Late Pulmonary Autograft Dilation: Can We Make a Good Operation Great? The Supported Ross.

The Ross procedure is an excellent option for aortic valve replacement resulting in outstanding hemodynamic performance and the ability to avoid systemic anticoagulation. The long-term durability of the autograft is generally good but concerns for later aortic root dilation with ensuing neoaortic insufficiency have prompted efforts to stabilize the autograft, root, sinuses and Sino-tubular junction in order to delay or entirely avoid late reinterventions on the neoaortic root. We have employed an inclusion technique, supporting the Auto-graft in a Terumo Gelweave™ Valsalva graft. We performed a retrospective study of all 129 patients undergoing the Ross procedure from 1992 to 2019 at Children's Wisconsin. Fifty-one underwent the supported Ross (SR) and 78 underwent unsupported Ross (UR). Structured clinical data was collected and echocardiograms were reviewed. Median follow-up was 4.9 years (up to 22.6 years) for UR patients and 3.6 years (up to 11.4 years) for SR patients. In order to provide a fair comparison, we sub -analyzed patients aged 10 to 18 years who underwent the Ross procedure, 16 who underwent the UR and 18 patients who underwent the SR. Change in aortic annulus diameter (P = 0.002), aortic sinus diameter (P = 0.001) change in left ventricular function (P = 0.039) and change in aortic insufficiency (P = 0.008) were all worse in UR. The SR is simple, reproducible, and predictable. It seems to prevent change in annulus diameter, sinus diameter and to reduce late neoaortic insufficiency. Longer follow-up with a larger group of patients is required to draw definitive conclusions.

Coarctation Duration and Severity Predict Risk of Hypertension Precursors in a Preclinical Model and Hypertensive Status Among Patients.

BACKGROUND: Coarctation of the aorta (CoA) often leads to hypertension posttreatment. Evidence is lacking for the current >20 mm Hg peak-to-peak blood pressure (BP) gradient (BPGpp) guideline, which can cause aortic thickening, stiffening, and dysfunction. This study sought to find the BPGpp severity and duration that avoid persistent dysfunction in a preclinical model and test if predictors translate to hypertension status in patients with CoA. METHODS: Rabbits (n=75; 5-12/group) were exposed to mild, intermediate, or severe CoA (≤12, 13-19, ≥20 mm Hg BPGpp) for ≈1, 3, or 22 weeks using dissolvable and permanent sutures with thickening, stiffening, contraction, and endothelial function evaluated via multivariate regression. Relevance to patients with CoA (n=239; age, 0.01-46 years; median 3.7 months) was tested by retrospective review of predictors (preoperative BPGpp, surgical age, etc.) versus follow-up hypertension status. RESULTS: CoA duration and severity were predictive of aortic remodeling and active dysfunction in rabbits, and hypertension in patients with CoA. Interaction between patient age and BPGpp at surgery contributed significantly to hypertension, similar to rabbits, suggesting preclinical findings translate to patients. Machine learning decision tree analysis uncovered that preoperative BPGpp and surgical age predict risk of hypertension along with residual postoperative BPGpp. CONCLUSIONS: These findings suggest the current BPGpp threshold determined decades ago is likely too high to prevent adverse coarctation-induced aortic remodeling. The results and decision tree analysis provide a foundation for revising CoA treatment guidelines considering the interaction between CoA severity and duration to limit the risk of hypertension.

Coarctation duration and severity predict risk of hypertension precursors in a preclinical model and hypertensive status among patients.

Background: Coarctation of the aorta (CoA) often leads to hypertension (HTN) post-treatment. Evidence is lacking for the current >20 mmHg peak-to-peak blood pressure gradient (BPGpp) guideline, which can cause aortic thickening, stiffening and dysfunction. This study sought to find the BPGpp severity and duration that avoid persistent dysfunction in a preclinical model, and test if predictors translate to HTN status in CoA patients. Methods: Rabbits (N=75; 5-12/group) were exposed to mild, intermediate or severe CoA (≤12, 13-19, ≥20 mmHg BPGpp) for ~1, 3 or 22 weeks using dissolvable and permanent sutures with thickening, stiffening, contraction and endothelial function evaluated via multivariate regression. Relevance to CoA patients (N=239; age=0.01-46 years; median 3.7 months) was tested by retrospective review of predictors (preoperative BPGpp, surgical age, etc.) vs follow-up HTN status. Results: CoA duration and severity were predictive of aortic remodeling and active dysfunction in rabbits, and HTN in CoA patients. Interaction between patient age and BPGpp at surgery contributed significantly to HTN, similar to rabbits, suggesting preclinical findings translate to patients. Machine learning decision tree analysis uncovered that pre-operative BPGpp and surgical age predict risk of HTN along with residual post-operative BPGpp. Conclusions: These findings suggest the current BPGpp threshold determined decades ago is likely too high to prevent adverse coarctation-induced aortic remodeling. The results and decision tree analysis provide a foundation for revising CoA treatment guidelines considering the interaction between CoA severity and duration to limit the risk of HTN.

The Supported vs Unsupported Ross in Pediatric Patients: Neoaortic Root and Ventricular Function.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Nuclear Cell-Free DNA Predicts Adverse Events After Pediatric Cardiothoracic Surgery.

BACKGROUND: Preoperative risk stratification in cardiac surgery includes patient and procedure factors that are used in clinical decision-making. Despite these tools, unidentified factors contribute to variation in outcomes. Identification of latent physiologic risk factors may strengthen predictive models. Nuclear cell-free DNA (ncfDNA) increases with tissue injury and drops to baseline levels rapidly. The goal of this investigation is to measure and to observe ncfDNA kinetics in children undergoing heart operations with cardiopulmonary bypass (CPB), linking biomarkers, organ dysfunction, and outcomes. METHODS: This is a prospective observational study of 116 children <18 years and >3 kg undergoing operations with CPB. Plasma ncfDNA samples were collected and processed in a stepwise manner at predefined perioperative time points. The primary outcome measure was occurrence of postoperative cardiac arrest or extracorporeal membrane oxygenation. RESULTS: Data were available in 116 patients (median age, 0.9 years [range, 0-17.4 years]; median weight, 7.8 kg [range, 3.2-98 kg]). The primary outcome was met in 6 of 116 (5.2%). Risk of primary outcome was 2% with ncfDNA <20 ng/mL and 33% with ncfDNA >20 ng/mL (odds ratio, 25; CI, 3.96-158; P = .001). Elevated ncfDNA was associated with fewer hospital-free days (P < .01). CONCLUSIONS: This study analyzes ncfDNA kinetics in children undergoing operations with CPB for congenital heart disease. Elevated preoperative ncfDNA is strongly associated with postoperative arrest and extracorporeal membrane oxygenation. Further studies are needed to validate this technology as a tool to predict morbidity in children after cardiac surgical procedures.

Outcomes Following Surgery to Address Shone Syndrome in Children.

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.

Comparison of Patch Materials for Pulmonary Artery Reconstruction.

Various patch materials with variable cost are used for pulmonary artery reconstruction. An analysis of reintervention based on type of patch material might inform value-based decision making. This was a retrospective review of 214 sites of pulmonary artery reconstruction at a single center from 2000 to 2014. We excluded patients with unifocalization of aortopulmonary collaterals. Primary outcome was reintervention for each type of patch. Total number of patch sites was 214 (180 patients). Median follow-up was 3.7 years. Patch materials and number of sites were branch patch homograft (92), bovine pericardium (44), autologous pericardium (41), and porcine intestinal submucosal patch (37). Median age and weight at the time of patch reconstruction were 12.1 months and 8.5 kg. Reintervention occurred at 34 sites (15.9%). With Cox proportional hazards regression, the following variables were associated with reinterevention: preoperative renal failure - hazard ratio of 4.36 (1.87-10.16), P < 0.001 and weight at surgery - hazard ratio 0.93 (0.89-0.98), P = 0.004. Patch type was not related to reintervention (P = 0.197). Cost per unit patch ranged from $0 (dollars, US) for untreated autologous pericardium to $6,105 for homograft branch patch. In this retrospective analysis, there was no relationship between type of patch used for main or central branch pulmonary artery reconstruction and subsequent reintervention on that site. This finding, combined with the widely disparate costs of patches, may help inform value-based decision making.

Interventions Associated With Treatment of Low Cardiac Output After Stage 1 Norwood Palliation.

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.