Arterial switch operation: factors impacting survival in the current era

The Arterial Switch Operation in the Developing World: Risk Factors and Current Outcomes

BACKGROUND

Published data on the outcomes of the arterial switch operation in the developing world are limited. We sought to identify the midterm outcomes of and risk factors for mortality and morbidity in patients undergoing the arterial switch operation at a high-volume center in Vietnam.

METHODS

A retrospective review was conducted of 608 patients who underwent an arterial switch operation for the treatment of transposition of the great arteries (TGA; n = 509) or double-outlet right ventricle TGA (DORV-TGA; n = 99) at a single center from 2010 to 2021.

RESULTS

Overall early mortality was 5.9%, and late mortality was 1%. Multivariate Cox regression showed weight at operation of <3 kg (P < .001), prolonged aortic cross-clamp time (P < .001), and need for secondary aortic cross-clamp (P = .011) as risk factors for overall mortality. The actuarial 10-year survival rate was 93%. The overall cardiac reoperation rate was significantly higher in patients with DORV-TGA (hazard ratio [HR], 16.43; 95% CI, 4.70-57.43; P < .001). The rate of freedom from cardiac reoperation at 10 years was 94%. Risk factors for outflow tract reoperation were patients with DORV-TGA (HR, 23.28; 95% CI, 2.86-189.66; P = .003), single coronary artery (HR, 4.1; 95% CI, 1.16-14.46; P = .028), and mild aortic valve regurgitation observed in 3.7% of patients.

CONCLUSIONS

The outcomes of the arterial switch operation in a low- and middle-income country were satisfactory. Nevertheless, the complexity of the procedure and lower weight of patients are still challenges. Patients with DORV-TGA and single coronary artery need to be closely followed up.

Role of transesophageal echocardiography in early detection of myocardial ischemia before electrocardiography changes post arterial switch operation

Myocardial ischemia after arterial switch operation is most commonly associated with imperfect translocation of coronary arteries to the neoaorta. Early post-operative myocardial ischemia is the main cause of morbidity and mortality in these patients. We present a rare case of intra-operative myocardial ischemia after ASO, detected with transesophageal echocardiography before electrocardiography changes.

Arterial Switch for Transposition of the Great Arteries: Treatment Timing, Late Outcomes, and Risk Factors

Background

Reports of long-term mortality and reintervention after transposition of the great arteries with intact ventricular septum treatment, although favorable, are mostly limited to single-center studies. Even less is known about hospital resource utilization (days at hospital) and the impact of treatment choices and timing on outcomes.

Objectives

The purpose of this study was to describe survival, reintervention and hospital resource utilization after arterial switch operation (ASO) in a national dataset.

Methods

Follow-up and life status data for all patients undergoing ASO between 2000 and 2017 in England and Wales were collected and explored using multivariable regressions and matching.

Results

A total of 1,772 patients were identified, with median ASO age of 9.5 days (IQR: 6.5-14.5 days). Mortality and cardiac reintervention at 10 years after ASO were 3.2% (95% CI: 2.5%-4.2%) and 10.7% (95% CI: 9.1%-12.2%), respectively. The median time spent in hospital during the ASO spell was 19 days (IQR: 14, 24). Over the first year after the ASO patients spent 7 days (IQR: 4-10 days) in hospital in total, decreasing to 1 outpatient day/year beyond the fifth year. In a subgroup with complete risk factor data (n = 652), ASO age, and balloon atrial septostomy (BAS) use were not associated with late mortality and reintervention, but cardiac or congenital comorbidities, low weight, and circulatory/renal support at ASO were. After matching for patient characteristics, BAS followed by ASO and ASO as first procedure, performed within the first 3 weeks of life, had comparable early and late outcomes, including hospital resource utilization.

Conclusions

Mortality and hospital resource utilization are low, while reintervention remains relatively frequent. Early ASO and individualized use of BAS allows for flexibility in treatment choices and a focus on at-risk patients.

Impact of Coronary Artery Anatomy in Arterial Switch Operation: In-hospital and Post-discharge Outcomes

OBJECTIVE

The influence of the coronary artery anatomy on the prognosis of patients receiving an arterial switch operation (ASO) is currently controversial, and the risk factors for this operation may change in more complicated patients. This study aimed to investigate the influence of coronary artery anomalies on the in-hospital and post-discharge outcomes of ASO in patients with transposition of the great arteries (TGA) and Taussig-Bing anomaly (TBA).

METHODS

We retrospectively reviewed 206 patients who underwent ASO from January 2007 to December 2019. The median age at operation was 33 [interquartile range (IQR): 20-71] days. Median follow-up time was 7.2 years (IQR: 4.0-10.3 years).

RESULTS

Coronary anomalies were present in 86 patients (41.7%), with 9 (4.4%) of them having a single coronary artery. Additional coronary features included intramural courses in 5 (2.4%) patients, ostial stenosis in 1 (0.5%) patient, and accessory coronary artery orifices in 5 (2.4%) patients. There were 32 (15.5%) in-hospital deaths and 8 (4.6%) post-discharge deaths, yielding an overall survival of 81.3%, 80.7% and 79.9% at 1, 5 and 10 years, respectively. Mortality due to ASO has been drastically decreased since 2013. Patients with a single coronary artery had higher rate of in-hospital mortality, but this finding was not statistically significant. The earlier surgical era (OR: 2.756) and a longer cardiopulmonary bypass time (OR: 2.336) were significantly associated with in-hospital mortality, while coronary patterns were not. An intramural coronary artery (HR: 10.034) and a patient age of older than 1 year at the time of ASO (HR: 9.706) were independent predictors of post-discharge mortality.

CONCLUSION

ASO remains the procedure of choice for TGA with coronary anomalies with acceptable in-hospital and post-discharge outcomes in terms of overall survival and freedom of reoperation. However, intramural coronary artery is an independent risk factor for post-discharge mortality. Timely surgery within the 1st year of life helps improve overall midterm survival of ASO.

Nine-Year Experience with the Arterial Switch Operation with Closed Coronary Transfer

BACKGROUND

Coronary artery transfer is a critical step of the arterial switch operation (ASO) for transposition of the great arteries (TGA). Strategies for coronary transfer include open transfer before neo-aortic anastomosis or closed transfer after neo-aortic anastomosis. This study reports outcomes of ASO with closed coronary transfer at a single institution.

METHODS

A retrospective analysis was performed of patients undergoing ASO for TGA from November 2006 to September 2015. Closed coronary transfer was universally employed. Patients were classified into simple versus complex coronary anatomy groups. The primary outcome was overall survival. Secondary outcomes included reoperation-free survival, coronary re-intervention, and aortic insufficiency.

RESULTS

Ninety-six consecutive patients underwent ASO for TGA. Median follow-up was 5.8 years. Thirty-five (36%) of patients had complex coronary anatomy, which was associated with significantly longer cardiopulmonary bypass and aortic cross-clamp time. Overall survival was 97.4%, and reoperation-free survival was 83.6%. There was no difference in survival or reoperation-free survival between patients with simple versus complex coronary anatomy. Hispanic ethnicity, side-by-side great arteries, and urgent or emergent operation were significantly associated with the composite outcome of reoperation or mortality. There were no coronary interventions after ASO, and the incidence of moderate or greater aortic insufficiency was 2.1% at hospital discharge and 1.5% in follow-up.

CONCLUSIONS

Closed coronary transfer during ASO has excellent short and mid-term results. Despite variable and often complex coronary anatomy, coronary ischemic events following ASO are avoidable. Closed coronary transfer has a low risk of aortic valve injury or insufficiency.

Pulse oximetry as a screening test for congenital heart disease in newborns

BACKGROUND

Congenital heart disease (CHD) can be fatal if not diagnosed at the early phases of life. Available diagnostic tools for screening critical CHD are mostly invasive and costly.

AIM

The current study aimed to validate the use of pulse oximetry as a non-invasive and cost-effective tool to screen critical CHD.

MATERIAL AND METHODS

This observational study was conducted in a tertiary care teaching institute. A total of 1,082 asymptomatic term neonates (aged 2-24 h) were screened by pulse oximetry and clinical examination for the detection of critical CHD. Neonates with abnormal pulse oximetry and clinical examination findings were subjected to confirm the presence of CHD.

RESULTS

The incidence of critical CHD in asymptomatic newborns was found to be 0.5% (5/1000 live births). Echocardiography confirmed five cases of critical CHD. Pulse oximetry alone could detect 80%, and clinical examination alone could detect 60% of the CHD cases, while combining both methods gave 100% detection rate.

CONCLUSION

Pulse oximetry is a simple, cost-effective, and reliable tool to diagnose critical CHD. In majority of the newborns who have not undergone fetal echocardiography, the underlying critical CHD can be missed, and in such cases, pulse oximetry screening offers an effective way to minimise the undiagnosed discharge risk.

Coronary transfer in the arterial switch operation: the modified closed technique

Arterial switch operation for transposition of great arteries (TGA) is the choice of surgical treatment for this condition. Conventional "open" coronary transfer technique has been commonly employed with good results in experienced hands. A modified "closed" technique of coronary transfer, with a more accurate coronary artery placement taking into account a distended aorta, along with anterior interrupted sutures to reduce purse stringing and other advantages is described.

Ventricular and atrial function and deformation is largely preserved after arterial switch operation

OBJECTIVE

To test the hypothesis that ventricular and atrial function are different between patients with transposition of the great arteries (TGA) after arterial switch operation (ASO) and healthy controls.

METHODS

103 consecutive patients with TGA (median age: 16.7 years, 4.3-39.6 years, 71.8% male) were compared with 77 controls (median age: 15.4 years, 6.3-43.2 years, 66.2% male). Biventricular and biatrial function were assessed using standard cardiovascular magnetic resonance (CMR) techniques and feature tracking. Group comparison was performed with conventional non-parametrical statistics and machine learning methods to find the variables most discriminative between patients and controls. These variables were used to build a multivariable logistic regression model to assess the case-control status.

RESULTS

Markers of left and right ventricular function (LV; RV) (ejection fraction, MAPSE, TAPSE, LV long-axis strain) as well as LV global longitudinal (-20.7 (-24.1; -17.9) vs -23.7 (-26.1; -21.6), p<0.001), circumferential (-29.4 (-32.2; -26.5) vs -30.5 (-33.6; 29), p=0.001) and atrial longitudinal strain (left atrium (LA): 23.3 (18.6; 28.8) vs 36.7 (30.7; 44), p<0001; right atrium: 21.7 (18.2; 27.8) vs 34.9 (26.9; 40.3), p<0.001) were reduced in patients compared with controls using non-parametrical testing. The logistic regression model including the most discriminative variables from univariate and machine learning analysis demonstrated significant differences between patients and controls only for TAPSE and LA global longitudinal strain.

CONCLUSIONS

Biventricular and biatrial function are largely preserved after ASO for TGA. Using a comprehensive CMR protocol along with statistical machine learning methods and a regression approach, only RV longitudinal function and LA function are significantly impaired.

Intramural coronary pattern in patients with transposition: incidence and impact on follow-up

OBJECTIVES

Coronary complications are still the main reason for early mortality after an arterial switch operation. The high incidence of coronary anomalies in patients with transposition of the great arteries may increase the difficulty of coronary transfer, and among them, an intramural pattern was shown to be an independent risk factor of early mortality. However, recently published studies have reported that this rare coronary variant has no impact on the survival rate. The aim of this study was to assess the frequency of intramural coronary patterns in patients with transposition and the impact on overall mortality after an arterial switch operation. Additionally, we presented all coronary arrangements associated with intramural patterns in our cohort and the surgical techniques used to manage them successfully.

METHODS

All arterial switch operations were retrospectively reviewed. In each case, the surgical reports contained detailed graphical representations and coronary anatomy patterns. All operatively confirmed intramural patterns were included in the analysis.

RESULTS

Among 806 patients, 271 patients had coronary anomalies (33.62%), and 28 patients had an intramural pattern (3.47%), which was frequently associated with other complex coronary anomalies (P < 0.001). Overall survival was significantly higher in patients with intramural coronary artery patterns than in those with other coronary variants (21.34% vs 8.74%, P = 0.024, log-rank test).

CONCLUSIONS

Intramural patterns associated with transposition remain a surgical challenge and increase overall mortality in our cohort. To reliably confirm or reject the significance of the observed impact of this rare coronary variant, a multicentre data analysis is required.

Factors Affecting Health-Related Quality of Life After the Arterial Switch Operation

BACKGROUND

Long-term morbidity and mortality outcomes of the arterial switch operation (ASO) in patients with transposition of the great arteries and Taussig-Bing anomaly are excellent. With an increasing number of patients reaching adolescence and adulthood, more attention is directed toward quality of life. Our study aimed to determine the health-related quality of life (hrQoL) outcomes in patients after the ASO and identify factors influencing their hrQoL.

METHODS

In this cross-sectional study, hrQoL of patients after ASO was assessed with the German version of the Short Form-36 (SF-36) and the potential association of specified clinical factors was analyzed. Patients of at least 14 years of age who underwent ASO in our institution from 1983 were considered eligible.

RESULTS

Of the 355 questionnaires sent to eligible patients, 261 (73%) were available for analysis. Compared to the reference population, patients who had undergone ASO had a significantly higher score in all subscales of the SF-36 except for vitality (P < .01). Patients with an implanted pacemaker (P = .002), patients who required at least one reoperation (P < .001), and patients currently taking cardiac medication (P < .004) or oral anticoagulation (P = .036) had lower physical component scores compared to patients without these factors.

CONCLUSIONS

Patients' self-assessed and self-reported hrQoL after ASO (using German version of the Short Form 36) is very good. In this population, hrQoL is influenced by reoperation, the need for a pacemaker, and current cardiac medication or anticoagulant use. The development of strategies designed to mitigate or minimize the requirements for, and/or impact of these factors may lead to better hrQoL in this patient population.

Transposition of the Great Arteries-Are We Doing Better? Correlating Outcome to Change in Renal Function Over 2 Decades of Arterial Switch Operation

OBJECTIVES

It is believed that management of neonates with dextro-transposition of the great arteries is constantly improving. Renal function may play a role in the prognosis of patients after congenital heart surgery. The aim of this study was to describe the outcome of neonates who underwent arterial switch operation during the past 2 decades using renal function as a surrogate marker for morbidity and mortality.

DESIGN

Retrospective cohort study.

SETTING

Dedicated cardiac ICU of a university-affiliated pediatric medical center.

PATIENTS

Infants who underwent arterial switch surgery in 1993-2015.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The cohort included 336 infants who underwent arterial switch operation for dextro-transposition of the great arteries (n = 169, 50%), transposition of the great arteries/ventricular septal defect (n = 133, 40%), or Taussig-Bing anomaly (n = 34, 10%). Between 1993-1998 and 2012-2015, the mean minimal postoperative estimated glomerular filtration rate rose from 30 mL/min/1.73 m to 40 mL/min/1.73 m (p < 0.05), and the proportion of patients with estimated glomerular filtration rate less than 30 mL/min/1.73 m decreased from 56% to 23% (p < 0.05). The daily furosemide dosage decreased from 4 mg/kg/d to 0.5 mg/kg/d (p < 0.05). Urinary output on operative day 0 decreased over time, but urinary output on operative day 2 significantly increased. Maximal lactate levels and time to lactate normalization decreased steadily. Dialysis was performed in only a few patients in the early periods, and in none in the last 6 years. The mean mortality rate of patients with dextro-transposition of the great arteries and transposition of the great arteries/ventricular septal defect decreased to 2.7% in the last 6 years. The odds ratio of a prolonged hospital stay (≥ 28 d) in a patient with estimated glomerular filtration rate less than 30 mL/min/1.73 m was 18.79, and in a patient with transposition of the great arteries/ventricular septal defect, 3.39. The odds ratio of dying after Rashkind atrial septostomy was 4.42.

CONCLUSIONS

During the past 2 decades, there has been significant improvement in outcome of patients undergoing transposition of the great arteries repair. Renal function was found to be a good prognostic marker of morbidity and mortality.

Modified Closed Coronary Transfer is a Good Alternative to the Trap-Door Method During Arterial Switch Operation: a Retrospective Propensity-Matched Comparison

Objective

To compare the early and long-term results of patients in whom was performed modified closed coronary transfer with the results of patients in whom was performed trap-door transfer techniques by utilizing propensity-matching analysis to provide optimal identical patient matching for the groups.

Methods

From August 2015 to December 2017, 127 consecutive patients underwent arterial switch operation due to simple and complex transposition of the great arteries, with or without additional arch and complex coronary pattern, by a single surgical team included into the study. Of these, in 70 patients it was performed modified closed coronary transfer technique and in 57 patients it was performed trap-door style coronary transfer technique. The patients were divided into two groups in terms of coronary transfer method. In the final model, after propensity matching, 47 patients from each group having similar propensity score were included into the study.

Results

There was no significant difference between the groups regarding patient characteristics. Cross-clamp time and operation time were significantly lower in the modified technique group compared with the other group (P=0.03 and P=0.05, respectively). When compared the early and late postoperative outcomes, there was no significant difference between the groups. Postoperative echocardiographic findings were mostly similar between the groups.

Conclusion

The patients in whom was performed our modified technique demonstrate overall good outcomes and the current technique ensures shorter arterial cross-clamp and operation times. It may be an alternative method to the trap-door technique for the coronary transfer during the arterial switch operation.

Screening for congenital heart disease in a Singapore neonatal unit

INTRODUCTION

Congenital heart disease (CHD) is a leading cause of infant mortality. The aim of this study was to evaluate the efficacy of a neonatal screening programme for CHD before the introduction of pulse oximetry.

METHODS

This was a retrospective review of live births in the period 2003-2012. Cases of CHD were detected through prenatal ultrasonography and/or postnatal examination, and confirmed using two-dimensional echocardiography. Data was rigorously checked against multiple sources. The antenatal detection rate, sensitivity, specificity, predictive values and likelihood ratios of the screening programme were analysed for all cases of CHD and critical CHD.

RESULTS

The incidence of CHD was 9.7 per 1,000 live births. The commonest CHD was ventricular septal defect (54.8%). The antenatal detection rate was three times higher in the critical CHD group (64.0%) compared to the group as a whole (21.1%). The sensitivity and specificity of screening was 64.5% and 99.7% for all CHD, and 92.9% and 99.1% for the critical CHD group, respectively. The positive likelihood ratio was 215 and 103, while the negative likelihood ratio was 0.36 and 0.07 for all CHD and critical CHD, respectively.

CONCLUSION

The CHD screening programme had excellent specificity but limited sensitivity. The high positive likelihood ratios indicate that where sufficient risk factors for CHD are present, a positive result effectively confirms the presence of CHD. The low negative likelihood ratio for critical CHD indicates that, where prior suspicion for critical CHD is low, a negative result is reassuring.

Association Between Variation in Preoperative Care Before Arterial Switch Operation and Outcomes in Patients With Transposition of the Great Arteries

BACKGROUND

The arterial switch operation (ASO) is the gold standard operative correction of neonates with transposition of the great arteries and intact ventricular septum, with excellent operative survival. The associations between patient and surgeon characteristics and outcomes are well understood, but the associations between variation in preoperative care and outcomes are less well studied.

METHODS

A multicenter retrospective cohort study of infants undergoing neonatal ASO between January 2010 and September 2015 at hospitals contributing data to the Pediatric Health Information Systems database was performed. The association between preoperative care (timing of ASO, preoperative use of balloon atrial septostomy, prostaglandin infusion, mechanical ventilation, and vasoactive agents) and operative outcomes (mortality, length of stay, and cost) was studied with multivariable mixed-effects models.

RESULTS

Over the study period, 2159 neonates at 40 hospitals were evaluated. Perioperative mortality was 2.8%. Between hospitals, the use of adjuvant therapies and timing of ASO varied broadly. At the subject level, older age at ASO was associated with higher mortality risk (age >6 days: odds ratio, 1.90; 95% CI, 1.11-3.26; P=0.02), cost, and length of stay. Receipt of a balloon atrial septostomy was associated with lower mortality risk (odds ratio, 0.32; 95% CI, 0.17-0.59; P<0.001), cost, and length of stay. Later hospital median age at ASO was associated with higher odds of mortality (odds ratio, 1.15 per day; 95% CI, 1.02-1.29; P=0.03), longer length of stay ( P<0.004), and higher cost ( P<0.001). Other hospital factors were not independently associated with the outcomes of interest.

CONCLUSIONS

There was significant variation in preoperative care between hospitals. Some potentially modifiable aspects of perioperative care (timing of ASO and septostomy) were significantly associated with mortality, length of stay, and cost. Further research on the perioperative care of neonates is necessary to determine whether modifying practice on the basis of the observed associations translates into improved outcomes.

Left ventricular remodelling in long-term survivors after the arterial switch operation for transposition of the great arteries

Aims

The objective of this study was to quantify imaging markers of myocardial fibrosis and assess myocardial function in long-term transposition of the great arteries survivors after the arterial switch operation (ASO).

Methods and results

Paediatric ASO patients were prospectively studied by cardiac magnetic resonance imaging, including first-pass myocardial perfusion, late gadolinium enhancement, and T1 relaxometry, as well as echocardiography for left ventricular (LV) systolic and diastolic function including strain analysis, with comparison to healthy controls. Thirty ASO patients (mean age 15.4 ± 2.9 years vs. 14.1 ± 2.6 years in 28 controls, P = 0.04) were included. Patients had normal LV ejection fraction (EF) (57 ± 5% vs. 59 ± 5%, P = 0.07), but end-diastolic and end-systolic volumes were increased (104 ± 20 mL/m2 vs. 89 ± 10 mL/m2, P < 0.01 and 46 ± 13 mL/m2 vs. 36 ± 7 mL/m2, P < 0.01, respectively). Longitudinal strain at two-, three-, and four-chamber levels of the LV were lower in ASO patients (-19.0 ± 2.6% vs. -20.9 ± 2.3%, P = 0.006, -17.7 ± 2.0% vs. -19.1 ± 2.4%, P = 0.02, and -18.9 ± 1.9% vs. -20.1 ± 1.7%, P = 0.01, respectively), while circumferential strain was higher at all short-axis levels (-24.6 ± 2.3% vs. -19.3 ± 1.6%, P < 0.001 at the mid-ventricular level). LV native T1 times were higher in ASO patients (1042 ± 27 ms vs. 1011 ± 27 ms, P < 0.01) and correlated with LV mass/volume ratio (R = 0.60, P < 0.001). Myocardial scarring or myocardial perfusion defects were not observed in our cohort.

Conclusion

Children and adolescents after ASO have normal LV systolic function, in line with their overall good clinical health. At a myocardial level however, imaging markers of diffuse myocardial fibrosis are elevated, along with an altered LV contraction pattern. Whether these abnormalities will progress into future clinically significant dysfunction and whether they are harbingers of adverse outcomes remains to be studied.

Does Coronary Reimplantation After Neoaortic Reconstruction Increase Aortic Regurgitation?

Coronary reimplantation after neoaortic reconstruction (CRANR) in the arterial switch operation (ASO) allows easy selection of accurate coronary transfer sites in the distended neoaorta. However, neoaortic valve injury may occur during coronary reimplantation. We determined whether the CRANR procedure increased the incidence of aortic valve regurgitation (AR) after ASO. Between March 1994 and August 2017, 227 patients underwent ASO. Since September 2000 CRANR has been performed on 155 patients and open coronary reimplantation (OCR) on 72. Patients who had undergone aortocoronary flaps procedures (n = 13), had early or late mortality (n = 27), or lacked data (n = 11) were excluded. We enrolled and retrospectively reviewed the medical records of 176 patients who were followed up for postoperative AR: 38 underwent OCR and 138 underwent CRANR. We compared the incidences of early and late postoperative AR in both groups. We defined mild or greater AR as "significant AR." The groups did not differ in body weight at operation, great artery relationship, and coronary artery anatomy. The incidences of significant AR at discharge were 21.1% (8/38) in the OCR group and 16.6% (23/138) in the CRANR group (p = 0.53). The freedom from significant AR at 5 years was 59.9% in the OCR group and 62.4% in the CRANR group with no difference between the two groups (p = 0.73). Moderate AR occurred in one patient in the CRANR group. No surgical intervention was required for the aortic valve in either group. ASO using the CRANR technique did not increase the incidence of postoperative early and late AR.

No difference found in safety or efficacy of balloon atrial septostomy performed at the bedside versus the catheterisation laboratory

BACKGROUND

Balloon atrial septostomy is performed in infants with dextro-transposition of the great arteries to improve oxygenation before surgery. It is performed in the catheterisation laboratory with fluoroscopy or at the bedside using echocardiography. It is unclear whether procedural safety and efficacy is superior in one location versus the other, although the bedside procedure may improve resource utilisation and present an opportunity for reducing cost. This study compares safety and efficacy of atrial septostomy performed at the patient's bedside versus the catheterisation laboratory.

METHODS

Neonates with dextro-transposition of the great arteries who underwent balloon atrial septostomy from October, 2000 to January, 2014 were included. Medical and procedural records, echocardiograms, and catheterisation data were reviewed. Comparisons between the two procedural locations included patient demographics, pre- and post-procedure oxygen saturations, and outcomes. Complications reviewed included bleeding, arrhythmia, cardiac trauma, stroke, and death. Coronary artery evaluations were recorded. T-tests were used for continuous variables, and Fisher's exact tests were used for all categorical variables. Wilcoxon rank sum and analysis of covariance modelling were used for time variables and oxygen saturation, respectively.

RESULTS

A total of 88 infants met the inclusion criteria. Among them, 53 underwent septostomy at the bedside and 35 underwent septostomy in the catheterisation laboratory. No safety or outcome benefit was identified between the two procedural locations.

CONCLUSION

Septostomy performed at the bedside and in the catheterisation laboratory had similar outcomes and efficacy. Further, bedside septostomy has the advantage of no radiation exposure, and obviating risks with patient transfer from the ICU to the catheterisation laboratory.

Myocardial Stress Perfusion MRI: Experience in Pediatric and Young-Adult Patients Following Arterial Switch Operation Utilizing Regadenoson

Dextro-transposition of the great arteries (D-TGA) is one of the most common cyanotic heart lesions. The arterial switch operation (ASO) is the preferred surgical palliation for D-TGA. One of the primary concerns following the ASO is complications arising from the coronary artery transfer. There is a need for myocardial perfusion assessment within ASO patients. There is no report on the utility of regadenoson as a stress agent in children following ASO. Our objective was to observe the safety and feasibility of regadenoson as a pharmacologic stressor for perfusion cardiac MR in a pilot cohort of pediatric and young-adult patients who have undergone ASO. We reviewed our initial experience with regadenoson stress cardiac MR in 36 pediatric and young-adult patients 15.1 ± 4.5 years (range 0.2-22 years) with history of ASO. The weight was 61.6 ± 21.5 kg (range 3.8-93 kg). All patients underwent cardiac MR because of concern for ischemia. Subjects' heart rate and blood pressure were monitored and pharmacologic stress was induced by injection of regadenoson. We evaluated their hemodynamic response and adverse effects using changes in vital signs and onset of symptoms. A pediatric cardiologist and radiologist qualitatively assessed myocardial perfusion and viability images. All stress cardiac MR examinations were completed without adverse events. Resting heart rate was 72 ± 13 beats per minute (bpm) and rose to peak of 120 ± 17 bpm (95 ± 50% increase, p < 0.005) with regadenoson. Image quality was considered good or diagnostic in all cases. A total of 11/36 (31%) patients had a perfusion defect on the stress FPP images. 14 of the 36 patients (39%) underwent cardiac catheterization within 6 months of the CMR and the findings showed excellent agreement. Regadenoson may be a useful coronary hyperemia agent to utilize for pediatric patients following arterial switch procedure when there is concern for ischemia. The ability to administer as a single bolus with one IV makes it advantageous in pediatrics. In a limited number of cases, regadenoson stress perfusion showed excellent agreement with cardiac catheterization.

Pulse oximetry screening for critical congenital heart defects

BACKGROUND

Health outcomes are improved when newborn babies with critical congenital heart defects (CCHDs) are detected before acute cardiovascular collapse. The main screening tests used to identify these babies include prenatal ultrasonography and postnatal clinical examination; however, even though both of these methods are available, a significant proportion of babies are still missed. Routine pulse oximetry has been reported as an additional screening test that can potentially improve detection of CCHD.

OBJECTIVES

• To determine the diagnostic accuracy of pulse oximetry as a screening method for detection of CCHD in asymptomatic newborn infants• To assess potential sources of heterogeneity, including:○ characteristics of the population: inclusion or exclusion of antenatally detected congenital heart defects;○ timing of testing: < 24 hours versus ≥ 24 hours after birth;○ site of testing: right hand and foot (pre-ductal and post-ductal) versus foot only (post-ductal);○ oxygen saturation: functional versus fractional;○ study design: retrospective versus prospective design, consecutive versus non-consecutive series; and○ risk of bias for the "flow and timing" domain of QUADAS-2.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 2) in the Cochrane Library and the following databases: MEDLINE, Embase, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Health Services Research Projects in Progress (HSRProj), up to March 2017. We searched the reference lists of all included articles and relevant systematic reviews to identify additional studies not found through the electronic search. We applied no language restrictions.

SELECTION CRITERIA

We selected studies that met predefined criteria for design, population, tests, and outcomes. We included cross-sectional and cohort studies assessing the diagnostic accuracy of pulse oximetry screening for diagnosis of CCHD in term and late preterm asymptomatic newborn infants. We considered all protocols of pulse oximetry screening (eg, different saturation thresholds to define abnormality, post-ductal only or pre-ductal and post-ductal measurements, test timing less than or greater than 24 hours). Reference standards were diagnostic echocardiography (echocardiogram) and clinical follow-up, including postmortem findings, mortality, and congenital anomaly databases.

DATA COLLECTION AND ANALYSIS

We extracted accuracy data for the threshold used in primary studies. We explored between-study variability and correlation between indices visually through use of forest and receiver operating characteristic (ROC) plots. We assessed risk of bias in included studies using the QUADAS-2 tool. We used the bivariate model to calculate random-effects pooled sensitivity and specificity values. We investigated sources of heterogeneity using subgroup analyses and meta-regression.

MAIN RESULTS

Twenty-one studies met our inclusion criteria (N = 457,202 participants). Nineteen studies provided data for the primary analysis (oxygen saturation threshold < 95% or ≤ 95%; N = 436,758 participants). The overall sensitivity of pulse oximetry for detection of CCHD was 76.3% (95% confidence interval [CI] 69.5 to 82.0) (low certainty of the evidence). Specificity was 99.9% (95% CI 99.7 to 99.9), with a false-positive rate of 0.14% (95% CI 0.07 to 0.22) (high certainty of the evidence). Summary positive and negative likelihood ratios were 535.6 (95% CI 280.3 to 1023.4) and 0.24 (95% CI 0.18 to 0.31), respectively. These results showed that out of 10,000 apparently healthy late preterm or full-term newborn infants, six will have CCHD (median prevalence in our review). Screening by pulse oximetry will detect five of these infants as having CCHD and will miss one case. In addition, screening by pulse oximetry will falsely identify another 14 infants out of the 10,000 as having suspected CCHD when they do not have it.The false-positive rate for detection of CCHD was lower when newborn pulse oximetry was performed longer than 24 hours after birth than when it was performed within 24 hours (0.06%, 95% CI 0.03 to 0.13, vs 0.42%, 95% CI 0.20 to 0.89; P = 0.027).Forest and ROC plots showed greater variability in estimated sensitivity than specificity across studies. We explored heterogeneity by conducting subgroup analyses and meta-regression of inclusion or exclusion of antenatally detected congenital heart defects, timing of testing, and risk of bias for the "flow and timing" domain of QUADAS-2, and we did not find an explanation for the heterogeneity in sensitivity.

AUTHORS' CONCLUSIONS

Pulse oximetry is a highly specific and moderately sensitive test for detection of CCHD with very low false-positive rates. Current evidence supports the introduction of routine screening for CCHD in asymptomatic newborns before discharge from the well-baby nursery.

Coronary artery spasm in a neonate with transposition of great arteries: a rare complication and reason for heart transplant

Arterial switch operation has become the standard of care for d-transposition of great arteries and has excellent short- and long-term outcomes. We report the case of a newborn with a diagnosis of d-transposition of great arteries with intact ventricular septum and a low-risk coronary artery anatomy who developed coronary artery vasospasm while coming off bypass following arterial switch operation in the operating room. The coronary artery spasm led to severe biventricular dysfunction and need for extracorporeal membranous oxygenation support. Despite extracorporeal membranous oxygenation and inotropic support, there was no improvement in the left ventricular function, and cardiac transplantation was performed after 8 days. The explanted heart showed extensive infarction of both ventricles. Both the coronary ostei were patent with no evidence of thrombus, suggesting coronary artery vasospasm rather than embolus or thrombus formation. This is the first case of coronary artery vasospasm in a neonate with d-transposition of great arteries leading to cardiac transplantation. We speculate that early identification of patients who are at a high risk for coronary vasospasm and prophylactic or timely infusion of papaverine directly into the coronary arteries may be beneficial in this condition.

Five-year experience with immediate extubation after arterial switch operations for transposition of great arteries

Objectives

We sought to identify preoperative, intraoperative and anatomical factors associated with immediate extubation (IE) after arterial switch operation for d-transposition of great arteries (dTGA).

Methods

This was a single-centre retrospective study performed from 1 January 2010 to 30 June 2015. IE was defined as successful extubation in the operating room (OR). Univariate/bivariate regression of preoperative, intraoperative and anatomical variables was used to determine associations with IE.

Results

Of 32 patients in the dTGA spectrum (age at operation 6 days), 18 (56%) underwent IE. Twelve (71%) of the 17 patients with an intact ventricular septum and 6 (43%) of the 14 patients with ventricular septal defect (VSD) underwent IE, whereas none of the patients with double outlet right ventricle or aortic arch obstruction ( n  = 4) did. Patients who had cardiopulmonary bypass time (CPB) >173 min ( P  = 0.01), lowest temperature on CPB (T min) ≤ 30.4°C ( P  = 0.04) and aortic cross-clamp time >86 min ( P  = 0.04) were more likely to be left intubated at the end of the procedure. There was no significant difference in patient's chronological age, gestational age, post-conceptual age, weight, coronary anatomy or prevalence of VSD between those who did and did not undergo IE. There was a median increase in intensive care unit (ICU) length of stay (LOS) by 1 day (33%, P  = 0.03) and ICU costs by $12 338 (15%, P  = 0.06) in non-IE patients. The OR turnover time ( P  = 0.09) and reintubation rate ( P  = 1) at 24 h post-extubation did not differ between those who did and did not have IE. There was no myocardial dysfunction evident on predismissal echocardiography in either group.

Conclusions

In this cohort of infants, post repair for TGA, 56% were extubated immediately in the OR. Greater CPB and cross-clamp times and T min ≤ 30.4°C were associated with a lesser likelihood of IE. IE was associated with shorter ICU length of stay.

Transposition of the Great Arteries in the Developing World: Surgery and Outcomes

BACKGROUND

Little has been published regarding surgery for transposition of the great arteries (TGA) in the developing world.

OBJECTIVES

This study sought to identify patient characteristics, surgical interventions, institutional characteristics, risk factors for mortality, and outcomes among patients undergoing surgery for TGA in this setting.

METHODS

Developing world congenital heart surgical programs submitted de-identified data to a novel international collaborative database as part of a quality improvement project. We conducted a retrospective cohort study that included all cases of TGA with intact ventricular septum and TGA with ventricular septal defect performed from 2010 to 2013. Demographic, surgical, and institutional characteristics and their associations with in-hospital mortality were identified.

RESULTS

There were 778 TGA operations performed at 26 centers, 480 (62%) for TGA with intact ventricular septum and 298 (38%) for TGA with ventricular septal defect. Most (80%) were single-stage arterial switch operations, but 20% were atrial baffling procedures (atrial switch operation) or 2-stage repairs (pulmonary artery band followed by arterial switch operation). Age at operation was >30 days in one-half of the cases and did not vary significantly with operation type. Survival was 85% and did not significantly vary with age at operation or operation type. Preceding septostomy was infrequently reported (16%) and was not associated with surgical mortality. Mortality was associated with lower World Health Organization weight/body mass index-for-age percentile and lower institutional volume of TGA repair.

CONCLUSIONS

Surgical repair of TGA performed in the developing world is associated with an early survival of 85%. Type of surgical repair and age at operation varied considerably, but no associations with mortality were identified. In contrast, poor nutrition and small surgical volume were most strongly associated with mortality. Multicenter collaborative quality improvement efforts may benefit patients with TGA in the developing world.

Evaluation of commissural malalignment of aortic-pulmonary sinus using cardiac CT for arterial switch operation: comparison with transthoracic echocardiography

BACKGROUND

There are limited data regarding the influence of commissural malalignment of the aortic-pulmonary sinus on the arterial switch operation.

OBJECTIVE

To compare diagnostic accuracy between cardiac CT and echocardiography for evaluating commissural malalignment of aortic-pulmonary sinus in children with complete transposition of the great arteries and to seek potential clinical implication of commissural malalignment on the arterial switch operation.

MATERIALS AND METHODS

In 37 patients (35 boys; median age: 8 days, range: 3-80 days) with complete transposition of the great arteries who had tricuspid semilunar valves and underwent an arterial switch operation, the degree of the commissural rotation of the aortic-pulmonary sinus was assessed on cardiac CT (n=37) and echocardiography (n=35). With surgical finding as a reference, cardiac CT was compared with echocardiography in identifying commissural malalignment in 35 patients. The influence of the height difference between the semilunar valves measured by cardiac CT on the identification of commissural malalignment with cardiac CT and echocardiography was evaluated. The impact of commissural malalignment on coronary transfer techniques was evaluated.

RESULTS

In operative findings, the commissures of the semilunar valves were aligned in 24 patients and malaligned in 13. With surgical findings as a reference, cardiac CT showed higher, but not statistically significant (P>0.05), sensitivity (91.7% vs. 75.0%), specificity (87.0% vs. 78.3%) and accuracy (88.6% vs. 77.1%) for the diagnosis of the malalignment than echocardiography. The measured height difference between the semilunar valves did not affect the identification of the malalignment with cardiac CT and echocardiography. The surgical malalignment group showed a higher requirement of modified coronary transfer techniques than the surgical aligned group (11/13 vs. 11/24, P=0.03).

CONCLUSION

Cardiac CT and echocardiography appear useful for evaluating commissural malalignment of the semilunar valves in patients with complete transposition of the great arteries frequently requiring modified coronary transfer techniques at during an arterial switch operation.

Outcomes after Arterial Switch Operation for Simple Transposition

Without intervention, babies born with transposed great arteries (TGA) are doomed to a rapid death. Jatene and coworkers deserve the credit for performing the first successful arterial switch operation (ASO) in a patient with TGA and ventricular septal defect (VSD) in 1975. Since then ASO has become the procedure of choice in most medical centers. This review article summarizes the historical aspects of arterial switch operation and assesses this procedure's outcomes.

Arterial Switch for Transposition of the Great Arteries With Large Ventricular Septal Defect and for Taussig Bing Anomaly: Experience From a Tertiary Care Center in the Developing World

BACKGROUND

Results of the arterial switch operation (ASO) for transposition of the great arteries (TGA) with large ventricular septal defect (VSD) and for Taussig Bing anomaly (TBA) in a tertiary care center of a developing country were retrospectively analyzed.

METHODS

From January 2007 through June 2013, a total of 30 patients with TBA and 54 patients having TGA with large VSD underwent ASO with VSD closure. Age at surgery for TBA was 27 days to 7 years (median age 3 months) and for TGA with VSD it was 1 day to 6 years (median age 2 months). In all, 46.7% of patients with TBA and 30% of patients with TGA/VSD presented with sepsis secondary to pneumonitis and were taken for surgery when the infection was under control. In all, 13% of patients with TBA and 5.5% of patients with TGA/VSD were on intermittent positive pressure ventilation (IPPV) prior to and continuing up to the time of surgery.

RESULTS

On multivariate analysis, factors associated with mortality were the presence of preoperative IPPV for pneumonia (P < .006) and the need for peritoneal dialysis following surgery (P < .028). Neither diagnosis of TBA or TGA/VSD nor any associated anatomical feature (including aortic arch obstruction, unusual coronary anatomy, great artery relationship, or mitral valve anomaly) was found to be related to high early mortality or late complications. Follow-up was 92% complete, with a mean duration of follow-up of 4.1 years. Freedom from reoperation was 98% at five years, and actuarial survival was 83.3% at five years.

CONCLUSIONS

Our experience at a tertiary center in a developing country suggests that preoperative need for IPPV for pneumonia is a major determining factor for mortality and morbidity in patients undergoing ASO for TBA and TGA/VSD. This appears to be of greater consequence than details of the underlying disease per se.

Pulse oximetry as a screening tool for detecting major congenital heart defects in Indian newborns

OBJECTIVE

To evaluate the use of pulse oximetry as a screening tool for detecting major congenital heart defects (CHDs) in Indian newborns.

DESIGN

Cross-sectional observational study.

PATIENTS

In a community hospital of north India, babies born during a specific 8 h period of the day were recruited over a period of 3 years. Newborns with incomplete documentation were excluded.

INTERVENTION

Routine clinical examination, pulse oximetry and bedside echocardiography.

OUTCOME MEASURES

Any abnormalities in clinical examination and pulse oximetry were recorded. CHDs were diagnosed using bedside echocardiography. Accuracy of pulse oximetry, clinical examination and their combination for detecting major CHDs was calculated.

RESULTS

Among the 19 009 newborns screened, 70 had major CHDs at birth (44 serious, 26 critical). Pulse oximetry detected 39 major (sensitivity 55.7%, 95% CI 44.1% to 66.8%; specificity 68.3%, 67.6% to 68.9%) and 22 critical CHDs (sensitivity 84.6%, 66.5% to 93.9%; specificity 68.3%, 67.6% to 68.9%). Addition of pulse oximetry to clinical examination significantly improved sensitivity for major CHDs (35.7% (25.5% to 47.4%) to 75.7% (64.5% to 85.3%), p<0.01) and critical CHDs (11.5% (4.0% to 29.0%) to 84.6% (66.5% to 93.9%), p<0.01).

CONCLUSIONS

Pulse oximetry is a sensitive screening tool for detecting major CHDs in Indian newborns. It adds significant value to the current practice of using clinical examination as a sole screening tool for detecting major CHDs. However, specificity of pulse oximetry was much lower in our study. Possible reasons for low specificity could be non-repetition of pulse oximetry in newborns with initial lower saturations, high prevalence of infections and respiratory issues in our cohort and use of non-motion tolerant oximeter.

Impact of Coronary Artery Anatomy in Arterial Switch Procedure on Early Mortality and Morbidity

OBJECTIVE

Arterial switch operation has become the treatment of choice for neonates with transposition of the great arteries. The most important step of the procedure is transferring the coronary arteries to the neoaorta successfully. This study shows the impact of coronary anatomy on early mortality and morbidity after arterial switch operation.

METHODS

Ninety-two patients with transposition of the great arteries who underwent arterial switch operation between October 2010 and September 2014 were included in this retrospective study. The patients were classified into two groups: group I (n = 68, patients with usual coronary artery anatomy) and group II (n = 24, patients with unusual coronary artery anatomy). Median age was 10 days (6-25 days) in group I and 14 days (7-29 days) in group II. In group I, 25 patients had ventricular septal defect, nine patients had coarctation of the aorta or distal aortic arch hypoplasia, seven patients had Taussig Bing anomaly. In group II, nine patients had ventricular septal defect, one patient had coarctation of aorta, and one patient had Taussig Bing anomaly.

RESULTS

Regarding the postoperative variables, no significant statistical difference was found between two groups. But cardiopulmonary bypass time is significantly longer in group II (P = .004). There was no difference in complications including the mortality (P = .265). It is statistically found that associated anomalies did not affect the mortality and complication rates. All mortality cases (n = 4) were related to ventricular dysfunction in group II, whereas only four of the eight patients died because of ventricular dysfunction in group I.

CONCLUSION

Coronary artery pattern was not a predictor of mortality in early postoperative period. There may be an impact of unusual coronary artery pattern on the development of ventricular dysfunction as a cause of mortality.

Coronary artery problems late after arterial switch operation for transposition of the great arteries

BACKGROUND

The incidence of late coronary artery abnormalities after arterial switch operation (ASO) for d-loop transposition of the great arteries may be underestimated.

METHODS AND RESULTS

We retrospectively reviewed coronary artery morphology in 40 of 97 patients who survived the first year after ASO. Seven asymptomatic patients developed significant late coronary artery abnormalities. One patient died suddenly at home with severe left coronary artery (LCA) ostial stenosis at age 3.8 years. The second patient collapsed during exercise at age 9.6 years due to ventricular fibrillation and severe LCA ostial stenosis despite prior negative exercise stress test (EST) and myocardial perfusion imaging (MPI). The third patient was found to have moderate ostial stenosis of the LCA with negative EST and MPI. The fourth patient with exercise-induced ST-T depression and myocardial perfusion defect was shown to have complete LCA occlusion with collateral vessel formation. Three other patients had complete proximal obliteration of either of the coronary arteries with collateral supply. An additional 4 asymptomatic patients had trivial-mild narrowing of the LCA on routine selective coronary angiogram.

CONCLUSIONS

Incidence of late coronary stenosis or occlusion was not infrequent after ASO (11.3%) and presented usually without preceding symptoms and often after negative non-invasive screening. We advocate routine coronary imaging in all patients after ASO before they participate in competitive sports.

Evaluation of a comprehensive cardiovascular magnetic resonance protocol in young adults late after the arterial switch operation for d-transposition of the great arteries

BACKGROUND

In adults with prior arterial switch operation (ASO) for d-transposition of the great arteries, the need for routine coronary artery assessment and evaluation for silent myocardial ischemia is not well defined. In this observational study we aimed to determine the value of a comprehensive cardiovascular magnetic resonance (CMR) protocol for the detection of coronary problems in adults with prior ASO for d-transposition of the great arteries.

METHODS

Adult ASO patients (≥18 years of age) were recruited consecutively. Patients underwent a comprehensive stress perfusion CMR protocol that included measurement of biventricular systolic function, myocardial scar burden, coronary ostial assessment and myocardial perfusion during vasodilator stress by perfusion CMR. Single photon emission computed tomography (SPECT) was performed on the same day as a confirmatory second imaging modality. Stress studies were visually assessed for perfusion defects (qualitative analysis). Additionally, myocardial blood flow was quantitatively analysed from mid-ventricular perfusion CMR images. In unclear cases, CT coronary angiography or conventional angiography was done.

RESULTS

Twenty-seven adult ASO patients (mean age 23 years, 85% male, 67% with a usual coronary pattern; none with a prior coronary artery complication) were included in the study. CMR stress perfusion was normal in all 27 patients with no evidence of inducible perfusion defects. In 24 cases the coronary ostia could conclusively be demonstrated to be normal. There was disagreement between CMR and SPECT for visually-assessed perfusion defects in 54% of patients with most disagreement due to false positive SPECT.

CONCLUSIONS

Adult ASO survivors in this study had no CMR evidence of myocardial ischemia, scar or coronary ostial abnormality. Compared to SPECT, CMR provides additional valuable information about the coronary artery anatomy. The data shows that the asymptomatic and clinically stable adult ASO patient has a low pre-test probability for inducible ischemia. In this situation it is likely that routine evaluation with stress CMR is unnecessary.

Repair of early left main stem stenosis after switch operation using an autologous innominate vein patch

We describe the repair of the postoperative left main stem stenosis of a 24-day old male patient who initially underwent arterial switch operation for dextro-transposition of the great arteries. The repair was facilitated by using an autologous left innominate vein patch, while there was a shortage of suitable repair material in this neonate. Postoperative echocardiogram prior to discharge confirmed a satisfactory flow through the left main stem and improved left ventricle function.

Adenosine stress myocardial perfusion scintigraphy in pediatric patients after arterial switch operation

Context:

Arterial switch operation (ASO) has become the established treatment for correction of transposition of great arteries (TGA). Despite the immediate correction of abnormal hemodynamics, acute and delayed complications related to the coronaries may cause morbidity and mortality.

Aims:

We evaluated the incidence of perfusion abnormalities and safety of adenosine by stress–rest myocardial perfusion single-photon emission computed tomography (SPECT) [myocardial perfusion scintigraphy (MPS)] using Tc-99m Sestamibi (MIBI) in asymptomatic children post-ASO.

Settings and Design:

Prospective study.

Materials and Methods:

We conducted a prospective, single-institutional study where stress–rest MPS was performed on 10 children of age between 1.25 and 6 years. Two of the patients had additional ventricular septal defect, one patient had left ventricular outflow tract obstruction, and another had Taussig–Bing anomaly. All the patients underwent corrective surgery as a single-stage procedure at the age of 176 ± 212 days (range 9-560 days). Adenosine was administered at a rate of 140 μg/kg/min intravenously as continuous infusion for duration of 6 min.

Statistical Analysis Used:

All the continuous variables were summarized as mean ± standard deviation, or range and median. Mann–Whitney test for unpaired data and Wilcoxon Rank test for paired samples were used.

Results:

The average increase in heart rate over the basal heart rate after adenosine stress was 59.7 ± 17.0%. No acute or remote complications were observed in any case. None of the patients demonstrated myocardial perfusion defects, either at rest or after adenosine stress.

Conclusions:

MPS post-adenosine induced vasodilatation is safe and feasible in patients of ASO for transposition of great arteries. One-stage repair, implantation of excised coronary buttons within neo-aortic sinus, and minimal or no mobilization of proximal coronaries may eliminate the occurrence of perfusion defects in patients of corrected TGA.

Characteristics and outcomes of transposition of great arteries in the neonatal period

INTRODUCTION AND OBJECTIVES

Transposition of the great arteries is a prevalent congenital heart defect with a high survival rate and a good long-term outcome, especially if managed with early surgical intervention during the neonatal period. In this study, our main objective was to describe patient characteristics and outcomes and to identify possible predictors of early and long-term morbidity and mortality.

METHODS

Retrospective analysis through review of clinical and surgical charts of patients with transposition of the great arteries admitted to the service of neonatology during 2000-2011.

RESULTS

The study included 136 patients; 119 of them had undergone corrective surgery during the neonatal period. Patients were divided into 3 groups: group I, 81 cases of isolated transposition; group II, 24 cases with ventricular septal defect; and group III, 31 with "complex" transposition of the great arteries. The overall postoperative survival was 96.7% (115 of 119 patients); no patients from group I died after surgery. Duration of surgery, intubation, inotropic treatment, and length of stay were higher in patients in groups II and III. The overall survival rate after an average of 6 years of follow-up was 90.4% 123 of 136 patients, with no deaths after discharge in group I. The most frequent residual defect during cardiac follow-up was supravalvular pulmonary stenosis, in 33 of 113 patients that had follow-up data.

CONCLUSIONS

In our study, the survival rate was high in patients with transposition of great arteries and especially in those undergoing arterial switch. The number of subsequent residual heart defects was low.

Cardiac autonomic function in adolescents operated by arterial switch surgery

BACKGROUND

Children with transposition of the great arteries, in whom an arterial switch operation (ASO) is performed, have been shown to have an increased incidence of sudden death, which may be due to cardiac autonomic imbalance and repolarisation instability. We hypothesised that i) cardiac norepinephrine (NE) kinetics and ii) arterial baroreflex sensitivity (BRS), reflecting sympathetic activity and vagal function respectively, are altered in this group.

METHODS AND RESULTS

17 children (15.8 ± 1.5 years of age) with ASO-surgery in the neonatal period were studied. 17 had cardiac BRS assessed by spontaneous fluctuations of systolic blood pressure and RR-interval, and repolarisation was measured as QT variability index. Matched healthy subjects were controls. Cardiac vagal function and repolarisation pattern were unchanged following ASO-surgery. At cardiac catheterisation, we infused tritiated NE in 8 of these children to examine total body and cardiac sympathetic function at baseline and following 5 min of adenosine infusion to induce reflex sympathetic activation. Blood was sampled simultaneously from the aorta and coronary sinus. Cardiac fractional extraction of ([3H])NE was substantially lower in operated children, being 56 ± 10 vs. 82 ± 9% (p=0.0001). Following i.v. adenosine in the operated group, NE total body spillover doubled vs. baseline (p<0.002) and the coronary venous-arterial concentration gradient of ([3H])dihydroxyphenylglycol increased 4-fold (p=0.04).

CONCLUSIONS

Arterial switch operation performed neonatally appears to leave cardiac vagal function intact and, although cardiac sympathetic activation in response to adenosine occurs, cardiac neuronal NE reuptake is impaired. This may be pro-arrhythmic by reducing removal capacity of NE from the cardiac synaptic cleft.

Abnormal mitral valve anatomy in d-transposition of the great arteries: anatomic characterization and surgical outcomes

Mitral valve anomalies can occur with S,D,D-transposition of the great arteries (d-TGA). Their influence on surgical technique and outcome after an arterial switch operation (ASO) has not been well described. Patients with d-TGA who underwent ASO from February 1990 to January 2011 were identified. Echocardiograms, operative reports, hospital course, and latest follow-up evaluation were reviewed. A total of 218 infants underwent ASO at a median age of 15.8 days. Survival was 95 % during a mean follow-up period of 60 months. Nine patients (4 %) were found to have similar mitral valve anomalies including anterior malalignment conoventricular septal defect, anterior displacement of the mitral valve toward the left ventricular outflow tract (LVOT), malpositioning of the posteromedial papillary muscle, unusual rotation of the mitral valve leaflets orienting the commissure toward the anterior ventricular septum, and redundant mitral valve tissue extending into the LVOT. Coarctation was more frequent in this subgroup (33 vs. 10 %; p = 0.05). Preoperative echocardiography consistently indicated suspicion of a cleft mitral valve with chordal attachments to the ventricular septum causing potential LVOT obstruction. Operative inspection did not identify a cleft or anomalous attachments in any patient, and no valvuloplasty or chordal manipulation was performed. The average hospital length of stay were similar (30.7 vs. 25.3 days; p = 0.54). One patient died late due to progressive LVOT obstruction, and one required heart transplantation. No patient had significant mitral valve regurgitation. We conclude that mitral valve anomalies associated with d-TGA are rare but present with consistent anatomic features and higher risk of coarctation. Unusual mitral valve apparatus positioning and chordal redundancy can suggest the need for valvuloplasty and chordal resection preoperatively, but this is rarely needed.

Cardiovascular outcomes after the arterial switch operation for D-transposition of the great arteries

BACKGROUND

Data regarding long-term outcomes after the arterial switch operation for D-transposition of the great arteries are scarce.

METHODS AND RESULTS

A single-institution retrospective cohort study was conducted to assess cardiovascular outcomes after an arterial switch operation between 1983 and 1999. Patients without follow-up visits within 3 years were contacted and secondary sources of information obtained. Overall, 400 patients, 154 (38.3%) with a ventricular septal defect, 238 (59.5%) with an intact septum, and 9 (2.3%) with a Taussig-Bing anomaly, were followed for a median of 18.7 years. In perioperative survivors, overall and arrhythmia-free survival rates at 25 years were 96.7±1.8% and 96.6±0.1%, respectively. Late mortality was predominantly a result of sudden deaths and myocardial infarction. At 25 years, 75.5±2.5% remained free from surgical or catheter-based reintervention. Freedom from an adverse cardiovascular event was 92.9±1.9% at 25 years. Independent predictors were a single right coronary artery (hazard ratio, 4.58; 95% confidence interval, 1.32-15.90), P=0.0166) and postoperative heart failure (hazard ratio, 6.93; 95% confidence interval, 1.57-30.62; P=0.0107). At last follow-up, the left ventricular ejection fraction was 60.3±8.9%, 97.3% had class I symptoms, and 5.2% obstructive coronary artery disease. Peak oxygen uptake was 35.1±7.6 mL/kg/min (86.1±15.1% predicted), with a chronotropic index <80% in 34.2%. At least moderate neoaortic and pulmonary regurgitation were present in 3.4% and 6.6%, respectively, and more than mild neoaortic and pulmonary stenosis in 3.2% and 10.3%.

CONCLUSIONS

Long-term and arrhythmia-free survival is excellent after arterial switch operation. Although sequelae include chronotropic incompetence and neoaortic, pulmonary, and coronary artery complications, most patients maintain normal systolic function and exercise capacity.

Midterm results after arterial switch operation for transposition of the great arteries: a single centre experience

Background

The arterial switch operation (ASO) has become the surgical approach of choice for d-transposition of the great arteries (d-TGA). There is, however an increased incidence of midterm and longterm adverse sequelae in some survivors. In order to evaluate operative risk and midterm outcome in this population, we reviewed patients who underwent ASO for TGA at our centre.

Methods

In this retrospective study 52 consecutive patients with TGA who underwent ASO between 04/1991 and 12/1999 were included. To analyze the predictors for mortality and adverse events (coronary stenoses, distortion of the pulmonary arteries, dilatation of the neoaortic root, and aortic regurgitation), a multivariate analysis was performed. The follow-up time was ranged from 1–10 years (mean 5 years, cumulative 260 patient-years).

Results

All over mortality rate was 15.4% and was only observed in the early postoperative period till 1994. The predictors for poor operative survival were low APGAR-score, older age at surgery, and necessity of associated surgical procedures. Late re-operations were necessary in 6 patients (13.6%) and included a pulmonary artery patch enlargement due to supravalvular stenosis (n = 3), coronary revascularisation due to coronary stenosis in a coronary anatomy type E, aortic valve replacement due to neoaortic valve regurgitation (n = 2), and patch-plasty of a pulmonary vein due to obstruction (n = 1). The dilatation of neoaortic root was not observed in the follow up.

Conclusions

ASO remains the procedure of choice for TGA with acceptable early and late outcome in terms of overall survival and freedom of reoperation. Although ASO is often complex and may be associated with morbidity, most patients survived without major complications even in a small centre.

Pulse oximetry screening for critical congenital heart defects in asymptomatic newborn babies: a systematic review and meta-analysis

BACKGROUND

Screening for critical congenital heart defects in newborn babies can aid in early recognition, with the prospect of improved outcome. We assessed the performance of pulse oximetry as a screening method for the detection of critical congenital heart defects in asymptomatic newborn babies.

METHODS

In this systematic review, we searched Medline (1951-2011), Embase (1974-2011), Cochrane Library (2011), and Scisearch (1974-2011) for relevant citations with no language restriction. We selected studies that assessed the accuracy of pulse oximetry for the detection of critical congenital heart defects in asymptomatic newborn babies. Two reviewers selected studies that met the predefined criteria for population, tests, and outcomes. We calculated sensitivity, specificity, and corresponding 95% CIs for individual studies. A hierarchical receiver operating characteristic curve was fitted to generate summary estimates of sensitivity and specificity with a random effects model.

FINDINGS

We screened 552 studies and identified 13 eligible studies with data for 229,421 newborn babies. The overall sensitivity of pulse oximetry for detection of critical congenital heart defects was 76·5% (95% CI 67·7-83·5). The specificity was 99·9% (99·7-99·9), with a false-positive rate of 0·14% (0·06-0·33). The false-positive rate for detection of critical congenital heart defects was particularly low when newborn pulse oximetry was done after 24 h from birth than when it was done before 24 h (0·05% [0·02-0·12] vs 0·50 [0·29-0·86]; p=0·0017).

INTERPRETATION

Pulse oximetry is highly specific for detection of critical congenital heart defects with moderate sensitivity, that meets criteria for universal screening.

FUNDING

None.

Long-term outcome of direct neopulmonary artery reconstruction during the arterial switch procedure

BACKGROUND

Neopulmonary stenosis at anastomosis site is one of the most frequent complications after the arterial switch procedure for transposition of the great arteries. The surgical technique is a crucial factor associated with the frequency of stenotic complications. We present the outcomes of direct neopulmonary anastomosis during the arterial switch procedure in patients with simple transposition. This research was to assess the efficacy of this surgical technique based on the incidence of postprocedural supravalvular neopulmonary stenosis (SVPS).

METHODS

Among 545 patients operated on in our department between 1992 and 2009, the 346 consecutive survivors who had undergone simple transposition in the first month of life were included in this analysis. Switch procedures were performed with direct neopulmonary artery anastomosis in 318 patients (92%); in the remaining 28 (8%), the risk of coronary artery compression required the use of a pericardial patch for pulmonary reconstruction.

RESULTS

Neopulmonary stenosis occurred in 9 patients (2.6%): 5 had undergone direct neopulmonary reconstruction, and 4 had been treated with a patch. Balloon angioplasty of SVPS was performed twice in 1 patient. No patients required reoperation to treat neopulmonary stenosis. In multivariate analysis (logistic regression), patch reconstruction (odds ratio, 27.5; p=0.001) and nonfacing commissures (odds ratio, 11.1; p=0.004) were correlated significantly with the incidence of SVPS.

CONCLUSIONS

Direct neopulmonary artery anastomosis during arterial switch is an interesting alternative to patch reconstructions and ensures a good postoperative result with low rates of complications and SVPS.