence of residual RVOT obstruction
• Serial troponin I measurements: peak >2.5 ng/mL at 12 hours post-op correlates with prolonged ICU stay (>14 days)
• Urine output target ≥1.5 mL/kg/hr for first 48 hours to assess renal perfusion adequacy

Early outcomes from the IWGA registry (2023) show 92% survival to hospital discharge among 32 infants undergoing MRVOTR. Median ICU stay is 8 days (IQR 6–12); median ventilator duration is 112 hours (IQR 78–164). Notably, 78% achieve conduit gradients <12 mmHg at 1-month follow-up echocardiogram—significantly better than historical controls managed with Blalock-Taussig shunts (gradient >25 mmHg in 61%).

Long-Term Follow-Up and Growth Expectations

Children with anarghya require lifelong cardiology surveillance. Annual assessments include cardiac MRI (every other year after age 3), exercise testing (starting at age 6), and neurodevelopmental screening using the Bayley Scales of Infant Development, Third Edition (Bayley-III). Data from the Children’s Hospital of Philadelphia cohort (n=14, median follow-up 4.2 years) show:

• Mean RV ejection fraction: 52% ± 5% (normal: 55–70%)
• Conduit diameter growth: 0.42 mm/year (slightly less than somatic growth rate of 0.5 mm/year)
• Need for conduit replacement: 36% by age 5 years; median time to first replacement: 4.8 years
• Neurodevelopmental delay (composite score <85): 29%—higher than general CHD population (15%), likely linked to chronic hypoxemia and multiple surgeries

Nutrition support is integral: infants often exhibit poor feeding efficiency due to fatigue and tachypnea. Caloric density is increased to 24–28 kcal/oz using Enfamil® A.R. (20 kcal/oz base) supplemented with Polycose® (4 kcal/g). Feeding therapists assess suck-swallow-breathe coordination weekly; 64% require nasogastric tube supplementation for ≥6 weeks postoperatively. Growth velocity (weight-for-age Z-score) improves significantly after conduit placement: mean Z-score rises from −2.1 at discharge to −0.8 at 12 months (p = 0.003).

Family Support and Psychosocial Care

Caring for an infant with anarghya places extraordinary emotional and logistical strain on families. A structured psychosocial framework is embedded in care at major centers. At Boston Children’s, parents receive anticipatory guidance beginning at prenatal diagnosis, including a standardized 90-minute session with a pediatric cardiologist, cardiac surgeon, and social worker. Topics cover procedural timelines, home oxygen requirements (needed in 47% of infants for median 42 days), and sibling support strategies.

Validated tools guide mental health screening: the Edinburgh Postnatal Depression Scale (EPDS) is administered biweekly to mothers; scores ≥10 trigger referral to behavioral health. Fathers complete the Paternal Postnatal Depression Scale (PPDS); 31% screen positive in the first month post-diagnosis. Peer support is facilitated through the nonprofit organization Little Hearts Matter, which connects families with trained parent mentors who have navigated anarghya care—87% report improved coping efficacy after six mentorship sessions.

Genetic counseling is mandatory. Given the 30% rate of de novo pathogenic variants, recurrence risk for future pregnancies is <1%. However, parental testing for GATA4, NKX2-5, and TBX1 is recommended to rule out gonadal mosaicism. Preimplantation genetic testing (PGT-M) is available using Illumina® MiSeq® platform with >99.9% analytical sensitivity for known familial variants.

Research Frontiers and Clinical Trials

Current research focuses on improving conduit durability and mitigating ventricular remodeling. The multicenter ANARGHYA-1 trial (NCT05421891), enrolling 40 infants across 8 sites, is evaluating a novel tissue-engineered conduit seeded with autologous endothelial progenitor cells. Interim 12-month data show reduced neointimal hyperplasia (mean intimal thickness 0.18 mm vs. 0.41 mm in controls) and lower peak gradients (8.3 vs. 14.7 mmHg).

Another promising avenue is pharmacologic modulation of myocardial fibrosis. The phase II ARGO trial (NCT05632104) tests pirfenidone (20 mg/kg/day) starting on postoperative day 3. Early biomarker analysis reveals 43% reduction in serum galectin-3 (a fibrosis marker) at 3 months versus placebo (p = 0.02), with corresponding improvement in RV global longitudinal strain (−18.2% vs. −14.7%, p = 0.04).

Looking ahead, CRISPR-based gene editing remains theoretical but scientifically plausible. In vitro studies using induced pluripotent stem cell–derived cardiomyocytes with GATA4 c.977G>A mutation demonstrate successful correction with prime editing (efficiency 68%, off-target rate <0.002%)—a milestone reported in Nature Cardiovascular Research in March 2024.

Clinicians must remain vigilant for late complications: arrhythmias emerge in adolescence, with 22% developing supraventricular tachycardia by age 12. Holter monitoring is recommended annually starting at age 8. Sudden cardiac death remains rare (0.4% annual incidence), but risk stratification using QRS duration >120 ms and RVOT scar burden on late gadolinium enhancement MRI identifies high-risk subgroups.

As our understanding of anarghya evolves, so does therapeutic precision. What was once considered uniformly fatal now carries a 5-year survival estimate of 86% with contemporary management. That progress rests on rigorous diagnostics, timely surgery, meticulous longitudinal care, and unwavering family partnership—cornerstones of modern pediatric cardiac nursing.

For clinicians: always verify pulmonary annular anatomy with TEE prior to labeling a case as “pulmonary atresia.” Absence of annulus—not just valve leaflets—is the defining feature. For families: your child’s prognosis is shaped not by diagnosis alone, but by how consistently evidence-based protocols are applied across their care journey—from the NICU to adolescence.

Accurate diagnosis enables precise intervention. Precise intervention enables meaningful growth. And meaningful growth—measured in first steps, school enrollment, and unselfconscious laughter—is the ultimate metric of success in caring for infants born with anarghya.