Ryan R. Davies

Listing and Transplanting Adults With Congenital Heart Disease

Background— An increasing number of patients with congenital heart disease (CHD) are reaching adulthood and may require heart transplantation. The survival of these patients after listing and transplantation has not been evaluated. Methods and Results— A total of 41 849 patients (aged >18 years) were listed for primary transplantation during 1995–2009. Patients with a history of CHD (n=1035; 2.5%) were compared with those with other causes (non-CHD group) (n=40 814; 97.5%); 26 055 (62.3%) reached transplantation and were subdivided into those with (reoperation group; n=10 484; 40.2%) and without (nonreoperation group; n=15 571; 59.8%) a previous sternotomy. Survival on the waiting list was similar between groups, but mechanical ventricular assistance was not associated with superior survival to transplantation among CHD patients. CHD patients were more likely to have body mass index <18.5 at transplantation (P<0.0001), were younger, and had fewer comorbidities. Early mortality among patients with CHD was high (reoperation, 18.9% versus 9.6%; P<0.0001; nonreoperation, 16.6% versus 6.3%; P<0.0001), but by 10 years, overall survival was equivalent (53.8% versus 53.6%). Analysis was limited by the lack of specific information regarding the CHD diagnosis in most patients. Conclusions— Adults with CHD have high 30-day mortality but better late survival after heart transplantation. Mechanical circulatory assistance does not improve waiting list survival in these patients. This may be due to a combination of highly complex reoperative surgery and often poor preoperative systemic health.

Outcomes after transplantation for “failed” Fontan: A single-institution experience

OBJECTIVE Despite the excellent outcomes in the current era after the Fontan procedure, it continues to have an inherent risk of failure. Cardiac transplantation provides 1 option for treating these patients; however, the indications for, timing of, and outcomes after, transplantation remain undefined. We examined our own institutional experience with transplantation for failed Fontan. METHODS The records of 155 patients transplanted for congenital heart disease at a single institution from June 1984 to September 2007 were reviewed. Of these patients, 43 had undergone a previous Fontan procedure (25 male, 15 female; median age, 14.5 years; range, 1-47; 23 classic Fontan, 13 lateral tunnel, 4 extracardiac conduit, and 3 revised to shunt). The predictors of short- and long-term survival were evaluated, and the Fontan patients were compared with all other patients with congenital heart disease (n = 129, 78 male, 51 female). RESULTS The most common indications for transplantation included protein-losing enteropathy (PLE) (39.5%), chronic heart failure (41.8%), and acute post-Fontan failure (9.3%). The transplants performed in Fontan patients were more likely to require pulmonary artery reconstruction (85.4% vs 42.9%; P < .0001) and had longer cardiopulmonary bypass times (278 vs 179 minutes; P < .0001). The 90-day mortality rate was greater in the Fontan group (35.0% vs 20.0%; P = .055). No correlation was observed between the interval from Fontan to transplantation and morality; however, renal failure was a strong predictor of early mortality (odds ratio, 10.8; 95% confidence interval, 1.5-75.7). CONCLUSIONS Transplantation is an acceptable treatment for patients with a failed Fontan. Clinical factors (instead of the indication for transplantation) appear to have the greatest correlation with early mortality.

Bilateral pulmonary arterial banding results in an increased need for subsequent pulmonary artery interventions.

OBJECTIVE Despite increasing use of bilateral branch pulmonary artery banding (bPAB), both as a temporary stabilizing treatment and as part of comprehensive hybrid management of hypoplastic left heart syndrome, little is known about the long-term outcomes of the pulmonary arteries (PAs) in banded patients. PATIENTS AND METHODS We conducted a retrospective review of all patients with ductal-dependent systemic circulation (2001-2013) undergoing bPAB placement at a single institution (bPAB, n = 50); patients who underwent a stage I Norwood procedure (Norwood, n = 53) were used for comparison. The need for PA interventions (surgical arterioplasty, balloon angioplasty, and stent implantation) and PA growth were assessed. RESULTS Bands were in place for a median of 76 days. PA growth and size were similar between groups, but bPAB patients required more interventions (1.4 ± 2.9 vs 0.5 ± 1.2, P = .01). In competing risks analysis, only 20% of bPAB patients were alive and free from intervention at 5 years after bPAB removal. Multivariable Cox proportional hazards regression of operative interventions within the bPAB group demonstrated the following risk factors: subsequent 2-ventricle repairs (hazard ratio [HR], 2.2; 95% confidence interval [CI], 0.7-6.7), smallest band diameter (HR per additional millimeter, 0.059; 95% CI, 0.004-0.849), and duration of band placement more than 90 days (HR, 3.5; 95% CI, 1.0-12.6). Hemodynamics and Fontan candidacy did not differ between groups. CONCLUSIONS Patients with bPAB require additional interventions at earlier time points than Norwood patients. Patients with smaller bands and longer duration of banding are at high risk. Despite stenoses requiring additional interventions, Fontan candidacy is maintained.

Predictive value of perioperative near-infrared spectroscopy for neurodevelopmental outcomes after cardiac surgery in infancy

OBJECTIVE The study objective was to expand on prior research examining intraoperative regional cerebral oxygen saturation (rSO(2)) measured by near-infrared spectroscopy (NIRS) by evaluating the predictive value of perioperative NIRS monitoring for neurodevelopmental outcomes after infant cardiac surgery. METHODS Cross-sectional neurodevelopmental evaluation at 24 months of age with the Bayley Scales of Infant and Toddler Development, Third Edition was performed for patients who underwent cardiac surgery with perioperative NIRS monitoring between 2007 and 2010. Retrospective clinical data were extracted from the electronic medical record. Evaluation of selected NIRS measures, including preoperative rSO(2) (baseline) as well as rSO(2) nadir and percent decrease from baseline during the intraoperative and early postoperative periods, was undertaken. RESULTS Perioperative NIRS and neurodevelopmental data were available for 31 patients without chromosomal anomalies who underwent cardiac surgery during infancy at a median age of 0.43 months. Optimal thresholds on NIRS measures identified through receiver operating characteristic analyses were intraoperative percent decrease of 52% for receptive communication delay and postoperative rSO(2) nadir of 56% for cognitive delay and 49% for gross motor delay. When considered in conjunction with other clinical characteristics in stepwise linear regression analyses, intraoperative percent decrease of more than 52% entered into the final model for receptive communication outcome and postoperative rSO(2) nadir of less than 56% entered into the final model for cognitive outcome. CONCLUSIONS Perioperative NIRS monitoring seems to enhance the ability to predict neurodevelopmental outcome. Specific NIRS measures associated with neurodevelopmental outcome, as well as optimal thresholds, seem to differ across the continuum of the perioperative period.

Ventricular assist devices as a bridge-to-transplant improve early post-transplant outcomes in children

BACKGROUND The use of ventricular assist devices (VADs) to bridge pediatric patients to transplant or recovery has been expanding. There are few current pediatric data assessing the impact of VAD support on post-transplant survival. METHODS We performed a retrospective review of all pediatric (≤18 years old, n = 4,028) transplants performed between 1995 and 2011 and contained within the United Network for Organ Sharing data set. Transplants were divided into three eras: early (1995 to 2002, n = 1,450); intermediate (2003 to 2007, n = 1,138); and recent (2008 to 2011, n = 1,440). VADs were present at transplant in 398 patients (9.8%). Outcomes among patients with and without VADs were assessed and compared across eras. RESULTS The use of VADs for bridge to transplant has increased (early 1.1%, intermediate 10.5%, recent 17.9%; p < 0.0001). Mean weight among VAD-supported patients (early 63.5 kg, intermediate 42.3 kg, recent 28.8 kg; p < 0.0001) has decreased during this period. VAD patients <10 kg had an increased risk of stroke (odds ratio [OR] = 4.9, 95% confidence interval [CI] 2.1 to 10.8) compared with non-mechanical support patients. In multivariable analyses, extracorporeal VADs were the only type of VAD associated with higher post-transplant mortality (OR = 3.0, 95% CI 0.8 to 10.6). Other types of VAD had lower mortality (OR = 0.5, 95% CI 0.2 to 1.0). Long-term survival was unaffected by the use of a VAD pre-transplant. CONCLUSIONS Pediatric patients bridged to transplantation with VADs are increasingly younger and smaller. Complication rates remain high among patients <10 kg. Early post-transplant survival among intracorporeal and paracorporeal VAD patients is excellent and better when compared with unsupported patients. The use of short-term support devices is associated with higher post-transplant mortality. Long-term survival is unaffected by VAD use.

Longitudinal Assessment of Growth in Hypoplastic Left Heart Syndrome: Results From the Single Ventricle Reconstruction Trial

Background We sought to characterize growth between birth and age 3 years in infants with hypoplastic left heart syndrome who underwent the Norwood procedure. Methods and Results We performed a secondary analysis using the Single Ventricle Reconstruction Trial database after excluding patients <37 weeks gestation (N=498). We determined length‐for‐age z score (LAZ) and weight‐for‐age z score (WAZ) at birth and age 3 years and change in WAZ over 4 clinically relevant time periods. We identified correlates of change in WAZ and LAZ using multivariable linear regression with bootstrapping. Mean WAZ and LAZ were below average relative to the general population at birth (P<0.001, P=0.05, respectively) and age 3 years (P<0.001 each). The largest decrease in WAZ occurred between birth and Norwood discharge; the greatest gain occurred between stage II and 14 months. At age 3 years, WAZ and LAZ were <−2 in 6% and 18%, respectively. Factors associated with change in WAZ differed among time periods. Shunt type was associated with change in WAZ only in the Norwood discharge to stage II period; subjects with a Blalock‐Taussig shunt had a greater decline in WAZ than those with a right ventricle‐pulmonary artery shunt (P=0.002). Conclusions WAZ changed over time and the predictors of change in WAZ varied among time periods. By age 3 years, subjects remained small and three times as many children were short as were underweight (>2 SD below normal). Failure to find consistent risk factors supports the strategy of tailoring nutritional therapies to patient‐ and stage‐specific targets. Clinical Trial Registration URL: http://clinicaltrials.gov/. Unique identifier: NCT00115934.

Lower socioeconomic status is associated with worse outcomes after both listing and transplanting children with heart failure.

The relationship between SES and outcomes surrounding pediatric cardiac transplantation is complex and influenced by recipient race. Broad‐based studies of SES have not been performed. A retrospective review of all 5125 primary pediatric heart transplants performed in the United States between 2000 and 2011. Patients were stratified by SES based on zip code of residence and U.S. census data (low SES: 1637; mid‐SES: 2253; high SES: 1235). Survival following listing and transplantation was compared across strata. Risk‐adjusted long‐term mortality on the waitlist was higher among low SES patients (hazard 1.32, CI 1.07–1.63). The relationship between SES and outcomes varied by race. Early risk‐adjusted post‐transplant outcomes were worst among high SES patients (10.8% vs. low SES: 8.9%, p < 0.05). The incidence of non‐compliance was higher among low SES patients (p < 0.0001). Long‐term risk‐adjusted patient survival was poorer among low (hazard 1.41, CI 1.10–1.80) and mid‐SES (1.29, 1.04–1.59) groups. Low SES is associated with worse outcomes on both the waitlist and late following transplantation. Higher SES patients had more complex transplants with higher early mortality. Further research should be directed at identifying and addressing underlying causal factors for these disparities.

Current Spectrum of Surgical Procedures Performed for Ebstein's Malformation: An Analysis of The Society of Thoracic Surgeons Congenital Heart Surgery Database

BACKGROUND Ebsteins malformation is a rare congenital cardiac anomaly. Available data are limited to individual reports demonstrating highly variable approaches. We sought to understand the spectrum of surgical treatment of Ebsteins anomaly across institutions. METHODS A retrospective review of surgical procedures performed on patients with primary diagnosis of Ebsteins malformation (2002 through 2009) in The Society of Thoracic Surgeons Congenital Heart Surgery Database (STS-CHSD) was conducted. RESULTS A total of 595 operations on 498 patients with Ebsteins anomaly were included: 116 on neonates (19%), 122 on infants (21%), 264 on children (44%), and 93 on adults (16%). Average annual institutional case volumes were low (median, 1 per year; range, 0 to 8 per year). Neonates had a high rate of palliative procedures: systemic-to-pulmonary artery shunts with or without tricuspid valve closure (43; 37.1%) and tricuspid valve closure (10; 8.6%); Ebsteins repair or tricuspid valvuloplasty was performed in 32%. The most common procedures among infants were superior cavopulmonary connections (62; 50.8%) and systemic-to-pulmonary shunt (10; 8.2%). Among older patients, procedures were primarily in three categories: tricuspid valve surgery (children, 54.5%; adults, 68.8%), arrhythmia procedures (children, 8.7%; adults, 17.3%), and Fontan (children, 14.8%). In-hospital mortality was high in neonatal patients (23.4%) in comparison with infants (4.1%), children (0.7%), and adults (1.1%). CONCLUSIONS Surgery for Ebsteins anomaly consists of a wide range of procedures, with low individual institutional volumes. Mortality is highest among neonates. A prospective multicenter inception cohort study would be valuable to better define indications for specific strategies of surgical management.

Midterm Results of the Modified Ross/Konno Procedure in Neonates and Infants

BACKGROUND The management of congenital aortic stenosis in neonates and infants continues to be a surgical challenge. We have performed the modified Ross-Konno procedure for patients who have severe aortic insufficiency or significant residual stenosis after balloon aortic dilation. The midterm results of this procedure were evaluated in this subset of patients. METHODS Between 1994 and 2010, a total of 24 patients younger than 1 year of age underwent the modified Ross-Konno procedure. The diagnoses were aortic stenosis with or without subaortic stenosis (n = 16), Shones complex (n = 7), and interrupted aortic arch with subaortic stenosis (n = 1). The aortic root was replaced with a pulmonary autograft, and the left ventricular outflow tract (LVOT) was enlarged with a right ventricular infundibular free wall muscular extension harvested with the autograft. RESULTS Age at operation ranged from 1 to 236 days (median 28 days). The median follow-up period was 81 months (range 1-173 months). There was 1 early death and no late mortality. Overall the 1-, 2-, and 5-year survival rate was 95% ± 4.5%. Freedom from aortic stenosis was 94.7% ± 5.1% at 1, 2, and 5 years. Less than mild aortic insufficiency was 93.3% ± 6.4% at 2 years, and 74.7% ± 12.9% at 5 years. In total, 23 reoperations and reinterventions were performed; 14 were allograft conduit replacements. Two patients required aortic valve plasty. None required valve replacement. The reintervention-free rate was 64.6% ± 10.8% at 2 years and 36.9% ± 11.3% at 5 years. CONCLUSIONS Pulmonary autografts demonstrated good durability with low mortality and morbidity. This study shows that the modified Ross-Konno procedure can be a practical choice in selective cases for complex LVOT stenosis in neonates and infants.

Surgical Reconstruction of Tracheal Stenosis in Conjunction With Congenital Heart Defects

BACKGROUND Surgical reconstruction is the primary method of treating airway obstruction in children. Tracheal stenosis is frequently associated with congenital heart defects, which may further complicate the overall management strategy. The purpose of this study was to review our experience with surgical reconstruction of airway obstruction in conjunction with congenital heart defects. METHODS This was a retrospective review of our surgical experience with tracheal stenosis from February 2003 to August 2011. Twenty-seven patients were identified in our database. Six patients had isolated, congenital tracheal stenosis, and 21 had tracheal stenosis in association with congenital heart defects. There were two identifiable subgroups. Thirteen patients had airway stenoses identified concurrently with congenital heart defects and underwent combined repair. The second group comprised 8 patients who had previous correction of their congenital heart defects and experienced delayed presentation of tracheal (n = 6) or bronchial (n = 2) obstruction. RESULTS The median age at surgery was 9 months. There were 2 postoperative deaths, both in children with single ventricle. The median duration of follow-up for the entire cohort of 25 surviving patients was 4 years. None of the patients have required reoperations on the trachea; 5 have had minor reinterventions. CONCLUSIONS The data demonstrate that tracheal obstruction is frequently found in conjunction with congenital heart defects. Nearly one third of our patients had delayed presentation of airway obstruction that was identified subsequent to previous congenital heart defect repair. Tracheal reconstructive techniques were effective regardless of the cause of the airway obstruction.