Comparing apples to apples: Exploring public reporting of congenital cardiac surgery outcomes based on common congenital heart operations

OBJECTIVE

We sought to simplify reporting of outcomes in congenital heart surgery that compares well-defined patient groups and accommodates multiple stakeholder needs while being easily understandable.

METHODS

We selected 19 commonly performed congenital heart surgeries ranging in complexity from repair of atrial septal defects to the Norwood procedure. Strict inclusion/exclusion criteria ensured the creation of 19 well-defined diagnosis/procedure cohorts. Preoperative, procedural, and postoperative data were collected for consecutive eligible patients from 9 centers between January 1, 2016, and December 31, 2021. Unadjusted operative mortality rates and hospital length of stay for each of the 19 diagnosis/procedure cohorts were summarized in aggregate and stratified by each center.

RESULTS

Of 8572 eligible cases included, numbers in the 19 diagnosis/procedure cohorts ranged from 73 for tetralogy of Fallot repair after previous palliation to 1224 for ventricular septal defect (VSD) repair for isolated VSD. In aggregate, the unadjusted mortality ranged from 0% for atrial septal defect repair to 28.4% for hybrid stage I. There was significant heterogeneity in case mix and mortality for different diagnosis/procedure cohorts across centers (eg, arterial switch operation/VSD, n = 7-42, mortality 0%-7.4%; Norwood procedure, n = 16-122, mortality 5.3%-25%).

CONCLUSIONS

Reporting of institutional case volumes and outcomes within well-defined diagnosis/procedure cohorts can enable centers to benchmark outcomes, understand trends in mortality, and direct quality improvement. When made public, this type of report could provide parents with information on institutional volumes and outcomes and allow them to better understand the experience of each program with operations for specific congenital heart defects.

Right ventricular papillary muscle approximation to the septum as an adjunct technique during tricuspid valve repair in congenital heart surgery

OBJECTIVE

Tricuspid regurgitation is often caused by leaflet splaying from displaced papillary muscles or ventricular dilatation. Traditional annuloplasty may not address this mechanism. The present study describes a single institution's experience using right ventricular papillary muscle approximation for tricuspid valve repair.

METHODS

Right ventricular papillary muscle approximation consists of suturing the anterior papillary muscle to a point of the septum (septum or septal papillary muscle) that optimizes leaflet coaptation. We describe our technique and analyze clinical data of patients undergoing tricuspid valve repair with right ventricular papillary muscle approximation during congenital heart surgery between 2012 and 2021.

RESULTS

Right ventricular papillary muscle approximation was performed as an adjunct procedure in 207 of 825 tricuspid valve repairs (25.1%). Discharge tricuspid regurgitation grade was mild tricuspid regurgitation or less in 153 patients (73.9%), and 140 patients (67.6%) had mild tricuspid regurgitation or less at a median latest follow-up of 3.2 years (interquartile range, 0.7-6.8). Thirty patients (14.5%) underwent 11 early tricuspid valve reinterventions (3 due to right ventricular papillary muscle approximation dehiscence) and 21 late tricuspid valve reinterventions. Estimated 5-year freedom from tricuspid valve reintervention was 84% (95% CI, 77.0-89.2). Systemic right ventricle physiology (odds ratio, 2.88, P = .048) and multiple mechanisms of tricuspid regurgitation (odds ratio, 7.35, P = .038) were significant predictors of tricuspid valve reintervention on multivariable analysis.

CONCLUSIONS

Tricuspid valve repair with right ventricular papillary muscle approximation demonstrates acceptable short-term durability, but similar to other tricuspid valve repair strategies is less durable in patients with systemic right ventricle pressure and multiple mechanisms of tricuspid regurgitation. Right ventricular papillary muscle approximation is a safe and effective adjunct technique that should be considered in patients with tricuspid regurgitation caused by leaflet splaying from displaced papillary muscles or right ventricle dilatation.

Impact of Age-Related Change in Caval Flow Ratio on Hepatic Flow Distribution in the Fontan Circulation

BACKGROUND

The Fontan operation is a palliative technique for patients born with single ventricle heart disease. The superior vena cava (SVC), inferior vena cava (IVC), and hepatic veins are connected to the pulmonary arteries in a total cavopulmonary connection by an extracardiac conduit or a lateral tunnel connection. A balanced hepatic flow distribution (HFD) to both lungs is essential to prevent pulmonary arteriovenous malformations and cyanosis. HFD is highly dependent on the local hemodynamics. The effect of age-related changes in caval inflows on HFD was evaluated using cardiac magnetic resonance data and patient-specific computational fluid dynamics modeling.

METHODS

SVC and IVC flow from 414 patients with Fontan were collected to establish a relationship between SVC:IVC flow ratio and age. Computational fluid dynamics modeling was performed in 60 (30 extracardiac and 30 lateral tunnel) patient models to quantify the HFD that corresponded to patient ages of 3, 8, and 15 years, respectively.

RESULTS

SVC:IVC flow ratio inverted at ≈8 years of age, indicating a clear shift to lower body flow predominance. Our data showed that variation of HFD in response to age-related changes in caval inflows (SVC:IVC, 2, 1, and 0.5 corresponded to ages, 3, 8, and 15+, respectively) was not significant for extracardiac but statistically significant for lateral tunnel cohorts. For all 3 caval inflow ratios, a positive correlation existed between the IVC flow distribution to both the lungs and the HFD. However, as the SVC:IVC ratio changed from 2 to 0.5 (age, 3-15+) years, the correlation's strength decreased from 0.87 to 0.64, due to potential flow perturbation as IVC flow momentum increased.

CONCLUSIONS

Our analysis provided quantitative insights into the impact of the changing caval inflows on Fontan's long-term HFD, highlighting the importance of SVC:IVC variations over time on Fontan's long-term hemodynamics. These findings broaden our understanding of Fontan hemodynamics and patient outcomes.

Erector spinae plane blocks for opioid-sparing multimodal pain management after pediatric cardiac surgery

OBJECTIVE

Peripheral regional anesthesia is proposed to enhance recovery. We sought to evaluate the efficacy of bilateral continuous erector spinae plane blocks (B-ESpB) for postoperative analgesia and the impact on recovery in children undergoing cardiac surgery.

METHODS

Patients aged 2 through 17 years undergoing cardiac surgery in the enhanced recovery after cardiac surgery program were prospectively enrolled to receive B-ESpB at the end of the procedure, with continuous infusions via catheters postoperatively. Participants wore an activity monitor until discharge. B-ESpB patients were retrospectively matched with control patients in the enhanced recovery after cardiac surgery program. Outcomes of the matched clusters were compared using exact conditional logistic regression and generalized linear modeling.

RESULTS

Forty patients receiving B-ESpB were matched to 78 controls. There were no major complications from the B-ESpB or infusions, and operating room time was longer by a median of 31 minutes. While blocks were infusing, patients with B-ESpB received fewer opioids in oral morphine equivalents than controls at 24 hours (0.60 ± 0.06 vs 0.78 ± 0.04 mg/kg; P = .02) and 48 hours (1.13 ± 0.08 vs 1.35 ± 0.06 mg/kg; P = .04), respectively. Both groups had low median pain scores per 12-hour period. There was no difference in early mobilization, length of stay, or complications.

CONCLUSIONS

B-ESpBs are safe in children undergoing cardiac surgery. When performed as part of a multimodal pain strategy in an enhanced recovery after cardiac surgery program, pediatric patients with B-ESpB experience good pain control and require fewer opioids in the first 48 hours.

Association of tetralogy of Fallot and complete atrioventricular canal: a single-centre 40-year experience

OBJECTIVES

Outcome data in tetralogy of Fallot (ToF) and complete atrioventricular canal (CAVC) are limited. We report our experience for over 40 years in this patient population.

METHODS

Single-centre, retrospective analysis of patients who underwent surgical repair with the diagnosis of ToF-CAVC from 1979 to 2022, divided into 2 different periods and compared.

RESULTS

A total of 116 patients were included: 1979-2007 (n = 61) and 2008-2021 (n = 55). Balanced CAVC (80%) and Rastelli type C CAVC (81%) were most common. Patients in the later era were younger (4 vs 14 months, P < 0.001), fewer had trisomy 21 (60% vs 80%, P = 0.019) and fewer had prior palliative prior procedures (31% vs 43%, P < 0.001). In the earlier era, single-patch technique was more common (62% vs 16%, P < 0.001), and in recent era, double-patch technique was more common (84% vs 33%, P < 0.001). In the earlier era, right ventricular outflow tract was most commonly reconstructed with transannular patch (51%), while in more recent era, valve-sparing repairs were more common (69%) (P < 0.001). In-hospital mortality was 4.3%. The median follow-up was 217 and 74 months for the first and second eras. Survival for earlier and later eras at 2-, 5- and 10-year follow-up was (85.1%, 81.5%, 79.6% vs 94.2%, 94.2%, 94.2% respectively, log-rank test P = 0.03).

CONCLUSIONS

The surgical approach to ToF-CAVC has evolved over time. More recently, patients tended to receive primary repair at younger ages and had fewer palliative procedures. Improved surgical techniques allowing for earlier and complete repair have shown a decrease in mortality, more valve-sparing procedures without an increase in total reoperations. Presented at the 37th EACTS Annual Meeting, Vienna, Austria.

Prognostic utility of a novel risk prediction model of 1-year mortality in patients surviving to discharge after surgery for congenital or acquired heart disease

OBJECTIVE

We sought to develop a novel risk prediction model of 1-year mortality after congenital heart surgery that accounts for clinical, anatomic, echocardiographic, and socioeconomic factors.

METHODS

This was a single-center, retrospective review of consecutive index operations for congenital or acquired heart disease, from January 2011 to January 2021, among patients with known survival status at 1 year after discharge from the index hospitalization. The primary outcome was postdischarge mortality at 1 year. Variables of interest included age, prematurity, noncardiac anomalies or syndromes, the Childhood Opportunity Index, primary procedure, major adverse postoperative complications, and the Residual Lesion Score. Logistic regression was used to develop a weighted risk score for the primary outcome. Internal validation using a bootstrap-resampling approach was performed.

RESULTS

Of 10,412 consecutive operations for congenital or acquired heart disease, 8808 (84.6%) cases met entry criteria, including survival to discharge. There were 190 (2.2%) deaths at 1 year postdischarge. A weighted risk score was formulated on the basis of the variables in the final risk prediction model, which included all aforementioned risk factors of interest. This model had a C-statistic of 0.82 (95% confidence interval, 0.80-0.85). The median risk score was 6 (interquartile range, 4-8) points. Patients were categorized as low (score 0-5), medium (score 6-10), high (score 11-15), or very high (score 16-20) risk. The expected probability of mortality was 0.4% ± 0.2%, 2.0% ± 1.1%, 10.1% ± 5.0%, and 36.6% ± 9.6% for low-risk, medium-risk, high-risk, and very high-risk patients, respectively.

CONCLUSIONS

A risk prediction model of 1-year mortality may guide prognostication and follow-up of patients after discharge after surgery for congenital or acquired heart disease.

Growth of the Neo-Aortic Root and Prognosis of Transposition of the Great Arteries

BACKGROUND

Neo-aortic root dilatation can lead to significant late morbidity after the arterial switch operation (ASO) for dextro-transposition of the great arteries (d-TGA).

OBJECTIVES

We sought to examine the growth of the neo-aortic root in d-TGA.

METHODS

A single-center, retrospective cohort study of patients who underwent the ASO between July 1, 1981 and September 30, 2022 was performed. Morphology was categorized as dextro-transposition of the great arteries with intact ventricular septum (d-TGA-IVS), dextro-transposition of the great arteries with ventricular septal defect (d-TGA-VSD), and double-outlet right ventricle-transposition of the great arteries type (DORV-TGA). Echocardiographically determined diameters and derived z scores were measured at the annulus, sinus of Valsalva, and sinotubular junction immediately before the ASO and throughout follow-up. Trends in root dimensions over time were assessed using linear mixed-effects models. The association between intrinsic morphology and the composite of moderate-severe aortic regurgitation (AR) and neo-aortic valve or root intervention was evaluated with univariable and multivariable Cox proportional hazards models.

RESULTS

Of 1,359 patients who underwent the ASO, 593 (44%), 666 (49%), and 100 (7%) patients had d-TGA-IVS, d-TGA-VSD, and DORV-TGA, respectively. Each patient underwent a median of 5 echocardiograms (Q1-Q3: 3-10 echocardiograms) over a median follow-up of 8.6 years (range: 0.1-39.3 years). At 30 years, patients with DORV-TGA demonstrated greater annular (P < 0.001), sinus of Valsalva (P = 0.039), and sinotubular junction (P = 0.041) dilatation relative to patients with d-TGA-IVS. On multivariable analysis, intrinsic anatomy, older age at ASO, at least mild AR at baseline, and high-risk root dilatation were associated with moderate-severe AR and neo-aortic valve or root intervention at late follow-up (all P < 0.05).

CONCLUSIONS

Longitudinal surveillance of the neo-aortic root is warranted long after the ASO.

Mitochondrial transplantation preserves myocardial function and viability in pediatric and neonatal pig hearts donated after circulatory death

OBJECTIVE

Mitochondrial transplantation has been shown to preserve myocardial function and viability in adult porcine hearts donated after circulatory death (DCD) . Herein, we investigate the efficacy of mitochondrial transplantation for the preservation of myocardial function and viability in neonatal and pediatric porcine DCD heart donation.

METHODS

Circulatory death was induced in neonatal and pediatric Yorkshire pigs by cessation of mechanical ventilation. Hearts underwent 20 or 36 minutes of warm ischemia time (WIT), 10 minutes of cold cardioplegic arrest, and then were harvested for ex situ heart perfusion (ESHP). Following 15 minutes of ESHP, hearts received either vehicle (VEH) or vehicle containing isolated autologous mitochondria (MITO). A sham nonischemic group (SHAM) did not undergo WIT, mimicking donation after brain death heart procurement. Hearts underwent 2 hours each of unloaded and loaded ESHP perfusion.

RESULTS

Following 4 hours of ESHP perfusion, left ventricle developed pressure, dP/dt max, and fractional shortening were significantly decreased (P < .001) in DCD hearts receiving VEH compared with SHAM hearts. In contrast, DCD hearts receiving MITO exhibited significantly preserved left ventricle developed pressure, dP/dt max, and fractional shortening (P < .001 each vs VEH, not significant vs SHAM). Infarct size was significantly decreased in DCD hearts receiving MITO as compared with VEH (P < .001). Pediatric DCD hearts subjected to extended WIT demonstrated significantly preserved fractional shortening and significantly decreased infarct size with MITO (P < .01 each vs VEH).

CONCLUSIONS

Mitochondrial transplantation in neonatal and pediatric pig DCD heart donation significantly enhances the preservation of myocardial function and viability and mitigates against damage secondary to extended WIT.

Postoperative Troponin Levels in Children Undergoing Open Heart Surgery With and Without Coronary Intervention

We aimed to characterize the ranges, temporal trends, influencing factors, and prognostic significance of postoperative troponin levels after congenital heart surgery. This single-center retrospective study included patients from 2006 to 2021 who had ≥ 1 postoperative troponin-T measurement collected within 96 h of congenital heart surgery (CHS). Patients were grouped as Anomalous Aortic Origin of the Coronary Artery-"AAOCA repair," or congenital heart surgery with "Other Coronary Interventions" other than AAOCA repair, or "No Coronary Intervention." In each group, information on concomitant surgery requiring one or more of the following-atriotomy, ventriculotomy, right ventricular muscle bundle resection, and/or septal myectomy-was collected. Clinical correlates of troponin values were analyzed in three postoperative windows: < 8, 8-24, and 24-48 h. The highest median [range] troponin levels (ng/mL) for the samples were 0.34 [0.06, 1.32] at < 8 h for "AAOCA repair," 1.35 [0.14, 12.0] at < 8 h for those undergoing CHS with "Other Coronary Interventions," and 0.87 [0.06, 25.1] at 8-24 h for those undergoing CHS with "No Coronary Interventions." Atriotomy was associated with higher median troponin levels in the AAOCA group at < 8 h (0.40 [0.31, 0.77] vs. 0.29 [0.17, 0.54], P = 0.043) and in the Other Coronary Intervention group at 8-24 h (1.67 [1.04, 2.63] vs. 0.40 [0.19, 1.32], P = 0.002). Patients experiencing major postoperative complications (vs. those who did not) had higher troponin levels in the AAOCA group as early as 8-24 h (0.36 [0.24, 0.57] vs. 0.21 [0.14, 0.33], P = 0.03). Similar findings were noted in the Coronary Intervention (2.20 [1.34, 3.90] vs. 1.11 [0.51, 2.90], P = 0.028) and No Coronary Intervention (2.2 [1.49, 15.1] vs. 0.74 [0.40, 2.34], P = 0.027) groups but earlier at < 8 h. In the AAOCA group, 2/18 (11%) troponin outliers experienced cardiac arrest in comparison to 0/80 (0%) non-outliers (P = 0.032). In the Other Coronary Intervention group, troponin outliers had longer median times to ICU discharge (10 vs. 4 days) and hospital discharge (21 vs. 10 days) (both P < 0.001). Postoperative troponin levels depend on a multitude of factors and may have prognostic value in patients undergoing congenital heart surgery with coronary interventions.

Transcatheter Palliation With Pulmonary Artery Flow Restrictors in Neonates With Congenital Heart Disease: Feasibility, Outcomes, and Comparison With a Historical Hybrid Stage 1 Cohort

BACKGROUND

Neonates with complex congenital heart disease and pulmonary overcirculation have been historically treated surgically. However, subcohorts may benefit from less invasive procedures. Data on transcatheter palliation are limited.

METHODS

We present our experience with pulmonary flow restrictors (PFRs) for palliation of neonates with congenital heart disease, including procedural feasibility, technical details, and outcomes. We then compared our subcohort of high-risk single ventricle neonates palliated with PFRs with a similar historical cohort who underwent a hybrid Stage 1. Cox regression was used to evaluate the association between palliation strategy and 6-month mortality.

RESULTS

From 2021 to 2023, 17 patients (median age, 4 days; interquartile range [IQR], 2-8; median weight, 2.5 kilograms [IQR, 2.1-3.3]) underwent a PFR procedure; 15 (88%) had single ventricle physiology; 15 (88%) were high-risk surgical candidates. All procedures were technically successful. At a median follow-up of 6.2 months (IQR, 4.0-10.8), 13 patients (76%) were successfully bridged to surgery (median time since PFR procedure, 2.6 months [IQR, 1.1-4.4]; median weight, 4.9 kilograms [IQR, 3.4-5.8]). Pulmonary arteries grew adequately for age, and devices were easily removed without complications. The all-cause mortality rate before target surgery was 24% (n=4). Compared with the historical hybrid stage 1 cohort (n=23), after adjustment for main confounding (age, weight, intact/severely restrictive atrial septum or left ventricle to coronary fistulae), the PFR procedure was associated with a significantly lower all-cause 6-month mortality risk (adjusted hazard ratio, 0.26 [95% CI, 0.08-0.82]).

CONCLUSIONS

Transcatheter palliation with PFR is feasible, safe, and represents an effective strategy for bridging high-risk neonates with congenital heart disease to surgical palliation, complete repair, or transplant while allowing for clinical stabilization and somatic growth.

Natural history of aortic root dilatation and pathologic aortic regurgitation in tetralogy of Fallot and its morphological variants

OBJECTIVE

We sought to characterize the natural history of aortic root dilatation and aortic regurgitation in tetralogy of Fallot (TOF).

METHODS

A single-center review of patients who underwent TOF repair from January 1960 to December 2022 was performed. Morphology was categorized as TOF-pulmonary stenosis or TOF-variant (including TOF-pulmonary atresia and TOF-pulmonary atresia-major aortopulmonary collateral arteries). Echocardiographically determined diameters and derived z scores were measured at the annulus, sinus of Valsalva, and sinotubular junction immediately before TOF repair and throughout follow-up. Linear mixed-effects models assessed trends in dimensions over time.

RESULTS

Of 2205 patients who underwent primary repair of TOF at a median age of 4.9 months (interquartile range, 2.3-20.5 months) and survived to discharge, 1608 (72.9%) patients had TOF-pulmonary stenosis and 597 (27.1%) patients had TOF-variant. At a median postoperative follow-up of 14.4 years (interquartile range, 3.3-27.6 years; range, 0.1-62.6 years), 313 (14.2%) patients had mild or greater aortic regurgitation and 34 (1.5%) patients required an aortic valve or root intervention. The overall mean rates of annular, sinus of Valsalva, and sinotubular junction growth were 0.5 ± 0.2, 0.6 ± 0.3, and 0.7 ± 0.5 mm/year, respectively. Root z scores remained stable with time. At baseline, patients with TOF-variant had larger diameters and z scores at the annulus, sinus of Valsalva, and sinotubular junction, compared with patients with TOF-pulmonary stenosis (all P values < .05). Over time, patients with TOF-variant demonstrated relatively greater annular (P = .020), sinus of Valsalva (P < .001), and sinotubular junction (P < .001) dilatation. Patients with ≥75th percentile root growth rates had a higher incidence of mild or greater aortic regurgitation (P < .001), moderate or greater aortic regurgitation (P < .001), and aortic valve repair or replacement (P = .045).

CONCLUSIONS

Patients with TOF-variant are at comparatively greater risk of pathologic root dilatation over time, warranting closer longitudinal follow-up.

Prognostic Utility of a Risk Prediction Model for Pre-Discharge Major Residual Lesions or Unplanned Reinterventions Following Congenital Mitral Valve Repair

OBJECTIVE

We sought to develop a risk prediction model for pre-discharge major mitral valve (MV) residual lesions or unplanned MV reinterventions following congenital MV repair.

METHODS

Patients that underwent congenital MV repair (excluding primary repair, but including secondary repair, of canal-type defects) at a single institution from 01/2000-12/2020 and survived to discharge were retrospectively reviewed. The primary outcome was major MV residua (mean gradient >6 mmHg or ≥moderate regurgitation on the discharge echocardiogram) or pre-discharge unplanned MV reintervention. Risk factors of interest included age, single ventricle physiology, preoperative and intraoperative post-repair MV stenosis and regurgitation severity, MV annular diameter z-score, systemic ventricle ejection fraction, unfavorable anatomy, concomitant left-heart procedure, and various technique-related categories. Logistic regression was used to develop a weighted risk score for the primary outcome. Internal validation using bootstrap-resampling was performed.

RESULTS

Of 866 patients that underwent congenital MV repair at a median age of 2.7 (IQR 0.7-9.1) years, 202 (23.3%) patients developed the primary outcome. The final risk prediction model had a C-statistic of 0.82 (95% CI 0.78-0.85). A weighted risk score was formulated per the variables in this model. The median risk score was 8 (IQR 6-11) points. Patients were categorized as low (score 0-5), medium (score 6-10), high (score 11-15), or very high (score ≥16) risk. The probability of the primary outcome was 5.0±1.7%, 15.2±6.7%, 45.9±12.6%, and 76.7±8.8% for low, medium, high, and very high risk patients, respectively.

CONCLUSIONS

Our risk prediction model may guide prognostication of patients following congenital MV repair.

Model of Ischemia and Reperfusion Injury in Rabbits

The protocol here provides a simple, highly replicable methodology to induce in situ acute regional myocardial ischemia in the rabbit for non-survival and survival experiments. New Zealand White adult rabbit is sedated with atropine, acepromazine, butorphanol, and isoflurane. The animal is intubated and placed on mechanical ventilation. An intravenous catheter is inserted into the marginal ear vein for the infusion of medications. The animal is pre-medicated with heparin, lidocaine, and lactated Ringer's solution. A carotid cut-down is performed to obtain arterial line access for blood pressure monitoring. Select physiologic and mechanical parameters are monitored and recorded by continuous real-time analysis. With the animal sedated and fully anesthetized, either a fourth intercostal space small left thoracotomy (survival) or midline sternotomy (non-survival) is performed. The pericardium is opened, and the left anterior descending (LAD) artery is located. A polypropylene suture is passed around the second or third diagonal branch of the LAD artery, and the polypropylene filament is threaded through a small vinyl tube, forming a snare. The animal is subjected to 30 min of regional ischemia, achieved by occluding the LAD by tightening the snare. Myocardial ischemia is confirmed visually by regional cyanosis of the epicardium. Following regional ischemia, the ligature is loosened, and the heart is allowed to re-perfuse. For both survival and non-survival experiments, the myocardial function can be assessed via an echocardiography (ECHO) measurement of the fractional shortening. For non-survival studies, data from sonomicrometry collected using three digital piezoelectric ultrasonic probes implanted within the ischemic area and the left ventricle developed pressure (LVDP) using an apically inserted left ventricle (LV) catheter can be continuously acquired for evaluating the regional and global myocardial function, respectively. For survival studies, the incision is closed, a left needle thoracentesis is performed for pleural air evacuation, and postoperative pain control is achieved.

A Risk Prediction Model for Reintervention After Total Anomalous Pulmonary Venous Connection Repair

BACKGROUND

Outcomes after total anomalous pulmonary venous connection (TAPVC) repair remain suboptimal due to recurrent pulmonary vein (PV) obstruction requiring reinterventions. We sought to develop a clinical prediction rule for PV reintervention after TAPVC repair.

METHODS

Data from consecutive patients who underwent TAPVC repair at a single institution from January 1980 to January 2020 were retrospectively reviewed after Institutional Review Board approval. The primary outcome was postdischarge (late) unplanned PV surgical or transcatheter reintervention. Echocardiographic criteria were used to assess PV residual lesion severity at discharge (class 1: no residua; class 2: minor residua; class 3: major residua). Competing risk models were used to develop a weighted risk score for late reintervention.

RESULTS

Of 437 patients who met entry criteria, there were 81 (18.5%) reinterventions at a median follow-up of 15.6 (interquartile range, 5.5-22.2) years. On univariable analysis, minor and major PV residua, age, single-ventricle physiology, infracardiac and mixed TAPVC, and preoperative obstruction were associated with late reintervention (all P < .05). The final risk prediction model included PV residua (class 2: subdistribution hazard ratio [SHR], 4.8; 95% CI, 2.8-8.1; P < .001; class 3: SHR, 6.4; 95% CI, 3.5-11.7; P < .001), age <1 year (SHR, 3.3; 95% CI, 1.3-8.5; P = .014), and preoperative obstruction (SHR, 1.8; 95% CI, 1.1-2.8; P = .015). A risk score comprising PV residua (class 2 or 3: 3 points), age (neonate or infant: 2 points), and obstruction (1 point) was formulated. Higher risk scores were significantly associated with worse freedom from reintervention (P < .001).

CONCLUSIONS

A risk prediction model of late reintervention may guide prognostication of high-risk patients after TAPVC repair.

Impact of Residual Lesion Severity on Neurodevelopmental Outcomes Following Congenital Heart Surgery in Infancy and Childhood

Children with congenital heart disease are at increased risk of neurodevelopmental delay throughout their lifespan. This risk is exacerbated following congenital heart surgery (CHS) in infancy. However, there are few modifiable risk factors for postoperative neurodevelopmental delay. In this study, we assessed the Residual Lesion Score (RLS), a quality assessment metric that evaluates residual lesion severity following CHS, as a predictor of neurodevelopmental delay. This was a single-center, retrospective review of patients who underwent CHS from 01/2011 to 03/2021 and post-discharge neurodevelopmental evaluation from 12 to 42 months of age using the Bayley Scales of Infant Development, 3rd Edition (BSID-III). RLS was assigned per published criteria: RLS 1, no residua; RLS 2, minor residua; and RLS 3, major residua or pre-discharge reintervention. Associations between RLS and BSID-III scores, as well as trends in neurodevelopmental outcomes over time, were evaluated. Of 517 patients with median age at neurodevelopmental testing of 20.0 (IQR 18.0-22.7) months, 304 (58.8%), 146 (28.2%), and 67 (13.0%) were RLS 1, 2, and 3, respectively. RLS 3 patients had significantly lower scaled scores in the cognitive, receptive, and expressive communication, and fine and gross motor domains, compared with RLS 1 patients. Multivariable models accounted for 21.5%-31.5% of the variation in the scaled scores, with RLS explaining 1.4-7.3% of the variation. In a subgroup analysis, RLS 3 patients demonstrated relatively fewer gains in cognitive, expressive communication, and gross motor scores over time (all p < 0.05). In conclusion, RLS 3 patients are at increased risk for neurodevelopmental delay, warranting closer follow-up and greater developmental support for cognitive, language, and motor skills soon after surgery.

A Neonatal Heterotopic Rat Heart Transplantation Model for the Study of Endothelial-to-Mesenchymal Transition

Endocardial fibroelastosis (EFE), defined by subendocardial tissue accumulation, has major impacts on the development of the left ventricle (LV) and precludes patients with congenital critical aortic stenosis and hypoplastic left heart syndrome (HLHS) from curative anatomical biventricular surgical repair. Surgical resection is currently the only available therapeutic option, but EFE often recurs, sometimes with an even more infiltrative growth pattern into the adjacent myocardium. To better understand the underlying mechanisms of EFE and to explore therapeutic strategies, an animal model suitable for preclinical testing was developed. The animal model takes into consideration that EFE is a disease of the immature heart and is associated with flow disturbances, as supported by clinical observations. Thus, the heterotopic heart transplantation of neonatal rat donor hearts is the basis for this model. A neonatal rat heart is transplanted into an adolescent rat's abdomen and connected to the recipient's infrarenal aorta and inferior vena cava. While perfusion of the coronary arteries preserves the viability of the donor heart, flow stagnation within the LV induces EFE growth in the very immature heart. The underlying mechanism of EFE formation is the transition of endocardial endothelial cells to mesenchymal cells (EndMT), which is a well-described mechanism of early embryonic development of the valves and septa but also the leading cause of fibrosis in heart failure. EFE formation can be macroscopically observed within days after transplantation. Transabdominal echocardiography is used to monitor the graft viability, contractility, and the patency of the anastomoses. Following euthanasia, the EFE tissue is harvested, and it shows the same histopathological characteristics as human EFE tissue from HLHS patients. This in vivo model allows for studying the mechanisms of EFE development in the heart and testing treatment options to prevent this pathological tissue formation and provides the opportunity for a more generalized examination of EndMT-induced fibrosis.

Natural History of Truncal Root Dilatation and Truncal Valve Regurgitation in Truncus Arteriosus

BACKGROUND

The natural history of the dilated truncal root in repaired truncus arteriosus (TA) is incompletely understood.

METHODS

A single-center review of patients who underwent TA repair between January 1984 and December 2018 was performed. Echocardiographically determined root diameters and derived z scores were measured at the annulus, sinus of Valsalva (SoV), and sinutubular junction (STJ) immediately before TA repair and throughout follow-up. Linear mixed-effects models assessed trends in root dimensions over time.

RESULTS

Of 193 patients who underwent TA repair at a median age of 12 days (interquartile range, 6-48 days) and survived to discharge, 34 (17.6%), 110 (57.0%), and 49 (25.4%) patients had bicuspid, tricuspid, and quadricuspid truncal valves, respectively. Median postoperative follow-up was 11.6 years (interquartile range, 4.4-22.0 years; range, 0.1-34.8 years). Truncal valve or root intervention was required in 38 patients (19.7%). The mean rates of annular, SoV, and STJ growth were 0.7 ± 0.3 mm/y, 0.8 ± 0.5 mm/y, and 0.9 ± 0.4 mm/y, respectively. Root z scores remained stable with time. At baseline, compared with patients with tricuspid leaflet anatomy, bicuspid patients had larger diameters at the SoV (P = .003) and STJ (P = .029), whereas quadricuspid patients had larger STJ diameters (P = .004). Over time, the bicuspid and quadricuspid cohorts demonstrated comparatively greater annular dilatation (both P < .05). Patients with ≥75th percentile root growth rates had a higher incidence of moderate-severe truncal regurgitation (P = .019) and truncal valve intervention (P = .002).

CONCLUSIONS

Root dilatation in TA persisted for up to 30 years after primary repair. Patients with bicuspid and quadricuspid truncal valves demonstrated greater root dilatation over time and required more valve interventions. Continued longitudinal follow-up is warranted in this higher-risk cohort.

Impact of Neighborhood Socioeconomic Status on Outcomes Following First-Stage Palliation of Single Ventricle Heart Disease

Background The impact of neighborhood socioeconomic status (SES) on outcomes following first-stage palliation of single ventricle heart disease remains incompletely characterized. Methods and Results This was a single-center, retrospective review of consecutive patients who underwent the Norwood procedure from January 1, 1997 to November 11, 2017. Outcomes of interest included in-hospital (early) mortality or transplant, postoperative hospital length-of-stay, inpatient cost, and postdischarge (late) mortality or transplant. The primary exposure was neighborhood SES, assessed using a composite score derived from 6 US census-block group measures related to wealth, income, education, and occupation. Associations between SES and outcomes were assessed using logistic regression, generalized linear, or Cox proportional hazards models, adjusting for baseline patient-related risk factors. Of 478 patients, there were 62 (13.0%) early deaths or transplants. Among 416 transplant-free survivors at hospital discharge, median postoperative hospital length-of-stay and cost were 24 (interquartile range, 15-43) days and $295 000 (interquartile range, $193 000-$563 000), respectively. There were 97 (23.3%) late deaths or transplants. On multivariable analysis, patients in the lowest SES tertile had greater risk of early mortality or transplant (odds ratio [OR], 4.3 [95% CI, 2.0-9.4; P<0.001]), had longer hospitalizations (coefficient 0.4 [95% CI, 0.2-0.5; P<0.001]), incurred higher costs (coefficient 0.5 [95% CI, 0.3-0.7; P<0.001]), and had greater risk of late mortality or transplant (hazard ratio, 2.2 [95% CI, 1.3-3.7; P=0.004]), compared with those in the highest tertile. The risk of late mortality was partially attenuated with successful completion of home monitoring programs. Conclusions Lower neighborhood SES is associated with worse transplant-free survival following the Norwood operation. This risk persists throughout the first decade of life and may be mitigated with successful completion of interstage surveillance programs.

Mitochondrial transplantation: Effects on chemotherapy in prostate and ovarian cancer cells in vitro and in vivo

Prostate and ovarian cancers affect the male and female reproductive organs and are among the most common cancers in developing countries. Previous studies have demonstrated that cancer cells have a high rate of aerobic glycolysis that is present in nearly all invasive human cancers and persists even under normoxic conditions. Aerobic glycolysis has been correlated with chemotherapeutic resistance and tumor aggressiveness. These data suggest that mitochondrial dysfunction may confer a significant proliferative advantage during the somatic evolution of cancer. In this study we investigated the effect of direct mitochondria transplantation on cancer cell proliferation and chemotherapeutic sensitivity in prostate and ovarian cancer models, both in vitro and in vivo. Our results show that the transplantation of viable, respiration competent mitochondria has no effect on cancer cell proliferation but significantly decreases migration and alters cell cycle checkpoints. Our results further demonstrate that mitochondrial transplantation significantly increases chemotherapeutic sensitivity, providing similar apoptotic levels with low-dose chemotherapy as that achieved with high-dose chemotherapy. These results suggest that mitochondria transplantation provides a novel approach for early prostate and ovarian cancer therapy, significantly increasing chemotherapeutic sensitivity in in vitro and in vivo murine models.

Timing of reintervention influences survival and resource utilization following first-stage palliation of single ventricle heart disease

OBJECTIVE

Outcomes after first-stage palliation of single-ventricle heart disease are influenced by many factors, including the presence of residual lesions requiring reintervention. However, there is a dearth of information regarding the optimal timing of reintervention. We assessed if earlier reintervention would be favorably associated with in-hospital outcomes among patients requiring unplanned reinterventions after the Norwood operation.

METHODS

This was a single-center, retrospective review of all patients who underwent the Norwood procedure from January 1997 to November 2017 and required a predischarge unplanned surgical or transcatheter reintervention on 1 or more subcomponent areas repaired at the index operation. Outcomes of interest included in-hospital mortality or transplant, postoperative hospital length of stay, and inpatient cost. Associations between timing of reintervention and outcomes were assessed using logistic regression (mortality or transplant) or generalized linear models (postoperative hospital length of stay and cost), adjusting for baseline patient-related and procedural factors.

RESULTS

Of 500 patients who underwent the Norwood operation, 92 (18.4%) required an unplanned reintervention. Median time to reintervention was 12 days (interquartile range, 5-35 days). There were 31 (33.7%) deaths or transplants, median postoperative hospital length of stay was 49 days (interquartile range, 32-87 days), and median cost was $328,000 (interquartile range, $204,000-$464,000). On multivariable analysis, each 5-day increase in time to reintervention increased the odds of mortality or transplant by 20% (odds ratio, 1.2; 95% confidence interval, 1.1-1.3; P = .004). Longer time to reintervention was also significantly associated with greater postoperative hospital length of stay (P < .001) and higher cost (P < .001).

CONCLUSIONS

For patients requiring predischarge unplanned reinterventions after the Norwood operation, earlier reintervention is associated with improved in-hospital transplant-free survival and resource use.

Residual Lesion Severity Predicts Midterm Outcomes After Congenital Aortic Valve Repair

BACKGROUND

We sought to validate the technical performance score (TPS) as a predictor of midterm outcomes after congenital aortic valve repair.

METHODS

This was a single-center, retrospective review of consecutive patients who underwent aortic valve repair between January 1, 2011, and December 31, 2019. Predischarge echocardiograms were used to assign a TPS for each index operation as class 1, no aortic valve residua; class 2, minor aortic valve residua; or class 3, major aortic valve residua or predischarge reintervention for major residua. The primary outcome was postdischarge (late) unplanned aortic valve reintervention. Secondary outcomes included late mortality and at least moderate aortic regurgitation or stenosis at the latest follow-up or before the earliest reintervention. Associations between TPS and outcomes were assessed using competing risk, Cox proportional hazards, or logistic regression models, adjusting for preoperative patient- and procedure-related covariates.

RESULTS

Of 507 patients, there were 110 (21.7%) reinterventions, 22 (4.3%) deaths, and 67 (13.2%) cases of at least moderate aortic regurgitation or stenosis at the latest follow-up or earliest reintervention. On multivariable analysis, class 3 patients had a greater risk of reintervention (subdistribution hazard ratio, 2.6; 95% CI, 1.3-5.1; P = .005) and mortality (hazard ratio, 5.3; 95% CI. 1.1-25.2; P = .038) compared with class 1 patients. Adjusting for duration of follow-up, class 3 patients also had a greater risk of at least moderate aortic regurgitation or stenosis at the latest follow-up or earliest reintervention (odds ratio, 7.7; 95% CI, 2.5-24.2; P < .001) vs class 1 patients.

CONCLUSIONS

Patients with major residua after congenital aortic valve repair have significantly worse midterm outcomes compared with those with no residua, warranting closer follow-up.

Contemporary Socioeconomic and Childhood Opportunity Disparities in Congenital Heart Surgery

BACKGROUND

While singular measures of socioeconomic status have been associated with outcomes after surgery for congenital heart disease, the multifaceted pathways through which a child's environment impacts similar outcomes remain incompletely characterized. We sought to evaluate the association between childhood opportunity level and adverse outcomes after congenital heart surgery.

METHODS

Data from patients undergoing congenital cardiac surgery from January 2011 to January 2020 at a quaternary referral center were retrospectively reviewed. Outcomes of interest included predischarge (early) mortality or transplant, postoperative hospital length-of-stay, inpatient cost of hospitalization, postdischarge (late) mortality or transplant, and late unplanned reintervention. The primary predictor was a US census tract-based, nationally-normed composite metric of contemporary child neighborhood opportunity comprising 29 indicators across 3 domains (education, health and environment, and socioeconomic), categorized as very low, low, moderate, high, and very high. Associations between childhood opportunity level and outcomes were evaluated using logistic regression (early mortality), generalized linear (length-of-stay and cost), Cox proportional hazards (late mortality), or competing risk (late reintervention) models, adjusting for baseline patient-related factors, case complexity, and residual lesion severity.

RESULTS

Of 6133 patients meeting entry criteria, the median age was 2.0 years (interquartile range, 3.6 months-8.3 years). There were 124 (2.0%) early deaths or transplants, the median postoperative length-of-stay was 7 days (interquartile range, 5-13 days), and the median inpatient cost was $76 000 (interquartile range, $50 000-130 000). No significant association between childhood opportunity level and early mortality or transplant was observed (P=0.21). On multivariable analysis, children with very low and low opportunity had significantly longer length-of-stay and incurred higher costs compared with those with very high opportunity (all P<0.05). Of 6009 transplant-free survivors of hospital discharge, there were 175 (2.9%) late deaths or transplants, and 1008 (16.8%) reinterventions at up to 10.5 years of follow-up. Patients with very low opportunity had a significantly greater adjusted risk of late death or transplant (hazard ratio, 1.7 [95% CI, 1.1-2.6]; P=0.030) and reintervention (subdistribution hazard ratio, 1.9 [95% CI, 1.5-2.3]; P<0.001), versus those with very high opportunity.

CONCLUSIONS

Childhood opportunity level is independently associated with adverse outcomes after congenital heart surgery. Children from resource-limited settings thus constitute an especially high-risk cohort that warrants closer surveillance and tailored interventions.

Early Experience With Reverse Double Switch Operation for the Borderline Left Heart

This study reviews our early experience with the "reverse" double switch operation (R-DSO) for borderline left hearts. A retrospective review of children with borderline left hearts who underwent R-DSO between 2017 and 2021 was conducted. Patient characteristics and early hemodynamic and clinical outcomes were collected. R-DSO was performed in 8 patients with no operative or postoperative deaths; 5 underwent decompressing bidirectional Glenn. Left ventricular (LV) poor-compliance was the dominant pathophysiology. Four patients had undergone staged LV recruitment but were not candidates for anatomical biventricular circulation due to LV hypoplasia and/or diastolic dysfunction. 7/8 patients had risk factors for Fontan circulation including pulmonary vein stenosis, pulmonary hypertension, and pulmonary artery stenosis. Median age at R-DSO was 3.7 years (19 months-12 years). All patients were in sinus rhythm at discharge. At median follow-up of 15 months (57 days-4.1 years) no mortalities, reoperations or heart transplants had occurred. All patients had normal morphologic LV systolic function. In one patient, pre-existing pulmonary hypertension (HTN) resolved after R-DSO. Reinterventions included transcatheter mitral valve replacement for residual mitral stenosis and neo-pulmonary balloon valvuloplasty. In 4 patients follow-up catheterization done at a median of 519 days (320 days-4 years) demonstrated median cardiac index of 3.2 L/min/m2 (2.2-4); median sub-pulmonary left ventricular end diastolic pressure was 9 mm Hg (7-15); median inferior vena cava/baffle pressure was 8 mm Hg (7-13). R-DSO is an alternative to anatomical biventricular repair or single ventricle palliation in patients with borderline left hearts and can result in low inferior vena cava pressures and favorable early results. This approach can also relieve pulmonary HTN and allow future transplant candidacy.

Outcomes of Repair of Congenital Aortic Valve Lesions Using Autologous Pericardium vs Porcine Intestinal Submucosa

BACKGROUND

Outcomes following congenital aortic valve (AoV) repair are plagued by progressive dysfunction of currently available leaflet substitute materials.

OBJECTIVES

We compared the long-term outcomes of congenital AoV repair using porcine intestinal submucosa vs autologous pericardium (AP).

METHODS

This was a single-center retrospective review of all patients who underwent congenital AoV repair with either porcine intestinal submucosa or AP from October 2009 to March 2013. The primary outcome was postdischarge (late) unplanned AoV reintervention. Secondary outcomes included number of late AoV reinterventions and a composite of at least moderate aortic regurgitation or stenosis at latest follow-up or before the first reintervention. Associations between leaflet repair material and outcomes were assessed using multivariable regression models, adjusting for prespecified patient-related and operative variables.

RESULTS

Of 26 porcine intestinal submucosa and 49 AP patients who met entry criteria, the median age was 11.0 years (IQR: 4.7-16.6 years). At a median follow-up of 8.5 years (IQR: 4.4-9.6 years), 17 (65.4%) porcine intestinal submucosa and 22 (44.9%) AP patients underwent at least 1 AoV reintervention. On multivariable analysis, porcine intestinal submucosa use was significantly associated with unplanned AoV reintervention (HR: 4.6; 95% CI: 2.2-9.8; P < 0.001), number of postdischarge AoV reinterventions (incidence rate ratio: 1.7; 95% CI: 1.0-2.9; P = 0.037), and at least moderate aortic regurgitation or stenosis at latest follow-up or before the first reintervention (OR: 5.0; 95% CI: 1.2-21.0; P = 0.027).

CONCLUSIONS

Aortic valvuloplasty with porcine intestinal submucosa is associated with earlier time to reintervention compared with autologous pericardium. The search for the ideal AoV leaflet repair material continues.

A multi-disciplinary, comprehensive approach to management of children with heterotaxy

Heterotaxy (HTX) is a rare condition of abnormal thoraco-abdominal organ arrangement across the left-right axis of the body. The pathogenesis of HTX includes a derangement of the complex signaling at the left-right organizer early in embryogenesis involving motile and non-motile cilia. It can be inherited as a single-gene disorder, a phenotypic feature of a known genetic syndrome or without any clear genetic etiology. Most patients with HTX have complex cardiovascular malformations requiring surgical intervention. Surgical risks are relatively high due to several serious comorbidities often seen in patients with HTX. Asplenia or functional hyposplenism significantly increase the risk for sepsis and therefore require antimicrobial prophylaxis and immediate medical attention with fever. Intestinal rotation abnormalities are common among patients with HTX, although volvulus is rare and surgical correction carries substantial risk. While routine screening for intestinal malrotation is not recommended, providers and families should promptly address symptoms concerning for volvulus and biliary atresia, another serious morbidity more common among patients with HTX. Many patients with HTX have chronic lung disease and should be screened for primary ciliary dyskinesia, a condition of respiratory cilia impairment leading to bronchiectasis. Mental health and neurodevelopmental conditions need to be carefully considered among this population of patients living with a substantial medical burden. Optimal care of children with HTX requires a cohesive team of primary care providers and experienced subspecialists collaborating to provide compassionate, standardized and evidence-based care. In this statement, subspecialty experts experienced in HTX care and research collaborated to provide expert- and evidence-based suggestions addressing the numerous medical issues affecting children living with HTX.

Staged Ventricular Septation in Double-Inlet Ventricle - A Strategy to Avoid Fontan?

Single-stage ventricular septation for double-inlet left or right ventricle (DILV or DIRV) has historically been associated with poor outcomes. We hypothesize that staged ventricular septation may demonstrate favorable clinical outcomes to be an alternative to Fontan palliation. This single-center retrospective study reviewed patients with DILV or DIRV who underwent staged ventricular septation between 2015-2021. The strategy involves pulmonary artery banding or Norwood procedure during infancy (stage 1), followed by partial ventricular septation to anchor the septum, while maintaining systemic RV pressure to avoid septal shift (stage 2). Residual septal defects are closed with pulmonary artery band removal at stage 3. Results are reported as median (interquartile range). Twelve patients underwent partial ventricular septation. At a median follow-up time of 17 months (8-30) after stage 2, there were no interstage deaths or cardiac transplants; LV dysfunction was observed in one patient. Hemodynamic evaluation after stage 2 demonstrated median left atrial pressure of 9.5 mm Hg (8.9-11.5), cardiac index of 3.4 L/min/m2 (3.2-3.6), and RV and LV indexed end-diastolic volumes of 52 ml/m2 (41-67) and 105 ml/m2 (81-115), respectively. Five patients have progressed to stage 3; one required pacemaker for complete heart block. Unplanned reintervention was required in 4 patients after stage 1, 2 patients after stage 2, and 3 patients after stage 3. Staged ventricular septation is an alternative to single-ventricle palliation in a subset of double-inlet ventricle patients and is associated with acceptable early outcomes. Further studies are necessary to determine long-term outcomes.

Mechanical strain triggers endothelial-to-mesenchymal transition of the endocardium in the immature heart

BACKGROUND

Endothelial-to-mesenchymal-transition (EndMT) plays a major role in cardiac fibrosis, including endocardial fibroelastosis but the stimuli are still unknown. We developed an endothelial cell (EC) culture and a whole heart model to test whether mechanical strain triggers TGF-β-mediated EndMT.

METHODS

Isolated ECs were exposed to 10% uniaxial static stretch for 8 h (stretch) and TGF-β-mediated EndMT was determined using the TGF-β-inhibitor SB431542 (stretch + TGF-β-inhibitor), BMP-7 (stretch + BMP-7) or losartan (stretch + losartan), and isolated mature and immature rats were exposed to stretch through a weight on the apex of the left ventricle. Immunohistochemical staining for double-staining with endothelial markers (VE-cadherin, PECAM1) and mesenchymal markers (αSMA) or transcription factors (SLUG/SNAIL) positive nuclei was indicative of EndMT.

RESULTS

Stretch-induced EndMT in ECs expressed as double-stained ECs/total ECs (cells: 46 ± 13%; heart: 15.9 ± 2%) compared to controls (cells: 7 ± 2%; heart: 3.1 ± 0.1; p < 0.05), but only immature hearts showed endocardial EndMT. Inhibition of TGF-β decreased the number of double-stained cells significantly, comparable to controls (cells/heart: control: 7 ± 2%/3.1 ± 0.1%, stretch: 46 ± 13%/15 ± 2%, stretch + BMP-7: 7 ± 2%/2.9 ± 0.1%, stretch + TGF-β-inhibitor (heart only): 5.2 ± 1.3%, stretch + losartan (heart only): 0.89 ± 0.1%; p < 0.001 versus stretch).

CONCLUSIONS

Endocardial EndMT is an age-dependent consequence of increased strain triggered by TGF- β activation. Local inhibition through either rebalancing TGF-β/BMP or with losartan was effective to block EndMT.

IMPACT

Mechanical strain imposed on the immature LV induces endocardial fibroelastosis (EFE) formation through TGF-β-mediated activation of endothelial-to-mesenchymal transition (EndMT) in endocardial endothelial cells but has no effect in mature hearts. Local inhibition through either rebalancing the TGF-β/BMP pathway or with losartan blocks EndMT. Inhibition of endocardial EndMT with clinically applicable treatments may lead to a better outcome for congenital heart defects associated with EFE.

Bioprosthetic Aortic Valve Hemodynamics: Definitions, Outcomes, and Evidence Gaps: JACC State-of-the-Art Review

A virtual workshop was organized by the Heart Valve Collaboratory to identify areas of expert consensus, areas of disagreement, and evidence gaps related to bioprosthetic aortic valve hemodynamics. Impaired functional performance of bioprosthetic aortic valve replacement is associated with adverse patient outcomes; however, this assessment is complicated by the lack of standardization for labelling, definitions, and measurement techniques, both after surgical and transcatheter valve replacement. Echocardiography remains the standard assessment methodology because of its ease of performance, widespread availability, ability to do serial measurements over time, and correlation with outcomes. Management of a high gradient after replacement requires integration of the patient's clinical status, physical examination, and multimodality imaging in addition to shared patient decisions regarding treatment options. Future priorities that are underway include efforts to standardize prosthesis sizing and labelling for both surgical and transcatheter valves as well as trials to characterize the consequences of adverse hemodynamics.

Long-Term Outcomes of Patients Requiring Unplanned Repeated Interventions After Surgery for Congenital Heart Disease

BACKGROUND

Unplanned catheter-based or surgical reinterventions after congenital heart operations are independently associated with operative mortality and increased postoperative length of stay.

OBJECTIVES

This study assessed the long-term outcomes of transplant-free survivors of hospital discharge requiring predischarge reinterventions after congenital cardiac surgery.

METHODS

Data from patients who required predischarge reinterventions in the anatomic area of repair after congenital cardiac surgery and survived to hospital discharge at a quaternary referral center from January 2011 to December 2019 were retrospectively reviewed. Previously published echocardiographic criteria were used to assess the severity of persistent residual lesions at discharge (Grade 1, no residua; Grade 2, minor residua; and Grade 3, major residua). Outcomes included postdischarge (late) mortality or transplant and unplanned reintervention. Associations between predischarge residual lesion severity and outcomes were assessed by using Cox or competing risk models, adjusting for baseline patient characteristics, case complexity, and preoperative risk factors.

RESULTS

Among the 408 patients who met entry criteria, there were 58 (14.2%) postdischarge deaths or transplants and 208 (51.0%) late reinterventions at a median follow-up of 3.0 years (IQR: 1.1-6.8 years). Greater predischarge residual lesion severity was associated with worse transplant-free survival and freedom from reintervention (both, P < 0.05). On multivariable analyses, Grade 3 patients had an increased risk of postdischarge mortality or transplant (HR: 4.8; 95% CI: 2.0-11; P < 0.001) and late reintervention (subdistribution HR: 2.1; 95% CI: 1.4-3.1; P < 0.001) vs Grade 1 patients.

CONCLUSIONS

Among transplant-free survivors requiring predischarge reinterventions after congenital cardiac surgery, those with persistent major residua have significantly worse long-term outcomes. These high-risk patients warrant closer surveillance.

Direct Cardiac Compression Devices to Augment Heart Biomechanics and Function

The treatment of end-stage heart failure has evolved substantially with advances in medical treatment, cardiac transplantation, and mechanical circulatory support (MCS) devices such as left ventricular assist devices and total artificial hearts. However, current MCS devices are inherently blood contacting and can lead to potential complications including pump thrombosis, hemorrhage, stroke, and hemolysis. Attempts to address these issues and avoid blood contact led to the concept of compressing the failing heart from the epicardial surface and the design of direct cardiac compression (DCC) devices. We review the fundamental concepts related to DCC, present the foundational devices and recent devices in the research and commercialization stages, and discuss the milestones required for clinical translation and adoption of this technology. Expected final online publication date for the Annual Review of Biomedical Engineering, Volume 24 is June 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Contemporary outcomes of the double switch operation for congenitally corrected transposition of the great arteries

OBJECTIVE

To determine the contemporary outcomes of the double switch operation (DSO) (ie, Mustard or Senning + arterial switch).

METHODS

A single-institution, retrospective review of all patients with congenitally corrected transposition of the great arteries undergoing a DSO.

RESULTS

Between 1999 and 2019, 103 patients underwent DSO with a Mustard (n = 93) or Senning (n = 10) procedure. Segmental anatomy was (S, L, L) in 93 patients and (I, D, D) in 6 patients. Eight patients had heterotaxy and 71 patients had a ventricular septal defect. Median age was 2.1 years (range, 1.8 months-40 years), including 34 patients younger than age 1 year (33%). Median weight was 10.9 kg (range, 3.4-64 kg). Sixty-one patients had prior pulmonary artery bands for a median of 1.1 years (range, 14 days-12.9 years; interquartile range, 0.7-3.1 years). Median intensive care unit and hospital lengths of stay were 5 and 10 days, respectively. Median follow-up was 3.4 years (interquartile range, 1-9.8 years) and 5.2 years (interquartile range, 2.3-10.7 years) in 79 patients with >1 year follow-up. At latest follow-up, aortic, mitral, tricuspid valve regurgitation, and left ventricle dysfunction was less than moderate in 96%, 98%, 96%, and 93%, respectively. Seventeen patients underwent reoperation: neoaortic valve intervention (n = 10), baffle revision (n = 5), and ventricular septal defect closure (n = 4). At latest follow-up, 17 patients (17%) had a pacemaker and 27 (26%) had cardiac resynchronization therapy devices. There were 2 deaths and 2 transplants. Transplant-free survival was 94.6% at 5 years. Risk factors for death or transplant included longer cardiopulmonary bypass time and older age at DSO.

CONCLUSIONS

The outcomes of the DSO are promising. Earlier age at operation might favor better outcomes. Progressive neoaortic regurgitation and reinterventions on the neo-aortic valve are anticipated problems.

Major Aortopulmonary Collateral Arteries Requiring Percutaneous Intervention Following the Arterial Switch Operation: A Case Series and Systematic Review

Background: Dextro transposition of the great arteries (d-TGA) is the most common critical congenital cardiac defect surgically treated in the neonatal period by arterial switch operation (ASO). Major aortopulmonary collaterals (MAPCAs) can be present in this population and may complicate the early postoperative period. Our aim was to review our institutional data and systematically review the available literature to provide further insight on the clinical significance of MAPCAs during the early postoperative course after ASO. Methods: This is a retrospective study of patients with simple d-TGA who underwent ASO between March 1998 and September 2020 at Boston Children's Hospital. The MEDLINE, Embase, and Cochrane databases were searched from inception to June 2020. Results: Of the 671 d-TGA patients who underwent ASO at our center, 13 (1.9%) were diagnosed with MAPCAs. Five were diagnosed before ASO, while eight were diagnosed after ASO. Of these, two patients required catheterization for MAPCAs coiling during the same hospitalization on the 2nd and 11th postoperative days. The systematic review retrieved a total of 34 articles after duplicates were removed. Finally, nine studies reporting on 23 patients were deemed eligible for our analysis. The average time to MAPCAs coiling was 12 days, while the mean hospital stay was 36 days. Conclusions: MAPCAs should be included in the differential diagnosis of ASO complicated by cardiac or respiratory failure, or pulmonary hemorrhage acutely postoperatively. Once managed, recovery of these patients is predictable, and mortality is low. Further studies investigating the diagnostic value of echocardiography and the long-term outcomes of these MAPCAs are necessary.

Mitochondrial Transplantation for Organ Rescue

Mitochondrial transplantation involves the replacement or augmentation of native mitochondria damaged, by ischemia, with viable, respiration-competent mitochondria isolated from non-ischemic tissue obtained from the patient's own body. The uptake and cellular functional integration of the transplanted mitochondria appears to occur in all cell types. Efficacy and safety have been demonstrated in cell culture, isolated perfused organ, in vivo large animal studies and in a first-human clinical study. Herein, we review our findings and provide insight for use in the treatment of organ ischemia- reperfusion injury.

Abnormal Flow Conditions Promote Endocardial Fibroelastosis Via Endothelial-to-Mesenchymal Transition, Which Is Responsive to Losartan Treatment

•

EFE is a congenital cardiac pathology contributing to increased morbidity and mortality. The pathologic triggers of EFE remain to be characterized.

•

To determine whether abnormal flow promotes EFE development, we used in vivo neonatal rodent surgical models and an in vitro model using human primary endocardial cells

•

We established novel surgical model with flow profiles seen in patients that develop EFE. Static and turbulent flow conditions promoted EFE development in neonatal rodent hearts.

•

Losartan treatment is shown to significantly ameliorate EFE progression and decreases mRNA and protein expression of EndoMT markers in neonatal rodent hearts.

•

RNAseq analysis of human endocardial cells subjected to different flow conditions show that normal flow suppresses gene expression critical for mesenchymal differentiation and Notch signaling.

Endocardial fibroelastosis (EFE) is defined by fibrotic tissue on the endocardium and forms partly through aberrant endothelial-to-mesenchymal transition. However, the pathologic triggers are still unknown. In this study, we showed that abnormal flow induces EFE partly through endothelial-to-mesenchymal transition in a rodent model, and that losartan can abrogate EFE development. Furthermore, we translated our findings to human endocardial endothelial cells, and showed that laminar flow promotes the suppression of genes associated with mesenchymal differentiation. These findings emphasize the role of flow in promoting EFE in endocardial endothelial cells and provide a novel potential therapy to treat this highly morbid condition.

Single-Leaflet Aortic Valve Reconstruction Utilizing the Ozaki Technique in Patients With Congenital Aortic Valve Disease

Evaluate outcomes of single leaflet aortic valve reconstruction using Ozaki sizer and template. Single institute retrospective analysis between August 2015 and August 2019. Thirty-three patients, median age 9.3 years and weight 29.2 kg underwent single leaflet Ozaki repair. Preoperative indications were: AR (n = 17), AS (n = 3) or AS/AR (n = 13). Baseline anatomy was unicuspid (n = 15), bicuspid (n = 9) or tricuspid (n = 9). Two patients had endocarditis. Prior interventions included balloon valvuloplasty (n = 22) and aortic valve repair (n = 9). Pre-op average native annulus diameter was 19.6 mm and peak echo gradient was 36 mm Hg. Autologous pericardium, Photofix and CardioCel bovine pericardium were used in 26, 5, and 2 patients. Non-coronary sinus enlargement was required in 3 and aortic root reduction in 9 patients. Single leaflet reconstruction was done for the right coronary cusp (n = 25), non-coronary cusp in (n = 6) and left coronary cusp (n = 2). Additional procedures were done in 30 patients. Median ICU and hospital LOS were 2.1 and 6.3 days. There were no early re-interventions or conversions to valve replacement and one unrelated mortality.en At discharge, all patients had < moderate AR and/or AS with average peak gradients of 15 mm Hg. The median follow-up was 1.1 year, (IQR 0.7-1.8 years). Freedom from ≥ moderate AR and AS at 2 years was 76% and 86%. One patient required surgical re-intervention for severe AR 1.5 years after surgery for inflammatory infiltrate with calcification and fibrosis. Single-leaflet aortic valve leaflet reconstruction utilizing the Ozaki technique has promising early results and can be considered in patients when there are acceptable native leaflets.

Enhancing Recovery in Congenital Cardiac Surgery

BACKGROUND

The benefits of a comprehensive enhanced recovery after surgery (ERAS®) program for the congenital heart disease population are largely unknown. We evaluated adherence and outcomes following a recently implemented enhanced recovery program (ERP) in congenital cardiac surgery.

METHODS

Patients undergoing elective surgery for simple and moderately complex congenital cardiac surgery followed institutional ERP guidelines since 10/2018. Adherence to guidelines over a 12-month period (P2) was compared to implementation data (P1:5 months). The association of outcomes with continuous time was estimated using linear regression.

RESULTS

Among 559 patients (representing 40% of the cardiac surgical volume) following the ERP over a period of 17 months, no differences in patient characteristics were observed between periods, except higher incidence of prior operations in P2. Adherence to many aspects of guidelines improved from P1 to P2. Notably, operating room extubation: 27% in P2 vs.16% in P1, p=0.006; decrease in median ventilation time: 6.0-hrs (IQR 0-9.2) in P2 vs. 7.6-hrs (IQR 3.8-12.3) in P1, p=0.002. In addition, there was a reduction in opioids, reported as oral morphine equivalents (OME), most significant for intraoperative OME: 5.00 mg/kg (3.11-7.60) in P2 vs. 6.05 mg/kg (3.77-9.78) in P1, p=0.001. There was no difference in overall intensive care unit (ICU) and postoperative length of stay except in lower risk surgeries. Surgical outcomes were similar in the two periods.

CONCLUSIONS

An enhanced recovery program reduced the use of opioids, led to more OR extubation and reduced mechanical ventilation duration in patients undergoing congenital cardiac surgery.

Importance of Preserved Tricuspid Valve Function for Effective Soft Robotic Augmentation of the Right Ventricle in Cases of Elevated Pulmonary Artery Pressure

Purpose

In clinical practice, many patients with right heart failure (RHF) have elevated pulmonary artery pressures and increased afterload on the right ventricle (RV). In this study, we evaluated the feasibility of RV augmentation using a soft robotic right ventricular assist device (SRVAD), in cases of increased RV afterload.

Methods

In nine Yorkshire swine of 65–80 kg, a pulmonary artery band was placed to cause RHF and maintained in place to simulate an ongoing elevated afterload on the RV. The SRVAD was actuated in synchrony with the ventricle to augment native RV output for up to one hour. Hemodynamic parameters during SRVAD actuation were compared to baseline and RHF levels.

Results

Median RV cardiac index (CI) was 1.43 (IQR, 1.37–1.80) L/min/m² and 1.26 (IQR 1.05–1.57) L/min/m² at first and second baseline. Upon PA banding RV CI fell to a median of 0.79 (IQR 0.63–1.04) L/min/m². Device actuation improved RV CI to a median of 0.87 (IQR 0.78–1.01), 0.85 (IQR 0.64–1.59) and 1.11 (IQR 0.67–1.48) L/min/m² at 5 min (p = 0.114), 30 min (p = 0.013) and 60 (p = 0.033) minutes respectively. Statistical GEE analysis showed that lower grade of tricuspid regurgitation at time of RHF (p = 0.046), a lower diastolic pressure at RHF (p = 0.019) and lower mean arterial pressure at RHF (p = 0.024) were significantly associated with higher SRVAD effectiveness.

Conclusions

Short-term augmentation of RV function using SRVAD is feasible even in cases of elevated RV afterload. Moderate or severe tricuspid regurgitation were associated with reduced device effectiveness.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13239-021-00562-7

A geometrically adaptable heart valve replacement

Congenital heart valve disease has life-threatening consequences that warrant early valve replacement; however, the development of a growth-accommodating prosthetic valve has remained elusive. Thousands of children continue to face multiple high-risk open-heart operations to replace valves that they have outgrown. Here, we demonstrate a biomimetic prosthetic valve that is geometrically adaptable to accommodate somatic growth and structural asymmetries within the heart. Inspired by the human venous valve, whose geometry is optimized to preserve functionality across a wide range of constantly varying volume loads and diameters, our balloon-expandable synthetic bileaflet valve analog exhibits similar adaptability to dimensional and shape changes. Benchtop and acute in vivo experiments validated design functionality, and in vivo survival studies in growing sheep demonstrated that mechanical valve expansion accommodated growth. As illustrated in this work, dynamic size adaptability with preservation of unidirectional flow in prosthetic valves thus offers a paradigm shift in the treatment of heart valve disease.

Mitochondrial transplantation for myocardial protection in diabetic hearts

OBJECTIVES

Type 2 diabetes causes mitochondrial dysfunction, which increases myocardial susceptibility to ischaemia-reperfusion injury. We investigated the efficacy of transplantation of mitochondria isolated from diabetic or non-diabetic donors in providing cardioprotection from warm global ischaemia and reperfusion in the diabetic rat heart.

METHODS

Ex vivo perfused hearts from Zucker diabetic fatty (ZDF fa/fa) rats (n = 6 per group) were subjected to 30 min of warm global ischaemia and 120 min reperfusion. Immediately prior to reperfusion, vehicle alone (VEH) or vehicle containing mitochondria isolated from either ZDF (MTZDF) or non-diabetic Zucker lean (ZL +/?) (MTZL) skeletal muscle were delivered to the coronary arteries via the aortic cannula.

RESULTS

Following 30-min global ischaemia and 120-min reperfusion, left ventricular developed pressure was significantly increased in MTZDF and MTZL groups compared to VEH group (MTZDF: 92.8 ± 5.2 mmHg vs MTZL: 110.7 ± 2.4 mmHg vs VEH: 44.3 ± 5.9 mmHg; P < 0.01 each); and left ventricular end-diastolic pressure was significantly decreased (MTZDF 12.1 ± 1.3 mmHg vs MTZL 8.6 ± 0.8 mmHg vs VEH: 18.6 ± 1.5 mmHg; P = 0.016 for MTZDF vs VEH and P < 0.01 for MTZL vs VEH). Total tissue ATP content was significantly increased in both MT groups compared to VEH group (MTZDF: 18.9 ± 1.5 mmol/mg protein/mg tissue vs MTZL: 28.1 ± 2.3 mmol/mg protein/mg tissue vs VEH: 13.1 ± 0.5 mmol/mg protein/mg tissue; P = 0.018 for MTZDF vs VEH and P < 0.01 for MTZL vs VEH). Infarct size was significantly decreased in the MT groups (MTZDF: 11.8 ± 0.7% vs MTZL: 9.9 ± 0.5% vs VEH: 52.0 ± 1.4%; P < 0.01 each).

CONCLUSIONS

Mitochondrial transplantation significantly enhances post-ischaemic myocardial functional recovery and significantly decreases myocellular injury in the diabetic heart.