Atrioventricular valve repair in patients with functional single-ventricle physiology: impact of ventricular and valve function and morphology on survival and reintervention

Right Ventricular Remodeling and Function in Hypoplastic Left Heart Syndrome

The right ventricle (RV) in hypoplastic left heart syndrome (HLHS) becomes the systemic ventricle pumping against systemic afterload. It also has to adapt to an initially increased volume load followed by a decrease in volume load after Fontan completion. Anatomical HLHS subtype, therapeutic strategy, tricuspid valve regurgitation, recoarctation, and genetics influence RV size and function. The resulting remodeling process can be maladaptive and lead to ventricular systolic and diastolic dysfunction. While systolic dysfunction is a strong predictor for mortality before Fontan, there is increasing evidence for the impact of progressive diastolic dysfunction after Fontan. This comprehensive review summarizes the (recent) empirical observations that increased understanding of RV remodeling and function in HLHS. It aims at clinicians and researchers wishing to increase their understanding of the physiology of this disease. It highlights the potential for future scientific work on the assessment and preservation of myocardial health throughout the palliation.

Impact of Atrioventricular Valve Intervention at Each Stage of Single Ventricle Palliation

Background: Significant atrioventricular valve dysfunction can be associated with mortality or need for transplant in functionally univentricular heart patients undergoing staged palliation. The purposes of this study are to characterize the impact of concomitant atrioventricular valve intervention on outcomes at each stage of single ventricle palliation and to identify risk factors associated with poor outcomes in these patients. Methods: The Society of Thoracic Surgeons Congenital Heart Surgery Database was queried for functionally univentricular heart patients undergoing single ventricle palliation from 2013 through 2022. Separate analyses were performed on cohorts corresponding to each stage of palliation (1: initial palliation; 2: superior cavopulmonary anastomosis; 3: Fontan procedure). Bivariate analysis of demographics, diagnoses, comorbidities, preoperative risk factors, operative characteristics, and outcomes with and without concomitant atrioventricular valve intervention was performed. Multiple logistic regression was used to identify predictors associated with operative mortality or major morbidity. Results: Concomitant atrioventricular valve intervention was associated with an increased risk of operative mortality or major morbidity for each cohort (cohort 1: 62% vs 46%, P < .001; cohort 2: 37% vs 19%, P < .001; cohort 3: 22% vs 14%, P < .001). Black race in cohort 1 (odds ratio [OR] 3.151, 95% CI 1.181-9.649, P = .03) and preterm birth in cohort 2 (OR 1.776, 95% CI 1.049-3.005, P = .032) were notable predictors of worse morbidity or mortality. Conclusions: Concomitant atrioventricular valve intervention is a risk factor for operative mortality or major morbidity at each stage of single ventricle palliation. Several risk factors are associated with these outcomes and may be useful in guiding decision-making.

Atrioventricular valve surgery in patients with univentricular heart and two separate atrioventricular valves

OBJECTIVES

Atrioventricular valve regurgitation in patients with univentricular heart is a well-known risk factor for adverse outcomes and atrioventricular valve repair remains a particular surgical challenge.

METHODS

We reviewed all surgical atrioventricular valve procedures in patients with univentricular heart and two separate atrioventricular valves who underwent surgical palliation. Endpoints of the study were reoperation-free survival and cumulative incidence of reoperation.

RESULTS

Between 1994 and 2021, 202 patients with univentricular heart and two separate atrioventricular valve morphology underwent surgical palliation, with 15.8% (32/202) requiring atrioventricular valve surgery. Primary diagnoses were double inlet left ventricle (n = 14, 43.8%), double outlet right ventricle (n = 7, 21.9%), and congenitally corrected transposition of the great arteries (n = 7, 21.9%). Median weight at valve surgery was 10.6 kg (interquartile range, 7.9-18.9). Isolated left or right atrioventricular valve surgery was required in nine (28.1%) and 22 patients (68.8%), respectively. Concomitant left and right atrioventricular valve surgery was performed in one patient (3.1%). Closure of the left valve was conducted in four patients (12.5%) and closure of the right valve in three (9.4%). Operative and late mortality were 3.1% and 9.7%, respectively. Reoperation-free survival and cumulative incidence of reoperation at 10 years after surgery were 62.3% (standard error of the mean: 6.9) and 30.9% (standard error of the mean: 9.6), respectively.

CONCLUSIONS

In patients with univentricular heart and two separate atrioventricular valves, surgical intervention on these valves is required in a minority of patients and is associated with low mortality but high incidence of reoperation.

Sutureless Repair of Extracardiac Univentricular Total Anomalous Pulmonary Venous Connection

BACKGROUND

This study aimed to evaluate the results of sutureless repair of extracardiac total anomalous pulmonary venous connection (TAPVC) with a functional single ventricle at a single institution, including changes in the anastomotic site over time.

METHODS

The database contained 98 patients with single-ventricle anatomy who underwent extracardiac TAPVC repair from 1996 to 2022. The median age and body weight at surgery were 59 days and 3.8 kg, respectively. Eighty-seven patients had heterotaxy syndrome, and 42 had preoperatively obstructed TAPVC. Primary sutureless repair was performed in 18 patients, 13 of whom were neonates. The cross-sectional area of the anastomotic site of the atrium and pericardium was divided by the body surface area, and the changes in this value over time were assessed. The median follow-up was 5.2 years (range, 0-19.4 years).

RESULTS

Operative mortality and late mortality occurred in 2 (2.0%) and 38 (38.8%) patients, respectively. The actuarial survival rate at 5 years postoperatively was 56.2%. Multivariate analysis identified preoperatively obstructed TAPVC as a risk factor for mortality. Recurrent pulmonary venous stenosis (PVS) developed in 25 patients, thus giving a 5-year rate of freedom from PVS of 64.9%. Multivariate analysis revealed that sutureless repair significantly decreased the incidence of recurrent PVS. The cross-sectional anastomotic area tended to grow in accordance with the patients' growth.

CONCLUSIONS

Sutureless repair of extracardiac TAPVC with univentricular anatomy achieved acceptable results. The anastomotic site tended to grow over time and contributed to a decline in the rate of recurrent PVS.

Long-term outcomes of functional single ventricles associated with heterotaxy syndrome†

OBJECTIVES

The goal of this study was to determine the long-term surgical outcomes of patients with functional single ventricles associated with heterotaxy syndrome, risk factors for mortality and factors associated with Fontan stage completion.

METHODS

Overall, 279 patients with a functional single ventricle associated with heterotaxy syndrome who underwent an initial surgical procedure at our institute between 1978 and 2021 were grouped into 4 "eras" based on the surgical year during which the initial procedure was performed: era 1 (1978-1989, n = 71), era 2 (1990-1999, n = 98), era 3 (2000-2009, n = 64) and era 4 (2010-2021, n = 46). Neonatal surgery was more frequent in eras 3 and 4 than in eras 1 and 2.

RESULTS

Overall, 228 patients had right atrial isomerism; 120 patients (43.0%) had a total anomalous pulmonary venous connection; and 58 patients (20.8%) underwent an initial procedure as neonates. Overall survival rates at 10, 20 and 30 years after the initial procedure were 47.1%, 40.6% and 36.1%, respectively. Neonatal surgery (P < 0.001), total anomalous pulmonary venous connection repair at the initial procedure (P < 0.001) and early era (P < 0.001) were identified as risk factors for mortality, with the last 2 variables being negatively associated with Fontan stage completion (P < 0.001 for both).

CONCLUSIONS

Although era had a favourable effect on survival, total anomalous pulmonary venous connection with intrinsic pulmonary vein obstruction was associated with both mortality and Fontan stage completion.

CLINICAL REGISTRATION NUMBER

R19092.

Long-term outcomes of tricuspid valve intervention during stage 2 palliation in patients with a single right ventricle

OBJECTIVES

In patients with single ventricle physiology and a systemic right ventricle, tricuspid valve regurgitation increases the risk of adverse outcomes, and tricuspid valve intervention at the time of staged palliation further increases that risk in the postoperative period. However, long-term outcomes of valve intervention in patients with significant regurgitation during stage 2 palliation have not been established. The purpose of this study is to evaluate the long-term outcomes after tricuspid valve intervention during stage 2 palliation in patients with right ventricular dominant circulation in a multicenter study.

METHODS

The study was performed using the Single Ventricle Reconstruction Trial and Single Ventricle Reconstruction Follow-up 2 Trial datasets. Survival analysis was performed to describe the association among valve regurgitation, intervention, and long-term survival. Cox proportional hazards modeling was used to estimate the longitudinal association of tricuspid intervention and transplant-free survival.

RESULTS

Patients with tricuspid regurgitation at stage 1 or 2 had worse transplant-free survival (hazard ratio, 1.61; 95% confidence interval, 1.12-2.32; hazard ratio, 2.3; 95% confidence interval 1.39-3.82). Those with regurgitation who underwent concomitant valve intervention at stage 2 were significantly more likely to die or undergo heart transplantation compared with those with regurgitation who did not (hazard ratio, 2.93; confidence interval, 2.16-3.99). Patients with tricuspid regurgitation at the time of the Fontan had favorable outcomes regardless of valve intervention.

CONCLUSIONS

The risks associated with tricuspid regurgitation in patients with single ventricle physiology do not appear to be mitigated by valve intervention at the time of stage 2 palliation. Patients who underwent valve intervention for tricuspid regurgitation at stage 2 had significantly worse survival compared with patients with tricuspid regurgitation who did not.

Mechanical atrioventricular valve replacement in patients with single ventricle palliation

OBJECTIVES

Atrioventricular valve (AVV) replacements in patients with single-ventricle circulations pose significant surgical risks and are associated with high morbidity and mortality.

METHODS

From 1997 to 2021, 16 consecutive patients with functionally single-ventricle physiology underwent mechanical AVV replacement. Primary outcome was transplant-free survival. Secondary outcomes included major postoperative morbidity.

RESULTS

The median age of AVV replacement was 2 years old (interquartile range 0.6-3.8 years). All AVV replacements were performed with a St. Jude Medical mechanical valve, median 24 mm (range, 19-31mm). Extracorporeal membrane oxygenation (ECMO) was required in 4 patients. Operative mortality was 38% (6/16). There were 2 late deaths and 3 transplants. Transplant-free survival was 50% at 1 year, 37.5% at 5 years, and 22% at 10 years. Transplant-free survival was higher for patients with preserved ventricular function (P = 0.01). Difference in transplant-free survival at 1 year was 75% vs 25%, at 5 years was 62.5% vs 12.5% and at 10 years was 57% vs 0%. Three (19%) patients had complete heart block requiring permanent pacemaker insertion. 6 of 13 patients (46%) patients reached Fontan completion (3 patients operated at/after Fontan). Significant bleeding events occurred in 8 patients (50%) with 3 patients suffering major cerebrovascular accidents. There were 6 events of valve thrombosis in 5 patients, resulting in 2 deaths and 2 heart transplants.

CONCLUSIONS

Mechanical valve replacement carries significant morbidity and mortality risk. While it successfully salvages about half of patients with preserved ventricular function, careful consideration of alternative options should be made before embarking upon mechanical valve replacement.

Ex Vivo Modeling of Atrioventricular Valve Mechanics in Single Ventricle Physiology

Single ventricle physiology (SVP) is used to describe any congenital heart lesion that is unable to support independent pulmonary and systemic circulations. Current treatment strategies rely on a series of palliation surgeries that culminate in the Fontan physiology, which relies on the single functioning ventricle to provide systemic circulation while passively routing venous return through the pulmonary circulation. Despite significant reductions in early mortality, the presence of atrioventricular valve (AVV) regurgitation is a key predictor of heart failure in these patients. We sought to evaluate the biomechanical changes associated with the AVV in SVP physiologies. Left and right ventricles were sutured onto patient-derived 3D-printed mounts and mounted into an ex vivo systemic heart simulator capable of reproducing Norwood, Glenn, Fontan and Late Fontan physiologies. We found that the tricuspid anterior leaflet experienced elevated maximum force, average force, and maximum yank compared to the posterior and septal leaflets. Between physiologies, maximum yank was greatest in the Norwood physiology relative to the Glenn, Fontan, and Late Fontan physiologies. These contrasting trends suggest that long- and short-term mechanics of AVV failure in single ventricle differ and that AVV interventions should account for asymmetries in force profiles between leaflets and physiologies.

Tricuspid Valve Regurgitation in Hypoplastic Left Heart Syndrome: Current Insights and Future Perspectives

Hypoplastic Left Heart Syndrome (HLHS) is a congenital heart defect that requires a three-stage surgical palliation to create a single ventricle system in the right side of the heart. Of patients undergoing this cardiac palliation series, 25% will develop tricuspid regurgitation (TR), which is associated with an increased mortality risk. Valvular regurgitation in this population has been extensively studied to understand indicators and mechanisms of comorbidity. In this article, we review the current state of research on TR in HLHS, including identified valvular anomalies and geometric properties as the main reasons for the poor prognosis. After this review, we present some suggestions for future TR-related studies to answer the central question: What are the predictors of TR onset during the three palliation stages? These studies involve (i) the use of engineering-based metrics to evaluate valve leaflet strains and predict tissue material properties, (ii) perform multivariate analyses to identify TR predictors, and (iii) develop predictive models, particularly using longitudinally tracked patient cohorts to foretell patient-specific trajectories. Regarded together, these ongoing and future efforts will result in the development of innovative tools that can aid in surgical timing decisions, in prophylactic surgical valve repair, and in the refinement of current intervention techniques.

Atrioventricular septal defect in Fontan circulation: Right ventricular dominance, not valve surgery, adversely affects survival

OBJECTIVE

The effect of ventricular dominance and previous atrioventricular valve (AVV) surgery on patient outcomes after Fontan operation remains unclear. We sought to determine the effect of ventricular dominance and previous AVV surgery on transplantation-free survival and long-term AVV competency in patients with atrioventricular septal defect (AVSD) and Fontan circulation.

METHODS

We conducted a retrospective study of 1703 patients in the Australia and New Zealand Fontan Registry, who survived Fontan operation between 1987 and 2021.

RESULTS

Of 174 patients with AVSD, 60% (105/174) had right ventricular (RV) dominance and 40% (69/174) had left ventricular (LV) dominance. The cumulative incidence of moderate or greater AVV regurgitation at 25 years after Fontan operation in patients with LV dominance was 56% (95% CI, 35%-72%), compared with 54% (95% CI, 40%-67%) in patients with RV dominance (P = .6). Nonetheless, transplantation-free survival at 25 years in patients with LV dominance was 94% (95% CI, 86%-100%), compared with 67% (95% CI, 52%-87%) in patients with RV dominance (hazard ratio, 5.9; 95% CI, 1.4-25.4; P < .01). Of note, transplantation-free survival was not different in patients who underwent AVV surgery before or at Fontan completion compared with those who did not (15 years: 81% [95% CI, 62%-100%] vs 88% [95% CI, 81%-95%]; P = .3).

CONCLUSIONS

In patients with AVSD and Fontan circulation the rate of moderate or greater common AVV regurgitation is similar in those with LV and RV dominance. RV dominance, rather than previous AVV surgery, is a risk factor for death or transplantation.

The tricuspid valve in hypoplastic left heart syndrome: Echocardiography provides insight into anatomy and function

Tricuspid regurgitation (TR) is commonly seen in surgically palliated patients with hypoplastic left heart syndrome, and when significant, is associated with an increase in both morbidity and mortality. Tricuspid valve dysfunction appears to be the result of a combination of inherent structural malformations and the unique physiological circumstances resulting from right ventricular pressure and volume overload. Valve dysfunction evolves rapidly, and manifests early on in the surgical pathway. Whilst traditional echocardiographic imaging can identify anatomical defects and dysfunction resulting in varying degrees of regurgitation even at early stages, more sophisticated investigations such as 3D echocardiography, strain imaging and transesophageal 3DE might prove useful to better demonstrate the complex interactions between abnormal anatomy of the valve complex, ventricular function, mechanical synchrony, and TR. Recognition of specific mechanisms of TR can enhance patient-specific care by directing precise surgical interventions and by informing the best timing for intervention on the valve.

Force Profiles of Single Ventricle Atrioventricular Leaflets in Response to Annular Dilation and Leaflet Tethering

We sought to understand how leaflet forces change in response to annular dilation and leaflet tethering (LT) in single ventricle physiology. Explanted fetal bovine tricuspid valves were sutured onto image-derived annuli and ventricular mounts. Control valves (CON) were secured to a size-matched hypoplastic left heart syndrome (HLHS)-type annulus and compared to: (1) normal tricuspid valves secured to a size-matched saddle-shaped annulus, (2) HLHS-type annulus with LT, (3) HLHS-type annulus with annular dilation (dilation valves), or (4) a combined disease model with both dilation and tethering (disease valves). The specimens were tested in a systemic heart simulator at various single ventricle physiologies. Leaflet forces were measured using optical strain sensors sutured to each leaflet edge. Average force in the anterior leaflet was 43.2% lower in CON compared to normal tricuspid valves (P < 0.001). LT resulted in a 6.6% increase in average forces on the anterior leaflet (P = 0.04), 10.7% increase on the posterior leaflet (P = 0.03), and 14.1% increase on the septal leaflet (P < 0.001). In dilation valves, average septal leaflet forces increased relative to the CON by 42.2% (P = 0.01). In disease valves, average leaflet forces increased by 54.8% in the anterior leaflet (P < 0.001), 37.6% in the posterior leaflet (P = 0.03), and 79.9% in the septal leaflet (P < 0.001). The anterior leaflet experiences the highest forces in the normal tricuspid annulus under single ventricle physiology conditions. Annular dilation resulted in an increase in forces on the septal leaflet and LT resulted in an increase in forces across all 3 leaflets. Annular dilation and LT combined resulted in the largest increase in leaflet forces across all 3 leaflets.

Hypoplastic Left Heart Syndrome Across the Lifespan: Clinical Considerations for Care of the Fetus, Child, and Adult

Hypoplastic left heart syndrome (HLHS) is the most common anatomic lesion in children born with single ventricle physiology and is characterized by the presence of a dominant right ventricle and a hypoplastic left ventricle along with small left-sided heart structures. Diagnostic subgroups of HLHS reflect the extent of inflow and outflow obstruction at the aortic and mitral valves, specifically stenosis or atresia. If left unpalliated, HLHS is a uniformly fatal lesion in infancy. Following introduction of the Norwood operation, early survival has steadily improved over the past four decades, mirroring advances in operative and peri-operative management as well as reflecting refinements in patient surveillance and interstage clinical care. Notably, survival following staged palliation has increased from 0% to a 5-year survival of 60-65% for children in some centres. Despite the prevalence of HLHS in childhood with relatively favourable surgical outcomes in contemporary series, this cohort is only now reaching early adult life and longer-term outcomes have yet to be elucidated. In this article we focus on contemporary clinical management strategies for patients with HLHS across the lifespan, from fetal to adult life. Nomenclature and diagnostic considerations are discussed and current literature pertaining to putative genetic etiologies is reviewed. The spectrum of fetal and pediatric interventional strategies, both percutaneous and surgical, are described. Clinical, patient-reported and neurodevelopmental outcomes of HLHS are delineated. Finally, note is made of current areas of clinical uncertainty and suggested directions for future research are highlighted.

Surgical Strategies in Single Ventricle Management of Neonates and Infants

No area of congenital heart disease has undergone greater change and innovation than Single Ventricle management over the past 20 years. Surgical and catheter lab interventions have transformed outcomes such that in some subgroups more than 80% of these patients can survive into adulthood. Driven by parallel development in diagnostic imaging and cardiac intensive care, surgical management is focused on the neonatal period as the key time to creating a balanced circulation and limiting pulmonary blood-flow. Different configurations of the circulation including new types of surgical shunts and the role of 'hybrid' circulations provide greater options and better physiology. This overview will focus on these changes in surgical management and timing but also look at the exciting areas of regenerative therapies to improve ventricular function, and the concept of ventricular rehabilitation to achieve biventricular circulations in certain groups of patients. The importance of early (neonatal) intervention and multidisciplinary approach to management is emphasised, as well as looking beyond simply survival but also improving neurodevelopmental outcomes.

Insights from 3D Echocardiography in Hypoplastic Left Heart Syndrome Patients Undergoing TV Repair

BACKGROUND

Tricuspid regurgitation (TR) in hypoplastic left heart syndrome (HLHS) is associated with morbidity and mortality. TR mechanisms and the impact of tricuspid valve repair (TVR) are unclear. We examined HLHS TR mechanisms, TVR's impact on tricuspid valve (TV), and features of poor TVR durability.

METHODS

We retrospectively compared 35 HLHS TVR cases and 35 age/stage-matched HLHS controls who do not undergo TVR. Pre-operative 3-dimensional echocardiography (3DE) assessed overall TV morphology (prolapse, normal, tethered), leaflet morphology, vena contracta area, and TR location. Two-dimensional echocardiography measured TV annulus diameter, RV fractional area change (RVFAC), sphericity, and TR grade at three time points (pre-op, early post-op, and latest follow-up).

RESULTS

Pre-op, TVR group, and controls had no difference in age, RV function or shape, or TV dimension. TVR group most commonly had anterior leaflet prolapse followed by septal leaflet prolapse or tethering. TR jet arises centrally (63%) and anterior septally (26%). Posterior annuloplasty (69%), commissuroplasty (37%), and leaflet repair (37%) were surgical techniques commonly performed. At early post-op, TR grade and TV annulus decreased. At latest follow-up, TV annulus remained reduced; however, 50% had significant TR. 25% required TV reoperation. Larger vena contracta at TVR was associated with significant TR.

CONCLUSION

HLHS patients undergoing TVR had more anterior leaflet prolapse and central TR. While TVR initially reduces annular size and TR grade, 50% redevelop significant TR despite maintained annular reduction. The association of greater TR severity prior to repair with post-op recurrence raises the consideration for earlier repair of TR in HLHS patients.

De Vega Tricuspid Annuloplasty for Pediatric Patients: Growth Potential of the Plicated Annulus

Although De Vega annuloplasty is an important option for pediatric patients with functional tricuspid regurgitation (TR), little is known about its long-term results, including the future of the plicated annulus. We retrospectively reviewed our experience with pediatric patients who underwent the De Vega annuloplasty between 2005 and 2020. Tricuspid valve assessments were performed by transthoracic echocardiography. The targeted diameter of annular plication was 80 to 90% of normal tricuspid diameter, according to the patient's condition. The study included 55 patients (41 with biventricular physiology (group B), 14 with univentricular physiology (group U)) with a median follow-up of 5.0 years. Median age at operation was 5.0 years. There was one late death due to severe mitral regurgitation. Tricuspid valve reoperation was required in five patients and the 10-year freedom from reoperation was 91.9% for the entire cohort. The 10-year freedom from the composite adverse outcome of death, reoperation, and significant TR was 79.2% in group B versus 56.6% in group U (p = 0.034). TR grade significantly decreased after surgery (p < 0.001), without significant aggravation during the postoperative follow-up. No patients presented tricuspid stenosis. Mean Z-scores of annular diameter immediately after operation and at the latest follow-up were - 0.65 ± 0.56 versus - 0.47 ± 0.65 (p = 0.57). De Vega annuloplasty is a safe, efficient, and durable procedure for functional TR in pediatric patients including those with univentricular physiology, allowing adequate growth of the plicated annulus without the progression of tricuspid stenosis.

Outcomes of the Surgical Management of Atrial Isomerism and Functional Single Ventricle: A Single-Centered Cohort From China

Objectives: The management of atrial isomerism with complex congenital heart disease remains challenging. Experience has been largely obtained in advanced countries. The clinical diversity is greater in China. We evaluated the early- and medium-term outcomes of surgical treatment of these patients. Methods: We reviewed 86 patients of atrial isomerism with complex congenital heart disease undergoing varied surgeries in our center in 2008-2020. Cox regression models were used to analyze the risk factors for mortality. Results: There were 75 cases of right and 11 of left atrial isomerism. Eighty-three (96.5%) patients underwent single-ventricle staged palliation approach, with 10 early and 7 late deaths. The overall 1-, 5-, and 10-year survival rates were 84.7, 79.3, and 79.3%, respectively. Thirty-six (43.4%) patients completed the Fontan procedure with median age of 48 months and freedom from death or Fontan failure at 1-, 5-, and 8-years were 94.4, 87.4, and 80.7%, respectively. Concomitant total anomalous pulmonary venous connection [hazard ratio (HR): 5.15 (1.95-12.94), p = 0.008], more than moderate atrioventricular valve regurgitation [HR: 4.82 (2.42-6.79), p = 0.003], and the need for first-stage palliative surgery [HR: 4.58 (1.64-10.76), p = 0.015] were independent risk factors for mortality. Conclusions: Despite even greater clinical diversity, the surgical outcomes of atrial isomerism with complex congenital heart disease are improving in China. The early and intermediate outcomes are comparable to many previous reports. Concomitant total anomalous pulmonary venous connection, moderate or severe atrioventricular valve regurgitation, and the need for a first-stage palliative surgery are still independent risk factors for mortality.

Long-Term Outcomes of Atrioventricular Valve Surgery in Patients with Functional Single Ventricle: Should We Avoid Valve Replacement?

Atrioventricular valve regurgitation (AVVR) is associated with increased morbidity and mortality in patients with single ventricle physiology. The purpose of this study was to evaluate the long-term results of the surgical management of AVVR and to analyze the effects of AV valve replacement. The medical records of 38 single ventricle patients who underwent atrioventricular valve surgery more than once between January 2001 and March 2018 were retrospectively reviewed. We analyzed and compared clinical data of patients who underwent valve replacement as an initial treatment (n = 8) for AVVR with patients who initially underwent valve repair (n = 30). The median follow-up duration was 98.1 months (range, 0.9-209.6 months). There was one early mortality and seven late mortalities. Freedom from reoperation between the two groups at 15 years of follow-up was significantly different: 18.3% in the repair group and 100% in the replacement group (p = 0.013). The replacement group showed a better overall survival rate (100%) at 15 years than the repair group (68.5%) without statistical significance (p = 0.097). All mortalities occurred in the repair group. Nine patients in the repair group (30%) and one patient in the replacement group (12.5%) showed preoperative ventricular dysfunction. RV-type single ventricle with atrioventricular (AV) valve annular dilatation was found out as a risk factor of AVV replacement both in univariate (p = 0.04) and multivariate (p = 0.004) analysis. AV valve replacement might be considered as a primary treatment option for patients who have an annular dilation with an RV-type single ventricle rather than repeated valvuloplasty.

Impacts of stage 1 palliation and pre-Glenn pulmonary artery pressure on long-term outcomes after Fontan operation

OBJECTIVES

The present study was aiming to determine whether high mean pulmonary artery pressure before bidirectional cavopulmonary shunt is a risk factor for late adverse events in patients with low pulmonary artery pressure before total cavopulmonary connection (TCPC).

METHODS

We retrospectively reviewed the medical records of all patients undergoing both bidirectional cavopulmonary shunt and TCPC with available cardiac catheterization data.

RESULTS

A total of 316 patients were included in this study. The patients were divided into 4 groups according to mean pulmonary pressure: those with pre-Glenn <16 mmHg and pre-Fontan <10 mmHg (Group LL, n = 124), those with pre-Glenn ≥16 mmHg and pre-Fontan <10 mmHg (Group HL, n = 61), those with pre-Glenn <16 mmHg and pre-Fontan ≥10 mmHg (Group LH, n = 66) and those with pre-Glenn ≥16 mmHg and pre-Fontan ≥10 mmHg (Group HH, n = 65). Group HL showed significantly higher rate of adverse events after TCPC than Group LL (P = 0.02). In univariate linear analysis, a history of atrial septectomy at stage 1 palliation was associated with low pre-Glenn mean pulmonary artery pressure (Coefficient B -1.38, 95% confidence interval -2.53 to -0.24; P = 0.02), while pulmonary artery banding was a significant risk factor for elevated pre-Fontan mean pulmonary artery pressure (Coefficient B 1.68, 95% confidence interval 0.81 to 2.56, P < 0.001).

CONCLUSIONS

High mean pulmonary artery pressure before bidirectional cavopulmoary shunt (≥16mmHg) remains a significant risk factor for adverse events after TCPC even though mean pulmonary artery pressure decreased below 10 mmHg before TCPC.

Tricuspid valve repair in children with hypoplastic left heart syndrome: impact of timing and mechanism on outcome

OBJECTIVES

Our aim was to evaluate the results of tricuspid valve repair (TVr) in patients with hypoplastic left heart syndrome during staged reconstruction, focussing on the timing of the repair and the mechanisms of tricuspid regurgitation (TR).

METHODS

Records of 44 children with hypoplastic left heart syndrome who underwent a total of 62 tricuspid valve (TV) procedures during staged reconstruction were retrospectively analysed.

RESULTS

TVr was performed before stage II in 4 (9%) patients, at stage II in 23 (52%) patients, between stages II and III in 3 (7%) patients and at stage III in 14 (32%) patients. The median age at the first TV procedure was 5 months. At surgery, TR emanated commonly from the anteroseptal commissure in 21 (48%) patients. Anterior leaflet prolapse was observed most frequently (n = 23; 52%), followed by septal leaflet restriction (n = 22; 50%), dilated annulus (n = 21; 48%) and cleft anterior leaflet (n = 9; 21%). Surgical techniques included commissuroplasty in 27 (61.4%) patients, leaflet adaptation in 20 (44%) patients, partial annuloplasty in 11 (25%) patients, chordal reconstruction in 10 (23%) patients and cleft closure in 10 (23%) patients. Among all 44 patients, 27 (61%) patients had preoperative grade III TR and 17 (39%) patients had grade IV; postoperatively, there were no patients with grade IV, 25 patients with grade III (57%), 10 patients with grade II (23%) and 6 patients with grade I (14%). Fifteen patients required redo TV surgeries. Reoperation-free survival was 52% at 5 years. Lower weight at initial TVr predicted mortality [hazard ratio (HR) 0.7, P = 0.044] and reoperation (HR 0.8, P = 0.015). TVr before stage II was a risk for both reoperation (HR 5.5, P = 0.042) and TV replacement (HR 36.9, P = 0.013). Among morphological factors, septal leaflet restriction was a risk for reoperation (HR 4.7, P = 0.017) and anterior (HR 4.7, P = 0.037) and posterior (HR 7.3, P = 0.015) leaflet chordal anomaly for TV replacement.

CONCLUSIONS

Anterior leaflet prolapse and septal leaflet restriction are the main mechanisms of TR in hypoplastic left heart syndrome. Early-onset TR before stage II predicts worse outcome. Refinements to repair techniques in early infancy, especially for septal leaflet restrictions and chordal anomalies, are mandatory to improve outcomes.

Tricuspid Valve Tethering Is Associated with Residual Regurgitation after Valve Repair in Hypoplastic Left Heart Syndrome: A Three-Dimensional Echocardiographic Study

BACKGROUND

Tricuspid valve regurgitation (TR) is a risk factor for morbidity and mortality in children with hypoplastic left heart syndrome (HLHS). Surgical tricuspid valve (TV) repair is common, but durable repair remains challenging. The aim of this study was to examine mechanisms of TR requiring surgery, features associated with unsuccessful repair, and TV changes after surgical repair.

METHODS

Thirty-six patients with HLHS requiring TV repair (TVR) and 36 matched control subjects with HLHS were assessed using two-dimensional and three-dimensional echocardiography. Using three-dimensional echocardiography, TV coordinates from the annulus, leaflet, and ventricle were used to measure annular, leaflet, prolapse, and tethering values and anterior papillary muscle angle. TR grade and ventricular size, function, and shape were assessed using two-dimensional echocardiography.

RESULTS

Patients requiring TVR had greater total leaflet prolapse, larger TV annular and leaflet areas, and flatter annuli, with no difference in tethering, coaptation index, or anterior papillary muscle angle. In patients with HLHS, successful TVR at follow-up (58%) was associated with preoperative total leaflet prolapse (especially posterior). Unsuccessful repair was associated with preoperative tethering of the septal leaflet. TVR in patients with HLHS caused a reduction of total annular and leaflet size and reduced prolapse and tethering of the posterior leaflet but did not affect anterior leaflet prolapse or septal leaflet tethering.

CONCLUSIONS

Features associated with TVR include a flattened and dilated TV annulus with leaflet prolapse. The additional presence of a tethered septal leaflet before TVR is associated with significant postoperative TR. Current surgical techniques, predominantly posterior annuloplasty and commissuroplasty, adequately address annular size and posterior leaflet pathology, but not septal leaflet tethering. Individualized and innovative surgical techniques are vital to improve surgical repair success.

Valvular heart disease in congenital heart disease: a narrative review

Patients with congenital heart disease (CHD) are one of the fastest growing populations in cardiology, and valvular pathology is at the center of many congenital lesions. Derangements in valvular embryology lead to several anomalies prone to dysfunction, each with hemodynamic effects that require appropriate surveillance and management. Surgical innovation has provided new treatments that have improved survival in this population, though has also contributed to esotericism in patients who already have unique anatomic and physiologic considerations. Conduit and prosthesis durability are often monitored collaboratively with general and specialized congenital-focused cardiologists. As such, general cardiologists must become familiar with valvular disease with CHD for appropriate care and referral practices. In this review, we summarize the embryology of the semilunar and atrioventricular (AV) valves as a foundation for understanding the origins of valvular CHD and describe the mechanisms that account for heterogeneity in disease. We then highlight the categories of pathology from the simple (e.g., bicuspid aortic valve, isolated pulmonic stenosis) to the more complex (e.g., Ebstein's anomaly, AV valvular disease in single ventricle circulations) with details on natural history, diagnosis, and contemporary therapeutic approaches. Care for CHD patients requires collaborative effort between providers, both CHD-specialized and not, to achieve optimal patient outcomes.

Common atrioventricular valve surgery in children with functional single ventricle

OBJECTIVES

A common atrioventricular valve (CAVV) is considered to be a risk factor for early and late deaths in patients with functional single ventricle (FSV). CAVV surgery in patients with FSV is challenging and there is limited knowledge of the outcomes of CAVV repair with univentricular physiology.

METHODS

We reviewed all CAVV surgical procedures in patients with FSV who underwent univentricular palliation. End points of the study were survival after CAVV surgery and cumulative incidence of reoperation.

RESULTS

Between 1984 and 2019, 66 children with CAVV and FSV underwent single-ventricle palliation, of whom 45.5% (30/66) required CAVV surgery. Indication for surgery was moderate CAVV regurgitation in 40% (12/30) and severe CAVV regurgitation in 60% (18/30). CAVV repair was performed in 93.3% (28/30) and CAVV replacement in 6.7% (2/30). The median age and weight at surgery were 0.9 years (interquartile range 0.3-1.8) and 6.5 kg (interquartile range 3.9-8.7), respectively. Operative and late mortality were 23.3% and 8.7%, respectively. Survival and cumulative incidence of reoperation at 4 years after CAVV surgery were 68.9% [standard deviation (SD): 8.7] and 35.8% (SD: 9.1), respectively. Fontan completion was achieved in 60% (18/30). Survival at 4 years after birth was 69.7% (SD: 8.5) in 30 patients with CAVV surgery, whereas it was 83% (SD: 6.3) in 36 patients without CAVV surgery (P = 0.32).

CONCLUSIONS

CAVV surgery in patients with FSV is associated with substantial mortality and a high incidence of reoperation.

Tricuspid Regurgitation in Hypoplastic Left Heart Syndrome: Three-Dimensional Echocardiography Provides Additional Information in Describing Jet Location

BACKGROUND

Twenty-five percent of patients with hypoplastic left heart syndrome (HLHS) require tricuspid valve (TV) repair. The location of tricuspid regurgitation (TR) is important in determining the type of repair performed. Studies using three-dimensional echocardiography (3DE) have reported a high incidence of error on two-dimensional echocardiography (2DE) for the identification of TV leaflets. The aim of this study was to compare assessment of TR on 3DE and 2DE in patients with HLHS (jet location, TR grade, and reproducibility).

METHODS

A retrospective, single-center review was performed. Fifty-six patients with HLHS with available two-dimensional and three-dimensional echocardiograms, and mild or greater TR, were included. TR location, grade, vena contracta area, and TV annular diameter were measured on 2DE and 3DE. Reproducibility was assessed by blinded reviewers.

RESULTS

Three-dimensional echocardiography identified the primary jet location as central (57%) followed by anteroseptal (36%). There was poor agreement between findings on 3DE and 2DE for jet location (κ = 0.05; 95 CI, -0.08 to 0.19). Interobserver reproducibility for location on 3DE was excellent (κ = 0.8), whereas reproducibility for 2DE was poor (κ = 0.32). The most common jet location pre-Norwood and pre-Glenn was central (70%), whereas pre-Fontan and post-Fontan, jet location was central (45%) and anteroseptal (48%). Vena contracta area on 2DE correlated moderately with vena contracta area on 3DE (r = 0.60, P < .0001). TV annular diameters on 2DE and 3DE for lateral (r = 0.85, P < .0001) and anteroposterior (r = 0.74, P = .001) dimensions were strongly correlated.

CONCLUSIONS

In children with HLHS, assessment of TR location on 2DE had poor agreement with assessment on 3DE and was poorly reproducible. In contrast, TR jet location on 3DE was highly reproducible. Pre-Glenn, a central TR jet was the most common, while post-Glenn, central and anteroseptal locations were equal, highlighting the importance of preoperative identification of TR jet location in patients with HLHS.

Effect of Earlier Atrioventricular Valve Intervention on Survival After the Fontan Operation

Whereas the prevalence and impact of atrioventricular valve (AVV) regurgitation in patients with single ventricle physiology has become increasingly apparent, the optimal timing for valve intervention is unclear. To investigate this, we performed a retrospective review of all 1,167 patients from the Mayo Clinic Fontan database. Thirteen percent (153 patients) had AVV repair or replacement during their staged single ventricle palliation. We found that patients with right ventricular morphology and common AVV were at increased risk for AVV intervention. Patients who underwent AVV intervention had increased risk of death/transplant compared with those who did not (hazards ratio [HR] = 1.75, 95% CI 1.37 to 2.23, p <0.001). With respect to valve intervention timing, whereas AVV intervention before Fontan presented similar risk for death/transplant compared with no AVV intervention (HR = 0.85, 95% CI 0.32 to 2.27, p = 0.74), intervention at time of Fontan had a significantly higher risk (HR = 1.46, 95% CI 1.09 to 1.97, p = 0.01), and intervention after Fontan had a much more substantial risk (HR = 3.83, 95% CI 2.54 to 5.79, p <0.001). AVV repair failure occurred in 11% of patients. In terms of relative risk of valve repair versus replacement, in post-Fontan AVV intervention patients, AVV replacement carried a 2.9 fold risk of death/transplant compared with AVV repair. In conclusion, AVV disease remains a considerable challenge for durable Fontan physiology. This data demonstrates that earlier intervention on valve pathology improves survival with the Fontan circulation. Continued surveillance of single ventricle patients and prompt referral of those with valve pathology can improve outcomes in this challenging population.

Percutaneous transcatheter occlusion of left atrioventricular valve in a patient with single ventricle and severe atrioventricular valve regurgitation

Many patients with single ventricle physiology suffer from atrioventricular valve (AVV) regurgitation which may worsen their cardiac function and cause symptoms. It has been postulated that elimination of the nondominant hypoplastic AVV regurgitation, might improve the clinical status in patients post-Fontan surgery. We describe a case of hypoplastic left heart variant, post Fontan surgery who had severe left AVV regurgitation and underwent percutaneous transcatheter occlusion of the hypoplastic left AVV, using a VSD occluder device. At 3 months post procedure, the patient is improved. Transcatheter closure of a regurgitant hypoplastic AVV in a patient with single ventricle helps to improve the patient's cardiac function and clinical status.

Impact of intrapulmonary-artery septation to pulmonary vein obstruction for two-lung Fontan

OBJECTIVES

Patients with unbalanced pulmonary artery (PA) growth and decreased unilateral pulmonary circulation are considered unsuitable candidates for the Fontan procedure. Following our previous study on the utility of intrapulmonary-artery septation for patients with PA hypoplasia, we investigated its use in patients with pulmonary venous obstruction (PVO).

METHODS

We recruited 42 patients who underwent intrapulmonary-artery septation for unilateral PA hypoplasia and/or PVO between 1998 and 2018 and classified them into no PVO or PVO group. We analysed overall survival, success of the Fontan procedure and data from catheterization and echocardiography. In PVO, we evaluated the functional lung area before the Fontan procedure and the relevance of this parameter to operative outcomes.

RESULTS

The PVO and no-PVO group included 24 and 18 patients, respectively. One patient in the no-PVO and 6 patients in the PVO group died during follow-up; this difference was statistically significant (log-rank P = 0.040). In the no-PVO group, 15 (83%) patients achieved two-lung Fontan circulation. In the PVO group, 12 (50%) patients achieved two-lung Fontan circulation. Multivariate analysis revealed that functional lung area and shunt size [significantly larger in patients with functional lung area ≥50% in affected lung (P = 0.040)] were significant factors for successful two-lung Fontan procedure (P = 0.030).

CONCLUSIONS

Intrapulmonary-artery septation may contribute to increase functional lung area after PVO release to establish two-lung Fontan circulation in patients with PVO who have unbalanced PA growth and/or decreased unilateral pulmonary circulation.

Atrioventricular Valve Regurgitation in Single Ventricle Heart Disease: A Common Problem Associated With Progressive Deterioration and Mortality

The Fontan procedure has provided patients with single ventricle physiology extended survival into adulthood and in many cases has improved their quality of life. Atrioventricular valve regurgitation (AVVR) is common in single ventricle patients and is associated with increased risk of mortality. AVVR is more common in patients with a systemic tricuspid or common atrioventricular valve but is generally progressive irrespective of underlying valve morphology. AVVR can be attributable to diverse structural and functional abnormalities at multiple levels of the valvar apparatus, as well as ventricular dysfunction and dilation. Multiple imaging modalities including recent advances in 3‐dimensional echocardiography and cross‐sectional imaging have been used to further understand AVVR. Surgery to address AVVR must be tailored to the underlying mechanism and the timing of surgical repair should be chosen carefully. In this review, we discuss the etiologies, treatment options, surgical timing, and outcomes of valve repair or replacement for AVVR in patients with single ventricle congenital heart disease, with a focus on those with a Fontan circulation as AVVR is associated with increased risk for Fontan failure and mortality. In‐depth understanding of the current literature will help guide clinicians in their approach and management of AVVR in this population.

Direct measurement of atrioventricular valve regurgitant jets using 4D flow cardiovascular magnetic resonance is accurate and reliable for children with congenital heart disease: a retrospective cohort study

BACKGROUND

3D-time resolved flow (4DF) cardiovascular magnetic resonance (CMR) with retrospective analysis of atrioventricular valve regurgitation (AVVR) allows for internal validation by multiple direct and indirect methods. Limited data exist on direct measurement of AVVR by 4DF CMR in pediatric congenital heart disease (CHD). We aimed to validate direct measurement of the AVVR jet as accurate and reliable compared to the volumetric method (clinical standard by 2D CMR) and as a superior method of internal validation than the annular inflow method.

METHODS

We identified 44 consecutive patients with diverse CHD referred for evaluation of AVVR by CMR. 1.5 T or 3 T scanners, intravenous contrast, and a combination of parallel imaging and compressed sensing were used. Four methods of measuring AVVR volume (RVol) were used: volumetric method (VOL; the clinical standard) = stroke volume by 2D balanced steady-state free precession - semilunar valve forward flow (SLFF); annular inflow method (AIM) = atrioventricular valve forward flow [AVFF] - semilunar valve net flow (SLNF); and direct measurement (JET). AVFF was measured using static and retrospective valve tracking planes. SLFF, SLNF, AVFF, and JET were measured by 4DF phase contrast. Regurgitant fraction was calculated as [RVol/(RVol+SLNF)]× 100. Statistical methods included Spearman, Wilcoxon rank sum test/Student paired t-test, Bland Altman analysis, and intra-class coefficient (ICC), where appropriate.

RESULTS

Regurgitant fraction by JET strongly correlated with the indirect methods (VOL and AIM) (ρ = 0.73-0.80, p < 0.001) and was similar to VOL with a median difference (interquartile range) of - 1.5% (- 8.3-7.2%; p = 0.624). VOL had weaker correlations with AIM and JET (ρ = 0.69-0.73, p < 0.001). AIM underestimated RF by 3.6-6.9% compared to VOL and JET, p < 0.03. Intra- and inter- observer reliability were excellent for all methods (ICC 0.94-0.99). The mean (±standard deviation) inter-observer difference for VOL was 2.4% (±5.1%), p < 0.05.

CONCLUSIONS

In a diverse cohort of pediatric CHD, measurement of AVVR using JET is accurate and reliable to VOL and is a superior method of internal validation compared to AIM. This study supports use of 4DF CMR for measurement of AVVR, obviating need for expert prospective prescription during image acquisition by 2D CMR.

Percutaneous edge-to-edge repair for common atrioventricular valve regurgitation in a patient with heterotaxy syndrome, single ventricle physiology, and unbalanced atrioventricular septal defect

Congenital heart disease patients, specifically with unbalanced atrioventricular septal defects and common atrioventricular valves requiring single ventricle palliation, have substantial morbidity and mortality. Atrioventricular valve regurgitation (AVVR) is associated with poor outcomes in single ventricle patients, and many of them require surgical treatment of AVVR in their lifetimes. We describe a unique case of transcatheter edge-to-edge valve repair using the MitraClip system (Abbott, Chicago, IL) in a single ventricle patient with severe common AVVR.

Atrioventricular Valve Repair in Single Ventricle Physiology: Timing Matters

OBJECTIVES

Atrioventricular valve (AVV) regurgitation in patients with single ventricle (SV) physiology severely impacts prognosis; the appropriate timing for surgical treatment is unknown. We sought to study the results of surgical treatment of AVV regurgitation in SV patients and evaluate risk factors for mortality.

METHODS

Medical records of 81 consecutive patients with moderate or severe AAV regurgitation who were submitted to AVV repair or replacement during any stage of univentricular palliation between January 2013 and May 2017 were examined. We studied demographic data and perioperative factors looking for predictors that might have influenced the results. Binary logistic regression was used to assess the impact on postoperative ventricular dysfunction and mortality.

RESULTS

Median age and weight were seven months (interquartile range [IQR]: 3-24) and 5.2 kg (IQR: 3.7-11.2), respectively. Seventy (86.4%) patients underwent AVV repair, and 11 (13.6%) patients underwent AVV replacement. There was an association between AVV repair effectiveness and timing of intervention (P = .004). Atrioventricular valve intervention at the time of initial surgical palliation was associated with more ineffective repairs (P = .001), while AVV replacement was more common between Glenn and Fontan procedures (P = .004). Overall 30-day mortality was 30.5% (25 patients). In-hospital mortality was 49.4%, and it was higher when AVV repair was performed concomitant with initial (stage 1) palliation (64.1% vs 35.7%; P = .01) and when an effective repair was not achieved (75% vs 41%; P = .008). Multivariable analysis identified timing concomitant with stage 1 palliation as an independent risk factor for mortality (P = .01); meanwhile, an effective repair was a protective factor against in-hospital mortality (P = .05).

CONCLUSION

Univentricular physiology with AVV regurgitation is a high-risk group of patients. Surgery for AVV regurgitation at stage 1 palliation was associated with less effective repair and higher mortality in this initial experience. On the other hand, effective repair determined better outcomes, highlighting the importance of experience and the learning curve in the management of such patients.

Outcomes of Multistage Palliation of Infants With Single Ventricle and Atrioventricular Septal Defect

Background:

Published palliation outcomes of infants with functional single ventricle (SV) and common atrioventricular septal defect (AVSD) are poor due to associated cardiac and extracardiac anomalies and development of atrioventricular valve (AVV) regurgitation. We report current palliation results.

Methods:

From 2002 to 2012, 80 infants with functional SV with AVSD underwent multistage palliation. Competing-risks analyses modeled events after first-stage surgery and Glenn (death/transplantation vs next palliation surgery) and examined factors associated with survival and AVV intervention.

Results:

Sixty-eight (80%) patients received neonatal palliation: modified Blalock-Taussig shunt (n = 33, 41%), Norwood (n = 20, 25%), and pulmonary artery band (n = 15, 19%), whereas 12 (15%) received primary Glenn. On competing-risks analysis, one-year following first-stage surgery, 29% of patients had died or received transplantation and 62% had undergone Glenn. Five years following Glenn, 9% of patients had died or received transplantation and 68% had undergone Fontan. Overall eight-year survival was 64% and was lower in patients with genetic syndromes (53% vs 82%), patients requiring concomitant total anomalous pulmonary venous connection repair (53% vs 69%), and those requiring neonatal palliation (48% vs 100%). Factors associated with mortality were unplanned reoperation (hazard ratio [HR]: 3.7 [1.7-8.0], P = .001) and extracorporeal membrane oxygenation use (HR: 7.1 [3.0-16.6], P < .001). Initial AVV regurgitation ≥ moderate was associated with AVV intervention (HR: 6.2 [2.4-16.1], P = .002) with eight-year freedom from death or AVV intervention of 25% in those patients.

Conclusions:

Patients with SV with AVSD are a distinct group and commonly have associated cardiac and extracardiac malformations that complicate care and affect survival. The development of AVV regurgitation requiring intervention is common but does not affect survival.

Impact of Gestational Age on Surgical Outcomes in Patients With Functionally Single Ventricle

BACKGROUND

Younger gestational age (GA) is known to be associated with worse outcomes after congenital cardiac surgery. We sought to determine the impact of GA on surgical outcomes of single-ventricle palliation.

METHODS

Among the 284 patients with functionally single ventricle who were born between January 2005 and December 2014, 50 neonates were born prematurely (GA < 37 weeks) and 113 neonates in the early term period (37 weeks ≤ GA < 39 weeks). Initial palliation was required in 251 patients, whereas 33 patients received primary bidirectional cavopulmonary anastomosis (BCPA).

RESULTS

BCPA and the completion Fontan operation were performed in 200 and 169 patients, respectively. Overall survival at 5 years were 62.5% ± 2.9%. On Cox regression younger GA (hazard ratio, 1.14 per 1-week decrease; P = .007) was identified as a risk factor for increased interstage mortality (ISM) between initial palliation and BCPA. On subgroup analysis of the preterm or early-term patients with initial palliation (n = 145), younger postmenstrual age at initial palliation was associated with increased ISM before BCPA (hazard ratio, 1.18; P = .005). After BCPA, however, younger GA did not increase the risk of ISM between BCPA and the Fontan operation (P = .47).

CONCLUSIONS

Younger GA is a risk factor for ISM between initial palliation and BCPA. Deferral of initial palliation may be beneficial to decrease the risk of ISM in patients who were born at preterm or early term. Adverse effects of younger GA on survival disappeared once BCPA was performed.

Impact of Right Ventricular Geometry and Left Ventricular Hypertrophy on Right Ventricular Mechanics and Clinical Outcomes in Hypoplastic Left Heart Syndrome

BACKGROUND

Right ventricular (RV) function is a major determinant of survival in hypoplastic left heart syndrome (HLHS). However, the relation of RV geometry to myocardial mechanics and their relation to transplant-free survival are incompletely characterized.

METHODS

We retrospectively studied 48 HLHS patients from the Hospital for Sick Children, Toronto, (median age, 2.2; interquartile range, 3.62 years) at different surgical stages. Patients were grouped by the presence (n = 23) or absence (n = 25) of RV "apical bulging" defined as a sigmoid-shaped septum with the RV leftward apical segment contiguous with the left ventricular (LV) lateral wall. Regional and global RV strain were measured using speckle-tracking echocardiography, and regional strains were analyzed for patterns and peak values. These were compared between HLHS anatomical subtypes and between patients with versus without apical bulging. We further investigated the association between RV geometry and dysfunction with the outcomes of heart failure, death, or transplant.

RESULTS

RV global (-7.3% ± 2.8% vs -11.2% ± 4.4%; P = .001), basal septal (-3.8% ± 3.2% vs -11.4% ± 5.8%; P = .0001) and apicolateral (-5.1% ± 3.5% vs -8.0% ± 5.8%, P = .001) longitudinal strain were lower in patients with versus without apical bulging, respectively. Apical bulging was equally prevalent in all HLHS anatomical variants. Twenty of 22 (91%) patients with apical bulging displayed hypertrophy of the LV apical and lateral segments. Death or transplantation were approximately equal in both groups but related to reduced RV global strain in patients with (seven of seven) and not in those without apical bulging (two of eight; P = .022).

CONCLUSIONS

These results suggest that the finding of apical bulging is related to the presence of a hypertrophied hypoplastic LV, with a negative impact on regional and global RV function. Therefore, analysis of RV and LV geometry and mechanics may aid in the assessment and prognostication of this high-risk population.

Postoperative heart failure after stage 1 palliative surgery for single ventricle cardiac disease

Outcomes for patients with single ventricle congenital heart disease (SV-CHD) continue to improve over time. However, the prognosis for patients who develop heart failure immediately after surgery is poorly understood. We conducted a single-center, retrospective cohort study of patients with SV-CHD, who suffered postoperative heart failure. Of 1038 cardiac surgeries performed on 621 SV-CHD patients between 2004 and 2010, 125 patients met inclusion criteria, including non-septatable anatomy, stage 1 surgery, and verified low cardiac output or heart failure state per STS definition. Overall survival was 73.2% at 2 months, 64.9% at 1 year, 60.5% at 2 years, and 54.6% at 4 years. Inotrope dependence beyond 7 days post-op yielded 45% 2-year survival versus 68% for those who weaned from inotropes within 7 days (p = 0.02). Atrioventricular valve regurgitation (AVVR) influenced survival, and patients who developed renal failure or required ECMO fared poorly, even when they survived their hospitalization. Patients with postoperative heart failure and low cardiac output syndrome constitute a high-risk population beyond the term of the initial hospitalization and have an overall mid-term survival of 55% at 4 years. Wean from inotropic therapy is not completely reassuring in this population, as they have ongoing elevated risk of cardiac failure and death in the medium term. Ventricular dysfunction, AVVR, renal failure, and need for ECMO are all important prognostic factors for mid-term mortality. Inotrope dependence for > 7 days has important implications reaching beyond the hospitalization.

The Degree of Left Ventricular Hypoplasia Is Associated with Tricuspid Regurgitation Severity in Infants with Hypoplastic Left Heart Syndrome

Tricuspid valve regurgitation (TR) increases adverse outcomes in children with hypoplastic left heart syndrome (HLHS). Changes in tricuspid valve (TV) annulus and leaflet geometry have been described but the underlying causes for TR in HLHS remain uncertain. We aimed to examine the association between left ventricular (LV) size and TR in infants with HLHS as right ventricular (RV)-LV interactions may be important in TR development. Echocardiograms of 50 infants with HLHS were reviewed. LV size, RV function, TR grade, TV annulus z-score, and aortic arch obstruction were examined at birth and 1 year of age (or the latest study post-bidirectional Glenn anastomosis if the patient was < 1 year of age). 24/50 (48%) had severe LV hypoplasia and 26/50 (52%) had mild/moderate LV hypoplasia. At 1 year, 10/24 (42%) with severe LV hypoplasia had moderate/severe TR versus 0/26 in the mild/moderate LV hypoplasia group (p = 0.0002). TR progressed ( ≥ 1 grade) in 14/24(58%) with severe LV hypoplasia versus 5/26 (19%) with mild/moderate LV hypoplasia (p = 0.008). In this cohort, no association was found between the degree of TR and either RV function, TV annular z-score, or arch obstruction; or between the degree of LV hypoplasia and either RV function or TV annular z-score. In infants with HLHS, the severity and progression of TR is associated with the severity of LV hypoplasia. The mechanism for this association needs further exploration but suggests a role for RV-LV interactions in the development of TR.