Left-Sided Reoperations After Arterial Switch Operation: A European Multicenter Study

BACKGROUND

We sought to report the frequency, types, and outcomes of left-sided reoperations (LSRs) after an arterial switch operation (ASO) for patients with D-transposition of the great arteries (D-TGA) and double-outlet right ventricle (DORV) TGA-type.

METHODS

Seventeen centers belonging to the European Congenital Heart Surgeons Association (ECHSA) contributed to data collection. We included 111 patients who underwent LSRs after 7,951 ASOs (1.4%) between January 1975 and December 2010. Original diagnoses included D-TGA (n = 99) and DORV TGA-type (n = 12). Main indications for LSR were neoaortic valve insufficiency (n = 52 [47%]) and coronary artery problems (CAPs) (n = 21 [19%]).

RESULTS

Median age at reoperation was 8.2 years (interquartile range [IQR], 2.9-14 years). Seven patients died early after LSRs (6.3%); 4 patients with D-TGA (5.9%) and 3 patients with DORV TGA-type (25%) (p = 0.02). Median age at last follow-up was 16.1 years (IQR, 9.9-21.8 years). Seventeen patients (16%) required another reoperation, which was more frequent in patients with DORV- TGA type (4 of 9 [45%]) than in patients with D-TGA (13 of 95 [14%]). Late death occurred in 4 patients (4 of 104 [3.8%]). The majority of survivors were asymptomatic at last clinical examination (84 of 100 [84%]).

CONCLUSIONS

Reoperations for residual LSRs are infrequent but may become necessary late after an ASO, predominantly for neoaortic valve insufficiency and CAPs. Risk at reoperation is not negligible, and DORV TGA-type anatomy, as well as procedures on the coronary arteries, were significantly associated with a higher morbidity and a lower overall survival. Recurrent reoperations after LSRs may be required.

Preoperative Venovenous ECMO in an Infant With Late Diagnosis of Hypoplastic Left Heart Syndrome

Late diagnosis and late referral for the Norwood stage 1 procedure in patients with hypoplastic left heart syndrome is rare and associated with a higher mortality. We present a case of a cyanotic almost five-week-old infant with hypoplastic left heart syndrome, highly restrictive foramen ovale, and patent ductus arteriosus, who was bridged with venovenous extracorporeal membrane oxygenation to the Norwood stage 1 procedure.

Recoarctation After Norwood I Procedure for Hypoplastic Left Heart Syndrome: Impact of Patch Material

BACKGROUND

The development of recoarctation after the Norwood I procedure is a known complication in patients with hypoplastic left heart syndrome (HLHS).

METHODS

We reviewed data on 194 consecutive patients with HLHS who underwent the Norwood I procedure between 2000 and 2015. All patients who survived until the second stage of the procedure were included. Recoarctation was defined by the need for intervention, either catheter based or surgical. The aim of our study was to determine if the patch material used for the initial arch reconstruction had an influence on the development of recoarctation.

RESULTS

The study population consisted of 145 patients. The patch material used for aortic arch reconstruction was either a homograft (n = 87), autologous pericardium (n = 23), equine pericardium (n = 28), or other material (n = 7). Recoarctation was documented in 27 patients (18%) at a median time of 4.3 months (range, 1 to 28 months) after completion of Norwood I. Freedom from recoarctation was 85% ± 4%, 86% ± 7%, and 30% ± 22% at 2 years for homograft, autologous pericardium, and equine pericardium, respectively. Thirty-six percent of patients with equine pericardium exhibited recoarctation, significantly more than homograft patch (p < 0.01) or autologous pericardium (p = 0.002). Treatment for recoarctation was percutaneous balloon angioplasty in 19 patients, stent implantation in 3, and operative enlargement of the aortic arch in 5. On univariate analysis, arch reconstruction with equine pericardium was the only risk factor for recoarctation (hazard ratio, 6.0; 95% confidence interval, 2.6-14; p < 0.01).

CONCLUSIONS

The patch material used for reconstruction of the aortic arch in HLHS influences the rate of recoarctation following the Norwood I procedure. Equine pericardium cannot be recommended.

A novel de novo TBX5 mutation in a patient with Holt-Oram syndrome leading to a dramatically reduced biological function

Background

The Holt–Oram syndrome (HOS) is an autosomal dominant disorder affecting 1/100.000 live births. It is defined by upper limb anomalies and congenital heart defects with variable severity. We describe a dramatic phenotype of a male, 15‐month‐old patient being investigated for strict diagnostic criteria of HOS.

Methods and results

Genetic analysis revealed a so far unpublished TBX5 mutation, which occurs de novo in the patient with healthy parents. TBX5 belongs to the large family of T‐box transcription factors playing major roles in morphogenesis and cell‐type specification. The mutation located in the DNA‐binding domain at position 920 (C→A) leads to an amino acid change at position 85 (proline → threonine). Three‐dimensional analysis of the protein structure predicted a cis to trans change in the respective peptide bond, thereby probably provoking major conformational and functional alterations of the protein. The p.Pro85Thr mutation showed a dramatically reduced activation (97%) of the NPPA promoter in luciferase assays and failed to induce NPPA expression in HEK 293 cells compared to wild‐type TBX5 protein. The mutation did not interfere with the nuclear localization of the protein.

Conclusion

These results suggest that the dramatic functional alteration of the p.Pro85Thr mutation leads to the distinctive phenotype of the patient.

Mortality Following Congenital Heart Surgery in Adults Can Be Predicted Accurately by Combining Expert-Based and Evidence-Based Pediatric Risk Scores

Objectives:

Currently, there are few specific risk stratification models available to predict mortality following congenital heart surgery in adults. We sought to evaluate whether the predictive power of the common pediatric scores is applicable for adults. In addition, we evaluated a new grown-ups with congenital heart disease (GUCH) score specifically designed for adults undergoing congenital heart surgery.

Methods and Results:

Data of all consecutive patients aged 18 years or more, who underwent surgery for congenital heart disease (CHD) between 2004 and 2013 at our institution, were collected. We evaluated the Aristotle Basic Complexity (ABC), the Aristotle Comprehensive Complexity (ACC), the Risk Adjustment in Congenital Heart Surgery (RACHS-1), and the Society of Thoracic Surgeons (STS)–European Association for Cardiothoracic Surgery (EACTS) scores. The proposed GUCH score consists of the STS-EACTS score, the procedure-dependent and -independent factors of the ACC score, and age. The discriminatory power of the scores was assessed using the area under the receiver–operating characteristics curve (c-index). A total of 830 operations were evaluated. Hospital mortality was 2.9%. C-indexes were 0.67, 0.80, 0.62, 0.78, and 0.84 for the ABC, ACC, RACHS-1, STS-EACTS, and GUCH mortality scores, respectively.

Conclusion:

The evidence-based EACTS-STS score outperforms the expert-based ABC score. The expert-based ACC score is superior to the evidence-based EACTS-STS score since comorbidities are considered. Our proposed GUCH score outperforms all other scores since it integrates the advantages of the evidence-based EACTS-STS score for procedures and the expert-based ACC score for comorbidities. Evidence-based scores for adults with CHD should include comorbidities and patient ages.

Clinical outcome following total cavopulmonary connection: a 20-year single-centre experience

OBJECTIVES

This study aims to evaluate the clinical outcome following total cavopulmonary connection (TCPC) and to identify factors affecting early and late outcome.

METHODS

Between May 1994 and March 2015, 434 patients underwent TCPC with 50 lateral tunnels and 374 extracardiac conduits. The clinical outcome, exercise capacity and liver examination results were retrospectively reviewed.

RESULTS

Thirty-day survival was 98.2%, and the estimated survival rate at 15 years was 92.3%. Freedom from tachyarrhythmia at 15 years was 91.0%. Other late morbidities included bradyarrhythmia in 17, protein-losing enteropathy (PLE) in 15, thromboembolism in 3 and plastic bronchitis in 3 patients. At last follow-up, normal systemic ventricular function (ejection fraction >50%) was observed in 88.2%. Atrioventricular valve (AVV) regurgitation was mild or less in 90% of patients with systemic left ventricle, in 63% of those with systemic right ventricle and 58% of the patients with unbalanced atrioventricular septal defect or common inlet ventricles. Cardiopulmonary exercise capacity showed impaired peak oxygen uptake (71% of normal) in a sub-group of 120 patients at a mean of 9 years postoperatively. Biochemistry of 338 patients at last follow-up revealed a gamma-glutamyl transferase value beyond normal in 90 patients (26%), with a positive correlation between the level and the time after the initial operation (P < 0.01). Pre-TCPC high transpulmonary gradient emerged as a predictor for delayed hospital recovery (P = 0.002), late mortality (P = 0.016) and reoperation (P = 0.015) in multivariable analysis.

CONCLUSIONS

Contemporary TCPC can be performed with low risk and provides excellent survival in the long-term. Classic morbidities of the original Fontan procedure, such as Fontan pathway revision, tachyarrhythmia and thromboembolism seem mitigated. However, exercise limitations, PLE and liver dysfunction remain an issue. AVV insufficiency and ventricular dysfunction are still a concern.

Improved Exercise Performance in Patients With Tricuspid Atresia After the Fontan-Björk Modification With Pulsatile Systolic Pulmonary Flow

BACKGROUND

After the Fontan-Björk modification for tricuspid atresia, some patients show pulsatile systolic pulmonary flow. We compared the hemodynamic findings and the clinical presentation of patients with and without pulsatile systolic flow after atrioventricular connection.

METHODS

According to the pulmonary flow pattern by pulsed-wave Doppler assessment of transthoracic echocardiography, 41 patients after atrioventricular connection were divided into two groups: patients who showed dominant pulsatile systolic pulmonary flow (group P, n = 11), and patients who did not (group N, n = 30).

RESULTS

Mean follow-up time was 27.8 ± 4.7 years in group P and 25.3 ± 3.8 years in group N (p = 0.1). Patients in group P had significantly less frequently catheter ablation procedures for tachyarrhythmia (9% versus 50%, p = 0.03). No patient in group P had had cardiac decompensation, whereas 7 patients (23%) in group N had had an episode of cardiac decompensation (p = 0.08). Cardiopulmonary exercise testing revealed that patients in group P showed higher oxygen uptake compared with patients in group N (25.0 ± 7.3 versus 19.6 ± 6.0 mL · kg(-1) · min(-1), p = 0.03). Patients in group P showed higher systolic pulmonary artery pressure (21.3 ± 8.4 versus 16.8 ± 4.5 mm Hg, p = 0.05), higher right ventricular end-diastolic volume index (88.6 ± 30.2 versus 50.3 ± 28.5 mL · L(-1) · m(-2), p = 0.03), and higher right ventricle to left ventricle ratio of end-diastolic volume index (1.4 ± 0.6 to 0.7 ± 0.3, p = 0.01).

CONCLUSIONS

Patients with pulsatile systolic flow in the pulmonary artery had better hemodynamic and better exercise performance compared with patients without pulsatile systolic flow after atrioventricular connection. A sufficient volume and function of the right ventricle is a prerequisite to create pulsatile systolic flow.

Durability of down-sized homografts for the reconstruction of the right ventricular outflow tract

OBJECTIVES

Small-sized homografts are rare but may be required for the reconstruction of the right ventricular outflow tract (RVOT). Down-sizing adult-sized homografts can be an option to overcome the shortage of availability.

METHODS

Since 1994, we have been down-sizing adult-sized homografts by excising one cusp. The aim of the study was to analyse the durability of down-sized homografts and compare it with small-sized homografts in a paediatric population. All patients below a body weight of 14 kg were included in the study. The end-point of the study was homograft failure.

RESULTS

A total of 152 patients met the inclusion criteria of the study, of which 82 patients (54%) received a down-sized homograft. The median age was 17.1 (0.3-64.8) months and the mean weight 8.4 ± 3.4 kg. Fifty-eight patients (38%) were under 1 year and 10 (6.5%) under 1 month of age at the time of homograft implantation. The mean homograft size of the whole study population was 14.7 ± 2.5 mm and the mean z-score was 1.6 ± 0.9. The median follow-up time was 10 (0.03-19.7) years. Early mortality after homograft implantation was 5% (n = 8), 4 of these patients had received a down-sized homograft. The study population comprised early survivors, that is, 144 patients. During follow-up, a total of 46 homografts failed, 23 in each group, after a mean time of 5.7 ± 4.2 years. Freedom from homograft failure was 94.6 ± 2.6, 87.2 ± 4 and 68.6 ± 6.6% for down-sized homografts and 95.2 ± 2.7, 78.7 ± 5.5 and 61 ± 7% for small-sized homografts at 1, 5 and 10 years, respectively (P = 0.3). Risk factors for homograft failure in the multivariable analysis were a homograft z-score of <1 and age below 1 year at the time of implantation (P = 0.02).

CONCLUSION

Down-sized homografts demonstrated a durability similar to that of small-sized homografts. Therefore, down-sizing adult-sized homografts by creating a bicuspid valve to fit into the corresponding RVOT in children with congenital heart defects is an excellent method to overcome the shortage of small-sized homografts.

Tetralogy of Fallot and Hypoplastic Left Heart Syndrome - Complex Clinical Phenotypes Meet Complex Genetic Networks

In many cases congenital heart disease (CHD) is represented by a complex phenotype and an array of several functional and morphological cardiac disorders. These malformations will be briefly summarized in the first part focusing on two severe CHD phenotypes, hypoplastic left heart syndrome (HLHS) and tetralogy of Fallot (TOF). In most cases of CHD the genetic origin remains largely unknown, though the complexity of the clinical picture strongly argues against a dysregulation which can be attributed to a single candidate gene but rather suggests a multifaceted polygenetic origin with elaborate interactions. Consistent with this idea, genome-wide approaches using whole exome sequencing, comparative sequence analysis of multiplex families to identify de novo mutations and global technologies to identify single nucleotide polymorphisms, copy number variants, dysregulation of the transcriptome and epigenetic variations have been conducted to obtain information about genetic alterations and potential predispositions possibly linked to the occurrence of a CHD phenotype. In the second part of this review we will summarize and discuss the available literature on identified genetic alterations linked to TOF and HLHS.