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Long-term morbidity including hypertension often persists in coarctation patients despite current guidelines. Coarctation severity can be invasively assessed via peak-to-peak catheter pressure gradient (PPCG), which is estimated noninvasively via simplified Bernoulli equation and conventionally reported as peak instantaneous Doppler gradient (PIDG). However, underlying simplifications of the equation limit diagnostic accuracy. We studied the diagnostic performance of a new Doppler-based diastolic index called the continuous flow pressure gradient (CFPG) versus conventional indices in assessing coarctation severity.In a rabbit model mimicking human aortic coarctation, temporal blood pressure waveforms revealed the diastolic instantaneous pressure gradients and spectral Doppler features impacted by coarctation severity. We therefore hypothesized that CFPG provides superior correlation with coarctation gradients measured invasively. PIDG and CFPG were quantified using color flow echocardiography in humans and rabbits with discrete coarctations. Results were compared with PPCG in rabbits (n = 34) and arm-leg systolic gradients (n = 25) in humans via 1-way analysis of variance, Pearson's correlation, linear regression, and Bland-Altman analysis.A threshold of CFPG ≥ 4.6 mm Hg was identified via the Youden index as representative of PPCG ≥ 20 mm Hg (the current guideline value for coarctation intervention) in rabbits, while a CFPG ≥1.0 mm Hg represented an arm-leg systolic gradient ≥20 mm Hg in humans. Accuracy measures revealed superior correlation of CFPG (R

Background: Coarctation of the aorta (CoA; constriction of the proximal descending thoracic aorta) is among the most common congenital cardiovascular defects. Coarctation-induced mechanical perturbations trigger a cycle of mechano-transduction events leading to irreversible precursors of hypertension including arterial thickening, stiffening, and vasoactive dysfunction in proximal conduit arteries. This study sought to identify kinetics of the stress-mediated compensatory response leading to these alterations using a preclinical rabbit model of CoA. Methods: A prior growth and remodeling (G&R) framework was reformulated and fit to empirical measurements from CoA rabbits classified into one control and nine CoA groups of various severities and durations (n = 63, 5–11/group). Empirical measurements included Doppler ultrasound imaging, uniaxial extension testing, catheter-based blood pressure, and wire myography, yielding the time evolution of arterial thickening, stiffening, and vasoactive dysfunction required to fit G&R constitutive parameters. Results: Excellent agreement was observed between model predictions and observed patterns of arterial thickening, stiffening, and dysfunction among all CoA groups. For example, predicted vascular impairment was not significantly different from empirical observations via wire myography (p-value > 0.13). Specifically, 48% and 45% impairment was observed in smooth muscle contraction and endothelial-dependent relaxation, respectively, which were accurately predicted using the G&R model. Conclusions: The resulting G&R model, for the first time, allows for prediction of hypertension precursors at neonatal ages that is currently challenging to examine in preclinical models. These findings provide a validated computational tool for prediction of persistent arterial dysfunction and identification of revised severity–duration thresholds that may ultimately avoid hypertension from CoA.

In hypoplastic left heart syndrome, the size and function of the left ventricle vary and are dependent on the patency of the aortic valve. A patent native aortic valve, permitting left ventricular ejection, can augment cardiac output. We performed a retrospective chart review of patients with hypoplastic left heart syndrome and a stenotic aortic valve who underwent native aortic valvuloplasty at the time of Norwood and found that none of the eight patients identified had clinically significant aortic insufficiency. This case series suggests that surgical aortic valvuloplasty at Norwood is associated with aortic valve patency/augmented systemic cardiac output without the development of clinically significant aortic regurgitation at intermediate follow-up in a limited cohort.

Background Mortality after stage 1 palliation of hypoplastic left heart syndrome remains significant. Both cardiac output (CO) and systemic vascular resistance (SVR) contribute to hemodynamic vulnerability. Simultaneous measures of mean arterial pressure and somatic regional near infrared spectroscopy saturation can classify complex hemodynamics into 4 distinct states, with a low-CO state of higher risk. We sought to identify interventions associated with low-CO state occupancy and transition. Methods Perioperative data were prospectively collected in an institutional review board–approved database. Hemodynamic state was classified as high CO, high SVR, low SVR, and low CO using bivariate analysis. Associations of static and dynamic support levels and state classifications over 48 postoperative hours were tested between states and across transitions using mixed regression methods in a quasi-experimental design. Results Data from 10,272 hours in 214 patients were analyzed. A low-CO state was observed in 142 patients for 1107 hours. Both low CO and extracorporeal membrane oxygenation had increased mortality risk. The low-CO state was characterized by lower milrinone but higher catecholamine dose. Successful transition out of low CO was associated with increased milrinone dose and hemoglobin concentration. Increasing milrinone and hemoglobin levels predicted reduced risk of low CO in future states. Conclusions Bivariate classification objectively defines hemodynamic states and transitions with distinct support profiles. Maintaining or increasing inodilator and hemoglobin levels were associated with improved hemodynamic conditions and were predictive of successful future transitions from the low-CO state.

Background: Shone syndrome is characterized by coincident mitral valve stenosis and left ventricular outflow tract obstruction. Although first described in 1963, little research has expounded surgical outcomes. We sought to evaluate our experience with this cohort, emphasizing outcomes including mortality, morbidity, and cardiac function. Methods: A retrospective chart review of 46 patients who underwent operation for Shone syndrome between 1990 and May 2018 was conducted. Index operations included 32 repairs of the left ventricular outflow tract, four mitral valve repair/replacements, nine combined repairs, and one non-Shone’s repair. Median age at index procedure was 22 days (2 days-10 years). Mean follow-up was 9.1 years (2 months-21 years), and 70 additional operations (51 reoperations) were required. Three patients were lost to follow-up. Results: Overall survival was 95.7% with two late deaths. Freedom from death or transplant was 93.5%. Thirteen (28.3%) patients remained free from reoperation. Thirty-three patients required 51 reoperations of the left ventricle outflow tract (n = 12), mitral valve (n = 16), combined repairs (n = 21), and transplant (n = 1). At most recent follow-up, patients exhibited mitral stenosis (n = 21), aortic stenosis (n = 7), and diminished LV function (n = 2). Conclusion: Surgical correction of Shone’s offers excellent survival benefit, but reoperation burden is high, with >70% of patients requiring reintervention in the follow-up period. A total of 65% of patients developed recurrent obstruction of left ventricular inflow or outflow, however, ventricular function is preserved in the majority of patients. All but one patient had no functional deficits, classified as New York Heart Association I with > 60% requiring no medication.

Aortopulmonary collaterals (APCs) develop universally, but to varying degrees, in patients with single ventricle congenital heart disease (CHD). Despite their ubiquitous presence, APCs remain poorly understood. We sought to evaluate the association between APC burden and common non-invasive clinical variables. We conducted a single center, retrospective study of patients with single ventricle CHD and previous Glenn palliation who underwent pre-Fontan cardiac magnetic resonance (CMR) imaging from 3/2018 to 3/2021. CMR was used to quantify APC flow, which was normalized to aortic (APC/Q

We sought to characterize the clinical course and outcomes of intervention for Tetralogy of Fallot (TOF) with associated conal septal hypoplasia (CSH) compared to those with identifiable conal septum on initial newborn echocardiogram. We performed a retrospective, 1:2 case-control study of children with TOF anatomy, 33 with CSH and 66 with typical TOF, who underwent surgical repair from 1991-2019 at Children's Wisconsin. Data on echocardiographic anatomic features, systemic oxygen saturations, medical therapies, admissions, palliative interventions, operative strategies, and long-term follow-up were compared. The CSH group had fewer hypercyanotic spells (6% vs 42%, p 0.001), beta-blockers prescribed (12% vs 41%, p = 0.005), and hospital admissions for cyanosis (12% vs 44%; p = 0.001) prior to any intervention. Of 14 who required palliative intervention, 8 had balloon pulmonary valvuloplasty (BPV) (7 from the CSH group and 1 from the control group), and 6 had systemic-to-pulmonary artery shunts (all from the control group). Definitive repair was performed at a significantly older age in the CSH group (10.2 ± 10 vs 5.6 ± 5.9 months, p = 0.011), with less subpulmonary muscle resection (57.6% in vs 92.4%, p 0.001) and higher use of a transannular patch (84.8% vs 65.2%, p = 0.040). The average time to surgical reintervention was similar in both groups (9.7 ± 5.9 vs 8.6 ± 6.4 years in controls). We conclude that infants with TOF and CSH have a milder preoperative clinical course with fewer hypercyanotic spells or need for medical therapy. They also respond well to palliative BPV and can safely undergo later definitive repair compared to typical TOF with a well-developed conal septum.

Background Mortality after stage 1 palliation of hypoplastic left heart syndrome remains significant. Hemodynamic changes result from interaction of cardiac output (CO) and systemic vascular resistance (SVR). We sought to identify time-dependent changes in postoperative hemodynamic states and their associations with mortality. Methods Perioperative data were prospectively collected in an institutional review board–approved database. Hemodynamic state was classified as high CO, high SVR, low SVR, and low CO using bivariate analysis of mean arterial pressure and somatic regional near-infrared spectroscopic oximetry saturation. State classifications over 48 postoperative hours were modelled using multinomial logistic regressions for association with mortality. Results Data from 9614 of 10,272 hours in 214 patients were analyzed. Operative survival was 91%. The predominant state was high CO (46% time). Low CO state without extracorporeal membrane oxygenation (ECMO) was found in 52% of patients for 9.7% time. ECMO was employed in 24 (11.2%) patients for 10.4% time. State stability was 33%, with high SVR the least stable (17%) and high CO the most stable (53%). Transition from high CO increased in hours 1 to 12, mainly to low SVR. Transition to low CO was 18.4%, increasing in hours 1 to 12, mainly from high SVR. The transition risk to ECMO was 0.32%, and 0.74% during hours 1 to 12, only from low CO. Both low CO and ECMO had increased mortality risk. Conclusions Bivariate classification defines hemodynamic states with distinct physiologic, transition, and mortality risk profiles. High SVR state was unstable. Transition to ECMO occurred only from low CO, while the low SVR and high CO states were safest.

BACKGROUND: Difficulty weaning from cardiopulmonary bypass (CPB) or the need to return to CPB (collectively D-CPB) may occur after the Norwood procedure. We sought to evaluate the relationship between D-CBP and survival. METHODS: This was a retrospective chart review of all patients undergoing a Norwood procedure at our institution during the interval 2005-2017. Primary outcome was survival for the Norwood procedure. Secondary outcomes included various measures of morbidity. Successful wean from CBP (S-CPB) was defined as no need to return to full flow CPB during the initial definitive wean or after separation from CPB; otherwise the classification was difficulty with wean (D-CBP). Successful rescue in the D-CPB group was defined as not requiring extracorporeal life support (ECLS) either in the operating room or within the first three postoperative days. RESULTS: Of the 196 patients in the cohort, 49 were D-CPB. Survival for S-CPB was 92.5% (136/147) vs 71.4%% (35/49) for D-CPB (p = 0.001). Major morbidity occurred in 29.9% (44/147) in S-CPB vs 69.4 % (34/49) in D-CPB (p < 0.001). With multivariable analysis, D-CPB was significantly associated with mortality (OR=8.09; CI 2.72 – 24.05; p

The surgical treatment of mitral disease in pediatrics is challenging. Managing diversity in patient anatomy, growth, and the need for long-term anticoagulation requires trade-offs between imperfect solutions. We sought to assess our approach to pediatric mitral valve surgery and identify predictors associated with mortality and recurrent mitral disease. The medical records, echocardiograms, and operative reports of all patients who underwent surgical intervention on the mitral valve from January 2000 to April 2016 were reviewed. A total of 143 patients underwent mitral valve surgery, 64 of which were neonates or infants (ages 10-355 days) and 79 of which were children (ages 1-17.8 years). Neonates and infants had a higher preoperative New York Heart Association heart failure classification in comparison to children (P0.001) with a less severe degree of mitral valve insufficiency (P = 0.007). Postoperative outcomes for primary repair patients (n = 133) demonstrated significant differences in recurrence of mitral valve disease, with 38% of neonates/infants and 21% of children affected (P = 0.028). Five-year rates of mortality or transplant were 22% (8%, 33%) in neonates and infants compared to 4% (0%, 10%) in children, P = 0.013. Mitral valve surgery in neonates and infants is particularly high risk and is associated with higher rate of recurrence and reintervention early. However, if successful early, mitral valve repair in neonates and infants can result in a durable freedom from reintervention that parallels freedom from reintervention in older children undergoing repair. Further understanding of mechanisms of failure and better matching of anatomic substrate to strategy is needed.

Introduction: Coarctation of the aorta (CoA) severity is assessed via trans-CoA blood pressure gradient (BPG) estimated using simplified Bernoulli equation (SBE) with indices from noninvasive Doppler echocardiography (echo). However, simplifications of the SBE and inconsistent readings through a suboptimal insonation window limit diagnostic accuracy (DA). In a rabbit model mimicking human CoA (Fig. 1A), catheter vs. Doppler comparison of BPG revealed diastolic continuous-flow pressure gradient (CFPG) was independently associated with severity. We therefore hypothesized the unique properties of CFPG would improve DA in humans. Methods: SBE and CFPG were quantified using color flow Doppler in humans and rabbits with discrete non-recurrent CoA before repair (Fig. 1B). Quantifications used peak velocity proximal to (V p ) and at the CoA (V pk ), early diastolic velocity (V d ), doppler velocity index (DVI), and normalized diastolic pressure half-time (dPHT; see Fig. 1B and C for definitions). Results were compared with measured BPG in rabbits (peak-to-peak catheter BPG) and humans (upper-lower extremity BPG). There was a total of 18 human and 26 rabbit cases; significance was defined a priori as a BPG of ≥20 mmHg. A CFPG ≥4 mmHg threshold was identified by maximizing sensitivity plus specificity in receiver operative curves (ROC). Results: Accuracy measures (Fig. 1D) revealed the superior performance of CFPG vs. SBE. Although reports suggest Fig. 1- (A) MRI confirming morphological similarities between rabbit and human CoA, (B) Spectral Doppler images show diastolic continuous flow, (C) indices derived from the generalized Bernoulli equation assuming exponential diastolic pressure loss, (D) diagnostic performance for CFPG vs. conventional SBE.

The supported Ross is used to mitigate the neoaortic root dilation that has been described with the unsupported Ross. There is limited literature assessing the efficacy of the supported Ross in young patients. In this study, the fate of the neoaortic root was compared in the supported and unsupported Ross procedure in adolescent patients.A retrospective review was performed of patients who underwent the Ross procedure between 1996 and 2019. An analysis was conducted of patients aged 10 to 18 years who underwent the supported and unsupported Ross operation, without a Konno enlargement, to assess for longitudinal echocardiographic changes. Given differences in follow-up time, both regression analysis and Mann-Whitney nonparametric tests were used to correct for time from discharge to most recent follow-up.The median follow-up time for supported and unsupported Ross patients without a Konno enlargement was 2.90 years (0.21-13.03 years) and 12.13 years (2.63-19.47 years), respectively. Unsupported Ross patients experienced a higher rate of change per year in the aortic annulus (P = .003 and P = .014) and aortic sinus (P = .002 and P = .002) diameters, respectively. There was no significant difference in the rate of change of end-diastolic left ventricular internal diameter (P = .703 and P = .92) and aortic insufficiency (P = .687 and P = .215) between the supported and unsupported Ross patients.Progressive dilation of the neoaortic root in unsupported Ross patients is significantly mitigated with the supported Ross with excellent stability. The supported Ross is safe and effective and may play an increasing role in the management of children with aortic disease.

Background Arginine vasopressin is a nonapeptide hormone with effects on intracellular water transport and arterial tone that is used in distributive shock and following cardiopulmonary bypass. We sought to evaluate the safety and efficacy of vasopressin infusion on hemodynamics and fluid balance in the early postoperative period after Fontan completion. Methods We conducted a randomized, double-blinded, placebo-controlled study of vasopressin infusion for 24 hours after cardiopulmonary bypass for Fontan completion. Patient characteristics, hospital outcomes, and measures of hemodynamic parameters, urine output, chest tube drainage, fluid balance, laboratory data, and plasma arginine vasopressin concentrations were collected at baseline and for 48 postoperative hours. Data were analyzed using mixed-effect regressions. Results Twenty patients were randomized, 10 to vasopressin and 10 to placebo. Transpulmonary gradient (6.4 ± 0.5 vs 8.3 ± 0.5 mm Hg, P = .011) and chest tube drainage (23 ± 20 vs 40 ± 20 mL/kg, P = .028) for 48 hours after surgery were significantly lower in the vasopressin arm compared to placebo. Arginine vasopressin concentrations were elevated above baseline after surgery until 4 hours post cardiac intensive care unit admission in both arms, and higher in the vasopressin arm during postoperative infusion. No differences in sodium concentration, liver function, or renal function were noted between groups. Conclusions Vasopressin infusion after Fontan completion appears safe and was associated with reduced transpulmonary gradient and chest tube drainage in the early postoperative period. A larger multiinstitutional study may show further outcome benefit.

Thrombocytopenia and platelet dysfunction induced by extracorporeal blood circulation are thought to contribute to postsurgical bleeding complications in neonates undergoing cardiac surgery with cardiopulmonary bypass (CPB). In this study, we examined how changes in platelet function relate to changes in platelet count and to excessive bleeding in neonatal CPB surgery. Platelet counts and platelet P-selectin exposure in response to agonist stimulation were measured at four times before, during, and after CPB surgery in neonates with normal versus excessive levels of postsurgical bleeding. Relative to baseline, platelet counts were reduced in patients while on CPB, as was platelet activation by the thromboxane A2 analog U46619, thrombin receptor activating peptide (TRAP), and collagen-related peptide (CRP). Platelet activation by adenosine diphosphate (ADP) was instead reduced after platelet transfusion. We provide evidence that thrombocytopenia is a likely contributor to CPB-associated defects in platelet responsiveness to U46619 and TRAP, CPB-induced collagen receptor downregulation likely contributes to defective platelet responsiveness to CRP, and platelet transfusion may contribute to defective platelet responses to ADP. Platelet transfusion restored to baseline levels platelet counts and responsiveness to all agonists except ADP but did not prevent excessive bleeding in all patients. We conclude that platelet count and function defects are characteristic of neonatal CPB surgery and that platelet transfusion corrects these defects. However, since CPB-associated coagulopathy is multifactorial, platelet transfusion alone is insufficient to treat bleeding events in all patients. Therefore, platelet transfusion must be combined with treatment of other factors that contribute to the coagulopathy to prevent excessive bleeding.

Highlights •Many patients with adult CHD will experience a progressive decline in cardiopulmonary function leading to advanced HF. •These high-risk patients present unique anatomic and physiological challenges that may not be amenable to repair. •For highly selected patients, mechanical circulatory support and heart transplantation offer excellent short- and long-term outcomes. •Prospective registries are needed to determine optimal timing of referral, risk factors for adverse outcomes, and strategies for preservation of end-organ function.

Fontan fenestration reduces chest tube duration and shortens post-operative length of stay but is not universally performed. Using a large national database, we sought to describe current use of the Fontan fenestration, including factors associated with placement. The Virtual Pediatric System database was queried to identify patients with the Society of Thoracic Surgery code for a Fontan procedure during their admission from January 2009 until June 2016. Those undergoing a fenestrated Fontan were compared to those undergoing a non-fenestrated Fontan. Of the 1695 patients, 1084 (64%) had a fenestration placed. There was variation between centers with the range of fenestration placement being 8 to 100%. Those with a fenestration placed had lower weight, despite similar age, and were more likely to have a single right ventricle. Those with a fenestration had lower systolic blood pressure and greater need for mechanical ventilation within the first hour of admission to the intensive care unit after Fontan. Most patients still have a fenestration placed at the time of Fontan but this varies markedly by center. Fenestration placement is more common in higher risk patients including those with a systemic right ventricle. Further study is necessary to determine specific patient populations that benefit from fenestration placement at the time of Fontan.

The long-term outcome of patients with corrected transposition of the great arteries and associated lesions after physiologic repair is uncertain. Anatomic correction, utilizing the morphologic left ventricle as a systemic pumping chamber and the mitral valve as the systemic atrioventricular valve, is considered the preferred method, especially for patients with either tricuspid valve regurgitation, with Ebstein's malformation of the tricuspid valve, or with right ventricular dysfunction. The double switch employs both an atrial switch and arterial switch to "correct" the atrioventricular and ventriculoarterial discordance. Associated lesions are also repaired. The best outcomes with double switch are achieved with patients in the first few years of life even if reconditioning of morphologic left ventricle is required. However, the long-term function of the conduction system, the aortic valve, and the ventricles is variable and requires close surveillance.

Introduction: After atrioventricular septal defect (AVSD) repair, the degree of post-repair left atrioventricular valve regurgitation (LAVVR) at discharge is associated with need for re-intervention. Knowledge of the relationship between post-repair transesophageal echocardiogram (TEE) and discharge transthoracic echocardiogram (TTE) LAVVR could influence intraoperative decision-making. At present, this relationship has not been well-defined and to assess it, we undertook a retrospective study of a large cohort of AVSD patients. Methods: Between 11/2012-12/2018, 96 AVSD patients underwent surgical repair. Data included patient demographics, clinical characteristics, preoperative LAVV anomalies, surgical procedure and outcomes. LAVVR was graded as less than moderate or moderate and greater with statistical blinding techniques employed. Cohen’s kappa statistics were calculated to measure interobserver variability. Association between parameters was tested using univariate analysis. Results: Median age and weight at surgery for complete AVSD patients (68%) was 5 months and 5.6 kg respectively; for partial AVSD (32%), median age and weight was 27 months and 11.9 kg respectively. The median interval between echo studies was 6 days (IQR 4-12 days) with median length of stay of 8 days (IQR 5-16 days). There were no deaths. Post-repair TEE revealed less than moderate LAVVR in 86 patients (90%) and moderate or greater in 10 (10%). Overall, there was a discrepancy in LAVVR seen at discharge in 25 patients (26%) with 23/25 (92%) demonstrating a higher grade of LAVVR. Two patients underwent reoperation before discharge due to severe LAVVR. In univariate analysis, significant predictors for LAVVR discrepancy were younger age (p=0.032) and lower weight (p=0.032) at repair; preoperative LAVVR grade was a significant predictor for worsening LAVVR (p=0.038). Conclusions: Discrepancy between LAVVR grade on post-repair TEE and discharge TTE was present in 26% of AVSD patients with the vast majority changing to a higher grade. This important finding with implications for intraoperative decision-making should prompt further investigations into preoperative LAVV anomalies, surgical technique and postoperative factors influencing valvar function.

Introduction: Preoperative risk stratification in congenital cardiac surgery includes patient and procedure related factors, which may be used in clinical decision making as well program performance evaluation. Despite these tools, unidentified factors contribute to wide variation in outcomes both within and between centers. Identification of latent physiologic risk factors may strengthen predictive models. Hypothesis: Total cell-free DNA (TCF) functions as a biomarker for cellular injury as well as a pro-inflammatory cytokine. We hypothesized that elevated preoperative TCF would be associated with poor outcome following pediatric cardiac surgery requiring cardiopulmonary bypass (CPB). Methods: Prospective observational study of children age < 18 yr and wt > 3 kg undergoing planned CPB surgery. The Children’s Wisconsin Institutional Review Board approved the protocol . A serum TCF sample was obtained after induction of anesthesia prior to surgical incision. The primary outcome measure was a composite of postoperative cardiac arrest, ECMO, or death (CAED). Association of outcome to TCF was assessed by logistic regression with a cutpoint chosen by ROC curve exploration. Odds ratios with 95% CI were calculated. Results: Data were available in 117 patients, median age 0.9 years (range 0-17.4), median weight 7.8kg (range 3.2-98). The primary outcome (CAED) was met in 6/117 (5.1%). Table 1 summarizes characteristics of patients with and without CAED. Risk of CAED was 2% with TCF20 ng/ml (OR=18.2, CI 2.2- 212, p Conclusions: Preoperative TCF has an important association with postoperative cardiac arrest, ECMO, and death. Alternative or intensified treatment strategies could be considered in patients with elevated preoperative TCF.

OBJECTIVES: Injectable hydrogels are known to attenuate left-ventricular (LV) remodeling following myocardial infarction (MI), dependent on material mechanical properties. The effect of hydrogel injection on ischemic mitral regurgitation (IMR) resultant from LV remodeling remains relatively unexplored. This study uses multiple imaging methods to evaluate the efficacy of injectable hydrogels with tunable modulus to prevent post-MI development of IMR. METHODS: Posterolateral MI was induced in twenty sheep with subsequent epicardial injection of saline (control (MI); n=7), soft hydrogel (guest-host crosslinking (GH), modulus5 mL) regurgitant volumes. CONCLUSIONS: Injectable hydrogels attenuated subvalvular remodeling and leaflet tethering, preventing IMR development and normalizing LV flow dynamics. Hydrogels with a supraphysiological modulus yielded best outcomes.

Though the Fontan circulation provides long-term palliation for patients with univentricular hearts, failure of the circulation may ensue, leaving heart transplantation as the only definitive treatment. For Fontan patients awaiting transplant, both "right-sided" and "left-sided" symptoms may be present and severe, hence, biventricular mechanical circulatory support may be indicated. This can be provided by implantation of the total artificial heart (TAH), a procedure which is performed slightly differently than in patients with biventricular hearts. In this article, the unique aspects of implantation of this device in a patient with a Fontan operation are reviewed, with specific attention to the most commonly encountered anatomic variants of importance to the implanting surgeon.

Essentials Heparin-protamine balance (HPB) modulates bleeding after neonatal cardiopulmonary bypass (CPB). HPB was examined in 44 neonates undergoing CPB. Post-operative bleeding occurred in 36% and heparin rebound in 73%. Thrombin-initiated fibrin clot kinetic assay and partial thromboplastin time best assessed HPB. SUMMARY Background Neonates undergoing cardiopulmonary bypass (CPB) are at risk of excessive bleeding. Blood is anticoagulated with heparin during CPB. Heparin activity is reversed with protamine at the end of CPB. Paradoxically, protamine also inhibits blood coagulation when it is dosed in excess of heparin. Objectives To evaluate heparin-protamine balance in neonates undergoing CPB by using research and clinical assays, and to determine its association with postoperative bleeding. Patients/Methods Neonates undergoing CPB in the first 30 days of life were studied. Blood samples were obtained during and after surgery. Heparin-protamine balance was assessed with calibrated automated thrombography, thrombin-initiated fibrin clot kinetic assay (TFCK), activated partial thromboplastin time (APTT), anti-FXa activity, and thromboelastometry. Excessive postoperative bleeding was determined by measurement of chest tube output or the development of cardiac tamponade. Results and Conclusions Of 44 neonates enrolled, 16 (36%) had excessive postoperative bleeding. The TFCK value was increased. By heparin in neonatal blood samples, but was only minimally altered by excess protamine. Therefore, it reliably measured heparin in samples containing a wide range of heparin and protamine concentrations. The APTT most closely correlated with TFCK results, whereas anti-FXa and thromboelastometry assays were less correlative. The TFCK and APTT assay also consistently detected postoperative heparin rebound, providing an important continued role for these long-established coagulation tests in the management of postoperative bleeding in neonates requiring cardiac surgical repair. None of the coagulation tests predicted the neonates who experienced postoperative bleeding, reflecting the multifactorial causes of bleeding in this population.

Background Pulmonary valve replacement (PVR) is a common operation in patients with congenital heart disease (CHD). As survival with CHD improves, infective endocarditis (IE) is a growing complication after PVR. The aim of this study was to assess the incidence, risk factors, and clinical outcomes of IE after surgical PVR in patients with CHD at our institution. Methods Retrospective analysis of all cases of surgical PVR performed at Children's Hospital of Wisconsin between 1975 and 2016 was performed. All cases of IE after PVR were identified and clinical and imaging data were obtained by review of medical records. Results Out of 924 surgical PVRs, there were 19 (2%) cases of IE. The incidence of IE after surgical PVR was 333 cases per 100,000 person-years. The median age at diagnosis of IE was 21 years (range = 1.2-34 years) and the median time from PVR to diagnosis of IE was 9.4 years. The overall freedom from IE after PVR was 99.1%, 96.9%, and 93.4%, at 5, 10, and 15 years, respectively. There was no significant difference in freedom from IE based on valve type, including bovine jugular vein grafts. Patients with IE were more likely to have had a history of multiple PVRs, while length of follow-up after PVR, age at time of PVR, and gender were not significant risk factors. Eleven (58%) cases of IE required surgical intervention, while 8 (42%) were successfully treated with intravenous antibiotics alone. There were no deaths and no recurrences of IE after treatment. Conclusion The overall risk for IE after PVR is low. There was no association between age or type of pulmonary valve and risk of IE. The majority of cases require surgical intervention, but in general the outcomes of IE after PVR are good with low mortality and risk of recurrence.

Background:Thrombocytopenia and hypofibrinogenemia during neonatal cardiopulmonary bypass (CPB) contribute to bleeding and morbidity. Rotational thromboelastometry (ROTEM) is a viscoelastic assay with a rapid turnaround time. Data validating ROTEM during neonatal cardiac surgery remain limited. This study examined perioperative hemostatic trends in neonates treated with standardized platelet and cryoprecipitate transfusion during CPB. We hypothesized that ROTEM would predict thrombocytopenia, hypofibrinogenemia, and the correction thereof.Methods:Forty-four neonates undergoing CPB were included in this prospective observational study. Blood samples were obtained at Baseline, On CPB, Post-CPB, and Postoperative. The ROTEM analysis included extrinsically activated (Extem) and fibrinogen-specific (Fibtem) assays. Platelet-specific thromboelastometry (Pltem) values were calculated. Platelet and cryoprecipitate transfusion was initiated prior to termination of CPB.Results:Platelet count and Extem amplitude decreased significantly On CPB ( P < .0001), increased significantly Post-CPB ( P < .0001), and Postoperative values were not significantly different from Baseline. Extem amplitude at 10 minutes (A10) > 46.5 mm (AUC = 0.941) and Pltem A10 > 37.5 mm [area under curve (AUC) = 0.960] predicted platelet count > 100 × 103/μL, and they highly correlated with platelet count ( R = 0.89 and R = 0.90, respectively). Fibrinogen concentration and Fibtem amplitude decreased significantly On CPB ( P ≤ .0001) and normalized after cryoprecipitate transfusion. Fibtem A10 > 9.5 mm predicted fibrinogen >200 mg/dL (AUC = 0.817), but it correlated less well with fibrinogen concentration ( R = 0.65).Conclusions:ROTEM analysis during neonatal cardiac surgery is sensitive and specific for thrombocytopenia and hypofibrinogenemia, identifying deficits within 10 minutes. Platelet and cryoprecipitate transfusion during neonatal CPB normalizes platelet count, fibrinogen level, and ROTEM amplitudes.

It is unclear if neonatal tetralogy of Fallot repair offers better outcomes compared to repair later in infancy. We therefore conducted a meta-analysis comparing outcomes of neonatal and non-neonatal repair. Manuscripts were identified and reviewed for quality and bias with favorably scored manuscripts being included in the final meta-analysis. Several perioperative and postoperative variables were compared. A total of 8 studies with 3858 patients were included in the analysis. Of these patients, 19% underwent neonatal repair. Neonatal repair was associated with increased mortality, longer intensive care unit stays, and longer total hospital length of stay.

Because of the inadequacies inherent to a circulation supported by a single ventricle, many Fontan patients will experience failure of their circulation. To date, there is no medical regimen that reliably and consistently restores circulatory function in these patients. Because of the shortage of donor organs and the fact that many of these patients present with features that either preclude or render heart transplantation a high risk, there is an intense need to better understand how mechanical circulatory support (MCS) may benefit these patients. In this report, we share our experience of successful MCS and transplantation of three patients. Our experience and that of others is very encouraging, but also preliminary. In general, a systemic ventricular assist device, with or without a Fontan fenestration, is a reasonable consideration for a patient presenting with predominantly systolic dysfunction. A pulmonary/systemic venous assist device may be sufficient for the patient with preserved systolic function and failure of the systemic venous/lymphatic system; however, this remains speculative. The more comprehensive approach of a total artificial heart or bilateral support is attractive in theory, but beset by the need for a more complex operation. In all scenarios, early referral, before organ failure, is paramount to successful MCS.

We aim to describe the clinical course of a series of patients with hypoplastic left heart syndrome and refractory systolic heart failure supported with a HeartWare ventricular assist device (HVAD) following Fontan palliation. This is a retrospective review of three consecutive patients supported with a HVAD following Fontan palliation through February 2016. Data include patient characteristics, operative variables, postimplantation hemodynamic/device parameters, event outcomes, and duration of HVAD support. Patient ages were 11.7, 13.5, and 17.5 years, respectively, at the time of HVAD implant. The duration of HVAD support was 148, 272, and 271 days, respectively, of which 86, 222, and 211 were outpatient days. Inflow cannula position was the morphologic right ventricle with depth adjustment and manipulation of the tricuspid subvalvar apparatus to ensure good inflow. Echocardiographic, hemodynamic, and noninvasive oximetric monitoring resulted in high RPM settings for all patients. Despite various complications, all patients were successfully transplanted and discharged home alive. We present three patients bridged to transplantation using the HVAD following Fontan palliation. We demonstrate potential for durable support with transition to outpatient care while awaiting heart transplantation in a subset of patients status post Fontan surgery.