Single-Ventricle Palliation in Low- and Middle-Income Countries

Global leadership in paediatric and congenital cardiac care: education and empowerment to improve outcomes in low- and middle-income countries - an interview with Krishna Kumar, MD, DM FAHA

Dr Krishna Kumar is the focus of our sixth in a series of interviews in Cardiology in the Young entitled, "Global Leadership in Paediatric and Congenital Cardiac Care." Dr Kumar was born in Raurkela, India. He attended medical school at Maulana Azad Medical College in New Delhi, graduating in 1984. Dr Kumar then went on to complete internal medicine, emergency medicine, and adult cardiology training at All India Institute of Medical Sciences in 1988, 1989, and 1990, respectively. He then pursued paediatric cardiology training at Harvard Medical School in Boston, MA, USA. Dr Kumar began his clinical position as a paediatric cardiologist at Amrita Institute of Medical Sciences in Kochi, Kerala, India.During his impressive career, Dr Kumar has made significant contributions to educational advancement, research and innovation, public health advocacy, and clinical care. Dr Kumar is credited for distinguishing paediatric cardiology as a distinct subspecialty in India. He was a founding member of the Pediatric Cardiology Society of India and the original editor of the society's academic journal. Recognising the deficit of paediatric cardiology-trained physicians in low- and middle-income countries, Dr Kumar helped establish formal structured training programmes for paediatric cardiology in India. More recently, he established the Children's HeartLink Fellowships in paediatric cardiac sciences at Amrita Institute of Medical Sciences in Kochi and Institut Jantung Negara in Malaysia. Through educational programmes, Dr Kumar has taught countless caregivers and paediatricians, in India and neighbouring countries, the early identification and management of children with CHD. Dr Kumar has established a premier paediatric heart programme at Amrita Institute of Medical Sciences. As department Chief, he emphasises the importance of teamwork, advocacy, and continuous quality improvement. He has developed numerous low-cost strategies for the management of CHD. He has established large community-based studies on rheumatic heart disease and CHD in South India. Dr Kumar's focus on advocacy and policy change in India has made a substantial impact on early identification and treatment of CHD in the subcontinent. He has made a global impact on the care of paediatric cardiology patients through his educational programmes, research and innovation, large-scale research registries, and advocacy for public health policy changes. He is an incredibly humble and generous leader, and his patients and community are the source of his unending motivation.

Management of Hypoplastic Left Heart Syndrome in Low-Resource Settings and the Ethics of Decision-Making

Hypoplastic left heart syndrome (HLHS) is possibly the most challenging congenital heart defect to confront in any setting. The highly specialized infrastructure and resources needed to treat HLHS is not available in many low-resource settings. However, low-resource settings must not be assumed to be synonymous with low- and middle-income countries as national income is not necessarily indicative of a country's prioritization of healthcare resources. Besides, a low-resource setting may be institution-specific as well as country-specific. We have stratified institutional capabilities for addressing the requirements of treatment for HLHS into five levels based on the capacity for diagnosis, intervention, and post-discharge monitoring. Depending on institutional capabilities, children born with HLHS in low-resource settings experience a spectrum of outcomes ranging from death without diagnosis to the hybrid or Norwood stage 1 palliation. The decision-making is ethically challenging when resources are scarce and economic efficiency must be considered in the context of distributive justice. Even in settings that would be classified as resource-rich where survival after surgery and quality of life afterward keep improving, not every parent would choose surgical intervention for their hypothetical child with HLHS.

Risk factors for death or mechanical ventilation time after bidirectional cavopulmonary anastomosis in a developing country

BACKGROUND

Glenn procedure is performed for patients with cyanotic CHD and univentricular physiology and has a survival rate above 90%.

AIM

To evaluate the risk factors associated with a poor outcome after Glenn procedure.

METHODS

The data for this retrospective analysis were collected from a regional Brazilian registry of congenital heart surgeries (ASSIST initiative) from 2014 to 2019. Data from 97 patients who underwent the Glenn procedure were considered. The primary outcomes were prolonged mechanical ventilation (>24 hours post-operatively) or in-hospital death, alone and combined.

RESULTS

The overall in-hospital mortality was 13.4% (n = 13). Prolonged mechanical ventilation occurred in 52% (n = 51) of the patients. Our analysis found that risk factors for death or prolonged post-operative mechanical ventilation were cardiopulmonary bypass duration and post-operative lactate, whereas weight-for-age z-score and age at surgery were risk factors for prolonged mechanical ventilation. Cardiopulmonary bypass duration increased (adjusted odds ratio: 1.02; 95 % CI: 1.01, 1.03) and age at surgery decreased (adjusted odds ratio: 0.96; 95 % CI: 0.93, 0.99) the odds of the combined outcome.

CONCLUSIONS

Age at surgery, post-operative lactate, and low-weight-for-age z-score are associated with prolonged mechanical ventilation and death following the Glenn procedure.

Neurodevelopmental outcomes in congenital heart disease through the lens of single ventricle patients

PURPOSE OF REVIEW

This review aims to summarize and organize the current body of literature on this contemporary topic, alongside a more general discussion of neurodevelopmental complications of congenital heart disease.

RECENT FINDINGS

It is theorized that the causes of the neurodevelopment disabilities are multifactorial resulting from structural central nervous system abnormalities, haemodynamic alterations and/or biochemical changes. It is therefore imperative that all patients with single ventricle anatomy and physiology receive long-term neurologic and developmental assessments in addition to their cardiac monitoring.

SUMMARY

Advancements in surgical techniques and medical management have improved survivorship of these medically complex patients. Neurodevelopmental sequelae are one of the most common comorbidities affecting this patient population leading to long-term challenges in motor, language, social and cognitive skills.

Pharmacokinetics of treprostinil in children with functional single-ventricle pulmonary arterial hypertension: a randomized controlled trial

Background

Application of Treprostinil (TRE) in the patients with single ventricle (SV) physiology is very limited, and the optimal dose for children has not been determined. In this study, we aimed to analyze plasma samples to assess the attainment of clinically therapeutic concentrations of TRE and its efficacy and safety in the treatment of pediatric functional SV pulmonary arterial hypertension (FSV-PAH)..

Methods

Pediatric patients with FSV-PAH were recruited in this study. IV TRE at an initial rate of 5 ng/kg/min was administered through the femoral vein with an increase in rate to 10 ng/kg/min every 30 minuntil the aiming dose of 80 ng/kg/min had been reached. The drug was gradually discontinued after 12 h of treatment at a stable dose. The mean postoperative pulmonary artery pressure (mPAP), pulmonary-to-systemic arterial pressure ratio (Pp/Ps), and the ratio between arterial oxygen partial pressure and inhaled oxygen concentration (PaO₂/FiO₂) were used to evaluate the efficacy of TRE treatment. A multiple linear regression model was used to explore the relevant factors associated with TRE blood concentration.

Results

A total of eight patients were enrolled in the investigation, with an age range of 2.5-9.9 years. The median stable dose of TRE was 70 ng/kg/min with a range of 55-75 ng/kg/min. The median subliminal dose was 55 ng/kg/min with a range of 25-75 ng/kg/min. A linear relationship was established between the TRE dose and the plasma concentration. TRE blood concentrations were associated with dose and patient height. After TRE treatment, mPAP, Pp/Ps, and PaO₂/FiO₂ were significantly improved (P<0.05).

Conclusions

A linear relationship was found between the blood concentration of TRE and its dose. IV TRE was an effective therapy without serious side effects in pediatric patients with FSV-PAH.

Trial Registration

ClinicalTrials.gov Identifier: NCT02865733.

Is Doppler Echocardiography Adequate for Surgical Planning of Single Ventricle Patients?

PURPOSE

Surgical planning has shown great potential for optimizing outcomes for patients affected by single ventricle (SV) malformations. Phase-contrast magnetic resonance imaging (PC-MRI) is the routine technique used for flow acquisition in the surgical planning paradigm. However, PC-MRI may suffer from possible artifacts in certain cases; furthermore, this technology may not be readily available for patients in low and lower-middle-income countries. Therefore, this study aims to investigate the effectiveness of using Doppler echocardiography (echo-Doppler) for flow acquisitions of SV surgical planning.

METHODS

This study included eight patients whose blood flow data was acquired by both PC-MRI and echo-Doppler. A virtual surgery platform was used to generate two surgical options for each patient: (1) a traditional Fontan conduit and (2) a Y-graft. Computational fluid dynamics (CFD) simulations were conducted using the two flow acquisitions to assess clinically relevant hemodynamic metrics: indexed power loss (iPL) and hepatic flow distribution (HFD).

RESULTS

Differences exist in flow data acquired by PC-MRI and echo-Doppler, but no statistical significance was obtained. Flow fields, therefore, exhibit discrepancies between simulations using flow acquisitions by PC-MRI and echo-Doppler. In virtual surgery, the two surgical options were ranked based on these metrics. No difference was observed in the ranking of surgical options between using different flow acquisitions.

CONCLUSION

Doppler echocardiography is an adequate alternative approach to acquire flow data for SV surgical planning. This finding encourages broader usage of SV surgical planning with echo-Doppler when MRI may present artifacts or is not available, especially in low and lower-middle-income countries.

Pregnancy and early post-natal outcomes of fetuses with functionally univentricular heart in a low-and-middle-income country

BACKGROUND

Care of children with functionally univentricular hearts is resource-intensive.

OBJECTIVES

To analyse pregnancy and early post-natal outcomes of fetuses with functionally univentricular hearts in the setting of a low-middle-income country.

METHODS

A retrospective study was conducted during the period of January 2008-October 2019. Study variables analysed included gestational age at diagnosis, maternal and fetal comorbidities and cardiac diagnosis including morphologic type of single ventricle. Outcomes analysed included pregnancy outcomes, type of post-natal care and survival status on the last follow-up.

RESULTS

A total of 504 fetuses were included. Mean maternal age was 27.5 ± 4.8 years and mean gestational age at diagnosis was 25.6 ± 5.7 weeks. Pregnancy outcomes included non-continued pregnancies (54%), live births (42.7%) and loss to follow-up (3.3%). Gestational age at diagnosis was the only factor that impacted pregnancy outcomes (non-continued pregnancies 22.5 ± 3.5 vs. live births 29.7 ± 5.7 weeks; p < 0.001). Of the 215 live births, intention-to-treat was reported in 119 (55.3%) cases; of these 103 (86.6%) underwent cardiac procedures. Seventy-nine patients (36.7%) opted for comfort care. On follow-up (median 10 (1-120) months), 106 patients (21%) were alive. Parental choice of intention-to-.treat or comfort care was the only factor that impacted survival on follow-up.

CONCLUSIONS

Prenatal diagnosis of functionally univentricular hearts was associated with overall low survival status on follow-up due to parental decisions on not to continue pregnancy or non-intention-to-treat after birth. Early detection of these complex defects by improved prenatal screening can enhance parental options and reduce resource impact in low-and-middle-income countries.

Congenital heart disease in low-and-middle-income countries: Focus on sub-Saharan Africa

The etiology of congenital heart disease (CHD) is multifactorial. The birth prevalence of CHD is shaped by a wide variety of maternal, fetal, and neonatal risk factors, along with the rates of prenatal diagnosis and terminations of pregnancy, all of which have geographic variability Epidemiology data availability from low-and-middle-income countries (LMIC) on CHD prevalence, morbidity, and mortality are far more limited than from high income countries. Data on specific genetic, environmental, and prenatal risk associated with CHD are almost nonexistent. In this article, we will focus on defining what data are available, genetic risk factors, birth and overall prevalence, morbidity, and the impact of limited access to interventions, both surgery and cardiac catheterizations. We will highlight CHD in sub-Saharan Africa to detail epidemiology studies in the poorest regions of the world. Existing literature as well as estimates from the Global Burden of Disease Study (http://ghdx.healthdata.org) form the basis for this review. The intersection of poverty, high fertility rates, and limited access to care results in a unique profile of CHD in LMIC. CHD is not a preventable disease (by most standards), so early detection and access are our key interventions to improve the dire outcomes for children in low-resources settings of the world.