Combined en bloc heart and liver organ procurement.

A combined heart+liver transplant is the only option for survival in some patients with end-stage combined cardiac and hepatic disease. These patients may suffer from congenital or acquired cardiac disease. The potential aetiologies of the associated hepatic disease are heterogeneous and include systemic disease that impacts the liver as well as venous congestion in patients with functionally univentricular circulation. In the latter scenario, patients with functionally univentricular circulation often require complex cardiac reconstruction in the setting of a cardiac transplant after staged palliation. During cardiac procurement, our approach is to dissect the entire ascending aorta and aortic arch in continuity; the entire superior caval vein and innominate vein in continuity; and the pulmonary arteries from hilum to hilum if the donor is not a candidate for recovery of the lungs. The cardiac and abdominal organ procurement teams work in parallel during dissection and combined en bloc cardio-hepatectomy. This technique minimizes exposure of both organs to cold ischaemia. This video tutorial demonstrates the key steps for combined en bloc heart+liver organ procurement.

Hemorrhage and thrombosis in COVID-19-patients supported with extracorporeal membrane oxygenation: an international study based on the COVID-19 critical care consortium.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) is a rescue therapy in patients with severe acute respiratory distress syndrome (ARDS) secondary to COVID-19. While bleeding and thrombosis complicate ECMO, these events may also occur secondary to COVID-19. Data regarding bleeding and thrombotic events in COVID-19 patients on ECMO are sparse. METHODS: Using the COVID-19 Critical Care Consortium database, we conducted a retrospective analysis on adult patients with severe COVID-19 requiring ECMO, including centers globally from 01/2020 to 06/2022, to determine the risk of ICU mortality associated with the occurrence of bleeding and clotting disorders. RESULTS: Among 1,248 COVID-19 patients receiving ECMO support in the registry, coagulation complications were reported in 469 cases (38%), among whom 252 (54%) experienced hemorrhagic complications, 165 (35%) thrombotic complications, and 52 (11%) both. The hazard ratio (HR) for Intensive Care Unit mortality was higher in those with hemorrhagic-only complications than those with neither complication (adjusted HR = 1.60, 95% CI 1.28-1.99, p < 0.001). Death was reported in 617 of the 1248 (49.4%) with multiorgan failure (n = 257 of 617 [42%]), followed by respiratory failure (n = 130 of 617 [21%]) and septic shock [n = 55 of 617 (8.9%)] the leading causes. CONCLUSIONS: Coagulation disorders are frequent in COVID-19 ARDS patients receiving ECMO. Bleeding events contribute substantially to mortality in this cohort. However, this risk may be lower than previously reported in single-nation studies or early case reports. Trial registration ACTRN12620000421932 ( https://covid19.cochrane.org/studies/crs-13513201 ).

Pediatric Heart Transplantation Over 36 Years and Contemporary Volume-Outcome Analysis of UNOS.

BACKGROUND: This study examines 36 years of national pediatric heart transplantation data to 1) identify trends in transplant volume, centers, and one-year graft survival, and 2) assess how center transplant volume impacts outcomes over a contemporary 11-year period. METHODS: We performed a retrospective review of pediatric patients (<18 years) undergoing heart transplantation from 1/1/1987 to 12/31/2022 using the United Network for Organ Sharing Database. Trend analyses included the whole cohort, while volume-outcome analyses included a contemporary cohort to account for the temporal changes observed in transplant survival. Highest volume centers were defined by the number of heart transplants performed per center per year. RESULTS: Over 36 years, 11,828 pediatric heart transplants were performed. Transplant volume steadily rose, the number of centers remained stable, and one-year graft survival has improved significantly. In the contemporary era (2012-2022), 89 centers conducted 4,959 pediatric heart transplants. The top 15% high-volume centers (13 centers) accounted for 48.3% (2,393) of transplants, with an average of 16.7±3.8 transplants per center annually, compared to 3.9±3.1 for lower volume centers. Despite transplanting higher risk patients, high-volume centers had similar postoperative outcomes and improved long-term survival. CONCLUSIONS: While the number of US pediatric heart transplant centers has remained stable, pediatric heart transplant volume is steadily increasing, as is one-year graft survival. In a contemporary cohort, the top 15th percentile highest volume centers accounted for 48.3% of US pediatric heart transplants and transplanted higher risk patients with similar postoperative outcomes and improved longitudinal survival.

What is the weakest point of a secured aortic cannula in central extracorporeal membrane oxygenation?

PURPOSE: The purpose of this study was to compare techniques for securing the aortic extracorporeal membrane oxygenation (ECMO) cannula, using in vitro models. METHODS: Two models were studied: a tissue model using porcine aortas and a stand model replacing the aorta with a metal stand to study the system independent of the tissue. Interventions in each model were divided into three experimental groups: Group 1 (3-0 Prolene® + 20-French Medtronic Arterial Cannula EOPA™), Group 2 (4-0 Prolene® + 16-French Medtronic Arterial Cannula DLP Pediatric), and Group 3 (5-0 Prolene® + 8-French Medtronic Arterial Cannula DLP Pediatric). In separate experiments, both gradual and rapid forces were applied to the cannulas, starting with 9.8 Newtons and increasing exponentially if the cannula remained secured. Additionally, the method of securing the tourniquet and the number of ties securing the tourniquet to the cannula were evaluated. RESULTS: In the tissue model, even with a minimum force of 9.8 Newtons, the suture pulled through the aortic tissue, leaving sutures and ties intact. In the stand model, two purse-string sutures secured by two ligaclips held the cannula reliably and withstood higher total force. Dislodgement was prevented at forces close to 60 Newtons with only two hemostatic clips included in cannulation. CONCLUSIONS: The weakest part of the aortic ECMO cannulation system using in vitro experiments was the tissue. Assuming that these experiments translate in vivo, it is therefore critical to prevent any pull on the cannulas by securing ECMO cannulas and ECMO tubing to both the patient and the patient's bed. Sutures with a larger diameter withstand more force. Two medium hemostatic clips can secure Prolene® sutures within snares as safely as a mosquito hemostat. Two polypropylene purse-string sutures secured by two hemostatic clips were most reliable at greater forces. The rationale for publishing our experiments in this manuscript is to (1) communicate our quantification of possible contributing factors to this rare and likely catastrophic complication of unintended decannulation, (2) increase awareness about this potential complication, and (3) increase vigilance to assure prevention of this dreaded complication.

The safe addition of nitric oxide to the sweep gas of the extracorporeal membrane oxygenation circuit in a pediatric cardiac intensive care unit.

Background: Nitric Oxide (NO) is a naturally occurring modulator of inflammation found in the human body. Several studies in the pediatric cardiothoracic surgery literature have demonstrated some beneficial clinical effects when NO is added to the sweep gas of the cardiopulmonary bypass circuit.Purpose: Our primary aim was to determine the safety of incorporating nitric oxide into the oxygenator sweep gas of the extracorporeal membrane oxygenation (ECMO) circuit. Secondarily, we looked at important clinical outcomes, such as survival, blood product utilization, and common complications related to ECMO.Methods: We performed a single center, retrospective review of all patients at our institution who received ECMO between January 1, 2017 and March 31, 2023. We began additing NO to the ECMO sweep gas in 2019. Results: There were no instances of clinically significant methemoglobinemia with the addition of NO to the sweep gas (0% vs 0%, p = 1). The median daily methemoglobin level was higher in those who received NO via the sweep gas when compared to those who did not (1.6 vs 1.1, p = <0.001). Conclusions: The addition of NO to the sweep gas of the ECMO circuit is safe.

15-Year Analysis of Surgical Approaches and Outcomes for Coarctation in 132 Neonates and Infants.

A variety of surgical approaches exist to treat aortic coarctation in neonates and infants. Our institutional approach is designed to match the surgical approach to the individual anatomy of the patient. The objective of this study is to evaluate operative characteristics and outcomes of all neonates and infants who underwent surgical repair of coarctation of the aorta or hypoplastic aortic arch at University of Florida from 2006 to 2021, inclusive, either in isolation or with concomitant repair of atrial septal defect (ASD) and/or ventricular septal defect (VSD). A retrospective review was performed of 132 patients aged 0-1 year who underwent surgical repair of aortic coarctation or hypoplastic aortic arch between 2006 and 2021, inclusive, either in isolation or with concomitant repair of ASD and/or VSD. Patients were divided into two groups based on the surgical approach: Group 1 = Median Sternotomy and Group 2 = Left Lateral Thoracotomy. Continuous variables are presented as median (minimum-maximum); categorical variables are presented as N (%). The most common operative technique in Group 1 was end-to-side reconstruction with ligation of the aortic isthmus. The most common operative technique in Group 2 was extended end-to-end repair. Operative Mortality was one patient (1/132 = 0.76%). Transcatheter intervention for recurrent coarctation was performed in seven patients (7/132 = 5.3%). Surgical re-intervention for recurrent coarctation was performed in three patients (3/132 = 2.3%). From these data, one can conclude that a strategy of matching the surgical approach to the anatomy of neonates and infants who underwent surgical repair of aortic coarctation or hypoplastic aortic arch, either in isolation or with concomitant repair of ASD and/or VSD, is associated with less than 1% Operative Mortality and less than 3% recurrent coarctation requiring reoperation.

Nosocomial Infections in Adults Receiving Extracorporeal Membrane Oxygenation: A Review for Infectious Diseases Clinicians.

Over the past ten years, there has been a rapid expansion in the use of extracorporeal membrane oxygenation (ECMO) in the care of patients with refractory cardiac or respiratory failure. Infectious diseases clinicians must reconcile conflicting evidence from limited studies as they develop practices at their own institutions, which has resulted in considerably different practices globally. This review describes infection control and prevention as well as antimicrobial prophylaxis strategies in this population. Data on diagnostics and treatment for patients receiving ECMO with a focus on diagnostic and antimicrobial stewardship is then examined. This review summarizes gaps in the current ECMO literature and proposes future needs, including developing clear definitions for infections and encouraging transparent reporting of practices at individual facilities in future clinical trials.

Venovenous extracorporeal membrane oxygenation neck cannulation in an infant.

In this video tutorial, we present neck cannulation for venovenous extracorporeal membrane oxygenation using a crescent right atrial double lumen cannula in a 4-kg baby.

Comparison of different porcine models simulating myocardial cold ischemia of pediatric donor hearts.

BACKGROUND: Our team previously identified a stem cell-derived cardioprotective additive that can be added to standard cardioplegia to extend myocardial viability during prolonged myocardial cold ischemic time (CIT) in rodent models. The purpose of this study was to utilize a porcine model to compare in-vivo versus ex-vivo porcine simulation of CIT that accompanies cardiac transplantation in humans, in order to determine an optimal method for translation of our studies to larger animals. METHODS: Eight 39-55 kg Yorkshire X pigs were randomly assigned to either in-vivo or ex-vivo simulation. After administration of general anesthesia and endotracheal intubation, baseline measurement of left ventricular performance was obtained via transesophageal echocardiography (TEE). After midline sternotomy and heparin administration, the aorta was cross-clamped and two liters of HTK-Custodiol were introduced via the aortic root. The in-vivo method utilized cold ischemic heart storage in the chest cavity while supporting the experimental animal with cardiopulmonary bypass (CPB). The ex-vivo method involved standard cardiac procurement, cold ischemic storage outside of the body, and subsequent cardiac reperfusion utilizing cardiac reanimation in a Langendorff heart perfusion mode. After CIT, measurements of post-ischemic left ventricular performance were obtained via echocardiography. Results are presented as: Mean ± Standard Deviation (Median, Minimum-Maximum). RESULTS: Weight (kilograms) was similar in the in-vivo group and the ex-vivo group: 44 ± 1.8 (44, 42-46) versus 44 ± 5.1 (43.5, 39-51), respectively. Cold ischemic time (minutes) was longer in the ex-vivo group: 360 ± 0 (360, 360-360) versus 141 ± 26.7 (149, 102-163). Temperature (degrees Celsius) was colder in the ex-vivo group: 8 ± 0 (8, 8-8) versus 16.5 ± 4.2 (16, 12-16).In the in-vivo group, baseline ejection fraction and ejection fraction after CIT were: 48.25% ± 14.95% (48.5%, 33%-63%) and 41.25% ± 22.32% (41.5%, 20%-62%), respectively. In the ex-vivo group, baseline ejection fraction and ejection fraction after CIT were: 56.4% ± 5.9% (57%, 50%-67%) and 60.4% ± 7.7% (61.5%, 51.9%-67%), respectively. CONCLUSION: The ex-vivo technique is suitable to evaluate cardioplegia additives that may substantially extend myocardial tolerance to cold ischemia.

A single-institutional experience with 36 children less than 5 kilograms supported with the Berlin Heart: Comparison of congenital versus acquired heart disease.

OBJECTIVES: We reviewed outcomes in all 36 consecutive children <5 kg supported with the Berlin Heart pulsatile ventricular assist device at the University of Florida, comparing those with acquired heart disease (n = 8) to those with congenital heart disease (CHD) (n = 28). METHODS: The primary outcome was mortality. The Kaplan-Meier method and log-rank tests were used to assess group differences in long-term survival after ventricular assist device insertion. T-tests using estimated survival proportions were used to compare groups at specific time points. RESULTS: Of 82 patients supported with the Berlin Heart at our institution, 49 (49/82 = 59.76%) weighed <10 kg and 36 (36/82 = 43.90%) weighed <5 kg. Of 36 patients <5 kg, 26 (26/36 = 72.22%) were successfully bridged to transplantation. (The duration of support with ventricular assist device for these 36 patients <5 kg was [days]: median = 109, range = 4-305.) Eight out of 36 patients <5 kg had acquired heart disease, and all eight [8/8 = 100%] were successfully bridged to transplantation. (The duration of support with ventricular assist device for these 8 patients <5 kg with acquired heart disease was [days]: median = 50, range = 9-130.) Twenty-eight of 36 patients <5 kg had congenital heart disease. Eighteen of these 28 [64.3%] were successfully bridged to transplantation. (The duration of support with ventricular assist device for these 28 patients <5 kg with congenital heart disease was [days]: median = 136, range = 4-305.) For all 36 patients who weighed <5 kg: 1-year survival estimate after ventricular assist device insertion = 62.7% (95% confidence interval = 48.5-81.2%) and 5-year survival estimate after ventricular assist device insertion = 58.5% (95% confidence interval = 43.8-78.3%). One-year survival after ventricular assist device insertion = 87.5% (95% confidence interval = 67.3-99.9%) in acquired heart disease and 55.6% (95% confidence interval = 39.5-78.2%) in CHD, P = 0.036. Five-year survival after ventricular assist device insertion = 87.5% (95% confidence interval = 67.3-99.9%) in acquired heart disease and 48.6% (95% confidence interval = 31.6-74.8%) in CHD, P = 0.014. CONCLUSION: Pulsatile ventricular assist device facilitates bridge to transplantation in neonates and infants weighing <5 kg; however, survival after ventricular assist device insertion in these small patients is less in those with CHD in comparison to those with acquired heart disease.

The biological role and future therapeutic uses of nitric oxide in extracorporeal membrane oxygenation, a narrative review.

BACKGROUND: Nitric oxide (NO) is a gas naturally produced by the human body that plays an important physiological role. Specifically, it binds guanylyl cyclase to induce smooth muscle relaxation. NO's other protective functions have been well documented, particularly its protective endothelial functions, effects on decreasing pulmonary vascular resistance, antiplatelet, and anticoagulation properties. The use of nitric oxide donors as vasodilators has been known since 1876. Inhaled nitric oxide has been used as a pulmonary vasodilator and to improve ventilation perfusion matching since the 1990s. It is currently approved by the United States Food and Drug Administration for neonates with hypoxic respiratory failure, however, it is used off-label for acute respiratory distress syndrome, acute bronchiolitis, and COVID-19. PURPOSE: In this article we review the currently understood biological action and therapeutic uses of NO through nitric oxide donors such as inhaled nitric oxide. We will then explore recent studies describing use of NO in cardiopulmonary bypass and extracorporeal membrane oxygenation and speculate on NO's future uses.

Fish oil supplement use modifies the relationship between dietary oily fish intake and plasma n-3 PUFA levels: an analysis of the UK Biobank.

Observational evidence linking dietary n-3 PUFA intake and health outcomes is limited by a lack of robust validation of dietary intake using blood n-3 PUFA levels and potential confounding by fish oil supplement (FOS) use. We investigated the relationship between oily fish intake, FOS use and plasma n-3 PUFA levels in 121 650 UK Biobank (UKBB) participants. Ordinal logistic regression models, adjusted for clinical and lifestyle factors, were used to quantify the contribution of dietary oily fish intake and FOS use to plasma n-3 PUFA levels (measured by NMR spectroscopy). Oily fish intake and FOS use were reported by 38 % and 31 % of participants, respectively. Increasing oily fish intake was associated with a higher likelihood of FOS use (P < 0·001). Oily fish intake ≥ twice a week was the strongest predictor of high total n-3 PUFA (OR 6·7 (95 % CI 6·3, 7·1)) and DHA levels (6·6 (6·3, 7·1). FOS use was an independent predictor of high plasma n-3 PUFA levels (2·0 (2·0, 2·1)) with a similar OR to that associated with eating oily fish < once a week (1·9 (1·8, 2·0)). FOS use was associated with plasma n-3 PUFA levels that were similar to individuals in the next highest oily fish intake category. In conclusion, FOS use is more common in frequent fish consumers and modifies the relationship between oily fish intake and plasma n-3 PUFA levels in UKBB participants. If unaccounted for, FOS use may confound the relationship between dietary n-3 PUFA intake, blood levels of n-3 PUFAs and health outcomes.

After the storm: Extracorporeal membrane oxygenation after hemicraniectomy in a child.

Ventricular arrhythmias following neurological injury have been attributed to sympathetic surge in subarachnoid hemorrhage and traumatic brain injury. Despite associated risks of bleeding and thrombosis, veno-arterial extracorporeal membrane oxygenation (ECMO) in critically ill, clinically unstable postoperative neurosurgical patients can be lifesaving. In the context of neurological injury and the neurosurgical population, the literature available regarding ECMO utilization is limited, especially in children. We report a case of successful ECMO utilization in a child with malignant ventricular tachycardia after decompressive craniectomy for refractory intracranial hypertension following evacuation of extensive subdural empyema.

Randomised, placebo-controlled, phase 3 trial of the effect of the omega-3 polyunsaturated fatty acid eicosapentaenoic acid (EPA) on colorectal cancer recurrence and survival after surgery for resectable liver metastases: EPA for Metastasis Trial 2 (EMT2) study protocol.

INTRODUCTION: There remains an unmet need for safe and cost-effective adjunctive treatment of advanced colorectal cancer (CRC). The omega-3 polyunsaturated fatty acid eicosapentaenoic acid (EPA) is safe, well-tolerated and has anti-inflammatory as well as antineoplastic properties. A phase 2 randomised trial of preoperative EPA free fatty acid 2 g daily in patients undergoing surgery for CRC liver metastasis showed no difference in the primary endpoint (histological tumour proliferation index) compared with placebo. However, the trial demonstrated possible benefit for the prespecified exploratory endpoint of postoperative disease-free survival. Therefore, we tested the hypothesis that EPA treatment, started before liver resection surgery (and continued postoperatively), improves CRC outcomes in patients with CRC liver metastasis. METHODS AND ANALYSIS: The EPA for Metastasis Trial 2 trial is a randomised, double-blind, placebo-controlled, phase 3 trial of 4 g EPA ethyl ester (icosapent ethyl (IPE; Vascepa)) daily in patients undergoing liver resection surgery for CRC liver metastasis with curative intent. Trial treatment continues for a minimum of 2 years and maximum of 4 years, with 6 monthly assessments, including quality of life outcomes, as well as annual clinical record review after the trial intervention. The primary endpoint is CRC progression-free survival. Key secondary endpoints are overall survival, as well as the safety and tolerability of IPE. A minimum 388 participants are estimated to provide 247 CRC progression events during minimum 2-year follow-up, allowing detection of an HR of 0.7 in favour of IPE, with a power of 80% at the 5% (two sided) level of significance, assuming drop-out of 15%. ETHICS AND DISSEMINATION: Ethical and health research authority approval was obtained in January 2018. All data will be collected by 2025. Full trial results will be published in 2026. Secondary analyses of health economic data, biomarker studies and other translational work will be published subsequently. TRIAL REGISTRATION NUMBER: NCT03428477.

Defining the Spectrum of Hypoplastic Left Heart Syndrome (HLHS).

The 2021 International Paediatric and Congenital Cardiac Code and the Eleventh Revision of the International Classification of Diseases provide the following definition for hypoplastic left heart syndrome (HLHS): "Hypoplastic left heart syndrome (HLHS) is defined as a spectrum of congenital cardiovascular malformations with normally aligned great arteries without a common atrioventricular junction, characterized by underdevelopment of the left heart with significant hypoplasia of the left ventricle including atresia, stenosis, or hypoplasia of the aortic or mitral valve, or both valves, and hypoplasia of the ascending aorta and aortic arch." Although HLHS with intact ventricular septum (HLHS + IVS) and HLHS with ventricular septal defect (HLHS + VSD) are different cardiac phenotypes, both of these lesions are part of the spectrum of HLHS.

Outcomes of Children Supported With Pulsatile Paracorporeal Ventricular Assist Device: Congenital Versus Acquired Heart Disease.

BACKGROUND: We reviewed the outcomes of 82 consecutive pediatric patients (less than 18 years of age) supported with the Berlin Heart ventricular assist device (VAD), comparing those with congenital heart disease (CHD; n = 44) with those with acquired heart disease (AHD; n = 37). METHODS: The primary outcome was mortality after VAD insertion. Kaplan-Meier methods and log-rank tests were used to assess group differences in long-term survival. RESULTS: Forty-four CHD patients were supported (age: median = 65 days, range = 4 days-13.3 years; weight [kg]: median = 4, range = 2.4-42.3). Ten biventricular CHD patients were supported with eight biventricular assist devices (BiVADs), one left ventricular assist device (LVAD) only, and one LVAD converted to BiVAD, while 34 univentricular CHD patients were supported with single ventricle-ventricular assist devices (sVADs). In CHD patients, duration of VAD support was [days]: median = 134, range = 4-554. Of 44 CHD patients, 28 underwent heart transplantation, 15 died on VAD, and one was still on VAD. Thirty-seven AHD patients were supported (age: median = 1.9 years, range = 27 days-17.7 years; weight [kg]: median = 11, range = 3.1-112), including 34 BiVAD and 3 LVAD. In AHD patients, duration of VAD support was [days]: median = 97, range = 4-315. Of 37 AHD patients, 28 underwent transplantation, three died on VAD, five weaned off VAD (one of whom underwent heart transplantation 334 days after weaning), and one was still on VAD. One-year survival after VAD insertion was 59.9% (95% CI = 46.7%-76.7%) in CHD and 88.6% (95% CI = 78.8%-99.8%) in AHD, P = .0004. Five-year survival after VAD insertion was 55.4% (95% CI = 40.8%-75.2%) in CHD and 85.3% (95% CI = 74.0%-98.2%) in AHD, P = .002. CONCLUSIONS: Pulsatile VAD facilitates bridge-to-transplantation in neonates, infants, and children with CHD; however, survival after VAD insertion is worse in patients with CHD than in patients with AHD.

Quality analysis of publicly available information about hypoplastic left heart syndrome.

PURPOSE: Publicly available health information is increasingly important for patients and their families. While the average US citizen reads at an 8th-grade level, electronic educational materials for patients and families are often advanced. We assessed the quality and readability of publicly available resources regarding hypoplastic left heart syndrome (HLHS). METHODS: We queried four search engines for "hypoplastic left heart syndrome", "HLHS", and "hypoplastic left ventricle". The top 30 websites from searches on Google, Yahoo!, Bing, and Dogpile were combined into a single list. Duplicates, commercial websites, physician-oriented resources, disability websites, and broken links were removed. Websites were graded for accountability, content, interactivity, and structure using a two-reviewer system. Nonparametric analysis of variance was performed. RESULTS: Fifty-two websites were analysed. Inter-rater agreement was high (Kappa = 0.874). Website types included 35 hospital/healthcare organisation (67.3%), 12 open access (23.1%), 4 governmental agency (7.7%), and 1 professional medical society (1.9%). Median total score was 19 of 39 (interquartile range = 15.8-25.3): accountability 5.5 of 17 (interquartile range = 2.0-9.3), content 8 of 12 (interquartile range = 6.4-10.0), interactivity 2 of 6 (interquartile range = 2.0-3.0), and structure 3 of 4 (interquartile range = 2.8-4.0). Accountability was low with 32.7% (n = 17) of sites disclosing authorship and 26.9% (n = 14) citing sources. Forty-two percent (n = 22) of websites were available in Spanish. Total score varied by website type (p = 0.03), with open access sites scoring highest (median = 26.5; interquartile range = 20.5-28.6) and hospital/healthcare organisation websites scoring lowest (median = 17.5; interquartile range = 13.5-21.5). Score differences were driven by differences in accountability (p = 0.001) - content scores were similar between groups (p = 0.25). Overall readability was low, with median Flesch-Kincaid Grade Level of 11th grade (interquartile range = 10th-12th grade). CONCLUSIONS: Our evaluation of popular websites about HLHS identifies multiple opportunities for improvement, including increasing accountability by disclosing authorship and citing sources, enhancing readability by providing material that is understandable to readers with the full spectrum of educational background, and providing information in languages besides English, all of which would enhance health equity.