Implementation of Patient Blood Management in Orthotopic Heart Transplants: A Single Centre Retrospective Observational Review.

BACKGROUND: Blood transfusion in the perioperative cardiothoracic setting has accepted risks including deep sternal wound infection, increased intensive care unit length of stay, lung injury, and cost. It has an immunomodulatory effect which may cause allo-immunisation. This may influence long-term survival through immune-mediated factors. Targeting coagulation defects to reduce unnecessary or inappropriate transfusions may reduce these complications. METHODS: In 2012, an institution-wide patient blood management evidence-based algorithmic bleeding management protocol was implemented at The Prince Charles Hospital, Brisbane, Australia. The benefit of this has been previously reported in our lung transplant and cardiac surgery (excluding transplants) cohorts. This study aimed to investigate the effect of this on our orthotopic heart transplant recipients. RESULTS: After the implementation of the protocol, despite no difference in preoperative haemoglobin levels and higher risk patients (EuroSCORE 20 vs 26; p=0.013), the use of packed red blood cells (13.0 U vs 4.4 U; p=0.046) was significantly lower postoperatively and fresh frozen plasma was significantly lower both intra- and postoperatively (7.4 U vs 0.6 U; p<0.001, and 3.3 U vs 0.6 U; p=0.011 respectively). Concurrently, the use of prothrombin complex concentrate (33% vs 78%; p<0.001) and desmopressin (5% vs 22%; p=0.0028) was significantly higher in the post-protocol group, while there was less use of recombinant factor VIIa (15% vs 4%; p=0.058). Intraoperative units of cryoprecipitate also rose from 0.9 to 2.0 (p=0.006). CONCLUSIONS: We have demonstrated that a targeted patient blood management protocol with point-of-care testing for heart transplant recipients is correlated with fewer blood products used postoperatively, with some increase in haemostatic products and no evidence of increased adverse events.

CardioCel® for repair of congenital heart defects: nationwide results of over 1000 implants.

OBJECTIVES: To assess the mid-term performance of CardioCel for the repair of congenital heart defects. METHODS: Data were retrospectively collected from databases and hospital records in 3 congenital cardiac surgery centres in Australia. Kaplan-Meier curves and log-rank tests were used to test for associations between patient age, gender, patch type and site of implantation. Multivariable Cox regression was used to test whether any specific implantation site was associated with reintervention risk, after adjusting for age group, gender and patch type. RESULTS: A total of 1184 CardioCel patches were implanted in 752 patients under the age of 18 years. Median age at implant was 12 months [interquartile range (IQR) 3.6-84]. Median follow-up was 2.1 years (IQR 0.6-4.6). Probability of freedom from CardioCel-related reintervention was 93% [95% confidence interval (CI) 91-95] at 1 year, 91% (95% CI 88-93) at 3 years and 88% (95% CI 85-91) at 5 years, respectively. On multivariable regression analysis, aortic valve repair had a higher incidence of reintervention [hazard ratio (HR) = 7.15, P = 0.008] compared to other sites. The probability of reintervention was higher in neonates (HR = 6.71, P = 0.0007), especially when used for augmentation of the pulmonary arteries (HR = 14.38, P = 0.029), as compared to other age groups. CONCLUSIONS: CardioCel can be used for the repair of a variety of congenital heart defects. In our study, in patients receiving a CardioCel implant, reinterventions were higher when CardioCel was used to augment the pulmonary arteries in neonates and for aortic valve repair as compared to other sites.

Impact of Aortic Atresia After Fontan Operation in Patients With Hypoplastic Left Heart Syndrome.

BACKGROUND: Patients with aortic atresia have the worst prognosis in the spectrum of hypoplastic left heart syndrome. It remains unknown whether patients with aortic atresia continue to do poorly after Fontan operation. This study aimed to determine the association between aortic atresia and atrioventricular valve (AVV) function and clinical outcomes after Fontan operation in patients with hypoplastic left heart syndrome. METHODS: We performed a retrospective study of 1731 patients who survived the Fontan operation from the Australia and New Zealand Fontan Registry between 1975 and 2020. RESULTS: We identified 188 patients with hypoplastic left heart syndrome, including 99 (53%) with aortic atresia. Overall transplant-free survival and freedom from failure of Fontan circulation at 15 years was 91% (95% CI, 86%-96%) and 79% (95% CI, 71%-88%), respectively. The cumulative incidence of AVV operation at 15 years of age for patients with aortic atresia and aortic stenosis was 28% (95% CI, 19%-38%) and 14% (95% CI, 7%-22%; P = .03), respectively. The cumulative incidence of AVV failure (moderate or greater regurgitation or AVV operation) at 15 years of age for patients with aortic atresia and aortic stenosis was 50% (95% CI, 37%-61%) and 30% (95% CI, 19%-42%; P = .01). Patients with AVV failure were at increased risk of having moderately, or worse, decreased systolic ventricular function (odds ratio 6.7; 95% CI, 1.7-33; P = .01) and failure of Fontan circulation (hazard ratio 3.7; 95% CI, 1.5-9.1; P < .01). CONCLUSIONS: In patients with hypoplastic left heart syndrome, there is no significant difference in transplant-free survival after Fontan operation between patients with aortic atresia and patients with aortic stenosis. However, patients with aortic atresia have a much higher burden of AVV failure than patients with aortic stenosis. Atrioventricular valve failure is associated with failure of Fontan circulation.

Evaluation of the Precision of Kinetic Stem Cell (KSC) Counting for Specific Quantification of Human Mesenchymal Stem Cells in Heterogeneous Tissue Cell Preparations.

Kinetic stem cell (KSC) counting is a recently introduced first technology for quantifying tissue stem cells in vertebrate organ and tissue cell preparations. Previously, effective quantification of the fraction or dosage of tissue stem cells had been largely lacking in stem cell science and medicine. A general method for the quantification of tissue stem cells will accelerate progress in both of these disciplines as well as related industries like drug development. Triplicate samples of human oral alveolar bone cell preparations, which contain mesenchymal stem cells (MSCs), were used to estimate the precision of KSC counting analyses conducted at three independent sites. A high degree of intra-site precision was found, with coefficients of variation for determinations of MSC-specific fractions of 8.9% (p < 0.003), 13% (p < 0.006), and 25% (p < 0.02). The estimates of inter-site precision, 11% (p < 0.0001) and 26% (p < 0.0001), also indicated a high level of precision. Results are also presented to show the ability of KSC counting to define cell subtype-specific kinetics factors responsible for changes in the stem cell fraction during cell culture. The presented findings support the continued development of KSC counting as a new tool for advancing stem cell science and medicine.

Impact of Fontan Fenestration on Long-Term Outcomes: A Propensity Score-Matched Analysis.

Background The long-term impact of fenestration at the time of Fontan operation remains unclear. We aimed to review the early and long-term impact of Fontan fenestration in the Australia and New Zealand cohort. Methods and Results We reviewed 1443 patients (621 fenestrated, 822 nonfenestrated) from the Australia and New Zealand Fontan registry. Data were collected on preoperative demographics, operative details, and follow-up. Propensity-score matching was performed to account for the various preoperative and operative differences and risk factors. Primary outcomes were survival and freedom from failure. Median follow-up was 10.6 years. After propensity-score matching (407 matched pairs), there was no difference in survival (87% versus 90% at 20 years; P=0.16) or freedom from failure (73% versus 80% at 20 years; P=0.10) between patients with and without fenestration, respectively. Although patients with fenestration had longer bypass and cross-clamp times (P<0.001), there was no difference in hospital length of stay or prolonged pleural effusions (P=0.80 and P=0.46, respectively). Freedom from systemic and Fontan circuit thromboembolism was higher in the nonfenestrated group (89%; 95% CI, 88%-95%) than the fenestrated group (84%; 95% CI, 77%-89%; P=0.03). There was no difference in incidence of plastic bronchitis, protein-losing enteropathy, New York Heart Association Class III/IV symptoms, or Fontan takedown. Conclusions In the propensity score-matched analysis we have demonstrated no difference in long-term survival or freedom from Fontan failure in patients with and without fenestration. There was a higher incidence of long-term thromboembolic events in patients with fenestration. Overall, it appears that fenestration in Fontan circulation does not bring long-term benefits.

Outcomes of pulmonary valve leaflet augmentation for transannular repair of tetralogy of Fallot.

OBJECTIVE: To evaluate the midterm results of pulmonary valve leaflet augmentation in transannular repair of tetralogy of Fallot (TOF). METHODS: From 2007 to 2019, 131 patients underwent a transannular repair with pulmonary leaflet augmentation for TOF (n = 120) and double outlet right ventricle with pulmonary stenosis (n = 11). Patch material was expanded polytetrafluoroethylene (n = 76), glutaraldehyde-treated autologous pericardium (n = 47) and bovine pericardium (n = 8). RESULTS: Median age at repair was 8.9 months (interquartile range, 5.4-14.8). There was no operative mortality. Median follow-up was 6.25 years (interquartile range, 2.77-7.75). Freedom from severe pulmonary regurgitation (PR) was 85% (95% confidence interval [CI], 77%-90%) and 76% (95% CI, 66%-83%) at 1 and 5 years, respectively. Freedom from moderate or greater PR was 69% (95% CI, 60%-76%) and 30% (95% CI, 21%-39%) at 5 and 10 years, respectively. Three patients required pulmonary valve replacement for PR. Nine patients required pulmonary balloon valvuloplasty. Freedom from intervention for pulmonary valve stenosis was 98% (95% CI, 93%-99%) and 94% (95% CI, 87%-97%) at 1 and 5 years, respectively. One patient with severe PR had an indexed right ventricular volume >160 mL/m2. Use of expanded polytetrafluoroethylene resulted in a greater freedom from moderate or greater PR (log-rank test P < .001; Cox regression hazard ratio, 0.40; 95% CI, 0.25-0.63; P < .001). CONCLUSIONS: At midterm follow-up of transannular repair with pulmonary valve leaflet augmentation, severe PR occurs in less than 50% of patients. The expanded polytetrafluoroethylene patch performs better than pericardium.

The influence of coronary artery anatomy on mortality after the arterial switch operation.

OBJECTIVE: We sought to determine the influence of coronary artery anatomy on mortality in more than 1000 children undergoing the arterial switch operation. METHODS: All patients who underwent an arterial switch operation were identified from 2 hospital databases and reviewed retrospectively. Coronary anatomy was recorded from operative reports using the Leiden classification. RESULTS: An arterial switch operation was performed in 1033 children between 1983 and 2013. Coronary anatomy was normal in 697 patients (67%). The most common type of anomalous coronary anatomy was the circumflex coronary artery arising from sinus 2 (in 152 patients [15%]). Forty-seven patients (4.5%) had all coronary arteries arising from a single sinus. Of these 47 patients, 34 patients (3.3%) had a true single coronary artery. Fifty-two patients (5.0%) had an intramural coronary artery. Overall early mortality was 3.3% (34 out of 1033 patients) over the 30-year period. Early mortality was 3.0% (21 out of 697) for patients with normal coronary anatomy and 3.9% (13 out of 336) for any type of anomalous coronary anatomy. Early mortality was 3.3% (5 out of 152) for patients with the circumflex coronary artery arising from sinus 2, 6.4% (3 out of 47) for patients with all coronary arteries arising from a single sinus, and 5.9% (2 out of 34) for patients with a true single coronary artery. Early mortality for patients with intramural coronaries was 1.9% (1 out of 52). No coronary pattern was found to be a risk factor for mortality. CONCLUSIONS: Patients with anomalous coronary artery anatomy had higher rates of early mortality after the arterial switch operation but this was not statistically significant. Coronary artery reoperations were rare.

Reintervention and survival in 1428 patients in the Australian and New Zealand Fontan Registry.

OBJECTIVE: Patients undergoing single-ventricle palliation have experienced significant improvement in survival in the recent era. However, a substantial proportion of these patients undergo reoperations. We performed a review of the Australia and New Zealand (ANZ) Fontan Registry to determine the overall reintervention and reoperative burden in these patients. METHODS: A retrospective longitudinal cohort study was performed using data from patients who underwent a Fontan operation between 1975 and 2016 from the ANZ Fontan Registry. The data obtained included Fontan operation, reinterventions and most recent follow-up status. We examined the type and timing of reinterventions and survival. RESULTS: Of the 1428 patients identified, 435 (30%) underwent at least one reintervention after the Fontan operation: 110 patients underwent early reintervention and 413 underwent late reinterventions. Excluding Fontan conversion and transplantation, 220 patients underwent at least one interventional procedure and 209 patients underwent at least one reoperation. Fenestration closure and pacemaker-related procedures were the most common catheter and surgical interventions, respectively. The cumulative incidence of reintervention following Fontan was 23%, 37% and 55% at 10, 20 and 30 years, respectively. Survival and freedom from failure were worse in patients requiring later reintervention after Fontan surgery (51% vs 83% and 42% vs 69%, respectively at 30 years, p<0.001). This difference persisted after excluding pacemaker-related procedures (p<0.001). Operative mortality for non-pacemaker late reoperations after Fontan was 6%. CONCLUSIONS: A substantial proportion of Fontan patients require further intervention to maintain effective single-ventricle circulation. Patients undergoing reoperation after Fontan have higher rates of mortality and failure, despite intervention.

A comparison of pump-controlled retrograde trial off to arterio-venous bridging for weaning from venoarterial extracorporeal membrane oxygenation.

OBJECTIVES: The aim of the study is to compare a technique of pump-controlled retrograde trial off (PCRTO) to insertion of an arterio-venous (AV) bridge to conduct a trial from venoarterial extracorporeal membrane oxygenation (VA ECMO). METHODS: We studied all patients who were weaned from VA ECMO using either PCRTO or AV bridging from November 2014 to April 2018. Demographic data, indications for ECMO, duration of ECMO, duration of trial period off ECMO and survival were compared between the 2 groups. RESULTS: Seventy-nine patients were placed on VA ECMO from November 2014 to April 2018, of whom, 51 (65%) patients met the study inclusion criteria: 31 (61%) patients who had a trial period from VA ECMO using PCRTO and 20 (39%) patients who were weaned using an AV bridge. The indications for ECMO included cardiac (n = 16 and 11, respectively) and non-cardiac aetiologies (n = 15 and 9, respectively). There was 1 death in each group. The duration of the trial off VA ECMO was significantly shorter in the PCRTO group (median = 88.0 vs 196.6 min, P < 0.001). There were 2 conversions from PCRTO to AV bridging during the trial period off ECMO (2.9-kg neonate following a Norwood procedure and 2.2-kg patient following repair of ectopia cordis). CONCLUSIONS: PCRTO is a safe, simple and reproducible approach for enabling a trial period while preserving the circuit during weaning from VA ECMO. In our study, the duration of the trial period off VA ECMO was significantly shorter in the PCRTO group. PCRTO avoids manipulation of the ECMO circuit, provides a 'stress test' to evaluate cardiorespiratory reserve during the trial period off ECMO, is applicable for a wide variety of cardiac and non-cardiac indications and facilitates multiple attempts at weaning from ECMO.

Outcomes of Patients Undergoing Surgical Management of Multiple Ventricular Septal Defects.

Surgical treatment of multiple ventricular septal defects (VSDs) has advanced significantly in recent years, yet remains technically challenging. With high rates of complications and reoperations, we sought to assess the outcomes of patients undergoing a variety of management techniques for multiple VSDs. From 1988 to 2015, 157 consecutive patients underwent surgical management of multiple VSDs at a median age of 2.2 months (2 days-16 years). Sixty-nine patients (44%) had exclusively multiple VSDs, 62 patients (39%) had multiple VSDs with concomitant intracardiac anomalies, and 26 patients (17%) had multiple VSDs with aortic arch anomalies. The predominant techniques used at the initial operations were patch closure (84 patients), pulmonary artery band (83 patients), suture closure (37 patients), and sandwich technique (13 patients). Eighteen patients underwent ventriculotomies. There were 3 hospital deaths (2%). Mean follow-up time was 8.6 ± 6 years (1 day-22 years). Four patients died during follow-up, whereas freedom from reoperations was 52% (95% confidence interval 42-61%) at 16 years. Freedom from reoperation was significantly lower in the 1988-2002 era than in the post-2002 era (38% vs 73%, P = 0.016). Pacemaker implantation was ultimately required in 9% (14 of 150) of patients. No deleterious impact of a ventriculotomy could be detected. Surgical treatment of multiple VSDs can be performed with excellent short- and long-term survival, and normal late functional outcome, however, carries a significant rate of reoperation. The recent inclusion of absorbable pulmonary artery bands and the sandwich technique appear safe and are useful adjuncts in these patients.

In patients undergoing Fontan completion, does a younger age at operation result in better long-term exercise capacity and prognosis?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'In [patients undergoing Fontan completion], does [a younger age at operation] result in [better long-term exercise capacity and prognosis]?'. Altogether, 304 papers were found using the reported search, of which 10 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Of these, 2 recent large reviews describe a better or a non-significant trend towards better outcomes when the Fontan procedure is performed at a younger age. This is supported by 4 studies demonstrating better long-term exercise capacity when patients undergo Fontan completion at a younger age. Additionally, 2 other studies describe increased rates of failure, adverse events and arrhythmias with older age at Fontan completion. Two publications describe non-inferior outcomes in patients with an older age at Fontan completion, although limited by the number of patients and follow-up. We conclude that the Fontan operation should be performed at an early age (<7 years) because the data show higher survival and fewer adverse events, and the gradual decline in exercise capacity in Fontan patients appears accelerated when the Fontan operation is performed at older age.

Long-Term Outcome After Pulmonary Artery Banding in Children With Atrioventricular Septal Defects.

BACKGROUND: Patients with atrioventricular septal defect (AVSD) may require pulmonary artery banding (PAB), either as a part of a staged univentricular palliation or to allow delayed biventricular repair in patients presenting with early heart failure. The long-term outcomes of PAB in children with AVSD have not been previously reported. METHODS: All children with AVSD who underwent PAB at a single institution were included in the study. Data were obtained from medical records and correspondence with general practitioners and cardiologists. RESULTS: A total of 68 patients with complete AVSD underwent PAB, of whom 58.8% of patients (40 of 68) had balanced AVSD (bAVSD) and underwent PAB with intent to subsequently perform biventricular repair. The remaining 41.2% of patients (28 of 68) had unbalanced AVSD (uAVSD) and underwent PAB as part of staged univentricular repair. PAB was not associated with a short-term increase in atrioventricular valve (AVV) regurgitation (p = 0.24). In patients with bAVSD, 83.8% (95% confidence interval [CI]: 67.4% to 92.4%) achieved biventricular repair. Survival was 73.4% (95% CI: 54.3% to 85.5%) and freedom from left AVV operation was 60.0% (95% CI: 36.1% to 77.4%) at 20 years of follow-up. In patients with uAVSD, 61.9% (95% CI: 40.5% to 77.5%) had achieved Fontan completion at 10 years of follow-up. Survival was 60.9% (95% CI: 36.2% to 78.5%) and freedom from AVV operation was 78.6% (95% CI: 55.5% to 90.6%) at 20 years. CONCLUSIONS: PAB can be used in patients with AVSD without compromising AVV function. Most patients with bAVSD progress to biventricular repair, albeit with a high rate of AVV reoperation. Patients with uAVSD who undergo PAB have similar outcomes to the overall uAVSD population.

Propensity score matched analysis of partial atrioventricular septal defect repair in infancy.

OBJECTIVE: Partial atrioventricular septal defect (pAVSD) is usually repaired between 2 and 4 years of age with excellent results. Repair during infancy has been associated with poorer outcomes. However, most infants in reported series had heart failure or significant left atrioventricular valve (LAVV) regurgitation. The impact of surgery during infancy on outcomes remains unclear. METHODS: All children at three institutions who underwent repair of pAVSD from 1975 to 2015 were included. Infants (aged <1 year) were compared with older children in a propensity score matched analysis. Variables used to generate propensity scores were: failure to thrive, congestive heart failure, preoperative LAVV regurgitation, associated congenital heart disease, sex and the presence of trisomy 21. RESULTS: pAVSD repair was performed on 430 children, 17.4% (75/430) were infants. Infants (mean age 0.5±0.3 years) had higher rates of LAVV regurgitation, heart failure and additional cardiac malformations than older children (mean age 4.7±3.5 years). At 30 years, survival for infants was 82.1% (95% CI 70.1% to 89.6%) compared with 95.7% (95% CI 91.3% to 97.9%) in older children (P<0.001).Propensity score matching yielded 52 well-matched pairs. Survival at 30 years was 87.9% (95% CI 75.0% to 94.4%) for infants compared with 98.1% (95% CI 87.1% to 99.7%) for older children (P=0.04). There was no significant difference in freedom from reoperation between the groups. CONCLUSIONS: Despite matching for risk factors, survival after repair of pAVSD during infancy is lower than that when repair is performed in older children, with no difference in reoperation rates. This suggests that elective repair of pAVSD should be deferred until after infancy.

Absorbable pulmonary artery banding: a strategy for reducing reoperations.

Objectives: Pulmonary artery banding (PAB) remains in the armamentarium of techniques for several congenital cardiac anomalies, but necessitates a reoperation for eventual removal. We sought to assess the efficacy of an absorbable PAB in obviating the requirement for reoperation. Methods: From 2003 to 2015, 45 consecutive patients with a median age of 1.6 months (2 days-11 months) underwent placement of a polydioxanone absorbable PAB. In 28 patients (62%), the band was placed concomitantly to a ventricular septal defect (VSD) closure and in 17 (38%), the band was the sole procedure for the VSDs. Fourteen patients had additional cardiac anomalies and 9 patients had aortic arch anomalies, which were repaired at the time of absorbable PAB placement. Results: There was 1 hospital death. The band was removed early in 3 patients. Mean time to follow-up was 5.2 ± 3.5 years. Overall, 32 of the 41 patients discharged from hospital with absorbable PABs did not require reoperation on the VSDs or the band, resulting in a single-stage definitive repair of 78%. Median time to absorbable PAB resorption was 7.2 months (interquartile range, 5.0-10.4). Freedom from reoperation related to residual VSDs or PAB obstruction was 78% (95% CI: 61-87%) at 10 years. Conclusions: The use of absorbable polydioxanone PABs is an effective method of reducing reoperations for multiple VSDs. Their use should be incorporated in the surgical strategy for repair of muscular and residual VSDs.

A method for establishing class III medical device equivalence: sodium hyaluronate (GenVisc 850) for the treatment of knee osteoarthritis.

Although the concept of equivalence for drugs (generics) and biologics (biosimilars) has been readily adopted, the concept of equivalence or indistinguishable characteristics for class III medical devices has yet to be specifically addressed regarding a defined regulatory approval process in the US. In September 2015, GenVisc 850® (sodium hyaluronate), a hyaluronic acid approved for the treatment of knee osteoarthritis, was approved by the US Food and Drug Administration (FDA) based upon indistinguishable characteristics in comparison to an approved branded hyaluronic acid (Supartz®/Supartz FX™). The purpose of this paper is to review the methodology and report the main outcomes used to demonstrate clinical comparability of GenVisc 850 with Supartz/Supartz FX. The FDA approval was collectively attained using prospectively defined methods for preclinical, physical, and chemical testing, as well as noninferiority in clinical performance comparisons. Evidence from five randomized controlled studies of Supartz/Supartz FX vs saline control injections (used for Supartz approval), two randomized controlled trials of GenVisc 850 vs saline control injections, and one randomized controlled study of GenVisc 850 vs Supartz/Supartz FX provided evidence of safety for GenVisc 850. Efficacy was further assessed based on assessment of the same Supartz studies and three prospectively identified GenVisc 850 studies. A Bayesian network meta-analysis was used to demonstrate that the clinical efficacy of GenVisc 850 was noninferior to Supartz/Supartz FX and superior to saline control. Overall, safety of GenVisc 850 was similar to that of Supartz/Supartz FX and saline control injections, while efficacy of GenVisc 850 was noninferior to that of Supartz/Supartz FX and superior to saline control injections.