Cumulative comorbid conditions influence mortality risk after staged palliation for hypoplastic left heart syndrome and variants

Mortality and Heart Transplantation After Hybrid Palliation of Hypoplastic Left Heart Syndrome: A Systematic Review and Meta-Analysis

BACKGROUND

Newborns with hypoplastic left heart syndrome (HLHS) who are considered at increased risk for death following Norwood/Sano surgery often undergo hybrid palliation (HP) as initial surgery. We aimed to compile the HP experience in HLHS and its variants and assess the rates of, and risk factors for, death and heart transplantation.

METHODS

CINAHL, CINAHL PLUS, PubMed/MEDLINE, and SCOPUS were systematically searched for HP outcome studies of death or heart transplantation in HLHS between 1998 and 2022. Pooled incidence was estimated, and potential risk factors were identified using random-effects meta-analysis and reconstructed time-to-event data from Kaplan-Meier curves.

RESULTS

Thirty-three publications were included in our review. Overall, of 1,162 patients 417 died and 57 underwent heart transplantation, resulting in a combined outcome of 40.7%, (474/1,162). There was a trend toward decreasing mortality risk across the stages of palliation. Pooled mortality between HP and comprehensive stage 2 palliation was 25%, after stage 2 up to Fontan palliation was 16%, and 6% post-Fontan. The incidence of death or heart transplantation was higher in high-risk patients-43% died and 10% received heart transplantation.

CONCLUSION

Our systematic review and meta-analysis found high rates of death or heart transplantation in HP of HLHS patients between HP and Fontan surgeries. All patients should be closely followed during the initial interstage period, which is associated with the highest hazard. Prospective studies on appropriate patient selection, indications, and / or alternatives, as well as refining HP strategies for managing newborns with HLHS are needed to improve outcomes.

Using machine learning to predict five-year transplant-free survival among infants with hypoplastic left heart syndrome

Hypoplastic left heart syndrome (HLHS) is a congenital malformation commonly treated with palliative surgery and is associated with significant morbidity and mortality. Risk stratification models have often relied upon traditional survival analyses or outcomes data failing to extend beyond infancy. Individualized prediction of transplant-free survival (TFS) employing machine learning (ML) based analyses of outcomes beyond infancy may provide further valuable insight for families and healthcare providers along the course of a staged palliation. Data from both the Pediatric Heart Network (PHN) Single Ventricle Reconstruction (SVR) trial and Extension study (SVR II), which extended cohort follow up for five years was used to develop ML-driven models predicting TFS. Models incrementally incorporated features corresponding to successive phases of care, from pre-Stage 1 palliation (S1P) through the stage 2 palliation (S2P) hospitalization. Models trained with features from Pre-S1P, S1P operation, and S1P hospitalization all demonstrated time-dependent area under the curves (td-AUC) beyond 0.70 through 5 years following S1P, with a model incorporating features through S1P hospitalization demonstrating particularly robust performance (td-AUC 0.838 (95% CI 0.836-0.840)). Machine learning may offer a clinically useful alternative means of providing individualized survival probability predictions, years following the staged surgical palliation of hypoplastic left heart syndrome.

2024 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2024 AHA Statistical Update is the product of a full year's worth of effort in 2023 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. The AHA strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional global data, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Preterm Birth Is Associated With Adverse Cardiac Remodeling and Worse Outcomes in Patients With a Functional Single Right Ventricle

OBJECTIVE

To assess the effects of preterm birth on cardiac structure and function and transplant-free survival in patients with hypoplastic left heart syndrome and associated anomalies throughout the staged palliation process.

STUDY DESIGN

Data from the Single Ventricle Reconstruction trial were used to assess the impact of prematurity on echocardiographic measures at birth, Norwood, Stage II, and 14 months in 549 patients with a single functional right ventricle. Medical history was recorded once a year using medical records or telephone interviews. Cox regression models were applied to analyze transplant-free survival to age 6 years. Causal mediation analysis was performed to estimate the mediating effect of birth weight within this relationship.

RESULTS

Of the 549 participants, 64 (11.7%) were born preterm. Preterm-born participants had lower indexed right ventricle end-diastolic volumes at birth but higher volumes than term-born participants by age 14 months. Preterm-born participants had an increased risk of death or heart transplantation from birth to age 6 years, with an almost linear increase in the observed risk as gestational age decreased below 37 weeks. Of the total effect of preterm birth on transplant-free survival, 27.3% (95% CI 2.5-59.0%) was mediated through birth weight.

CONCLUSIONS

Preterm birth is associated with adverse right ventricle remodeling and worse transplant-free survival throughout the palliation process, in part independently of low birth weight. Further investigation into this vulnerable group may allow development of strategies that mitigate the impact of prematurity on outcomes in patients with hypoplastic left heart syndrome.