Paediatric aortic valve replacement using decellularized allografts: a multicentre update following 143 implantations and five-year mean follow-up.

OBJECTIVES: Decellularized aortic homografts (DAH) were introduced in 2008 as a further option for paediatric aortic valve replacement (AVR). METHODS: Prospective, multicentre follow-up of all paediatric patients receiving DAH for AVR in 8 European centres. RESULTS: A total of 143 DAH were implanted between February 2008 and February 2023 in 137 children (106 male, 74%) with a median age of 10.8 years (interquartile range 6.6-14.6). Eighty-four (59%) had undergone previous cardiac operations and 24 (17%) had undergone previous AVR. The median implanted DAH diameter was 21 mm (interquartile range 19-23). The median operation duration was 348 min (227-439) with a median cardiopulmonary bypass time of 212 min (171-257) and a median cross-clamp time of 135 min (113-164). After a median follow-up of 5.3 years (3.3-7.2, max. 15.2 years), the primary efficacy end-points peak gradient (median 14 mmHg, 9-28) and regurgitation (median 0.5, interquartile range 0-1, grade 0-3) showed good results but an increase over time. Freedom from death/explantation/endocarditis/bleeding/thromboembolism at 5 years were 97.8 ± 1.2/88.7 ± 3.3/99.1 ± 0.9/100 and 99.2 ± 0.8%, respectively. Freedom from death/explantation/endocarditis/bleeding/thromboembolism at 10 years were 96.3 ± 1.9/67.1 ± 8.0/93.6 ± 3.9/98.6 ± 1.4 and 86.9 ± 11.6%, respectively. In total, 21 DAH were explanted. Seven were replaced by a mechanical AVR, 1 Ross operation was performed and a re-do DAH was implanted in 13 patients with no redo mortality. The calculated expected adverse events were lower for DAH compared to cryopreserved homograft patients (mean age 8.4 years), and in the same range as for Ross patients (9.2 years) and mechanical AVR (13.0 years). CONCLUSIONS: This large-scale prospective analysis demonstrates excellent mid-term survival using DAH with adverse event rates comparable to paediatric Ross procedures.

Five-year results from a prospective, single-arm European trial on decellularized allografts for aortic valve replacement-the ARISE Study and ARISE Registry Data.

OBJECTIVES: Decellularized aortic homografts (DAH) were introduced as a new option for aortic valve replacement for young patients. METHODS: A prospective, EU-funded, single-arm, multicentre study in 8 centres evaluating non-cryopreserved DAH for aortic valve replacement. RESULTS: A total of 144 patients (99 male) were prospectively enrolled in the ARISE Trial between October 2015 and October 2018 with a median age of 30.4 years [interquartile range (IQR) 15.9-55.1]; 45% had undergone previous cardiac operations, with 19% having 2 or more previous procedures. The mean implanted DAH diameter was 22.6 mm (standard deviation 2.4). The median operation duration was 312 min (IQR 234-417), the median cardiopulmonary bypass time was 154 min (IQR 118-212) and the median cross-clamp time 121 min (IQR 93-150). No postoperative bypass grafting or renal replacement therapy were required. Two early deaths occurred, 1 due to a LCA thrombus on day 3 and 1 due ventricular arrhythmia 5 h postoperation. There were 3 late deaths, 1 death due to endocarditis 4 months postoperatively and 2 unrelated deaths after 5 and 7 years due to cancer and Morbus Wegener resulting in a total mortality of 3.47%. After a median follow-up of 5.9 years [IQR 5.1-6.4, mean 5.5 years. (standard deviation 1.3) max. 7.6 years], the primary efficacy end-points peak gradient with median 11.0 mmHg (IQR 7.8-17.6) and regurgitation of median 0.5 (IQR 0-0.5) of grade 0-3 were excellent. At 5 years, freedom from death/reoperation/endocarditis/bleeding/thromboembolism were 97.9%/93.5%/96.4%/99.2%/99.3%, respectively. CONCLUSIONS: The 5-year results of the prospective multicentre ARISE trial continue to show DAH to be safe for aortic valve replacement with excellent haemodynamics.

Matched comparison of decellularized homografts and bovine jugular vein conduits for pulmonary valve replacement in congenital heart disease.

For decades, bovine jugular vein conduits (BJV) and classic cryopreserved homografts have been the two most widely used options for pulmonary valve replacement (PVR) in congenital heart disease. More recently, decellularized pulmonary homografts (DPH) have provided an alternative avenue for PVR. Matched comparison of patients who received DPH for PVR with patients who received bovine jugular vein conduits (BJV) considering patient age group, type of heart defect, and previous procedures. 319 DPH patients were matched to 319 BJV patients; the mean age of BJV patients was 15.3 (SD 9.5) years versus 19.1 (12.4) years in DPH patients (p = 0.001). The mean conduit diameter was 24.5 (3.5) mm for DPH and 20.3 (2.5) mm for BJV (p < 0.001). There was no difference in survival rates between the two groups after 10 years (97.0 vs. 98.1%, p = 0.45). The rate of freedom from endocarditis was significantly lower for BJV patients (87.1 vs. 96.5%, p = 0.006). Freedom from explantation was significantly lower for BJV at 10 years (81.7 vs. 95.5%, p = 0.001) as well as freedom from any significant degeneration at 10 years (39.6 vs. 65.4%, p < 0.001). 140 Patients, matched for age, heart defect type, prior procedures, and conduit sizes of 20-22 mm (± 2 mm), were compared separately; mean age BJV 8.7 (4.9) and DPH 9.5 (7.3) years (p = n.s.). DPH showed 20% higher freedom from explantation and degeneration in this subgroup (p = 0.232). Decellularized pulmonary homografts exhibit superior 10-year results to bovine jugular vein conduits in PVR.

Simultaneous Aortic and Pulmonary Valve Replacement in Repaired Congenital Heart Disease.

OBJECTIVES: Patients with congenital heart disease frequently require surgical or percutaneous interventional valve replacement after initial congenital heart defect (CHD) repair. In some of these patients, simultaneous replacement of both semilunar valves is necessary, resulting in increased procedural complexity, morbidity, and mortality. In this study, we analyze the outcomes of simultaneous aortic and pulmonary valve replacements following multiple surgical interventions for CHD. METHODS: This was a retrospective study of 24 patients who after initial repair of CHD underwent single-stage aortic and pulmonary valve replacement at our institution between 2003 and 2021. RESULTS: The mean age of the patients was 28 ± 13 years; the mean time since the last surgery was 15 ± 11 years. Decellularized valved homografts (DVHs) were used in nine patients, and mechanical valves were implanted in seven others. In eight patients, DVHs, biological, and mechanical valves were implanted in various combinations. The mean cardiopulmonary bypass time was 303 ± 104 minutes, and aortic cross-clamp time was 152 ± 73 minutes. Two patients died at 12 and 16 days postoperatively. At a maximum follow-up time of 17 years (mean 7 ± 5 years), 95% of the surviving patients were categorized as New York Heart Association heart failure class I. CONCLUSIONS: Single-stage aortic and pulmonary valve replacement after initial repair of CHD remains challenging with substantial perioperative mortality (8.3%). Nevertheless, long-term survival and clinical status at the latest follow-up were excellent. The valve type had no relevant impact on the postoperative course. The selection of the valves for implantation should take into account operation-specific factors-in particular reoperability-as well as the patients' wishes.

Multivendor Evaluation of Automated MRI Postprocessing of Biventricular Size and Function for Children With and Without Congenital Heart Defects.

BACKGROUND: Manually segmenting cardiac structures is time-consuming and produces variability in MRI assessments. Automated segmentation could solve this. However, current software is developed for adults without congenital heart defects (CHD). PURPOSE: To evaluate automated segmentation of left ventricle (LV) and right ventricle (RV) for pediatric MRI studies. STUDY TYPE: Retrospective comparative study. POPULATION: Twenty children per group of: healthy children, LV-CHD, tetralogy of Fallot (ToF), and univentricular CHD, aged 11.7 [8.9-16.0], 14.2 [10.6-15.7], 14.6 [11.6-16.4], and 12.2 [10.2-14.9] years, respectively. SEQUENCE/FIELD STRENGTH: Balanced steady-state free precession at 1.5 T. ASSESSMENT: Biventricular volumes and masses were calculated from a short-axis stack of images, which were segmented manually and using two fully automated software suites (Medis Suite 3.2, Medis, Leiden, the Netherlands and SuiteHeart 5.0, Neosoft LLC, Pewaukee, USA). Fully automated segmentations were manually adjusted to provide two further sets of segmentations. Fully automated and adjusted automated segmentation were compared to manual segmentation. Segmentation times and reproducibility for each method were assessed. STATISTICAL TESTS: Bland Altman analysis and intraclass correlation coefficients (ICC) were used to compare volumes and masses between methods. Postprocessing times were compared by paired t-tests. RESULTS: Fully automated methods provided good segmentation (ICC > 0.90 compared to manual segmentation) for the LV in the healthy and left-sided CHD groups (eg LV-EDV difference for healthy children 1.4 ± 11.5 mL, ICC: 0.97, for Medis and 3.0 ± 12.2 mL, ICC: 0.96 for SuiteHeart). Both automated methods gave larger errors (ICC: 0.62-0.94) for the RV in these populations, and for all structures in the ToF and univentricular CHD groups. Adjusted automated segmentation agreed well with manual segmentation (ICC: 0.71-1.00), improved reproducibility and reduced segmentation time in all patient groups, compared to manual segmentation. DATA CONCLUSION: Fully automated segmentation eliminates observer variability but may produce large errors compared to manual segmentation. Manual adjustments reduce these errors, improve reproducibility, and reduce postprocessing times compared to manual segmentation. Adjusted automated segmentation is reasonable in children with and without CHD. EVIDENCE LEVEL: 3. TECHNICAL EFFICACY: Stage 2.

Idiopathic Aneurysm of the Aortic Arch in an Infant.

Congenital aortic aneurysms are rare disorders, usually associated with genetic aortic syndromes. Here, we describe the case of an idiopathic aortic arch aneurysm which had been diagnosed prenatally by fetal echocardiography. The diagnosis was confirmed after birth in the neonatal period and successful surgical resection of the aneurysm was performed at the age of 3 months. The idiopathic etiology of the aneurysm, its localization, and the early surgical resection render this case very unusual.

Le Cœur en Sabot: shape associations with adverse events in repaired tetralogy of Fallot.

BACKGROUND: Maladaptive remodelling mechanisms occur in patients with repaired tetralogy of Fallot (rToF) resulting in a cycle of metabolic and structural changes. Biventricular shape analysis may indicate mechanisms associated with adverse events independent of pulmonary regurgitant volume index (PRVI). We aimed to determine novel remodelling patterns associated with adverse events in patients with rToF using shape and function analysis. METHODS: Biventricular shape and function were studied in 192 patients with rToF (median time from TOF repair to baseline evaluation 13.5 years). Linear discriminant analysis (LDA) and principal component analysis (PCA) were used to identify shape differences between patients with and without adverse events. Adverse events included death, arrhythmias, and cardiac arrest with median follow-up of 10 years. RESULTS: LDA and PCA showed that shape characteristics pertaining to adverse events included a more circular left ventricle (LV) (decreased eccentricity), dilated (increased sphericity) LV base, increased right ventricular (RV) apical sphericity, and decreased RV basal sphericity. Multivariate LDA showed that the optimal discriminative model included only RV apical ejection fraction and one PCA mode associated with a more circular and dilated LV base (AUC = 0.77). PRVI did not add value, and shape changes associated with increased PRVI were not predictive of adverse outcomes. CONCLUSION: Pathological remodelling patterns in patients with rToF are significantly associated with adverse events, independent of PRVI. Mechanisms related to incident events include LV basal dilation with a reduced RV apical ejection fraction.

Serial assessment of early antibody binding to decellularized valved allografts.

Objectives: Decellularized homograft valves (DHV) appear to elicit an immune response despite efficient donor cell removal. Materials and methods: A semiquantitative Dot-Blot analysis for preformed and new recipient antibodies was carried out in 20 patients following DHV implantation on days 0, 1, 7, and 28 using secondary antihuman antibodies. Immune reactions were tested against the implanted DHV as well as against the stored samples of 5 non-implanted decellularized aortic (DAH) and 6 pulmonary homografts (DPH). Results: In this study, 20 patients (3 female and 17 male patients) were prospectively included, with a median age of 18 years and an IQR of 12-30 years. Six patients received DPH and 14 received DAH. The amount of antibody binding, averaged for all patients, decreased on post-operative days 1 and 7 compared to pre-operative values; and on day 28, antibody binding reached close to pre-operative levels (16.8 ± 2.5 on day 0, 3.7 ± 1.9 on day 1, 2.3 ± 2.7 on day 7, and 13.2 ± 3.7 on day 28). In comparison with the results in healthy controls, there was a higher amount of antibody binding to DAH than to DPH. The mean number of arbitrary units was 18.4 ± 3.1 in aortic and 12.9 ± 4.5 in pulmonary DHV (p = 0.140). Male patients exhibited higher antibody binding to aortic DHV than female patients (19.5 ± 2.1 vs. 1.6 ± 6.7). The p-value calculation was limited, as only two female patients received DAH. There was no correlation between the amount of overall antibody binding to DHV with respect to donor age (Kruskal-Wallis test p = 0.550). DHV recipients with a sex mismatch to the donor showed significantly less antibody binding (6.5 ± 1.8 vs. 13.7 ± 1.8; p = 0.003). Our main finding was an increase in antibody binding in younger patients receiving decellularized aortic allografts. This increase was higher in patients with early degeneration signs but was not specific to the individual DHV implanted nor previous DHV implantation. Antibody binding toward explanted DHV was significantly increased in implicating antibody-mediated DHV degeneration. Conclusion: Serial assessment of tissue-specific antibody binding revealed an increase in some patients within 4 weeks after surgery, who subsequently developed early signs of allograft degeneration. Further studies with larger sample sizes are needed to confirm the prognostic relevance of increased antibody activity in addition to targeted research efforts to identify the molecular agents triggering this type of antibody response.

5-Year results from the prospective European multi-centre study on decellularized homografts for pulmonary valve replacement ESPOIR Trial and ESPOIR Registry data.

OBJECTIVES: Early results from the prospective ESPOIR Trial have indicated excellent results for pulmonary valve replacement using decellularized pulmonary homografts (DPH). METHODS: A 5-year analysis of ESPOIR Trial patients was performed to provide an insight into the midterm DPH performance. ESPOIR Trial and Registry patients were matched with cryopreserved homografts (CH) patients considering patient age, type of heart defect and previous procedures to present the overall experience with DPH. RESULTS: A total of 121 patients (59 female) were prospectively enrolled (8/2014-12/2016), median age 16.5 years (interquartile range 11.2-29.8), and median DPH diameter 24 mm. One death (73 year-old) occurred during a median follow-up of 5.9 years (5.4-6.4), in addition to 2 perioperative deaths resulting in an overall mortality rate of 2.5%. One case of endocarditis in 637 patient-years was noticed, resulting in an incidence of 0.15% per patient-year. At 5 years, the mean peak gradient was 19.9 mmHg (9.9), mean regurgitation 0.9 (0.6, grade 0-3) and freedom from explantation/any reintervention 97.5% (1.5). The combined DPH cohort, n = 319, comprising both Trial and Registry data, showed significantly better freedom from explantation for DPH 95.5% (standard deviation 1.7) than CH 83.0% (2.8) (P < 0.001) and less structural valve degeneration at 10 years when matched to 319 CH patients [DPH 65.5% (standard deviation 4.4) and CH 47.3% (3.7), P = 0.11]. CONCLUSIONS: The 5-year data of the prospective ESPOIR Trial show excellent performance for DPH and low rates of adverse events. ESPOIR Registry data up to 15 years, including a matched comparison with CH, demonstrated statistically significant better freedom from explantation.

Impact of Right Ventricular Pressure Load After Repair of Tetralogy of Fallot.

Background Right ventricular outflow tract (RVOT) stenosis after repair of tetralogy of Fallot has been linked with favorable right ventricular remodeling but adverse outcomes. The aim of our study was to assess the hemodynamic impact and prognostic relevance of right ventricular pressure load in this population. Methods and Results A total of 296 patients with repaired tetralogy of Fallot (mean age, 17.8±7.9 years) were included in a prospective cardiovascular magnetic resonance multicenter study. Myocardial strain was quantified by feature tracking technique at study entry. Follow-up, including the need for pulmonary valve replacement, was assessed. The combined end point consisted of ventricular tachycardia and cardiac death. A higher echocardiographic RVOT peak gradient was significantly associated with smaller right ventricular volumes and less pulmonary regurgitation, but lower biventricular longitudinal strain. During a follow-up of 10.1 (0.1-12.9) years, the primary end point was reached in 19 of 296 patients (cardiac death, n=6; sustained ventricular tachycardia, n=2; and nonsustained ventricular tachycardia, n=11). A higher RVOT gradient was associated with the combined outcome (hazard ratio [HR], 1.03; 95% CI, 1.00-1.06; P=0.026), and a cutoff gradient of ≥25 mm Hg was predictive for cardiovascular events (HR, 3.69; 95% CI, 1.47-9.27; P=0.005). In patients with pulmonary regurgitation ≥25%, a mild residual RVOT gradient (15-30 mm Hg) was not associated with a lower risk for pulmonary valve replacement. Conclusions Higher RVOT gradients were associated with less pulmonary regurgitation and smaller right ventricular dimensions but were related to reduced biventricular strain and emerged as univariate predictors of adverse events. Mild residual pressure gradients did not protect from pulmonary valve replacement. These results may have implications for the indication for RVOT reintervention in this population.

Combined Prospective Seroconversion and PCR Data of Selected Cohorts Indicate a High Rate of Subclinical SARS-CoV-2 Infections-an Open Observational Study in Lower Saxony, Germany.

Despite lockdown measures, intense symptom-based PCR, and antigen testing, the SARS-CoV-2 pandemic spread further. In this open observational study conducted in Lower Saxony, Germany, voluntary SARS-CoV-2 PCR tests were performed from April 2020 until June 2021, supported by serum antibody testing to prove whether PCR testing in subjects with none or few symptoms of COVID-19 is a suitable tool to manage the pandemic. In different mobile stations, 4,817 subjects from three different working fields participated in the PCR testing. Serum antibody screening using the SARS-CoV-2 ViraChip IgG (Viramed, Germany) and the Elecsys Anti-SARS-CoV-2 assay (Roche, Germany) was performed alongside virus neutralization testing. Subjects were questioned regarding comorbidities and COVID-19 symptoms. Fifty-one subjects with acute SARS-CoV-2 infection were detected of which 31 subjects did not show any symptoms possibly characteristic for COVID-19. An additional 37 subjects reported a previous SARS-CoV-2 infection (total prevalence 1.82%). Seroconversion was discovered in 58 subjects with known SARS-CoV-2 infection and in 58 subjects that never had a positive PCR test. The latter had a significantly lower Charlson Comorbidity Index, and one third of them were asymptomatic. In 50% of all seroconverted subjects, neutralizing serum antibodies (NAbs) were detectable in parallel to N/S1 (n = 16) or N/S1/S2 antigen specific antibodies (n = 40) against SARS-CoV-2. NAb titers decreased within 100 days after PCR-confirmed SARS-CoV-2 acute infection by at least 2.5-fold. A relatively high rate of subclinical SARS-CoV-2 infections may contribute to the spread of SARS-CoV-2, suggesting that in addition to other intervention strategies, systematic screening of asymptomatic persons by PCR testing may significantly enable better pandemic control. IMPORTANCE Within this open observational study, repeated PCR (n > 4,700) and antibody screening (n > 1,600) tests were offered in three different working fields. The study identified 51 subjects with acute SARS-CoV-2 infection and 37 subjects reported to have had a positive PCR test taken externally. Thirty-one of the 51 subjects did not display any symptoms prior to testing. In addition, 58 subjects without PCR-confirmed SARS-CoV-2 infection were identified by seroconversion. Subjects, that had undergone SARS-CoV-2 infection without having noticed, more often had a low grade of immunization with no NAbs, but may have relevantly contributed to the spread of the pandemic. Based on these results, we suggest that both regular PCR and rapid test screening of symptomatic and asymptomatic individuals, specifically within groups or workplaces identifiable as having close quarter contact, thus increased infection transference risk, is necessary to better assess and therefore reduce the spread of a pandemic virus.

4D-flow cardiac magnetic resonance imaging after aortic root replacement with long-valved decellularized aortic homografts: comparison to valve-sparing aortic root replacement and healthy controls.

OBJECTIVES: Long-valved decellularized aortic homografts (DAH) may be used in young patients to treat aortic valve disease associated with aortic root dilatation, thereby eliminating the need for prosthetic material and anticoagulation. METHODS: Thirty-three male subjects in 3 equally sized cohorts were compared: patients following DAH implantation with a median age of 29 years [interquartile range (IQR) 27.5-37.5], patients post-valve-sparing aortic root replacement (VSARR), median 44 years (IQR 31.5-49) and healthy controls, median 33 years (IQR 28-40, P = 0.228). Time-resolved three-dimensional phase-contrast cardiac magnetic resonance imaging was performed to assess maximum blood flow velocity, pulse wave velocity, mechanical energy loss (EL), wall shear stress and flow patterns (vorticity, eccentricity, helicity) in 5 different planes of the aorta. RESULTS: The mean time between surgery and cardiovascular magnetic resonance was 2.56 ± 2.0 years in DAH vs 2.67 ± 2.1 in VSARR, P = 0.500. No significant differences in maximum velocity and pulse wave velocity were found between healthy controls and DAH across all planes. Velocity in the proximal aorta was significantly higher in VSARR (182.91 ± 53.91 cm/s, P = 0.032) compared with healthy controls. EL was significantly higher in VSARR in the proximal aorta with 1.85 mW (IQR 1.39-2.95) compared with healthy controls, 1.06 mW (0.91-1.22, P = 0.016), as well as in the entire thoracic aorta. In contrast, there was no significant EL in DAH in the proximal, 1.27 m/W (0.92-1.53, P = 0.296), as well as in the thoracic aorta, 7.7 m/W (5.25-9.90, P = 0.114), compared with healthy controls. There were no significant differences in wall shear stress parameters for all 5 regions of the thoracic aorta between the 3 groups. DAH patients, however, showed more vorticity, helicity and eccentricity in the ascending aorta compared with healthy controls (P < 0.019). CONCLUSIONS: Decellularized long aortic homografts exhibit near to normal haemodynamic parameters 2.5 years postoperatively compared with healthy controls and VSARR.

Pulmonary valve prostheses: patient's lifetime procedure load and durability. Evaluation of the German National Register for Congenital Heart Defects.

OBJECTIVES: We evaluated 4384 procedures performed between 1957 and 2018, collected in the National Register for Congenital Heart Defects, conducted on 997 patients with 1823 pulmonary valve replacements (PVRs), including 226 implanted via catheter [transcatheter valve (TCV)]. Main study targets are as follows: TCV benefit, valve type durability, decade-wise treatment changes and procedure frequencies over the lifetime of a PVR patient. METHODS: We studied TCV impact on surgical valve replacement (via Kaplan-Meier); pulmonary valve type-specific performance (Kaplan-Meier and Cox regressions with age group as stratification or ordinary variable); procedure interval changes over the decades (Kaplan-Meier); procedure load, i.e. frequency of any procedure/surgical PVR/interventional or surgical PVR by patient age (multistate analyses). RESULTS: TCV performance was equivalent to surgical PVRs and extended durability significantly. Homografts were most durable; Contegras lasted comparably less in older; and Hancock devices lasted less in younger patients. Matrix P-valves showed poorer performance. Age group stratification improves the precision of valve-specific explantation hazard estimations. The current median interval between procedures is 2.6 years; it became significantly shorter in most age groups below 40 years. At 30 years, 80% of patients had undergone ≥3 procedures, 20% ≥3 surgical PVRs and 42% ≥3 surgical or interventional PVRs. CONCLUSIONS: TCVs doubled freedom from explantation of conventional valves. Homografts' age group-specific explantation hazard ratio was lowest; Matrix P's hazard ratio was highest. Age-stratified Cox regressions improve the precision of prosthesis durability evaluations. The median time between procedures for PVR patients shortened significantly to 2.6 years. At 30 years, 42% had ≥3 PVRs.

Valve-sparing aortic root replacement in adult patients with congenital heart disease.

OBJECTIVES: Aortic root dilatation is frequently observed in patients with congenital heart defects (CHD), but has received little attention in terms of developing a best practice approach for treatment. In this study, we analysed our experience with aortic valve-sparing root replacement in patients following previous operations to repair CHD. METHODS: In this study, we included 7 patients with a history of previous surgery for CHD who underwent aortic valve-sparing operations. The underlying initial defects were tetralogy of Fallot (n = 3), transposition of great arteries (n = 2), coarctation of the aorta (n = 1), and pulmonary atresia with ventricle septum defect (n = 1). The patients' age ranged from 20 to 40 years (mean age 31 ± 6 years). RESULTS: David reimplantation was performed in 6 patients and a Yacoub remodelling procedure was performed in 1 patient. Four patients underwent simultaneous pulmonary valve replacement. The mean interval between the corrective procedure for CHD and the aortic valve-sparing surgery was 26 ± 3 years. There was no operative or late mortality. The patient with transposition of great arteries following an arterial switch operation was re-operated 25 months after the valve-sparing procedure due to severe aortic regurgitation. In all other patients, the aortic valve regurgitation was mild or negligible at the latest follow-up (mean 8.7 years, range 2.1-15.1 years). CONCLUSIONS: Valve-sparing aortic root replacement resulted in good aortic valve function during the first decade of observation in 6 of 7 patients. This approach can offer a viable alternative to root replacement with mechanical or biological prostheses in selected patients following CHD repair.

Residual immune response towards decellularized homografts may be highly individual.

OBJECTIVES: Decellularized homograft valves (DHVs) have shown promising clinical results, particularly in the treatment of congenital heart disease. However, DHV appears to elicit an immune response in a subset of young patients, indicated by early valve degeneration. As the decellularization process is quality controlled for each DHV, we hypothesized that there may be residual immunogenicity within the extracellular matrix of DHV. METHODS: A semi-quantitative dot blot analysis was established to screen for preformed recipient antibodies using secondary anti-human antibodies. Fifteen DHV samples (7 aortic, 8 pulmonary) were solubilized and exposed to serum from 20 healthy controls. RESULTS: The sera from young controls (n = 10, 18-25 years) showed significantly stronger binding of preformed antibodies than sera from older individuals (n = 10, 48-73 years). The difference between the means of arbitrary units was 15.1 ± 6.5 (P = 0.0315). There was high intraindividual variance in the mean amounts of arbitrary units of antibody binding with some healthy controls showing >10 times higher antibody binding towards 2 different DHV. The amount of preformed antibodies bound to DHVs was higher in aortic than in pulmonary DHVs. The mean number of antibody binding (in arbitrary units) was 17.2 ± 4.5 in aortic and 14.5 ± 4.7 in pulmonary DHV (P = 0.27). The amount of preformed antibodies bound to pulmonary DHVs was statistically significantly higher in the sera of healthy males (n = 10) than in the sera of healthy females (n = 10). The mean number of arbitrary units was 17.2 ± 4.2 in male and 11.7 ± 5.3 in female sera (P = 0.036). Antibody binding to aortic DHV was also higher in males, but not significant (18.8 ± 5.0 vs 15.6 ± 4.0). Blood group (ABO) incompatibility between the serum from controls and DHV showed no impact on antibody binding, and there was no age-related impact among DHV donors. CONCLUSIONS: Residual immunogenicity of decellularized homografts appears to exist despite almost complete cell removal. The established dot blot method allows a semi-quantitative assessment of the individual immune response towards extracellular DHV components and potentially the possibility of preoperative homograft matching.

Unsupervised Domain Adaptation From Axial to Short-Axis Multi-Slice Cardiac MR Images by Incorporating Pretrained Task Networks.

Anisotropic multi-slice Cardiac Magnetic Resonance (CMR) Images are conventionally acquired in patient-specific short-axis (SAX) orientation. In specific cardiovascular diseases that affect right ventricular (RV) morphology, acquisitions in standard axial (AX) orientation are preferred by some investigators, due to potential superiority in RV volume measurement for treatment planning. Unfortunately, due to the rare occurrence of these diseases, data in this domain is scarce. Recent research in deep learning-based methods mainly focused on SAX CMR images and they had proven to be very successful. In this work, we show that there is a considerable domain shift between AX and SAX images, and therefore, direct application of existing models yield sub-optimal results on AX samples. We propose a novel unsupervised domain adaptation approach, which uses task-related probabilities in an attention mechanism. Beyond that, cycle consistency is imposed on the learned patient-individual 3D rigid transformation to improve stability when automatically re-sampling the AX images to SAX orientations. The network was trained on 122 registered 3D AX-SAX CMR volume pairs from a multi-centric patient cohort. A mean 3D Dice of 0.86 ± 0.06 for the left ventricle, 0.65 ± 0.08 for the myocardium, and 0.77 ± 0.10 for the right ventricle could be achieved. This is an improvement of 25% in Dice for RV in comparison to direct application on axial slices. To conclude, our pre-trained task module has neither seen CMR images nor labels from the target domain, but is able to segment them after the domain gap is reduced. Code: https://github.com/Cardio-AI/3d-mri-domain-adaptation.

Cardiovascular magnetic resonance normal values in children for biventricular wall thickness and mass.

BACKGROUND: Pediatric patients are becoming increasingly referred for cardiovascular magnetic resonance (CMR). Measurement of ventricular wall thickness is typically part of the assessment and can be of diagnostic importance, e.g. in arterial hypertension. However, normal values for left ventricular (LV) and right ventricular (RV) wall thickness in pediatric patients are lacking. The aim of this study was to establish pediatric centile charts for segmental LV and RV myocardial thickness in a retrospective multicenter CMR study. METHODS: CMR was performed in 161 healthy children and adolescents with an age range between 6 and 18 years from two centers in the UK and Germany as well as from a previously published CMR project of the German Competence Network for Congenital Heart Defects. LV myocardial thickness of 16 segments was measured on the short axis stack using the American Heart Association segmentation model. In addition, the thickness of the RV inferior and anterior free wall as well as biventricular mass was measured. RESULTS: The mean age (standard deviation) of the subjects was 13.6 (2.9) years, 64 (39.7%) were female. Myocardial thickness of the basal septum (basal antero- and inferoseptal wall) was 5.2 (1.1) mm, and the basal lateral wall (basal antero- and inferolateral) measured 5.1 (1.2) mm. Mid-ventricular septum (antero- and inferoseptal wall) measured 5.5 (1.2) mm, and mid-ventricular lateral wall (antero- and inferolateral wall) was 4.7 (1.2) mm. Separate centile charts for boys and girls for all myocardial segments and myocardial mass were created because gender was significantly correlated with LV myocardial thickness (p < 0.001 at basal level, p = 0.001 at midventricular level and p = 0.005 at the apex) and biventricular mass (LV, p < 0.001; RV, p < 0.001). CONCLUSION: We established CMR normal values of segmental myocardial thickness and biventricular mass in children and adolescents. Our data are of use for the detection of abnormal myocardial properties and can serve as a reference in future studies and clinical practice.

Immunological and functional features of decellularized xenogeneic heart valves after transplantation into GGTA1-KO pigs.

Decellularization of xenogeneic heart valves might lead to excellent regenerative implants, from which many patients could benefit. However, this material carries various xenogeneic epitopes and thus bears a considerable inherent immunological risk. Here, we investigated the regenerative and immunogenic potential of xenogeneic decellularized heart valve implants using pigs deficient for the galactosyltransferase gene (GGTA1-KO) as novel large animal model. Decellularized aortic and pulmonary heart valves obtained from sheep, wild-type pigs or GGTA1-KO pigs were implanted into GGTA1-KO pigs for 3, or 6 months, respectively. Explants were analyzed histologically, immunhistologically (CD3, CD21 and CD172a) and anti-αGal antibody serum titers were determined by ELISA. Xenogeneic sheep derived implants exhibited a strong immune reaction upon implantation into GGTA1-KO pigs, characterized by massive inflammatory cells infiltrates, presence of foreign body giant cells, a dramatic increase of anti-αGal antibody titers and ultimately destruction of the graft, whereas wild-type porcine grafts induced only a mild reaction in GGTA1-KO pigs. Allogeneic implants, wild-type/wild-type and GGTA1-KO/GGTA1-KO valves did not induce a measurable immune reaction. Thus, GGTA1-KO pigs developed a 'human-like' immune response toward decellularized xenogeneic implants showing that immunogenicity of xenogeneic implants is not sufficiently reduced by decellularization, which detracts from their regenerative potential.

Three-step preoperative sequential planning for pulmonary valve replacement in repaired tetralogy of Fallot using computed tomography.

OBJECTIVES: Our goal was to compare results between a standard computed tomography (CT)-based strategy, the 'three-step preoperative sequential planning' (3-step PSP), for pulmonary valve replacement in repaired tetralogy of Fallot versus a conventional planning approach. METHODS: We carried out a retrospective study with unmatched and matched groups. The 3-step PSP comprised the planning of mediastinal re-entry, cannulation for cardiopulmonary bypass (CPB) and the main procedure, using standard 3-dimensional videos. Operative times (skin incision to CPB, CPB time, end of CPB to skin closure and cross-clamp time) as well as postoperative length of stay and in-hospital mortality were compared. RESULTS: Eighty-two patients (49% classical tetralogy of Fallot) underwent an operation (85% with pulmonary homograft) with 1.22% in-hospital mortality. The 3-step PSP (n = 14) and the conventional planning (n = 68) groups were compared. There were no statistically significant differences in the preoperative characteristics. Differences were observed in the total operative time (P = 0.009), skin incision to CPB (P = 0.034) and cross-clamp times (74 ± 33 vs 108 ± 47 min; P = 0.006), favouring the 3-step PSP group. Eight matched pairs were compared showing differences in the total operative time (263 ± 44 vs 360 ± 66 min; P = 0.008), CPB time (123 ± 34 vs 190 ± 43 min; P = 0.008) and postoperative length of stay (P = 0.031), favouring the 3-step PSP group. CONCLUSIONS: In patients with repaired tetralogy of Fallot undergoing pulmonary valve replacement, preoperative planning using a standard CT-based strategy, the 3-step PSP, is associated with shorter operative times and shorter postoperative length of stay.