Early detection and diagnosis

In the U.S., early detection of Critical CHD has been significantly enhanced by the widespread implementation of pulse oximetry screening, which became universal in 2011. ^{Reference Harold13,Reference McClain, Hokanson and Grazel14} Following its addition to the Recommended Uniform Screening Panel, most states enacted policies mandating or recommending universal screening by 24–48 hours of life. By 2016, 48 U.S. states had adopted screening policies, leading to broad national coverage. ^{Reference McClain, Hokanson and Grazel14} These policies have had a measurable impact. In an analysis of over 26 million births, states with mandatory screening experienced a 33.4% reduction in early infant deaths from Critical CHD, which was not observed in states with only nonmandatory screening, underscoring the importance of consistent policy enforcement. ^{Reference Abouk, Grosse, Ailes and Oster1}

In addition to postnatal screening, prenatal detection through obstetric ultrasound and foetal echocardiography is widely practiced and supported by structured referral systems and regionalised care. Prenatal diagnosis enables delivery at tertiary centres equipped for immediate cardiac intervention, improving perinatal outcomes. ^{Reference Pruetz, Wang and Noori15} Despite these advances, challenges remain in ensuring uniform implementation and data reporting. However, training programmes, standardised screening algorithms, and telemedicine consultation have helped optimise practices across a diverse healthcare system. ^{Reference McClain, Hokanson and Grazel14} These innovations have been particularly beneficial in mitigating geographic disparities in access to care, especially in remote or undeserved regions where specialist availability is limited.

In recent years, significant efforts by the Ministry of Health and local healthcare leaders in Vietnam have aimed to promote universal prenatal obstetric ultrasound screening and postnatal newborn screening using pulse oximetry. However, the programme has not yet been adopted as a national mandate, and its implementation remains inconsistent, largely dependent on the resources and infrastructure available at the local level. While several large urban hospitals offer prenatal ultrasound and postnatal screening for Critical CHD, most births occur in rural or district-level health centres, where such screening technologies and paediatric echocardiography are not routinely available. ^{Reference Phuc, Tin and Giang4,Reference Cao, Le, Ngo, Nguyen and Nguyen5} This results in delayed diagnosis of Critical CHD, with infants often presenting in critical condition outside referral centres. For instance, at Nhi Đồng 1 in Ho Chi Minh City, most patients with total anomalous pulmonary venous return were operated at a median age of 5.5 months, significantly later than in high-income countries. ^{Reference Phuc, Tin and Giang4}

Prenatal ultrasound use is reportedly increasing in Vietnam, with over 80% of pregnant individuals receiving at least three antenatal visits. However, prenatal diagnosis of CHD remains rare due to limited foetal echocardiography expertise, inadequate provider training, and the absence of formal referral or perinatal coordination systems. ^{Reference Phuc, Tin and Giang4,Reference Ha and Siddiqui16} Cultural beliefs, such as reluctance to expose newborns to public settings, and logistical issues such as lack of ambulances and limited access to prostaglandin E1, further compound delays in detection, initial resuscitation, and transfer. ^{Reference Phuc, Tin and Giang4,Reference Wamala, Gongwer and Doherty-Schmeck17} Prenatal diagnosis is an important area to focus on, and it has been proven to improve clinical outcome and lower neonatal care cost in resource-limited setting. ^{Reference Vaidyanathan, Rani and Kunde18} Delayed postnatal diagnosis in remote areas is often due to limited access to care, while in urban settings, parents may not seek well visits for asymptomatic infants, reflecting both cultural beliefs that healthcare is only for illness and the absence of structured national guidelines for routine paediatric visits. ^{Reference Murni, Wirawan and Patmasari19}

Despite progress, such as expanded health insurance for children under six, increased donor support, and growing local surgical capacity, Vietnam has yet to implement systematic national screening or standardised referral pathways. ^{Reference Phuc, Tin and Giang4,Reference Cao, Le, Ngo, Nguyen and Nguyen5} As a result, timely detection and coordinated care for infants with Critical CHD remain major challenges, especially in rural areas. Persistent gaps in infrastructure, workforce training, and policy execution highlight the urgent need for scalable screening programmes and strategic, system-level investments.

In rural areas of Vietnam with limited access to subspecialty care, the integration of artificial-intelligence-assisted echocardiographic screening offers a promising strategy to enhance early detection of CHD. ^{Reference Wang, Doan, Reddy and Jone20} By leveraging artificial intelligence to guide basic cardiac ultrasound image acquisition and interpretation, healthcare professionals below the physician level, such as nurses, midwives, and community health workers, who can be trained to perform frontline screening in underserved regions. This task-shifting model not only empowers local providers with practical skills but also facilitates the timely identification of CHD cases for referral to specialised centres. Coupled with telemedicine support and structured referral pathways, artificial-intelligence-assisted screening can serve as a scalable solution to bridge disparities in early CHD diagnosis and improve outcomes for children in remote communities.

Access to specialised paediatric cardiac care

Access to specialised paediatric cardiac care in the U.S. remains being shaped by significant regional, socio-economic, and racial disparities, despite overall improvements in workforce growth and subspecialist distribution. Millions of children in rural or underserved communities live more than 80 miles from a paediatric subspecialist, and many must travel over 100 miles for CHD surgery at high-volume centres. Specialised cardiac centres are concentrated in urban areas, and this geographic maldistribution contributes to worse outcomes for high-risk conditions such as hypoplastic left heart syndrome. Yet, system-level responses, including regionalisation of care, standardised referral networks, and expanded outreach through telemedicine and satellite clinics, have provided critical opportunities to mitigate these disparities to improve access to high-volume centres, mitigate geographic barriers, and promote timely access to interventions. ^{Reference Lopez, Baker-Smith and Flores11}

Vietnam’s paediatric cardiac care infrastructure is concentrated primarily in a few urban centres in the North, Central, and South Vietnam. ^{Reference Cao, Le, Ngo, Nguyen and Nguyen5} Access in rural provinces remains severely limited due to a combination of geographic, financial, and systemic barriers. ^{Reference Phuc, Tin and Giang4,Reference Cao, Le, Ngo, Nguyen and Nguyen5} By 2015, only about 20 paediatric cardiologists were actively practising in major cities, and rural areas lacked trained personnel altogether. ^{Reference Phuc, Tin and Giang4} While approximately 19 paediatric cardiac care centres had been established by that time, only a handful were equipped for neonatal surgery. As of 2023, there were 27 paediatric cardiac surgeons, at both senior and junior levels, serving across 15 cardiac centres nationwide, with only 7 having the capacity to perform neonatal CHD surgery. ^{Reference Cao, Le, Ngo, Nguyen and Nguyen5} Many of these surgeons also perform adult cardiac surgeries, further diluting subspecialty focus. This gap often leads to delayed referrals, with children frequently presenting in severe condition by the time they reach a tertiary facility. ^{Reference Phuc, Tin and Giang4}

The Heart Institute in Ho Chi Minh City was the first centre in Vietnam to provide cardiac care for children with CHD since 1992. It allocates 25% of its services to indigent patients. By 2016, it had conducted over 6,700 free surgeries, with extensive outreach and training programmes for provincial providers. ^{Reference Lajos and Carpentier7} In recent years, Nhi Đồng 1 and National Children’s Hospital have emerged as sustainable successful models in urban areas with outreach programmes that help mitigate some of these gaps. In 2023, the National Children’s Hospital reported performing 1,250 CHD surgeries with an early mortality rate of 1.6%, while Nhi Đồng 1 in Ho Chi Minh City performed 487 surgeries with a mortality rate of 0.83%. ^{Reference Cao, Le, Ngo, Nguyen and Nguyen5} These outcomes are consistent with international standards for low- and middle-income countries and reflect significant efforts from these centres. Despite such successes, the broader paediatric cardiac care system remains under-resourced, with ongoing challenges in referral coordination, surgical capacity, and postoperative critical care and follow-up care. Disparity persists at a systemic level and will require system-wide solutions to ensure equitable and comprehensive care for all children with CHD across Vietnam. A national registry using risk adjustment models, such as the risk adjustment for congenital heart surgery 1 (RACHS-1) would allow for robust benchmarking across centres, identification of care gaps, and systematic quality improvement. Moreover, national data collection would enhance transparency, support equitable resource allocation, and enable participation in international collaboratives such as the International Quality Improvement Collaborative, which has demonstrated reduced perioperative mortality in resource-limited settings. ^{Reference Jenkins, Castaneda and Cherian22}

One of the most sustainable and impactful cardiac screening outreach initiatives in Vietnam is the Rural Outreach Clinics programme led by VinaCapital Foundation, which delivers free cardiac screening directly to underserved and remote communities. ²³ By partnering with local authorities and transporting the nation’s leading cardiologists and surgeons to rural areas, Rural Outreach Clinics addresses healthcare disparities and key social determinants of health. Children from low-income families, often unable to access or afford care in urban centres, are screened, diagnosed, and referred through a coordinated system for free surgical or interventional treatment at partnering cardiac centres. Since its inception, Rural Outreach Clinics has screened 442,365 children and provided life-saving care to 9,472 children as of May 2025. The programme organises over 500 clinics annually across 49 provinces. This programme exemplifies the power of long-term public-private collaboration, combining medical expertise, logistical support, and financial resources to build a scalable and equitable healthcare model. Beyond immediate impact, the programme’s large dataset informs national health planning and reinforces the value of equity-driven, community-based strategies. Rural Outreach Clinics stands as a cornerstone of VinaCapital Foundation’s mission to “leave no child behind” and offers a replicable model for sustainable, inclusive paediatric care.

Surgical and intensive care capacity

In the United States, congenital cardiac care is supported by a robust infrastructure, with over 150 hospitals performing CHD surgery, most of which participate in national quality registries like the Society of Thoracic Surgeons CHD Database. Specialised surgical centres, paediatric cardiac ICUs, and integrated post-operative services provide 24/7 surgical availability, advanced critical care with high-intensity staffing, including access to mechanical circulatory support. This centralised, multidisciplinary system has led to survival for many forms of Critical CHD exceeding 90%, including complex procedures such as the Norwood operation and arterial switch operation. ^{Reference Lopez, Baker-Smith and Flores11}

In contrast, Vietnam continues to face significant limitations in surgical and intensive care capacity, including:

Long waiting lists

Despite recent improvements, infrastructure remains inadequate, and waiting lists for surgery remain long, especially for complex cases. ^{Reference Phuc, Tin and Giang4,Reference Cao, Le, Ngo, Nguyen and Nguyen5}

One notable success is the Nhi Đồng 1 programme in Ho Chi Minh City. ^{Reference Culbertson, Nguyen and Vu26} Three key pillars contributed to the success and sustainability of the CHD surgical programme at Nhi Đồng 1 since 2007 and serve as a model for replication. First, the programme emphasised accurate and standardised diagnosis, made possible by investments in modern echocardiographic equipment and extensive training of local cardiologists through international partnerships. Second, a commitment to high-quality surgical repair was upheld through intraoperative transoesophageal echocardiography and immediate re-intervention if residual defects were detected. Third, aggressive, protocol-driven postoperative care in a dedicated cardiovascular ICU ensured optimised recovery, supported by continuous training of both physicians and nurses (Figure 1). ^{Reference Culbertson, Nguyen and Vu26} In addition, the programme fostered long-term international collaboration, with recurring visits and case-based teaching from U.S. and Singaporean teams, enhancing the local team’s skills and autonomy. Equitable access was promoted through government-funded insurance for children under six and supplemental support from non-governmental organisations for families unable to afford care. Finally, local ownership and retention of trained staff, despite limited compensation, demonstrated the programme’s cultural integration and institutional commitment. These pillars collectively enabled a low surgical mortality rate (0.94%) and the growth of Nhi Đồng 1 into a national referral centre for CHD surgery.

Figure 1. Three key pillars of successful CHD surgical programme at Children’s Hospital 1. Cath/Angio = Cardiac catheterisation and angiography; CT/MRI = Computed tomography / magnetic resonance imaging; CPB = cardiopulmonary bypass; CXR = Chest X-ray; ECG = Electrocardiogram; ICU = Intensive care unit; TEE = Transoesophageal echocardiography.

Longitudinal and lifelong care

Longitudinal and lifelong care for individuals with CHD in the United States is characterised by structured, multidisciplinary, and guideline-driven care across the lifespan, including robust transition programmes from paediatric to adult CHD services, regular surveillance, and attention to social determinants of health. ^{Reference Zaidi, Alberts and Chowdhury3,Reference John, Jackson and Moons27} The American Heart Association emphasises the need for continuous, specialised follow-up, and transition education to mitigate gaps in care and improve outcomes. Despite this, gaps in care remain common, particularly during the transition to adulthood and are strongly influenced by social determinants of health such as insurance status, geographic access, and socio-economic factors. ^{Reference Lopez, Baker-Smith and Flores11}

In Vietnam, both intermediate and lifelong CHD care remain limited by less standardised training pathways, fewer specialised centres, and resource constraints. Most care is concentrated in major urban centres, with limited access in rural areas. There is limited public awareness for primary prevention and follow-up care, with the healthcare system primarily focused on acute, life-threatening conditions. There is a lack of formalised transition programmes, and follow-up is often inconsistent, with many patients lost to follow-up after childhood surgery. Efforts such as the Heart Institute model demonstrate that sustainable, high-quality care is possible with long-term investment in local training, infrastructure, and financial models that support indigent care. However, national systems for longitudinal surveillance, transition to adult care, and addressing social determinants of health are not yet widely implemented. ^{Reference Lajos and Carpentier7–Reference Corno9,Reference Nayak, Trieu and O’Dell28}

Data collection and quality improvement

Data collection and quality improvement initiatives for CHD in the United States are robust, with national and state-level registries, mandated newborn screening for Critical CHD, and widespread participation in quality improvement collaboratives, all of which have contributed to measurable reductions in perioperative mortality and improved outcomes. The American Academy of Paediatrics recommends standardised data collection, electronic data sharing, and linkage of newborn screening with birth defects monitoring and vital records to enable comprehensive surveillance and quality improvement. All U.S. states have implemented Critical CHD screening, and many participate in national databases and collaboratives, such as the Society of Thoracic Surgeons Congenital Heart Surgery Database and International Quality Improvement Collaborative, which have demonstrated reductions in mortality and infection rates through benchmarking and targeted interventions. ^{Reference Oster, Pinto and Pramanik2,Reference Jenkins, Castaneda and Cherian22,Reference Rahman, Zheleva and Cherian29}

In contrast, there is currently a lack of national Critical CHD registries and standardised data collection systems in Vietnam, making it difficult to benchmark outcomes, guide policy, or systematically improve care. Most data collection is centre-based, and participation in international collaboratives like International Quality Improvement Collaborative is limited to a few institutions. ^{Reference Lajos and Carpentier7,Reference Jenkins, Castaneda and Cherian22,Reference Rahman, Zheleva and Cherian29} Surgical outcome data are not available at most surgical centres, although early survival data are excellent at Nhi Đồng 1 and National Children’s Hospital. ^{Reference Cao, Le, Ngo, Nguyen and Nguyen5}

In addition, the National Children’s Hospital collects morbidity and mortality data for admitted neonates, including those with CHD. These important efforts are primarily hospital-based and not part of a national standardised registry. Da Nang General Hospital has implemented a procedural registry for structural heart interventions, developed in collaboration with international partners. This registry enables longitudinal follow-up and systematic data collection for patients undergoing congenital and structural heart interventions, although its scope is more limited and focused on patients treated during specific collaborative projects. ^{Reference Nayak, Trieu and O’Dell28} There is currently no national CHD registry in Vietnam, and systematic data collection is limited to a few major centres with international collaborations or specific quality improvement initiatives. ^{Reference Miles, Dung and Ha30} This limits the ability to identify gaps, monitor trends, or implement evidence-based quality improvement at a national level. ^{Reference Lajos and Carpentier7,Reference Jenkins, Castaneda and Cherian22,Reference Rahman, Zheleva and Cherian29}

Health policy and financing

Health policy and financing for CHD care in the U.S. are supported by a combination of public and private insurance reimbursement, philanthropy, and research grants, which enables significant investment in paediatric cardiac care despite the absence of a unified national child health policy. Insurance coverage (public and private) is a major determinant of access to CHD care, and disparities persist based on insurance status and socio-economic factors. ^{Reference Lopez, Baker-Smith and Flores11} However, the overall economic strength of the U.S. allows for broad access to advanced diagnostics, surgical interventions, and lifelong follow-up, with additional support from charitable organisations and research funding streams. ^{Reference Lopez, Baker-Smith and Flores11}

In Vietnam, families face high out-of-pocket costs for CHD care, and resource limitations constrain the implementation of national health action plans. Although public health insurance expansion has increased enrolment and utilisation, it has not significantly reduced out-of-pocket payments for high-cost services such as CHD surgery. The financial burden remains catastrophic for many families, particularly those with low income, and coverage for complex CHD interventions is often incomplete or unavailable. Sustainable models, such as Nhi Đồng 1 and National Children’s Hospital, have demonstrated that a mix of government support, philanthropy, and cross-subsidisation can provide partial financial protection and access for indigent patients. ^{Reference Nguyen, Leon-Wyss, Iyer and Pezzella8,Reference Pekerti, Vuong, Ho and Vuong31,Reference Tangcharoensathien, Hirabayashi, Topothai, Viriyathorn, Chandrasiri and Patcharanarumol32} The authors strongly believe that the models developed at these two institutions have laid a critical foundation, positioning the country to take the next step in national health policy aimed at improving care and outcomes for children with CHD across Vietnam.

Workforce development in congenital cardiac care

To become a CHD surgeon in the United States, the pathway involves a highly structured and standardised training system. This includes an undergraduate degree, medical school (4 years), general surgery residency (5 years), cardiothoracic surgery residency (2–3 years), and a CHD surgery fellowship (now 2 years, formerly 1 year), culminating in board certification by the American Board of Thoracic Surgery. ^{Reference Tchervenkov, Herbst and Jacobs6,Reference Jacob, Hussein and Van Wijk36,Reference Oh, Blitzer and Chen37} The fellowship requires minimum index case volumes, competency milestones, and a national curriculum, with recent reforms responding to feedback about operative experience and career preparedness. ^{Reference Oh, Blitzer and Chen37} Mentorship, structured feedback, and post-graduate support have emerged as key predictors of career satisfaction and retention in this demanding field. ^{Reference Oh, Blitzer and Chen37}

In contrast, Vietnam’s medical education lacks the depth of subspecialty structuring seen in high-income countries, although the system is undergoing transformation. Medical training typically begins directly after high school with a 6-year combined undergraduate and MD programme. After graduation, students may enter specialty training without a standardised national licencing examination, and postgraduate training pathways can vary significantly across institutions. ^{Reference Ha and Siddiqui16,Reference Fan, Tran, Kosik, Mandell, Hsu and Chen38} Accreditation is required for medical schools but not yet for specific medical education programmes such as paediatric cardiology or CHD surgery, and there has been no external evaluation of medical curricula at a national level. ^{Reference Ha and Siddiqui16} This limits the ability to ensure uniform quality across training institutions.

Specialty training in paediatric cardiology or CHD surgery in Vietnam is not formally delineated or nationally accredited. Instead, training often relies on informal mentorship, institutional partnerships, or short-term international programmes. ^{Reference Corno9} While select centres such as the Heart Centre in Ho Chi Minh City, or more recently, Nhi Đồng 1, National Children’s Hospital, and others have developed local expertise through sustained educational collaborations, Vietnam still lacks a structured national pipeline for training and producing congenital cardiac specialists.

Globally, paediatric cardiology and CHD surgery training remain fragmented in many regions. Despite formalisation in the U.S., U.K., and parts of Europe, training in low- and middle-income countries often relies on non-standardised, experience-based models that lack consistent case volume requirements, competency frameworks, or certification. ^{Reference McMahon, Tretter and Redington10,Reference Jacob, Hussein and Van Wijk36} In addition, the number of formally trained educators is limited, further constraining the ability to deliver effective education in congenital cardiac care. ^{Reference McMahon, Tretter and Redington10} Disparities in access to simulation, mentorship, and structured assessment limit skill acquisition in resource-constrained settings.