Long-term outcomes of tetralogy of Fallot repair: A 30-year experience with 960 patients.

OBJECTIVE: This study evaluates the long-term results of tetralogy of Fallot repair and assesses the risk factors for adverse outcomes. METHODS: This retrospective study included 960 patients who underwent transatrial transpulmonary tetralogy of Fallot repair between 1990 and 2020. RESULTS: A transannular patch was placed in 722 patients, and pulmonary valve preservation was achieved in 233 patients. The median age at tetralogy of Fallot repair was 9.4 (interquartile range, 6.2-14.2) months. The median follow-up duration was 10.6 (interquartile range, 5.4-16.3) years. There were 8 early deaths (0.8%) and 20 late deaths (2.1%). Genetic syndrome and pulmonary valve annulus Z score less than -3 were risk factors for mortality. The survival was 97.7% (95% confidence interval, 96.4-98.5) and 94.5% (95% confidence interval, 90.9-96.7) at 10 and 30 years, respectively. Freedom from any reoperation was 86.4% (95% confidence interval, 83.6-88.7) and 65.4% (95% confidence interval, 59.8-70.4) at 10 and 20 years, respectively. Postoperative right ventricular outflow tract peak gradient of 25 mm Hg or greater correlated with reoperation. Propensity score-matched analysis demonstrated that freedom from pulmonary valve replacement at 15 years was higher in the pulmonary valve preservation group compared with the transannular patch group (98.2% vs 78.4%, P = .004). Freedom from reoperation for right ventricular outflow tract obstruction at 15 years was lower in the pulmonary valve preservation group compared with the transannular patch group (P = .006). CONCLUSIONS: The long-term outcomes of tetralogy of Fallot repair are excellent. A postoperative right ventricular outflow tract peak gradient less than 25 mm Hg appears to be optimal to prevent reoperation. If the pulmonary valve size is suitable, pulmonary valve preservation reduces the risk of pulmonary valve replacement, yet increases the reoperation rate for right ventricular outflow tract obstruction.

Abbreviated Echocardiographic Screening for Rheumatic Heart Disease by Nonexperts with and without Offsite Expert Review: A Diagnostic Accuracy Study.

BACKGROUND: Early detection of rheumatic heart disease (RHD) through echocardiographic screening can facilitate early access to effective treatment, which reduces the risk for progression. Accurate, feasible approaches to echocardiographic screening that can be incorporated into routine health services are needed. The authors hypothesized that offsite expert review could improve the diagnostic accuracy of nonexpert-obtained echocardiographic images. METHODS: This prospective cross-sectional study was performed to evaluate the diagnostic accuracy of health worker-conducted single parasternal long-axis view with a sweep of the heart using hand-carried ultrasound for the detection of RHD in high-risk populations in Timor-Leste and Australia. In the primary analysis, the presence of any mitral or aortic regurgitation met the criteria for a positive screening result. Sensitivity and specificity were calculated for a screen-and-refer approach based on nonexpert practitioner assessment (approach 1) and for an approach using offsite expert review of nonexpert practitioner-obtained images to decide onward referral (approach 2). Each participant had a reference test performed by an expert echocardiographer on the same day as the index test. Diagnosis of RHD was determined by a panel of three experts, using 2012 World Heart Federation criteria. RESULTS: The prevalence of borderline or definite RHD among 3,329 participants was 4.0% (95% CI, 3.4%-4.7%). The sensitivity of approach 1 for borderline or definite RHD was 86.5% (95% CI, 79.5%-91.8%), and the specificity was 61.4% (95% CI, 59.7%-63.1%). Approach 2 achieved similar sensitivity (88.4%; 95% CI, 81.5%-93.3%) and improved specificity (77.1%; 95% CI, 75.6%-78.6%). CONCLUSION: Nonexpert practitioner-obtained single parasternal long-axis view with a sweep of the heart images, reviewed by an offsite expert, can detect borderline and definite RHD on screening with reasonable sensitivity and specificity. Brief training of nonexpert practitioners with ongoing support could be used as an effective strategy for scaling up echocardiographic screening for RHD in high-risk settings.

Impact of Fontan Fenestration on Long-Term Outcomes: A Propensity Score-Matched Analysis.

Background The long-term impact of fenestration at the time of Fontan operation remains unclear. We aimed to review the early and long-term impact of Fontan fenestration in the Australia and New Zealand cohort. Methods and Results We reviewed 1443 patients (621 fenestrated, 822 nonfenestrated) from the Australia and New Zealand Fontan registry. Data were collected on preoperative demographics, operative details, and follow-up. Propensity-score matching was performed to account for the various preoperative and operative differences and risk factors. Primary outcomes were survival and freedom from failure. Median follow-up was 10.6 years. After propensity-score matching (407 matched pairs), there was no difference in survival (87% versus 90% at 20 years; P=0.16) or freedom from failure (73% versus 80% at 20 years; P=0.10) between patients with and without fenestration, respectively. Although patients with fenestration had longer bypass and cross-clamp times (P<0.001), there was no difference in hospital length of stay or prolonged pleural effusions (P=0.80 and P=0.46, respectively). Freedom from systemic and Fontan circuit thromboembolism was higher in the nonfenestrated group (89%; 95% CI, 88%-95%) than the fenestrated group (84%; 95% CI, 77%-89%; P=0.03). There was no difference in incidence of plastic bronchitis, protein-losing enteropathy, New York Heart Association Class III/IV symptoms, or Fontan takedown. Conclusions In the propensity score-matched analysis we have demonstrated no difference in long-term survival or freedom from Fontan failure in patients with and without fenestration. There was a higher incidence of long-term thromboembolic events in patients with fenestration. Overall, it appears that fenestration in Fontan circulation does not bring long-term benefits.

Cardiac crises: Cardiac arrhythmias and cardiomyopathy during TANGO2 deficiency related metabolic crises.

BACKGROUND: TANGO2 deficiency disorder (TDD) is an autosomal recessive disease associated with metabolic crisis, lethal cardiac arrhythmias, and cardiomyopathy. Data regarding treatment, management, and outcomes of cardiac manifestations of TDD are lacking. OBJECTIVE: The purpose of this study was to describe TDD-related cardiac crises. METHODS: Retrospective multicenter chart review was made of TDD patients admitted with cardiac crises, defined as development of ventricular tachycardia (VT), cardiomyopathy, or cardiac arrest during metabolic crises. RESULTS: Twenty-seven children were admitted for 43 cardiac crises (median age 6.4 years; interquartile range [IQR] 2.4-9.8 years) at 14 centers. During crisis, QTc prolongation occurred in all (median 547 ms; IQR 504-600 ms) and a type I Brugada pattern in 8 (26%). Arrhythmias included VT in 21 (78%), supraventricular tachycardia in 3 (11%), and heart block in 1 (4%). Nineteen patients (70%) developed cardiomyopathy, and 20 (74%) experienced a cardiac arrest. There were 10 deaths (37%), 6 related to arrhythmias. In 5 patients, recalcitrant VT occurred despite use of antiarrhythmic drugs. In 6 patients, arrhythmias were controlled after extracorporeal membrane oxygenation (ECMO) support; 5 of these patients survived. Among 10 patients who survived VT without ECMO, successful treatment included intravenous magnesium, isoproterenol, and atrial pacing in multiple cases and verapamil in 1 patient. Initiation of feeds seemed to decrease VT events. CONCLUSION: TDD-related cardiac crises are associated with a high risk of arrhythmias, cardiomyopathy, cardiac arrest, and death. Although further studies are needed, early recognition and appropriate treatment are critical. Acutely, intravenous magnesium, isoproterenol, atrial pacing, and ECMO as a last resort seem to be the best current treatment options, and early initiation of feeds may prevent VT events.

Natural and Modified History of Atrioventricular Valve Regurgitation in Patients With Fontan Circulation.

BACKGROUND: Atrioventricular valve (AVV) regurgitation is increasingly prevalent in patients with a Fontan circulation. OBJECTIVES: We sought to determine the impact of ventricular dominance and AVV operation on outcomes in patients with a Fontan circulation and ≥moderate AVV regurgitation. METHODS: We conducted a retrospective study, including propensity score matching analysis, of 1,703 patients who survived Fontan operation in Australia and New Zealand from 1987 to 2021. RESULTS: Patients undergoing AVV operation were more likely to have right ventricular (RV) dominance or an atrioventricular septal defect. In the entire cohort, death or transplantation after Fontan operation was significantly higher in patients who underwent AVV operation before or at Fontan completion compared with those who did not (20 years: 18%; 95% CI: 8%-26% vs 13%; 95% CI: 10%-15%; P = 0.03). After propensity score matching, including for RV dominance, there was no significant difference in death or transplantation between the groups (20 years: 18%; 95% CI: 8%-26% vs 16%; 95% CI: 10%-22%; P = 0.41). Only patients with RV dominance who developed ≥moderate AVV regurgitation after Fontan operation were at increased risk of death or transplantation (HR: 2.8; 95% CI: 1.4-5.3; P < 0.01). In patients with left ventricular dominance, there was no significant difference in death or transplantation between patients with ≥moderate AVV regurgitation compared with those with 

Single-View Echocardiography by Nonexpert Practitioners to Detect Rheumatic Heart Disease: A Prospective Study of Diagnostic Accuracy.

BACKGROUND: Echocardiographic screening can detect asymptomatic cases of rheumatic heart disease (RHD), facilitating access to treatment. Barriers to implementation of echocardiographic screening include the requirement for expensive equipment and expert practitioners. We aimed to evaluate the diagnostic accuracy of an abbreviated echocardiographic screening protocol (single parasternal-long-axis view with a sweep of the heart) performed by briefly trained, nonexpert practitioners using handheld ultrasound devices. METHODS: Participants aged 5 to 20 years in Timor-Leste and the Northern Territory of Australia had 2 echocardiograms: one performed by an expert echocardiographer using a GE Vivid I or Vivid Q portable ultrasound device (reference test), and one performed by a nonexpert practitioner using a GE Vscan handheld ultrasound device (index test). The accuracy of the index test, compared with the reference test, for identifying cases with definite or borderline RHD was determined. RESULTS: There were 3111 enrolled participants; 2573 had both an index test and reference test. Median age was 12 years (interquartile range, 10-15); 58.2% were female. Proportion with definite or borderline RHD was 5.52% (95% CI, 4.70-6.47); proportion with definite RHD was 3.23% (95% CI, 2.61-3.98). Compared with the reference test, sensitivity of the index test for definite or borderline RHD was 70.4% (95% CI, 62.2-77.8), specificity was 78.1% (95% CI, 76.4-79.8). CONCLUSIONS: Nonexpert practitioners can be trained to perform single parasternal-long-axis view with a sweep of the heart echocardiography. However, the specificity and sensitivity are inadequate for echocardiographic screening. Improved training for nonexpert practitioners should be investigated.

Outcomes of Interrupted Aortic Arch Repair in Children With Biventricular Circulation.

BACKGROUND: To evaluate the outcomes after surgical repair of interrupted aortic arch in patients with biventricular circulation. METHODS: We reviewed all children from a single institution (N = 177) who had interrupted aortic arch repair between 1978 and 2018. Patients were separated into simple (n = 122) and complex (n = 55) group based on their concomitant anomalies. RESULTS: Median age at repair was 6 days (range, 1-298 days) and median weight was 3.1 kg (range, 0.95-5.1 kg). Median follow-up time was 11.5 years (mean 12.6 years; range, 0.1-35.9 years). Overall early mortality was 11.9% (21 of 177) and there were 5 late deaths. Era of surgery did not impact on overall survival (P = .37). Between 2000 and 2018, there was a significant difference in early mortality between the simple and complex group (3.2% [2 of 62] vs 24.1% [7 of 29], P = .002). There was an improvement in mortality in the simple group over time (P = .03). Competing risks analysis showed at 15 years after the initial operation 14% had died without arch reoperation, 15.2% had undergone aortic arch reoperation, and 70.8% were alive without arch reoperation. Reoperation on the aortic arch was more common in the complex group compared to the simple group (20.0% [11 of 55] vs 9.0% [11 of 122], P< .001). CONCLUSIONS: Survival of patients with interrupted aortic arch and associated simple anomalies has improved over time, although mortality in patients with complex congenital cardiac lesions remains high.

Augmentation of the pulmonary arteries at or prior to the Fontan procedure is not associated with worse long-term outcomes: a propensity-matched analysis from the Australia-New Zealand Fontan Registry†.

OBJECTIVES: Long-term data on the impact of pulmonary artery (PA) augmentation in patients who underwent the Fontan procedure are lacking. The aim of this study was to examine whether surgical or transcatheter PA augmentation at or prior to the Fontan procedure adversely affects the outcomes. METHODS: Data of 1436 patients from the Australia-New Zealand Fontan Registry (1975-2015) were analysed. Primary end point was death or Fontan failure. Cox regression with propensity score matching was used to determine risk or benefit conferred by PA augmentation. RESULTS: Forty-eight (3.3%) patients underwent PA augmentation following cavopulmonary shunt (surgical n = 14, balloon dilatation n = 16 and stent n = 18) and 105 (7.3%) patients underwent PA augmentation at the time of the Fontan procedure (surgical n = 104, stent n = 1). Median follow-up was 6.4 years with 10 deaths (6.5%) in the augmentation group and 10.5 years with 95 deaths (7.4%) in the non-augmentation group. The unadjusted Kaplan-Meier, log-rank test and Cox regression analysis demonstrated no significant difference in both end points between the 2 groups [death: hazard ratio (HR) 1.35, 95% confidence interval (CI) 0.70-2.60; P = 0.37 death or failure: HR 1.39, 95% CI 0.83-2.34; P = 0.21]. The propensity score matching yielded 131 matched pairs, with adequate balance for all covariates (the median residual bias = 0.05). The subsequent Cox regression demonstrated no significant difference in the risks of death (HR 1.30, 95% CI 0.49-3.41; P = 0.60) and death or Fontan failure (HR 0.92, 95% CI 0.46-1.85; P = 0.82). CONCLUSIONS: PA augmentation prior to or at the Fontan procedure does not confer worse long-term outcomes.

Long-Term Outcomes of Hypertrophic Cardiomyopathy Diagnosed During Childhood: Results From a National Population-Based Study.

BACKGROUND: Late survival and symptomatic status of children with hypertrophic cardiomyopathy have not been well defined. We examined long-term outcomes for pediatric hypertrophic cardiomyopathy. METHODS: The National Australian Childhood Cardiomyopathy Study is a longitudinal population-based cohort study of children (0-10 years of age) diagnosed with cardiomyopathy between 1987 and 1996. The primary study end point was time to death or cardiac transplantation. RESULTS: There were 80 patients with hypertrophic cardiomyopathy, with a median age at diagnosis of 0.48 (interquartile range, 0.1, 2.5) years. Freedom from death/transplantation was 86% (95% confidence interval [CI], 77.0-92.0) 1 year after presentation, 80% (95% CI, 69.0-87.0) at 10 years, and 78% (95% CI, 67.0-86.0) at 20 years. From multivariable analyses, risk factors for death/transplantation included symmetrical left ventricular hypertrophy at the time of diagnosis (hazard ratio, 4.20; 95% CI, 1.60-11.05; P=0.004), Noonan syndrome (hazard ratio, 2.88; 95% CI, 1.02-8.08; P=0.045), higher posterior wall thickness z score (hazard ratio, 1.45; 95% CI, 1.22-1.73; P<0.001), and lower fractional shortening z score (hazard ratio, 0.84; 95% CI, 0.74-0.95; P=0.005) during follow-up. Nineteen (23%) subjects underwent left ventricular myectomy. At a median of 15.7 years of follow-up, 27 (42%) of 63 survivors were treated with ß-blocker, and 13 (21%) had an implantable cardioverter-defibrillator. CONCLUSIONS: The highest risk of death or transplantation for children with hypertrophic cardiomyopathy is within 1 year after diagnosis, with low attrition rates thereafter. Many subjects receive medical, surgical, or device therapy.

Long-Term Outcomes of Childhood Left Ventricular Noncompaction Cardiomyopathy: Results From a National Population-Based Study.

BACKGROUND: Long-term outcomes for childhood left ventricular noncompaction (LVNC) are uncertain. We examined late outcomes for children with LVNC enrolled in a national population-based study. METHODS: The National Australian Childhood Cardiomyopathy Study includes all children in Australia with primary cardiomyopathy diagnosed before 10 years of age between 1987 and 1996. Outcomes for subjects with LVNC with a dilated phenotype (LVNC-D) were compared with outcomes for those with dilated cardiomyopathy. Propensity-score analysis was used for risk factor adjustment. RESULTS: There were 29 subjects with LVNC (9.2% of all cardiomyopathy subjects), with a mean annual incidence of newly diagnosed cases of 0.11 per 100 000 at-risk individuals. Congestive heart failure was the initial symptom in 24 of 29 subjects (83%), and 27 (93%) had LVNC-D. The median age at diagnosis was 0.3 (interquartile interval, 0.08-1.3) years. The median duration of follow-up was 6.8 (interquartile interval, 0.7-24.0) years for all subjects and 24.7 (interquartile interval, 23.3 - 27.7) years for surviving subjects. Freedom from death or transplantation was 48% (95% confidence interval [CI], 30-65) at 10 years after diagnosis and 45% (95% CI, 27-63) at 15 years. In competing-risk analysis, 21% of subjects with LVNC were alive with normal left ventricular systolic function, and 31% were alive with abnormal function at 15 years. Propensity-score matching between subjects with LVNC-D and those with dilated cardiomyopathy suggested a lower freedom from death/transplantation at 15 years after diagnosis in the subjects with LVNC-D (LVNC-D, 46% [95% CI, 26-66] versus dilated cardiomyopathy, 70% [95% CI, 42-97]; P=0.08). Using propensity-score inverse probability of treatment-weighted Cox regression, we found evidence that LVNC-D was associated with a greater risk of death or transplantation (hazard ratio, 2.3; 95% CI, 1.4-3.8; P=0.0012). CONCLUSIONS: Symptomatic children with LVNC usually present in early infancy with a predominant dilated phenotype. Long-term outcomes are worse than for matched children with dilated cardiomyopathy.

Outcomes of the Warden procedure for partial anomalous pulmonary venous drainage in children.

OBJECTIVES: When drainage of an anomalous pulmonary vein is high into the superior vena cava (SVC), traditional techniques of 1-patch or 2-patch repair may be challenging. The cavoatrial anastomosis technique (the Warden procedure) was developed to reduce the risk of sinus node dysfunction and SVC obstruction. Herein, we describe the outcomes of the Warden procedure in children at a single institution. METHODS: A retrospective study was conducted on all children with partial anomalous pulmonary venous drainage (PAPVD) undergoing the Warden procedure from 1996 to 2015. RESULTS: There were 42 PAPVD patients with a right upper pulmonary vein entering into the SVC undergoing the Warden procedure. The mean age of the patients at surgery was 5.5 years (71 days to 15.4 years). There was no operative mortality. Median hospital stay was 5 (3-25) days. One (2.4%) patient developed cavoatrial (SVC) obstruction. This patient required percutaneous intervention (stenting and balloon dilatation). There was 1 (2.4%) late death in a patient with PAPVD and pulmonary atresia due to a hypoxic brain injury following catheter intervention for a stenotic conduit. Survival was 97 ± 3% (95% confidence interval 83-100%) at 5 and 7 years. All patients were asymptomatic at a mean follow-up of 6 years (range 1 month to 21 years) after surgery. No patient had sick sinus syndrome, sinus node dysfunction or required permanent pacemaker at follow-up. CONCLUSIONS: The Warden procedure for repair of PAPVD to the SVC can be performed with no operative mortality or permanent pacemaker requirement. Mid-term outcomes are excellent with a low occurrence of SVC obstruction.

Long-Term Outcomes of Total Anomalous Pulmonary Venous Drainage Repair in Neonates and Infants.

BACKGROUND: Outcomes of operations for total anomalous pulmonary venous drainage (TAPVD) have improved. However, operations in the neonatal period and the development of postoperative pulmonary venous obstruction are associated with a high mortality rate. METHODS: A retrospective review was conducted for all neonates and infants (n = 214) who underwent operations for isolated TAPVD (1973 to 2014). RESULTS: Median age was 18 days (1 day to 1 year). There were 17 (7.9%) early deaths. Risk factors for early death were prolonged cardiopulmonary bypass time (p = 0.005) and neonatal age at the operation (p = 0.048). Early mortality was 2.5% for infants (n = 81) and 11% for neonates (n = 133; p = 0.021) during the entire study period. Hospital deaths for neonates remained unchanged during the four eras of 1973 to 1988, 1989 to 1998, 1999 to 2008, and 2009 to 2014. Survival at 10 and 20 years was 88% ± 2.2% (95% confidence interval, 82% to 91%). Reoperation for postoperative pulmonary venous obstruction was required in 22 patients (10%). Risk factors for reoperation were prolonged cardiopulmonary bypass time (p = 0.015), lower operative weight (p = 0.003), and an episode of postoperative pulmonary hypertensive crisis (p = 0.005). Freedom from reoperation at 20 years was 86% ± 3.2% (95% confidence interval, 78% to 91%). All survivors were asymptomatic at a mean of 13 ± 9 years (range, 1 month to 42 years) after the operation. CONCLUSIONS: Although isolated TAPVD repair in infants can be performed without death, the operation is associated with a high mortality rate in neonates that remained unchanged during the long study period. Survival beyond 1 year after the operation is associated with excellent long-term outcomes.

Surgical Intervention for Anomalous Origin of Left Coronary Artery From the Pulmonary Artery in Children: A Long-Term Follow-Up.

BACKGROUND: Anomalous left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital heart defect with limited data on long-term outcomes after surgical intervention. METHODS: We conducted a retrospective review of all children (N = 42) who underwent surgical repair of ALCAPA between 1980 and 2014 at the Royal Children's Hospital, Melbourne. RESULTS: Twenty-nine (69% [29 of 42]) patients underwent coronary reimplantation, 12 (29% [12 of 42]) had intrapulmonary baffle (Takeuchi) repair, and 1 (2% [1 of 42]) patient had ligation of the anomalous coronary artery. Nine (21%, 9 of 42) patients had concomitant mitral valve (MV) repair at the time of ALCAPA repair. A left ventricular assist device (LVAD) was used in 36% (15 of 42) of patients. Early mortality was 2.4% (1 of 42 patients). Median follow-up was 14 years (mean, 13 years; range, 4 months-31 years). There were no late deaths. Survival was 98% at 20 years. Freedom from reoperation was 81%, 81%, and 76% at 5, 10, and 20 years after operation, respectively. Eight patients underwent late MV repair or replacement at a median of 3 years (mean, 8 years; range, 2 months-25 years) after operation. Freedom from late MV repair or replacement was 86% at 5 and 10 years and 81% at 20 years after operation. Eleven (26% [11 of 42]) patients had severe mitral regurgitation (MR) preoperatively. Of those 11 patients, 5 (45% [5 of 11]) had concomitant MV repair at the time of ALCAPA repair, 3 (27% [3 of 11]) had late MV repair or replacement, and the remaining 3 (27% [3 of 11]) patients had mild MR at last follow-up. Thirty-six (90% [36 of 41]) patients had normal left ventricular function and 4 (10% [4 of 41]) patients had mildly reduced left ventricular (LV) function at last follow-up. CONCLUSIONS: ALCAPA can be operated on with good outcomes. Persistent MR and a moderate rate of late MV repair warrants close follow-up.

Excellent Long-Term Outcomes of the Arterial Switch Operation in Patients With Intramural Coronary Arteries.

BACKGROUND: Intramural coronary arteries may complicate coronary artery transfer during the arterial switch operation. We sought to determine the long-term outcomes of 28 patients with intramural coronary arteries who underwent an arterial switch operation at a single institution. METHODS: All patients who had intramural coronary arteries and underwent an arterial switch operation were identified from the hospital database and retrospectively reviewed. RESULTS: From 1983 to 2009, 720 patients underwent an arterial switch operation at our institution. Twenty-eight (3.9%, 28 of 720) had intramural coronary arteries. Patients with intramural coronary arteries had transposition of the great arteries (96%, n = 27) or Taussig-Bing anomaly (4%, n = 1). There were no deaths. Follow-up was 100% complete. Mean follow-up was 16.3 years (median, 15.5 years; range, 5.6 to 26.9 years). No patient required reoperation or catheter reintervention on the coronary arteries. Freedom from reoperation was 93% at 10 years. No patient had more than mild aortic regurgitation at last follow-up. Nine (32%, 9 of 28) patients had coronary angiograms at median 16 months (range, 14 months to 17 years) after arterial switch operation. All patients were asymptomatic at the time of angiogram. One patient had mild stenosis of the circumflex coronary artery demonstrated on a routine coronary angiogram 14 months postoperatively. All 28 patients were asymptomatic and in New York Heart Association functional class I at last follow-up. CONCLUSIONS: Patients with intramural coronary arteries are not at increased risk of death or coronary reinterventions and have excellent late outcomes after the arterial switch operation.

Sudden death in childhood cardiomyopathy: results from a long-term national population-based study.

BACKGROUND: Children with cardiomyopathy (CM) are at risk of sudden cardiac death (SCD), but the incidence and risk factors for this outcome are not clear. OBJECTIVES: This study sought to determine the incidence and risk factors for SCD in children with varying CM phenotypes from a long-term population-based study of childhood CM. METHODS: The NACCS (National Australian Childhood Cardiomyopathy Study) is an ongoing longitudinal cohort study including all children in Australia with primary CM who were diagnosed between January 1, 1987, and December 31, 1996, and were <10 years of age. The cumulative incidence and risk factors for SCD within individual CM phenotypes were explored using survival analysis. RESULTS: Of 289 eligible patients, 16 (5.5%) experienced SCD over a median follow-up of 11.9 years (interquartile range: 1.7 to 15.4). The risk of SCD varied according to CM phenotype (p=0.007). The cumulative incidence of SCD at 15 years was 5% for dilated cardiomyopathy (DCM), 6% for hypertrophic cardiomyopathy (HCM), 12% for restrictive cardiomyopathy, and 23% for left ventricular (LV) noncompaction. Older age at diagnosis, positive family history of CM, and severity of LV dysfunction were related to increased risk of SCD in patients with DCM, and a higher posterior wall thickness Z-score was the sole risk factor identified for patients with HCM. CONCLUSIONS: Predictors of SCD include CM phenotype, family history of CM (DCM), severity of systolic dysfunction (DCM), and extent of LV hypertrophy (HCM). Continuing follow-up of this cohort into adulthood is likely to reveal an ongoing risk of SCD.

Medium-term outcomes of bovine jugular vein graft and homograft conduits in children.

BACKGROUND: The bovine jugular vein (Contegra) conduit has been described as an alternative to the homograft for right ventricle (RV) to pulmonary artery (PA) connection. We assessed the outcomes of Contegra conduits and homografts at a single institution. METHODS: We conducted a retrospective review of children (n = 249) who underwent RV-to-PA conduit (Contegra or homograft) implantation from 2001 to 2011. RESULTS: Median operation age was 4.8 years (2 days-18 years). Indications for surgery were as follows: primary conduit insertion (n = 131; 53%), previous conduit failure (n = 57; 23%) or Ross procedure (n = 61; 25%). There were 113 (45%) Contegra conduits and 136 (55%) homografts (92 pulmonary, 44 aortic) inserted. Early mortality was 5% (n = 12). Overall survival was 89% (95% confidence interval (CI): 84-92%) at 5 years and 87% (95% CI: 81-92%) at 10 years. Mortality was associated with smaller conduit size (P = 0.044) and syndrome diagnosis (P = 0.012). Freedom from reoperation was 85% (95% CI: 77-91%) and 75% (95% CI: 59-86%) at 5 years for homografts and Contegra conduits, respectively. Patients required conduit replacement (15%) for endocarditis (n = 4; 11%) or graft failure (n = 34; 89%). Eleven patients developed distal conduit stenosis with the majority occurring in Contegra conduits (n = 7; 64%) (P = 0.004). A larger conduit (P = 0.007) was protective against reoperation. There was no difference in reoperation between conduits (P = 0.41). Mean follow-up was 5 ± 3.2 years (96% complete). Majority of survivors (99%) were in New York Heart Association Class II/I. CONCLUSION: The Contegra conduit and homograft demonstrate similar mid-term outcomes in children. Smaller conduit size is associated with higher graft failure and mortality.

Lipid accumulation in dysferlin-deficient muscles.

Dysferlin is a membrane associated protein involved in vesicle trafficking and fusion. Defects in dysferlin result in limb-girdle muscular dystrophy type 2B and Miyoshi myopathy in humans and myopathy in A/J(dys-/-) and BLAJ mice, but the pathomechanism of the myopathy is not understood. Oil Red O staining showed many lipid droplets within the psoas and quadriceps muscles of dysferlin-deficient A/J(dys-/-) mice aged 8 and 12 months, and lipid droplets were also conspicuous within human myofibers from patients with dysferlinopathy (but not other myopathies). Electron microscopy of 8-month-old A/J(dys-/-) psoas muscles confirmed lipid droplets within myofibers and showed disturbed architecture of myofibers. In addition, the presence of many adipocytes was confirmed, and a possible role for dysferlin in adipocytes is suggested. Increased expression of mRNA for a gene involved in early lipogenesis, CCAAT/enhancer binding protein-δ, in 3-month-old A/J(dys-/-) quadriceps (before marked histopathology is evident), indicates early induction of lipogenesis/adipogenesis within dysferlin-deficient muscles. Similar results were seen for dysferlin-deficient BLAJ mice. These novel observations of conspicuous intermyofibrillar lipid and progressive adipocyte replacement in dysferlin-deficient muscles present a new focus for investigating the mechanisms that result in the progressive decline of muscle function in dysferlinopathies.

Long-term outcomes of patients with absent pulmonary valve syndrome: 38 years of experience.

BACKGROUND: Absent pulmonary valve syndrome is associated with aneurysmal dilatation of the pulmonary arteries and compression of the tracheobronchial tree and may lead to significant respiratory compromise. We describe the outcomes of surgical correction of absent pulmonary valve syndrome and risk factors for mortality and reoperation. METHODS: A review of 52 patients with absent pulmonary valve syndrome who underwent surgical correction between 1975 and 2013 was conducted. The median age and weight at repair were 9 months (range, 4 days to 24.2 years) and 6.9 kg (range, 1.8 to 56 kg). Preoperative intubation was required in 15 patients (29%), and 21 patients (40%) underwent urgent repair. The pulmonary valve was replaced with a valved conduit in 16 patients (31%) or monocusp valve in 16 patients (31%). Valveless repair was performed in 20 patients (38%). Pulmonary artery reduction was performed in 39 patients (75%), and 2 patients (4%) underwent a Lecompte maneuver. RESULTS: The median follow-up time was 13 years (range, 1 month to 35 years). Early mortality was 18.8% (3 of 16) during 1975 through 1989, 19% (4 of 21) during 1990 through 2000, and 0% (0 of 15) during 2001 through 2013. Late mortality was 6.7% (3 of 45). Overall survival at 5, 10, and 20 years was 81.4%±5.6%. On multivariate analysis, preoperative ventilation (p=0.009) was the only risk factor for overall mortality. Freedom from late reoperation at 5, 10, and 20 years was 79.7%±6.9%, 69.4%±8.2%, and 52.1%±9.8%, respectively. No difference in reoperation rates was found between valved conduit, monocusp, or valveless techniques. Risk factors for late reoperation on multivariate analysis were prematurity (p=0.001) and neonatal primary repair (p=0.007). Longer postoperative ventilation periods were predicted by preoperative ventilation (p<0.001) and surgery during infancy (p=0.01). CONCLUSIONS: Long-term survival for absent pulmonary valve syndrome has improved during the last decade. Preoperative ventilation predicted longer postoperative ventilation and mortality.

Long-term outcomes of dilated cardiomyopathy diagnosed during childhood: results from a national population-based study of childhood cardiomyopathy.

BACKGROUND: Existing studies of childhood dilated cardiomyopathy deal mainly with early survival. This population-based study examines long-term outcomes for children with dilated cardiomyopathy. METHODS AND RESULTS: The diagnosis of dilated cardiomyopathy was based on clinical, echocardiographic, and pathological findings. The primary study end point included time to the combined outcome of death or cardiac transplantation. There were 175 patients 0 to <10 years of age at the time of diagnosis. Survival free from death or transplantation was 74% (95% confidence interval, 67-80) 1 year after diagnosis, 62% (95% confidence interval, 55-69) at 10 years, and 56% (95% confidence interval, 46-65) at 20 years. In multivariable analysis, age at diagnosis <4 weeks or >5 years, familial cardiomyopathy, and lower baseline left ventricular fractional shortening Z score were associated with increased risk of death or transplantation, as was lower left ventricular fractional shortening Z score during follow-up. At 15 years after diagnosis, echocardiographic normalization had occurred in 69% of surviving study subjects. Normalization was related to higher baseline left ventricular fractional shortening Z score, higher left ventricular fractional shortening Z score during follow-up, and greater improvement in left ventricular fractional shortening Z score. Children with lymphocytic myocarditis had better survival and a higher rate of echocardiographic normalization. At the latest follow-up, 100 of 104 of survivors (96%) were free of cardiac symptoms, and 83 (80%) were no longer receiving pharmacotherapy. CONCLUSIONS: Death or transplantation occurred in 26% of patients with childhood dilated cardiomyopathy within 1 year of diagnosis and ~1% per year thereafter. Risk factors for death or transplantation include age at diagnosis, familial cardiomyopathy, and severity of left ventricular dysfunction. The majority of surviving subjects are well and free of cardiac medication.

Surgical management of pulmonary artery sling in children.

OBJECTIVES: Pulmonary artery (PA) sling is a rare vascular anomaly associated with congenital tracheal stenosis. The natural history is poor and these patients often require early surgical intervention. We describe our experience with repair of this condition. METHODS: From 1984 to 2011, 21 patients with PA sling underwent repair at the Royal Children's Hospital (median age, 5.9 months). PA sling was associated with compression of the trachea in all patients. Tracheal surgery was required in 12 (57.1%) patients. All patients had an echocardiogram, and concomitant repair of coexisting cardiac anomalies was performed in 6 (28.6%, 6/21) patients. RESULTS: Operative mortality was 14.3% (3/21), occurring at 19 days, 4.4 months, and 5 months after surgery. Operative mortality for the first 10 years was 22.2% (1984-1993; 2/9), the next 10 years was 14.3% (1994-2003; 1/7), and 0% for the most recent 7 years (2004-2011; 0/5). All deaths occurred in patients requiring tracheal repair (25%, 3/12). No deaths have occurred since 2004 with introduction of the slide tracheoplasty technique. One (5.6%, 1/18) late death occurred at 8 months after repair. After tracheal repair, intervention for excessive granulations and tracheomalacia was necessary in 6 (50%, 6/12) patients. Median follow-up was 8 years (mean, 8.6 ± 6.4 years; range, 5 months to 20.6 years), and all survivors (100%, 17/17) remain asymptomatic. CONCLUSIONS: Children with PA sling who do not require tracheal surgery have excellent outcomes. Mortality is determined by the need for tracheal surgery. However, with the advent of the slide tracheoplasty technique, mortality can be reduced. Survival beyond 1 year after surgery offers excellent prognosis.