Long-Term Survival After Single-Ventricle Palliation: A Swedish Nationwide Cohort Study.

BACKGROUND: Long-term survival after single-ventricle palliation and the effect of dominant ventricle morphology in large, unselected series of patients are scarcely reported. METHODS AND RESULTS: This nationwide cohort study included all children undergoing operation with single-ventricle palliation during their first year of life in Sweden between January 1994 and December 2019. Data were obtained from institutional records and assessment of underlying cardiac anomaly and dominant ventricular morphology was based on complete review of medical records, surgical reports, and echocardiographic examinations. Data on vital status and date of death were retrieved from the Swedish Cause of Death Register, allowing for complete data on survival. Among 766 included patients, 333 patients (43.5%) were classified as having left or biventricular dominance, and 432 patients (56.4%) as having right ventricular (RV) dominance (of whom 231 patients had hypoplastic left heart syndrome). Follow-up was 98.7% complete (10 patients emigrated). Mean follow-up was 11.3 years (maximum, 26.7 years). Long-term survival was significantly higher in patients with left ventricular compared with RV dominance (10-year survival: 91.0% [95% CI, 87.3%-93.6%] versus 71.1% [95% CI, 66.4%-75.2%]). RV dominance had a significant impact on outcomes after first-stage palliation but was also associated with impaired survival after completed total cavopulmonary connection. In total, 34 (4.4%) patients underwent heart transplantation. Of these 34 patients, 25 (73.5%) had predominant RV morphology. CONCLUSIONS: This study provides clinically relevant knowledge about the long-term prognosis in patients with different underlying cardiac anomalies undergoing single-ventricle palliation. RV dominance had a significant impact on outcomes after initial surgical treatment but was also associated with impaired survival after completed Fontan circulation. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03356574.

Outcomes following surgical repair of absent pulmonary valve syndrome: 30 years of experience from a Swedish tertiary referral centre.

OBJECTIVES: Absent pulmonary valve syndrome is a rare congenital heart defect with pulmonary artery dilatation and secondary airway compression. Although preoperative respiratory support and early surgical repair with pulmonary arterioplasty are often required in patients with airway compromise, the need for extensive plasty in these patients and for plasty in general in those with no or mild respiratory issues remains debatable. METHODS: We performed a retrospective survey of patients with this diagnosis and repair from 1988 to 2018. RESULTS: Twenty patients were identified. The median age and weight at repair were 0.8 (0.1-2.4) years and 7.0 (2.5-13.8) kg and included a valved conduit in 17 (85%) patients and a transannular patch in 3 patients. Five (29%) patients were ventilator-dependent prior to repair at the age of 0.3 (0.1-0.4) years. Pulmonary arterioplasty was performed in 7 patients (35%), including all 5 with ventilator dependency and 2 with respiratory symptoms due to recurrent infections. Two patients (10%) with preoperative ventilator dependency underwent extensive intrahilar arterioplasty. Preoperative ventilator dependency was associated with earlier repair and reinterventions (P < 0.05). There were 3 late deaths among cases with repair after 2000 (n = 14), none with preoperative ventilator dependency. CONCLUSIONS: The long-term outcomes of patients with this rare defect are good, comparable to those of other previous studies. Reduction pulmonary arterioplasty, which in this study was used only in patients with respiratory distress and ventilator dependency, is associated with excellent survival. Reinterventions are common in these patients.

Impact of Left Ventricular Morphology on Adverse Outcomes Following Stage 1 Palliation for Hypoplastic Left Heart Syndrome: 20 Years of National Data From Sweden.

Background Hypoplastic left heart syndrome is associated with significant morbidity and mortality. We aimed to assess the influence of left ventricular morphology and choice of shunt on adverse outcome in patients with hypoplastic left heart syndrome and stage 1 palliation. Methods and Results This was a retrospective analysis of patients with hypoplastic left heart syndrome with stage 1 palliation between 1999 and 2018 in Sweden. Patients (n=167) were grouped based on the anatomic subtypes aortic-mitral atresia, aortic atresia-mitral stenosis (AA-MS), and aortic-mitral stenosis. The left ventricular phenotypes including globular left ventricle (Glob-LV), miniaturized and slit-like left ventricle (LV), and the incidence of major adverse events (MAEs) including mortality were assessed. The overall mortality and MAEs were 31% and 41%, respectively. AA-MS (35%) was associated with both mortality (all other subtypes versus AA-MS: interstage-I: hazard ratio [HR], 2.7; P=0.006; overall: HR, 2.2; P=0.005) and MAEs (HR, 2.4; P=0.0009). Glob-LV (57%), noticed in all patients with AA-MS, 61% of patients with aortic stenosis-mitral stenosis, and 19% of patients with aortic atresia-mitral atresia, was associated with both mortality (all other left ventricular phenotypes versus Glob-LV: interstage-I: HR, 4.5; P=0.004; overall: HR, 3.4; P=0.0007) and MAEs (HR, 2.7; P=0.0007). There was no difference in mortality and MAEs between patients with AA-MS and without AA-MS with Glob-LV (P>0.15). Patients with AA-MS (35%) or Glob-LV (38%) palliated with a Blalock-Taussig shunt had higher overall mortality compared with those palliated with Sano shunts, irrespective of the stage 1 palliation year (AA-MS: HR, 2.6; P=0.04; Glob- LV: HR, 2.1; P=0.03). Conclusions Glob-LV and AA-MS are independent morphological risk factors for adverse short- and long- term outcome, especially if a Blalock-Taussig shunt is used as part of stage 1 palliation. These findings are important for the clinical management of patients with hypoplastic left heart syndrome.

Changes in Heart Rate and Heart Rate Variability During Surgical Stages to Completed Fontan Circulation.

Arrhythmia is related to heart rate variability (HRV), which reflects the autonomic nervous regulation of the heart. We hypothesized that autonomic nervous ganglia, located at the junction of the superior vena cava's entrance to the heart, may be affected during the bidirectional Glenn procedure (BDG), resulting in reduced HRV. We aimed to investigate changes in heart rate and HRV in a cohort of children with univentricular heart defects, undergoing stepwise surgery towards total cavopulmonary connection (TCPC), and compare these results with healthy controls. Twenty four hours Holter-ECG recordings were obtained before BDG (n = 47), after BDG (n = 47), and after total cavopulmonary connection (TCPC) (n = 45) in patients and in 38 healthy controls. HRV was analyzed by spectral and Poincaré methods. Age-related z scores were calculated and compared using linear mixed effects modeling. Total HRV was significantly lower in patients before BDG when compared to healthy controls. The mean heart rate was significantly reduced in patients after BDG compared to before BDG. Compared to healthy controls, patients operated with BDG had significantly reduced heart rate and reduced total HRV. Patients with TCPC showed reduced heart rate and HRV compared with healthy controls. In patients after TCPC, total HRV was decreased compared to before TCPC. Heart rate was reduced after BDG procedure, and further reductions of HRV were seen post-TCPC. Our results indicate that autonomic regulation of cardiac rhythm is affected both after BDG and again after TCPC. This may be reflected as, and contribute to, postoperative arrhythmic events.

A national study of the outcome after treatment of critical aortic stenosis in the neonate.

OBJECTIVE: This study describes short-term and long-term outcome after treatment of critical valvular aortic stenosis in neonates in a national cohort, with surgical valvotomy as first choice intervention. METHODS: All neonates in Sweden treated for critical aortic stenosis between 1994 and 2016 were included. Patient files were analysed and cross-checked against the Swedish National Population Registry as of December 2017, giving complete survival data. Diagnosis was confirmed by reviewing echo studies. Critical aortic stenosis was defined as valvular stenosis with duct-dependent systemic circulation or depressed left ventricular function. Primary outcome was all-cause mortality and secondary outcomes were reintervention and aortic valve replacement. RESULTS: Sixty-one patients were identified (50 boys, 11 girls). Primary treatment was surgical valvotomy in 52 neonates and balloon valvotomy in 6. Median age at initial treatment was 5 days (0-26), and median follow-up time was 10.8 years (0.14-22.6). There was no 30-day mortality but four late deaths. Freedom from reintervention was 66%, 61%, 54%, 49%, and 46% at 1, 5, 10, 15, and 20 years, respectively. Median time to reintervention was 3.4 months (4 days to 17.3 years). Valve replacement was performed in 23 patients (38%). CONCLUSIONS: Surgical valvotomy is a safe and reliable treatment in these critically ill neonates, with no 30-day mortality and long-term survival of 93% in this national study. At 10 years of age, reintervention was performed in 54% and at end of follow-up 38% had had an aortic valve replacement.

Long-term results of aortic arch reconstruction with branch pulmonary artery homograft patches.

BACKGROUND: Homograft tissue is an important reconstructive material used in the surgical correction of a variety of congenital heart defects. The aim of this study is to evaluate the long-term outcome of pulmonary artery (PA) branch patches used in the reconstruction of the thoracic aorta in children. METHODS: Retrospective review of 124 consecutive pediatric patients undergoing corrective surgery for their congenital heart defects between 2001 and 2016. Survival, reoperation, and reintervention data were collected, as well as imaging data to assess for presence of recoarctation, dilation, or aneurysm formation in the area of patch reconstruction. RESULTS: Overall 15-year survival was 83.9% and 15-year freedom from reintervention in the area of patch reconstruction was 89.2%. Rates of mortality (0%), cardiac transplantation (0%), and reoperation (0.8%) attributable to the area of patch reconstruction were low. The frequency of catheter-based intervention in the area of patch reconstruction was 9.7%; such interventions were successful in all but one patient, who ultimately underwent successful surgical aortoplasty. CONCLUSIONS: Homograft patches harvested from PA branches are an effective reconstructive material used for reconstruction of the aorta in small children. Long-term results show no risk of aneurysm formation and low rates of stenosis formation.

Surgical Age and Morbidity After Arterial Switch for Transposition of the Great Arteries.

BACKGROUND: Transposition of the great arteries (TGA) is a complex congenital heart disease that requires early diagnosis as well as advanced surgical repair and postoperative support. This study sought to investigate the impact of surgical timing on early postoperative morbidity. METHODS: This study reviewed all patients with TGA repaired at a single institution (Skåne University Hospital, Lund, Sweden) by arterial switch operation (ASO) between June 2001 and June 2017. Major postoperative morbidity (MPM) and death within 30 days after ASOs were documented. Patients with double-outlet right ventricle, chromosomal abnormalities, and noncardiac diseases were excluded. MPM was defined as the presence of at least 1 of the following: delayed sternum closure, reoperation, prolonged mechanical ventilation, noninvasive ventilation after extubation, peritoneal dialysis, extracorporeal membrane oxygenation, and readmission. RESULTS: A total of 241 patients were included, with medians for birth weight, gestational week, and age at surgery of 3.5 kg, 39 weeks, and 5 days, respectively. MPM was encountered in 32.3% of patients. Prematurity (P = .001) and need for aortic arch repair at the time of ASO (P = .04) were associated with a significant increase in MPM. Non-A coronary anatomy, associated ventricular septal defect requiring surgical closure, and fetal diagnosis of TGA had no significant impact on MPM (P = .35, .08, and .21, respectively). There was no significant difference in MPM among the surgical groups (P = .49). CONCLUSIONS: Early complications after ASO do occur and are mostly associated with prematurity and the need for aortic arch repair. Timing of surgical repair does not seem to influence the rate of these complications.

Pacemaker treatment after Fontan surgery-A Swedish national study.

OBJECTIVE: Fontan surgery is performed in children with univentricular heart defects. Previous data regarding permanent pacemaker implantation frequency and indications in Fontan patients are limited and conflicting. We examined the prevalence of and risk factors for pacemaker treatment in a consecutive national cohort of patients after Fontan surgery in Sweden. METHODS: We retrospectively reviewed all Swedish patients who underwent Fontan surgery from 1982 to 2017 (n = 599). RESULTS: After a mean follow-up of 12.2 years, 13% (78/599) of the patients with Fontan circulation had received pacemakers. Patients operated with the extracardiac conduit (EC) type of total cavopulmonary connection had a significantly lower prevalence of pacemaker implantation (6%) than patients with lateral tunnel (LT; 17%). Mortality did not differ between patients with (8%) and without pacemaker (5%). The most common pacemaker indication was sinus node dysfunction (SND) (64%). Pacemaker implantation due to SND was less common among patients with EC. Pacemaker implantation was significantly more common in patients with mitral atresia (MA; 44%), double outlet right ventricle (DORV; 24%) and double inlet left ventricle (DILV; 20%). In contrast, patients with pulmonary atresia with intact ventricular septum and hypoplastic left heart syndrome were significantly less likely to receive a pacemaker (3% and 6%, respectively). CONCLUSIONS: Thirteen percent of Fontan patients received a permanent pacemaker, most frequently due to SND. EC was associated with a significantly lower prevalence of pacemaker than LT. Permanent pacemaker was more common in patients with MA, DORV, and DILV.

Preoperative Coronary Anatomy Assessment with Echocardiography and Morbidity After Arterial Switch Operation of Transposition of the Great Arteries.

In transposition of the great arteries (TGA), certain coronary patterns have been associated with major adverse events early after the arterial switch operation (ASO). We sought to determine the impact of preoperative echocardiographic (ECHO) diagnosis on the intra- and postoperative morbidity. All patients with TGA born between June 2001 and June 2017 and who underwent ASO were reviewed. Data on presumed coronary anatomy (CA) preoperatively were obtained from the preoperative ECHO report. Intraoperative CA was categorized according to Yacoub classification. Major postoperative morbidity included at least one of the following: delayed sternal closure (DSC), prolonged (> 72 h) mechanical ventilation, reintubation, peritoneal dialysis (PD), ECMO, reoperation, and readmission within 30 days after surgery. 240 patients with median age of 5 days (range 1-614) and mean weight at surgery was 3.6 kg (1.8-8.4) were included. Preoperative ECHO assessment of CA was available in 228 patients. Intraoperatively, 181 patients (75%) were found to have type A, 25 patients had type B or C or intramural (B-C-IM; 10%), and 34 patients had type D or E (D-E; 14%). Patients with types B, C, and intramural coronary (B-C-IM) had increased risk for delayed sternum closure (9/25 vs. 20/181 in type A and 8/34 in type D-E; p = 0.04), peritoneal dialysis (4/25 vs. 8/181 and 1/34; p = 0.04), and ECMO (2/25 vs. 1/131 and 1/34; p = 0.02). Within the B-C-IM group, preoperative ECHO raised suspicion of type A in 13 patients (i.e., incorrect diagnosis, ID; 52%), whereas non-A CA was suspected in 12 patients (i.e., correct diagnosis, CD; 48%). With the exception of reoperation, which was seen only in the ID subgroup (4/12 vs. 0/10 in the CD subgroup; p = 0.04), the intraoperative (cardiopulmonary bypass time and cross-clamp time) and postoperative morbidity indices were comparable in both ID and CD subgroups (p > 0.1). Although there is a significant risk for early postoperative morbidity in TGA patients with single, interarterial, and intramural CA, there seems to be relatively limited influence of preoperative ECHO assessment of coronary anatomy on this morbidity burden.

No evidence for mosaic pathogenic copy number variations in cardiac tissue from patients with congenital heart malformations.

The aim of this study was to investigate if pathogenic copy number variations (CNVs) are present in mosaic form in patients with congenital heart malformations. We have collected cardiac tissue and blood samples from 23 patients with congenital heart malformations that underwent cardiac surgery and screened for mosaic gene dose alterations restricted to cardiac tissue using array comparative genomic hybridization (array CGH). We did not find evidence of CNVs in mosaic form after array CGH analysis. Pathogenic CNVs that were present in both cardiac tissue and blood were detected in 2/23 patients (9%), and in addition we found several constitutional CNVs of unclear clinical significance. This is the first study investigating mosaicism for CNVs in heart tissue compared to peripheral blood and the results do not indicate that pathogenic mosaic copy number changes are common in patients with heart malformations. Importantly, in line with previous studies, our results show that constitutional pathogenic CNVs are important factors contributing to congenital heart malformations.

Smart placement of a mediastinal drain in a neonate who requires a postoperative open sternum.

Crowding of the mediastinum after complex cardiac repair procedures in neonates and young children is a frequent problem. To create space, the sternal wound is kept open, commonly with a plastic stent, for later closure. Despite this maneuver, space is still an issue, and appropriate placement of the mediastinal drain can become a challenge. In this article we describe a simple and effective way to eliminate the problem. Holes are made in the sternal stent, and the drain is pulled through these holes. The drain is elevated away from the heart surface and does not contribute to the crowding.