Longitudinal Assessment of Right Ventricular Function in Hypoplastic Left Heart Syndrome.

Overall survival of patients with hypoplastic left heart syndrome (HLHS) has shown continued improvement. Right ventricular (RV) dysfunction, in the long term, adversely affects prognosis in these patients. This study examines changes in echocardiographic markers of RV function in a longitudinal cohort. We retrospectively reviewed patients with HLHS managed at our institution from 7/1994 to 1/2016. Follow-up included surgical and clinical data, and echocardiographic measures. Measures of RV function preceding and following all three stages of single ventricular palliation were collected. Freedom from transplant-free survival was assessed by Kaplan-Meier analysis. Multivariable associations with time to death or transplant were explored using the Cox proportional hazards model. A total of 120 patients with HLHS were identified. Norwood operation was performed in all patients. The probability of survival for the cohort was 71 ± 4.4%, 69 ± 4.5% and 66 ± 4.7% at 1, 2 and 5 years respectively after stage I Norwood operation. RV fractional area change (FAC), compared to post-Norwood was decreased at all subsequent stages with the greatest change noted post-superior cavo-pulmonary shunt from 40.7 ± 9.3% to 31.1 ± 8.3% (p < 0.001). Similarly, tricuspid valve annular systolic excursion (TAPSE) Z-score declined from -2.9 ± 1.3 to -9.7 ± 1.3 (p < 0.001) with a decrement at every stage of evaluation. In comparison to patients with post-Norwood RV FAC >35% and TAPSE Z-score > -5, patients with RV FAC ≤ 35% and TAPSE Z-score ≤ -5 had a significantly lower transplant-free survival (p < 0.0001). In patients with HLHS undergoing staged palliation, decrement in RV function manifests longitudinally. Post-Norwood RV FAC and TAPSE Z-score appear to be early markers of poor outcome in this population.

Does liver biopsy accurately measure fibrosis in Fontan-associated liver disease? A comparison of liver biopsy pre-combined heart and liver transplant and liver explant post-transplant.

The accuracy of liver biopsy to stage fibrosis due to Fontan-associated liver disease (FALD) remains unclear. We compared the results of biopsy pre-combined heart and liver transplantation (CHLT) to the results of whole liver explant. Liver biopsy and explants from 15 Fontan patients (ages 16-49, median 28 years) were retrospectively reviewed. Staging was as follows: stage 0: no fibrosis, stage 1: pericellular fibrosis, stage 2: bridging fibrosis, and stage 3: regenerative nodules. There is no stage 4. Clinical characteristics including Model of End-stage Liver Disease eXcluding INR and Varices, Ascites, Splenomegaly, and Thrombocytopenia (VAST) scores were collected, and descriptive statistics and Mann-Whitney U tests were used to analyze the data. All patients had biopsies with at least bridging fibrosis, and all had nodularity on explant; transjugular biopsy never overestimated fibrosis. Explant showed higher-grade fibrosis (stage 3) than pre-CHLT biopsy (stage 2) in 6 of 15 patients and equal grade of fibrosis (stage 3) in 9 of 15 patients. Though clinical characteristics varied significantly, VAST score was ≥2 in all but two patients. Transjugular liver biopsy does not overestimate and can underestimate fibrosis in Fontan patients undergoing CHLT, likely due to the patchy nature of fibrosis in FALD.

Younger age remains a risk factor for prolonged length of stay after bidirectional cavopulmonary anastomosis.

OBJECTIVE: This study sets out to determine the influence of age at the time of surgery as a risk factor for post-operative length of stay after bidirectional cavopulmonary anastomosis. METHODS: All patients undergoing a Glenn procedure between January 2010 and July 2015 were included in this retrospective cohort study. Demographic data were examined. Standard descriptive statistics was used. A univariable analysis was conducted using the appropriate test based on data distribution. A propensity score for balancing the group difference was included in the multi-variable analysis, which was then completed using predictors from the univariable analysis that achieved significance of p<0.1. RESULTS: Over the study period, 50 patients met the inclusion criteria. Patients were separated into two cohorts of ⩾4 months (28 patients) and <4 months (22 patients). Other than height and weight, the two cohorts were indistinguishable in their pre-operative saturation, medications, catheterisation haemodynamics, atrioventricular valve regurgitation, and ventricular function. After adjusting group differences, younger age was associated with longer post-operative length of hospitalisation - adjusted mean 15 (±2.53) versus 8 (±2.15) days (p=0.03). In a multi-variable regression analysis, in addition to ventricular dysfunction (ß coefficient=8.8, p=0.05), Glenn procedures performed before 4 months were independently associated with longer length of stay (ß coefficient=-6.9, p=0.03). CONCLUSION: We found that Glenn procedures performed after 4 months of age had shorter post-operative length of stay when compared to a younger cohort. These findings suggest that balancing timing of surgery to decrease the inter-stage period should take into consideration differences in post-operative recovery with earlier operations.

Interstage evaluation of homograft-valved right ventricle to pulmonary artery conduits for palliation of hypoplastic left heart syndrome.

OBJECTIVE: Palliation of hypoplastic left heart syndrome with a standard nonvalved right ventricle to pulmonary artery conduit results in an inefficient circulation in part due to diastolic regurgitation. A composite right ventricle pulmonary artery conduit with a homograft valve has a hypothetical advantage of reducing regurgitation, but may differ in the propensity for stenosis because of valve remodeling. METHODS: This retrospective cohort study included 130 patients with hypoplastic left heart syndrome who underwent a modified stage 1 procedure with a right ventricle to pulmonary artery conduit from 2002 to 2015. A composite valved conduit (cryopreserved homograft valve anastomosed to a polytetrafluoroethylene tube) was placed in 100 patients (47 aortic, 32 pulmonary, 13 femoral/saphenous vein, 8 unknown), and a nonvalved conduit was used in 30 patients. Echocardiographic functional parameters were evaluated before and after stage 1 palliation and before the bidirectional Glenn procedure, and interstage interventions were assessed. RESULTS: On competing risk analysis, survival over time was better in the valved conduit group (P = .040), but this difference was no longer significant after adjustment for surgical era. There was no significant difference between groups in the cumulative incidence of bidirectional Glenn completion (P = .15). Patients with a valved conduit underwent more interventions for conduit obstruction in the interstage period, but this difference did not reach significance (P = .16). There were no differences between groups in echocardiographic parameters of right ventricle function at baseline or pre-Glenn. CONCLUSIONS: In this cohort of patients with hypoplastic left heart syndrome, inclusion of a valved right ventricle to pulmonary artery conduit was not associated with any difference in survival on adjusted analysis and did not confer an identifiable benefit on right ventricle function.

Mitral Stenosis and Aortic Atresia--A Risk Factor for Mortality After the Modified Norwood Operation in Hypoplastic Left Heart Syndrome.

BACKGROUND: There are conflicting reports regarding the importance of mitral stenosis and aortic atresia as a risk factor for Norwood mortality. This study reviews outcomes of this anatomic subgroup at our institution and examines the utility of preoperative cardiac catheterization and its correlation with clinical outcomes and pathology findings. METHODS: This is a single-center, retrospective review of hypoplastic left heart syndrome patients who underwent modified Norwood operation between October 2005 and May 2013. RESULTS: Fourteen of 74 hypoplastic left heart syndrome patients (19%) had mitral stenosis and aortic atresia. Operative mortality for MS/AA was 29% versus 7% for all other hypoplastic left heart syndrome anatomic subgroups (p = 0.04). Although only 19% of the entire cohort, the mitral stenosis and aortic atresia subgroup constituted 50% of the total operative mortality and the only interstage deaths. Autopsies support myocardial ischemia as the mechanism of death. Although preoperative angiography defined the presence of ventriculo-coronary connections, it did not clearly risk stratify patients in regard to operative mortality. CONCLUSIONS: Mitral stenosis and aortic atresia is a risk factor for perioperative myocardial ischemia and mortality. Further exploration of myocardial reserve is warranted.

Home monitoring program reduces interstage mortality after the modified Norwood procedure.

BACKGROUND: From 2002 to 2005, the interstage mortality after a modified Norwood procedure was 7% in our program. An interstage home monitoring program (HMP) was established to identify Norwood procedure patients at increased risk of decompensation and to reduce interstage mortality. METHODS: Results of the first 5 years of the Norwood HMP were reviewed retrospectively. Interstage was defined as the time between Norwood hospital discharge and admission for second stage surgical palliation. In the HMP, families documented oxygen saturation, heart rate, weight, and feedings daily. Nurse practitioners called each family at least weekly, and when issues arose, action plans were determined based on symptom severity. RESULTS: Between October 2005 and October 2010 there were 46 Norwood procedure patients who survived to hospital discharge. All were enrolled in the HMP. Forty-five patients had a Norwood procedure with right ventricle to pulmonary artery conduit, and 1 patient had a modified Blalock-Taussig shunt. Interstage survival was 100%. Nineteen patients (41%) were admitted interstage; 5 patients were admitted twice, 1 patient was admitted 4 times. Seventeen patients (37%) required interstage interventions. Eight patients (17%) required major interventions: conduit stenting, aortic arch balloon angioplasty, emergent shunt, or early Glenn surgery. Minor interventions included supplemental oxygen, blood transfusion, intravenous hydration, diuresis, anti-arrhythmic therapy, or feeding adjustments. CONCLUSIONS: In the first 5 years of the HMP, all infants discharged after a modified Norwood procedure survived the interstage period. The HMP altered clinical management in 37% of patients. Home monitoring of oxygen saturation, heart rate, weight, and feedings, along with comprehensive care coordination, allowed timely interventions and reduced interstage mortality from 7% to 0%.

One hundred useful references in pediatric cardiac intensive care: the 2012 update.

OBJECTIVE: The specialty of pediatric cardiac critical care has undergone rapid scientific and clinical growth in the last 25 years. The Board of Directors of the Pediatric Cardiac Intensive Care Society assembled an updated list of sentinel references focused on the critical care of children with congenital and acquired heart disease. We encouraged board members to select articles that have influenced and informed their current practice or helped to establish the standard of care. The objective of this article is to provide clinicians with a compilation and brief summary of these updated 100 useful references. DATA SOURCES: The list of 'One Hundred Useful References for Pediatric Cardiac Intensive Care' (2004) and relevant literature to the practice of cardiac intensive care. DATA SELECTION: A subset of Pediatric Cardiac Intensive Care Society board members compiled the initial list of useful references in 2004, which served as the basis of the new updated list. Suggestions for relevant articles were submitted by the Pediatric Cardiac Intensive Care Society board members and selected pediatric cardiac intensivists with an interest in this project following the Society's meeting in 2010. Articles were considered for inclusion if they were named in the original list from 2004 or were suggested by Pediatric Cardiac Intensive Care Society board members and published before December 31, 2011. DATA EXTRACTION: Following submission of the complete list by the Pediatric Cardiac Intensive Care Society board and contributing Society members, articles were complied by the two co-first authors (D.A., D.K.). The authors also performed Medline searches to ensure comprehensive inclusion of all relevant articles. The final list was then submitted to the Pediatric Cardiac Intensive Care Society board members, who ranked each publication. DATA SYNTHESIS: Rankings were compiled and the top 100 articles with the highest scores were selected for inclusion in this publication. The two co-first authors (D.A., D.K.) reviewed all existing summaries and developed summaries of the newly submitted articles. CONCLUSIONS: An updated compilation of 100 useful references for the critical care of children with congenital and acquired heart disease has been compiled and summarized here. Clinicians and trainees may wish to use this document as a reference for education in this complex and challenging subspecialty.

Implementation of a comprehensive interdisciplinary care coordination of infants and young children on Berlin Heart ventricular assist devices.

BACKGROUND: Young children supported on a ventricular assist device (VAD) can have prolonged hospitalizations awaiting heart transplantation. The adult VAD literature demonstrates that comprehensive programs optimize transplantation outcomes. The goal of this intervention was to create an interdisciplinary program to optimize care coordination and delivery in young children requiring a VAD. METHOD: This study was a case review. RESULTS: We have supported 8 infants and young children with Berlin Heart VAD. These children's hospitalizations have been more complex than those of our older VAD patients, and they have required intensive care for prolonged periods. An interdisciplinary group evaluated our practices and identified areas for potential improvement. The focus group from our intensive care unit introduced multiple interventions to optimize interdisciplinary care coordination and consistency of practice. These included (1) interdisciplinary care guidelines for chronically, critically ill patients; (2) institution of a primary cardiovascular intensive care unit (CVICU) physician and nurse practitioner system; (3) introduction of a psychological intervention for families to minimize the impact of their extended CVICU stay; (4) implementation of early jejunal feeds; (5) a focused developmental and rehabilitation protocol, 6) implementation of a structured approach to minimizing blood transfusions; (7) increased structure for our interdisciplinary rounds to optimize team communication; (8) comprehensive nursing education including wound care, anticoagulation management, and laboratory draws; and (9) a protocol for off-unit rehabilitative/developmental interventions. These changes in both practice and approach for young VAD patients have also been of benefit to other chronically, critically ill children in the CVICU, as well as to our CVICU team. CONCLUSION: Comprehensive interdisciplinary care coordination and standardized practice can be achieved in the critical care setting for complex pediatric heart failure patients who require long-term VAD support.

Pneumatic paracorporeal ventricular assist device in infants and children: initial Stanford experience.

BACKGROUND: Mechanical circulatory support with the Berlin Heart EXCOR pediatric ventricular assist device (VAD) has been used successfully in Europe for children with cardiac failure. Eighty-seven devices have been placed in North America through February 2007. We describe our single-center experience in 8 children. METHODS: Eight children (ages 4 to 55 months), with median weight of 9.6 kg and body surface area of 0.48 m(2), received the Berlin Heart VAD as a bridge to transplantation. All patients were in cardiogenic shock requiring multiple inotropes. Primary diagnoses were idiopathic dilated cardiomyopathy (n = 4), congenital heart disease (n = 3) and restrictive cardiomyopathy (n = 1). After device insertion, all patients were treated with an anti-coagulant (heparin or coumadin) and one or more platelet inhibitors (aspirin with clopidogrel or dipyridamole). RESULTS: Five patients received support with a left ventricular assist device (LVAD) and 3 with a biventricular device (BiVAD). Duration of support ranged from 2 to 234 days (median 57 days). Five patients (63%) were successfully bridged to transplantation; of these, 4 were discharged home and 1 died from early graft failure. Five patients developed post-operative neurologic events. Of these 5 events, 4 could be explained by embolism or hemorrhage. Device exchange was performed in 4 patients in the intensive care unit. CONCLUSIONS: In selected children, the Berlin Heart VAD can be used as a bridge to transplantation. In contrast to the published European experience, neurologic events occur frequently. Anti-coagulation and platelet inhibition strategies continue to evolve. Device exchange is technically feasible at the bedside and should be considered at the earliest visualization of thrombus formation.

Homograft valved right ventricle to pulmonary artery conduit as a modification of the Norwood procedure.

BACKGROUND: The use of a right ventricle to pulmonary artery (RV-PA) conduit in the Norwood procedure has been proposed to increase postoperative hemodynamic stability. A valve within the conduit should further decrease RV volume load. We report our clinical experience with this modification. METHODS AND RESULTS: From February 2002 through August 2005, we performed 88 consecutive Norwood procedures using RV-PA conduits. We used composite valved conduits made from cryopreserved homograft and polytetrafluoroethylene (PTFE) in 66 cases (54 pulmonary, 12 aortic homografts), other valved conduits in 14, and unvalved PTFE in 8 cases. Hospital survival was 88.6% overall and increased to 93.1% after the initial year. Early interventions were required in 18 patients (16 for cyanosis). Prestage II cardiac catheterization was performed at a mean age of 126 days. Mean Qp/Qs was 1, with mean aortic saturation 71%, mean O2 extraction 24%, and mean right ventricular end-diastolic pressure 9 mm Hg. Patient weight, use of an aortic homograft valve in the conduit, stage I palliation within the first year of our experience, and low O2 extraction and high transpulmonary gradient prestage II were risk factors for overall death. Early interventions were more frequent in aortic valve conduits compared with all other conduits. CONCLUSIONS: The valved RV-PA conduit was associated with low early mortality after the Norwood procedure. The majority of these patients had normal cardiac output and well-maintained RV function. There may be a higher risk for early conduit interventions and death when aortic valve homografts are used in the RV-PA conduit.

Extended resection and end-to-end anastomosis for aortic coarctation in infants: results of a tailored surgical approach.

BACKGROUND: The surgical repair of aortic coarctation in infants has evolved over time. This study evaluates our current approach utilizing extended end-to-end anastomosis without prosthetic material to enlarge all areas of aortic arch hypoplasia. METHODS: The Michigan Congenital Heart Center database was reviewed for infants who underwent repair of isolated aortic coarctation from January 1, 1990, to January 1, 2000. RESULTS: Eighty-three infants underwent surgical repair of isolated coarctation during this decade. Median age at repair was 21 days (range, 2 to 365). Repair was performed through thoracotomy in 72 patients. Because of severe transverse arch hypoplasia, the remaining 11 infants underwent median sternotomy with circulatory arrest. There were 2 deaths: 1 due to pulmonary hypertension in a patient with alveolar capillary dysplasia and 1 late death due to pneumonia in a patient with noncardiac anomalies. Neither patient had residual coarctation. Technique-related complications of bronchial compression, chylothorax, and vocal cord paralysis were noted in 4 patients. Follow-up data were available for 66 patients (80%) with mean follow-up duration of 4.5 years (SD +/- 3.1). Reintervention was required in 4 patients (6%). One underwent reoperation after 1 month, and 3 underwent balloon angioplasty within 7 months of initial repair. The remaining 61 patients are asymptomatic, on no antihypertensive medications, and have aortic arch gradients less than 15 mm Hg. One developed subaortic stenosis necessitating resection. CONCLUSIONS: Tailored surgical repair for aortic coarctation has a low rate (6%) of residual and recurrent coarctation even when performed in infants. Mortality and morbidity are low.

High systemic vascular resistance and sudden cardiovascular collapse in recovering Norwood patients.

BACKGROUND: Sudden death, remote from surgery, in patients with hypoplastic left heart syndrome (HLHS) after Norwood palliation is an important problem. The episodic nature of this syndrome has made its cause(s) difficult to ascertain. Observations made in hospitalized Norwood patients may afford insight into the pathophysiology of sudden death among these patients. METHODS: We conducted a retrospective chart review. RESULTS: Five patients with HLHS experiencing unremarkable recoveries from Norwood palliation, still hospitalized but extubated (only 1 in intensive care), had unexpected, acute decompensation 8 to 15 days postoperatively. All had acutely decreased peripheral perfusion; severe metabolic acidosis (mean HCO(3) = 9 mEq/L, range 6 to 11 mEq/L; mean arterial lactate = 16 mmol/L, range 10 to 20 mmol/L, normal less than 2 mmol/L); relatively high arterial pO(2), especially considering their low systemic perfusion (mean = 57 mm Hg, range 50 to 66 mm Hg on fraction of inspired oxygen (FiO(2)) less than 0.3 in 4 of 5 patients); and relatively high systolic blood pressure (mean systolic blood pressure = 91 mm Hg, range 78 to 116 mm Hg). During the preceding 24 hours, all had had systolic blood pressures of more than 85 mm Hg at multiple times. All were resuscitated with mechanical ventilation and administration of HCO(3) and intravenous inotropic agents or vasodilators (1 also required extracorporeal membrane oxygenation), with rapid resolution of their acidosis. After decompensating, all were treated with oral antihypertensive agents; 1 had an early hemi-Fontan. All survived to discharge. CONCLUSIONS: Increased systemic vascular resistance may be especially pernicious in Norwood patients-even remote from operation-as the condition increases myocardial work and O(2) consumption while diminishing systemic perfusion. Chronic and acutely increased systemic vascular resistance may account for some cases of sudden unexpected death in Norwood patients.