SARS-CoV-2 infection of thymus induces loss of function that correlates with disease severity.

BACKGROUND: Lymphopenia, particularly when restricted to the T-cell compartment, has been described as one of the major clinical hallmarks in patients with coronavirus disease 2019 (COVID-19) and proposed as an indicator of disease severity. Although several mechanisms fostering COVID-19-related lymphopenia have been described, including cell apoptosis and tissue homing, the underlying causes of the decline in T-cell count and function are still not completely understood. OBJECTIVE: Given that viral infections can directly target thymic microenvironment and impair the process of T-cell generation, we sought to investigate the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on thymic function. METHODS: We performed molecular quantification of T-cell receptor excision circles and κ-deleting recombination excision circles to assess, respectively, T- and B-cell neogenesis in SARS-CoV-2-infected patients. We developed a system for in vitro culture of primary human thymic epithelial cells (TECs) to mechanistically investigate the impact of SARS-CoV-2 on TEC function. RESULTS: We showed that patients with COVID-19 had reduced thymic function that was inversely associated with the severity of the disease. We found that angiotensin-converting enzyme 2, through which SARS-CoV-2 enters the host cells, was expressed by thymic epithelium, and in particular by medullary TECs. We also demonstrated that SARS-CoV-2 can target TECs and downregulate critical genes and pathways associated with epithelial cell adhesion and survival. CONCLUSIONS: Our data demonstrate that the human thymus is a target of SARS-CoV-2 and thymic function is altered following infection. These findings expand our current knowledge of the effects of SARS-CoV-2 infection on T-cell homeostasis and suggest that monitoring thymic activity may be a useful marker to predict disease severity and progression.

22q11.2 Deletion Syndrome: Impact of Genetics in the Treatment of Conotruncal Heart Defects.

Congenital heart diseases represent one of the hallmarks of 22q11.2 deletion syndrome. In particular, conotruncal heart defects are the most frequent cardiac malformations and are often associated with other specific additional cardiovascular anomalies. These findings, together with extracardiac manifestations, may affect perioperative management and influence clinical and surgical outcome. Over the past decades, advances in genetic and clinical diagnosis and surgical treatment have led to increased survival of these patients and to progressive improvements in postoperative outcome. Several studies have investigated long-term follow-up and results of cardiac surgery in this syndrome. The aim of our review is to examine the current literature data regarding cardiac outcome and surgical prognosis of patients with 22q11.2 deletion syndrome. We thoroughly evaluate the most frequent conotruncal heart defects associated with this syndrome, such as tetralogy of Fallot, pulmonary atresia with major aortopulmonary collateral arteries, aortic arch interruption, and truncus arteriosus, highlighting the impact of genetic aspects, comorbidities, and anatomical features on cardiac surgical treatment.

Late outcome of extracardiac Fontan patients: 32 years of follow-up.

OBJECTIVES: We sought to evaluate the long-term survival and risk factors for morbidity and mortality in our cohort of patients after extracardiac (EC) Fontan. METHODS: We collected and analysed follow-up data until September 2020 for all patients who underwent EC Fontan operation at our institution from November 1988 to November 2015. RESULTS: Out of 406 patients treated with EC Fontan at a mean age of 5.4 ± 4.5 years, 372 (91.6%) were discharged home; 15% were lost to follow-up. The median follow-up was 14.6 years (interquartile range 8.7-20.3). Two hundred patients (54%) had a good long-term outcome, with an event-free long-term survival, but late adverse events of any kind needing interventional or surgical reoperations were reported in 128 patients (34%). Forty-four patients (12%) developed late Fontan failure. Thirty-seven survivors (10%) had late arrhythmias, with the need for pacemaker implantation. Obstruction of the cavopulmonary pathway occurred in 49 patients (13%), but just 8 patients needed conduit surgical replacement. At 32 years, the survival probability was 84%. The risk of orthotopic heart transplant, considering death as a competing event (showed as cumulative incidence), was 12.5%. A preoperative diagnosis of hypoplastic left heart syndrome was an independent risk factor for the need for heart transplant. CONCLUSIONS: The EC Fontan shows satisfactory long-term survival and low incidence of adverse events and late failure. Conduit replacement is rare, and its longevity may not represent a substantial issue in these patients. However, as with other technical variants, the need for reoperations during long-term follow-up is a significant challenge.

The Modern Surgical Approach to Pulmonary Atresia with Ventricular Septal Defect and Major Aortopulmonary Collateral Arteries.

Pulmonary atresia with ventricular septal defect and major aortopulmonary collaterals is a complex congenital heart defect that includes a heterogeneous subgroup of patients. Variation in the sources of pulmonary blood flow contributes to the complexity of the lesion and the diversity of approaches to its management. Unifocalization and rehabilitation focus on mobilization of collateral arteries and growth of native pulmonary arteries, respectively, with the ultimate surgical goal of achieving separated systemic and pulmonary circulations with the lowest possible right ventricular pressure. Regardless of the strategy, outcomes have altered the natural history of the disease, with a complete repair rate of approximately 80% and low early and late mortality rates. Given this heterogeneity of pulmonary vasculature, a tailored approach should be adopted for each patient, using all diagnostic methods currently offered by technical developments.

Predictors of survival in paediatric mitral valve surgery: the impact of age at operation at late follow-up.

OBJECTIVES: The aim of this study was to elucidate predictors of death and reintervention after mitral valve (MV) surgery in children. METHODS: A single-centre retrospective study was performed enrolling 142 patients younger than 18 years who underwent primary index surgical mitral repair or replacement at Bambino Gesù Children's Hospital in Rome from July 1982 to April 2020. Patients with complete, transitional or partial atrioventricular septal defect and patients with single ventricle physiology were excluded. Patients were stratified according to the age group: group 1 (<1 year old), group 2 (1-5 years old) and group 3 (>5 years old). The composite primary outcome was freedom from death or transplant. The secondary outcome was freedom from redo MV surgery. RESULTS: Transplant-free survival was 89% at 5 years and 88% at 10 years. Stratified by age, group 1 had poorer outcome in comparison with other groups (log-rank test P = 0.105). Both univariate and multivariate analyses showed that age <1 year was a significant risk factor for death or transplant (P = 0.044). Age <1 year was associated with increased risk of reoperation (aHR = 3.38, P = 0.009), while the presence of genetic syndrome (aHR = 0.22) and preoperative EF% (aHR = 0.97) were protective factors for reoperation. CONCLUSIONS: The overall survival and freedom from reoperation in children undergoing MV surgery still need improvements. Younger age was a significant risk factor for death and reintervention both after repair and replacement of the MV. In particular, infants and neonates have a three-fold risk for death compared to children.

Blood flow characteristics after aortic valve neocuspidization in paediatric patients: a comparison with the Ross procedure.

AIMS: The aortic valve (AV) neocuspidization (Ozaki procedure) is a novel surgical technique for AV disease that preserves the natural motion and cardiodynamics of the aortic root. In this study, we sought to evaluate, by 4D-flow magnetic resonance imaging, the aortic blood flow characteristics after AV neocuspidization in paediatric patients. METHODS AND RESULTS: Aortic root and ascending aorta haemodynamics were evaluated in a population of patients treated with the Ozaki procedure; results were compared with those of a group of patients operated with the Ross technique. Cardiovascular magnetic resonance studies were performed at 1.5 T using a 4D flow-sensitive sequence acquired with retrospective electrocardiogram-gating and respiratory navigator. Post-processing of 4D-flow analysis was performed to calculate flow eccentricity and wall shear stress. Twenty children were included in this study, 10 after Ozaki and 10 after Ross procedure. Median age at surgery was 10.7 years (range 3.9-16.5 years). No significant differences were observed in wall shear stress values measured at the level of the proximal ascending aorta between the two groups. The analysis of flow patterns showed no clear association between eccentric flow and the procedure performed. The Ozaki group showed just a slightly increased transvalvular maximum velocity. CONCLUSION: Proximal aorta flow dynamics of children treated with the Ozaki and the Ross procedure are comparable. Similarly to the Ross, Ozaki technique restores a physiological laminar flow pattern in the short-term follow-up, with the advantage of not inducing a bivalvular disease, although further studies are warranted to evaluate its long-term results.

Ascending aortic extension to increase aortopulmonary space after comprehensive stage II palliation.

Aortic reconstruction at the time of the comprehensive stage II (CSII) procedure can be complicated by compression within the aortopulmonary space resulting in airway or pulmonary artery narrowing. We describe our experience with 2 patients with hypoplastic left heart syndrome and pulmonary artery stenosis after the CSII procedure. Both patients underwent an aortic extension with a Hemashield interposition graft to open up the aortopulmonary space. The patients were discharged from the hospital. In all cases the aortopulmonary space was enlarged, and the pulmonary arteries and airway were free from compression. Aortic extension is an option to be considered in children with pulmonary artery compression who previously had a CSII procedure.

[Denosumab and fracture risk in kidney transplant].

Background: Kidney transplant patients bear a higher risk of bone disease. The monoclonal antibody Denosumab (Den), by binding RANKL, reduces osteoclastic activity and increases mineral density (BMD), thus limiting the risk of bone fractures. We evaluated the efficacy and safety of Den in kidney transplant patients who developed bone fractures. Methods: Thirteen kidney transplant recipients (aged from 50 to 79 years 7M and 6F, with an average 9,9 years follow up after transplantation, and nearly normal renal function (GFR 62±15 ml/min/1.73m2), who developed low-energy vertebral fractures (21 dorsal and 1 lumbar) after transplantation, had been evaluated for 2 years with Dual-energy X-ray absorptiometry (DEXA) and morphometric absorptiometry (MXA) while receiving Den (four 60-mg doses). Data for vertebral heights and posterior-anterior height ratios (P/A), and BMD values for vertebral, femoral, and radius were obtained. The immunosuppressive regimen consisted of CNI and MMF, and 8 out of 13 were taking prednisone. A fixed dose of 450.000 UI-year of cholecalciferol was prescribed to all patients. Whole-PTH, 25-OHD3, and alkaline phosphatase (ALP) were also evaluated. Results: After 2 years of Den treatment, we observed a significative increase in vertebral T-score (from -2.12±0.35 to -1.67±0.35; p < 0.02), while T score of femoral neck and radius did not show significative variation (-1.86±0.21 versus -1.84±0.23 and -3.04±0.42 versus -3.19±0.45, respectively). We found a lower incidence of fracture/patient-year pre and post Den 0.17 [95 CI 0.11-0.24] vs 0.07 [95% CI 0.02-0.3] respectively. No significative variations were observed in whole-PTH (89.31±19.9 pg/ml versus 68.38±9.8 pg/ml), 25OHD3 (24.02±2.75ug/L versus 26.67±2.29 ug/L) and alkaline phosphatase (78.46±12.73UI/L versus 56.77±7.14UI/L). No adverse events were registered. Conclusions: Treatment with Den improve BMD in vertebral bone and possibly reduces the risk of low-energy vertebral fractures in kidney transplant patients.

Use of Transcarotid IMPELLA 2.5 Axial-Flow Pump Device for Left Ventricle Unloading During VA-ECMO Support in Pediatric Acute Heart Failure.

An alternative strategy for left ventricular (LV) venting during short-term mechanical circulatory support is use of Impella axial-flow pump. We present our transcarotid Impella 2.5 implantation technique using a polytetrafluoroethylene graft, in two children with acute heart failure treated primarily with venoarterial ECMO. The venoarterial extracorporeal membrane oxygenator and Impella support were maintained for 5 and 17 days, respectively. Transcarotid Impella implantation might be an alternative and feasible option in pediatrics patients affected by severe LV failure, as a bridge to decision or bridge to candidacy. Potentially, the Impella 2.5 device provides less invasive support for children with heart failure.

Use of carotid artery cannulation during redo sternotomy in congenital cardiac surgery: a single-centre experience.

OBJECTIVES: Management of resternotomy is often a difficult challenge in patients with congenital diseases who have undergone multiple sternotomies. Our goal was to report our single-centre experience with carotid cannulation using a graft interposed during redo sternotomy in complex cardiac reintervention procedures. METHODS: We performed a retrospective review of all patients who had undergone complex redo sternotomies between January 2019 and May 2020 utilizing a cervical cannulation technique with a Gore-Tex graft interposed on the carotid artery. We classified our population study on the basis of the primary diagnosis and the type of surgery. The primary outcomes of our analysis were the evaluation of the safety of the procedure in terms of survival and freedom from neurological events. RESULTS: We analysed 22 patients who had undergone previous complex operations. The median age and weight at the time of reintervention were 130.35 (range 0.46-435) months and 31.5 (range 2.2-85) kg, respectively. Composite graft carotid cannulation provided adequate arterial flow in all patients with a median arterial flow of 3.5 l/min/m2 (range 0.6-6). One major cardiac injury occurred during sternotomy when emergency cardiopulmonary bypass (CPB) was initiated. Moreover, during their hospital stays, all patients had an uneventful recovery without neurological or vascular complications and no cervical wound infections. CONCLUSIONS: Carotid cannulation using interposition of a side graft on the common carotid artery for arterial inflow is a reliable and safe method for initiation of CPB in complex redo surgeries in patients with congenital disease. Complications directly associated with this type of cannulation are uncommon and allow surgical re-entry with overall low risks.

Predictors of survival in paediatric mitral valve replacement.

OBJECTIVES: The aim of this study was to identify the predictors of death and of reintervention after mitral valve replacement (MVR) in children. METHODS: A single-centre retrospective study was performed including 115 patients under the age of 18 undergoing MVR between 1982 and 2019. For all patients, the ratio of prosthetic valve size (diameter in mm) to weight (kg) at surgery was calculated and long-term result was assessed. The primary outcome was freedom from mitral valve (MV) re-replacement. The composite secondary outcome was freedom from death or transplant. RESULTS: Fifty-four patients had a previous surgical attempt to MV repair. The median age at surgery was 5.5 years (interquartile range 1.21-9.87). Death/transplant-free survival was 77 ± 4% at 5 years and 72 ± 5% at 10 years. Univariate analysis showed a size/weight ratio higher than 2 and age <2 years as significant risk factors for death or transplant. Freedom from MV re-replacement at 5 and 10 years was 90 ± 3% and 72 ± 6%, respectively. Biological prosthesis implanted at first replacement (P = 0.007) and size/weight ratio higher than 2 (P = 0.048) were predictors of reoperation. Significant upsizing (P < 0.0001) of mitral prosthesis was observed at re-replacement. CONCLUSIONS: MVR is a viable strategy in children with unrepairable MV disease. Mortality can be predicted based on size/weight ratio and age <2 years. MV re-replacement can be performed with low morbidity and mortality and a larger-size prosthesis can often be placed at the time of redo.

Long-term veno-arterial extracorporeal membrane oxygenation as a bridge to heart-lung transplant.

En bloc heart-lung transplantation still represents definitive therapy for end-stage cardiopulmonary failure. However, patients may critically decompensate while awaiting suitable donor organs and necessitate veno-arterial extracorporeal membrane oxygenation. In this article, we describe the combined use of central cannulation with the Berlin Heart EXCOR ventricular assist device cannulae and the CentriMag centrifugal pump as an extended bridge to heart-lung transplantation in three pediatric patients.

Development of evidence-based guidelines: local working conditions hamper adaptation and use of recommendation.

INTRODUCTION: Clinical practice guidelines need rigorous and transparent methods for summarizing the evidence, rate its certainty and moving from evidence to recommendations. We describe an intervention to support local efforts to provide optimal and safer care bridging the gap between researchers and local busy clinicians. METHODS: A group of methodologists provided a wide range of research services to the medical community of a local non-teaching general hospital in Italy. Methodological support encompassed synthesis of evidence, rating of uncertainty and moving from evidence to recommendations. Local professionals were asked to judge GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology and its impact on patients' safety, professional liability, and guideline reliability. The research team then reflected on the barriers of implementing GRADE in local settings. RESULTS: Seven clinical recommendations about frequent complex medical conditions were produced. Few local clinicians completed the project. All clinicians found the GRADE methodology a guarantee for defending excellent standards of care. However, we identified a diffuse sense of inability to improve clinical behaviours as negative effects of general poor working conditions, in particular the strained health care workforce. DISCUSSION: Current financial constraints may be impeding the ability of clinicians in improving their clinical practice through adaptation and use of evidence. A successful integration of evidence-based guidelines cannot be separated from an activate promotion by the institutional management.