Christopher J. Petit

Preoperative Brain Injury in Transposition of the Great Arteries Is Associated With Oxygenation and Time to Surgery, Not Balloon Atrial Septostomy

Background— Preoperative brain injury is an increasingly recognized phenomenon in neonates with complex congenital heart disease. Recently, reports have been published that associate preoperative brain injury in neonates with transposition of the great arteries with the performance of balloon atrial septostomy (BAS), a procedure that improves systemic oxygenation preoperatively. It is unclear whether BAS is the cause of brain injury or is a confounder, because neonates who require BAS are typically more hypoxemic. We sought to determine the relationship between preoperative brain injury in neonates with transposition of the great arteries and the performance of BAS. We hypothesized that brain injury results from hypoxic injury, not from the BAS itself. Methods and Results— Infants with transposition of the great arteries (n=26) were retrospectively included from a larger cohort of infants with congenital heart disease who underwent preoperative brain MRI as part of 2 separate prospective studies. Data collected included all preoperative pulse oximetry recordings, all values from preoperative arterial blood gas measurements, and BAS procedure data. MRI scans were performed on the day of surgery, before the surgical repair. Of the 26 neonates, 14 underwent BAS. No stroke was seen in the entire cohort, whereas 10 (38%) of 26 patients were found to have hypoxic brain injury in the form of periventricular leukomalacia. Periventricular leukomalacia was not associated with BAS; however, neonates with periventricular leukomalacia had lower preoperative oxygenation (P=0.026) and a longer time to surgery (P=0.028) than those without periventricular leukomalacia. Conclusions— Preoperative brain injury in neonates with transposition of the great arteries is associated with hypoxemia and longer time to surgery. We found no association between BAS and brain injury.

Twenty-Five Year Experience With Balloon Aortic Valvuloplasty for Congenital Aortic Stenosis

Balloon aortic valvuloplasty (BAV) is the primary therapy for congenital aortic stenosis (AS). Few reports describe long-term outcomes. In this study, a retrospective single-institution review was performed of patients who underwent BAV for congenital AS. The following end points were evaluated: moderate or severe aortic insufficiency (AI) by echocardiography, aortic valve replacement, repeat BAV, surgical aortic valvotomy, and transplantation or death. From 1985 to 2009, 272 patients who underwent BAV at ages 1 day to 30.5 years were followed for 5.8 ± 6.7 years. Transplantation or death occurred in 24 patients (9%) and was associated with depressed baseline left ventricular shortening fraction (LVSF) (p = 0.04). Aortic valve replacement occurred in 42 patients (15%) at a median of 3.5 years (interquartile range 75 days to 5.9 years) after BAV and was associated with post-BAV gradient ≥25 mm Hg (p = 0.02), the presence of post-BAV AI (p = 0.03), and below-average baseline LVSF (p = 0.04). AI was found in 83 patients (31%) at a median of 4.8 years (interquartile range 1.4 to 8.7) and was inversely related to post-BAV gradient ≥25 mm Hg (p <0.04). AI was associated with depressed baseline LVSF (p = 0.02). Repeat valvuloplasty (balloon or surgical) occurred in 37 patients (15%) at a median of 0.51 years (interquartile range 0.10 to 5.15) and was associated with neonatal BAV (p <0.01), post-BAV gradient ≥25 mm Hg (p = 0.03), and depressed baseline LVSF (p = 0.05). In conclusion, BAV confers long-term benefits to most patients with congenital AS. Neonates, patients with post-BAV gradients ≥25 mm Hg, and patients with lower baseline LVSF experienced worse outcomes.

Association of Interstage Home Monitoring With Mortality, Readmissions, and Weight Gain A Multicenter Study from the National Pediatric Cardiology Quality Improvement Collaborative

Background— Daily home monitoring of oxygen saturation and weight has been reported to improve outcomes for patients with single-ventricle heart disease during the period between stage I palliation and stage II palliation. However, these studies have been limited to single institutions and used historical control subjects. Our objective was to determine the association of various interstage home monitoring strategies with outcomes using a multicenter cohort with contemporary control subjects. Methods and Results— We performed a retrospective cohort study using prospectively collected data from the National Pediatric Cardiology Quality Improvement Collaborative from 2008 to 2012. We compared interstage mortality, unscheduled readmissions, and change in weight-for-age Z score for various home monitoring strategies of oxygen saturation (n=494) or weight (n=472), adjusting for sex, syndrome, tricuspid regurgitation, arch obstruction, and shunt type. Overall interstage mortality was 8.1%, and 47% had ≥1 unscheduled readmission. We did not find any associations of home oxygen saturation or weight monitoring with mortality or readmission. Although there was no difference in weight-for-age Z score for daily (0.33±0.12) versus weekly (0.34±0.18, P=0.98) weight monitoring, daily home weight monitoring was superior to no home weight monitoring (−0.15±0.18; P<0.01). Conclusions— Home weight monitoring is associated with improved weight gain during the interstage period, but we did not find any benefits in other clinical outcomes for either home oxygen saturation monitoring or home weight monitoring.

Endovascular stents for relief of cyanosis in single-ventricle patients with shunt or conduit-dependent pulmonary blood flow.

Hypoxemia is a significant cause of early and interstage death in patients with single ventricle (SV). Obstruction of Blalock‐Taussig shunts (BTS) in patients with SV has traditionally been managed with surgical revision. Purpose: We report on the experience at our institution of deploying endovascular stents within BTS as well as obstructed right‐ventricle (RV) to pulmonary artery (PA) conduits in patients with modified Norwood (ie Sano modification). Methods: Medical records were reviewed for the time period between January 1, 2002 and November 30, 2005. All patients with SV who presented for intervention for BTS or RV‐PA conduit stenosis were reviewed. Specific endpoints reviewed included pre‐ and post‐intervention arterial oxygen saturation, type of intervention (stent vs. ballon dilation), need for subsequent surgical shunt/conduit revision, and interval to second stage palliation. Results: Fifteen patients with SV underwent intervention for acute cyanosis. Eight patients had BTS, and the other seven patients had RV‐PA conduit stenosis. Coronary stents were deployed in 14 of the 15 patients. Four patients also underwent balloon angioplasty of branch PAs. Oxygen saturations improved in all patients, with a mean increase of 13.9% (p = 0.0001). Four patients died before second stage palliation — one due to complications of the catheterization. Of the eleven remaining patients, nine have undergone second stage palliation; interval from intervention to Glenn ranged from 28–205 days (mean 163d). Two patients are awaiting cavo‐pulmonary anastamosis. Conclusions: Endovascular stenting in this high‐risk population is effective at improving oxygen saturation as well as obviating need to surgical shunt/conduit revision.

Single Ventricle Palliation in Low Weight Patients Is Associated With Worse Early And Midterm Outcomes

BACKGROUND While low weight is an established risk factor for operative mortality after single ventricle (SV) palliation, its influence on late outcomes is not well understood. We examined current-era effects of low weight at time of surgery on hospital mortality, progression through palliative stages, and survival. METHODS Five hundred and thirty infants with SV underwent first-stage palliation (2002 to 2012). Competing risk analysis modeled events after initial surgery and after Glenn. Regression models examined the effect of low weight 2.5 kg or less (n = 77 of 530, 14.5%) on early and late outcomes. RESULTS Initial palliation was Norwood (n = 284, 54%), modified Blalock-Taussig shunt (n = 173, 33%), and pulmonary artery band (n = 73, 14%). Competing risk analysis showed that at 6 months after initial palliation the proportion of patients who had died or received transplantation was 40% in patients 2.5 kg or less and 20% in patients greater than 2.5 kg (p < 0.001). Consequently, the proportion of patients who had progressed to Glenn was 33% in patients 2.5 kg or less and 59% in patients greater than 2.5 kg (p < 0.001). Subsequent to Glenn, progression toward Fontan was unaffected by initial weight. In addition to increased hospital mortality (odds ratio 1.86, 95% confidence interval [CI] 0.93% to 3.70%, p = 0.08); adjusted hazard analysis showed that weight 2.5 kg or less was associated with diminished late survival (hazard ratio 1.65, 95% CI 1.085% to 2.53%, p = 0.02) and that was evident for all palliation types and most SV morphologies. CONCLUSIONS Low weight at time of first-stage SV palliation is associated with an increase in both hospital mortality and interstage attrition, with subsequently fewer patients progressing toward the Glenn operation. The increased death hazard in low weight SV patients persists for almost 1 year after initial palliation, suggesting the need for more vigilant monitoring and out-patient care in those high-risk patients.

Aortic valve morphology is associated with outcomes following balloon valvuloplasty for congenital aortic stenosis.

Evaluate the incidence of various morphologic types of congenital AS, and the association between valve morphology and long‐term outcomes, including repeat BAV, AVR, and death/transplant.

Percutaneous Common Carotid Artery Access for Pediatric Interventional Cardiac Catheterization

Background—Surgical cutdown for access to the common carotid artery provides a more direct route for certain pediatric cardiac interventions and avoids femoral artery injury in small infants. The safety of percutaneous carotid access (PCA) in children is unknown. Methods and Results—Retrospective review of PCA at Texas Children’s Hospital and Children’s Healthcare of Atlanta. From July 2006 to November 2014, 42 patients underwent 47 attempts at catheterization via PCA. Median (range) age was 20 days (0 days–2.9 years) and weight was 3.2 kg (1.1–12.2). Two patients had failed PCA with no sequelae. Of the 45 catheterizations with successful PCA and sheath placement, 44 interventions were performed, the most common being stenting or stent redilation of the ductus arteriosus, balloon aortic valvuloplasty, and stenting or angioplasty of Blalock–Taussig shunts. After sheath withdrawal, hemostasis was achieved with manual compression, with no need for surgical control of bleeding. Follow-up carotid imaging was performed in all. Acutely, 3 patients developed carotid thrombosis with resolution in 1 and mild residual narrowing in 2 after anticoagulation therapy. At follow-up, 40 of 42 patients (95%) had a normal carotid artery, with 2 instances of mild stenosis. There were no neurological sequelae attributable to PCA. Conclusions—PCA is safe even in small infants, and hemostasis can be achieved without surgical repair, with a carotid patency rate superior to published data after surgical cutdown. Surgical cutdown is not routinely required for pediatric cardiac catheterization via the carotid artery.

Effect of Branch Pulmonary Artery Stenosis on Right Ventricular Volume Overload in Patients With Tetralogy of Fallot After Initial Surgical Repair

Right ventricular (RV) volume overload secondary to pulmonary regurgitation is common in patients after initial repair of tetralogy of Fallot (TOF) and is associated with adverse long-term outcomes. The objective of the present study was to determine the effect of branch pulmonary artery stenosis on the RV volume in patients with repaired TOF. We reviewed 178 cardiac magnetic resonance imaging studies in patients with repaired TOF. We defined bilateral stenosis as a Nakata index of ≤200 mm(2)/m(2) and concordant branch pulmonary artery cross-sectional area, unilateral stenosis as 1 branch pulmonary artery cross-sectional area ≤100 mm(2)/m(2) and 1 branch pulmonary artery cross-sectional area >100 mm(2)/m(2), and restrictive physiology as prograde main pulmonary artery diastolic flow. Of the 178 patients, 20 (11%) had bilateral stenosis, 47 (26%) unilateral stenosis, and 111 (63%) had no stenosis. The RV end-diastolic volume was lower in patients with bilateral (125 ± 27 ml/m(2)) or unilateral (131 ± 43 ml/m(2)) stenosis than in those without stenosis (149 ± 35 ml/m(2), p = 0.021 and p = 0.019, respectively). The main pulmonary artery regurgitant fraction was greater in patients without stenosis (47%, range 2% to 69%) than in those with bilateral (33%, range 9% to 59%; p = 0.009) or unilateral stenosis (40%, range 0% to 71%; p = 0.033). Restrictive physiology was more common in patients with bilateral (13 of 15, 87%) or unilateral (21 of 38, 55%) stenosis than in those without stenosis (28 of 85, 33%; p <0.001 and p = 0.017, respectively). In conclusion, in patients with repaired TOF, bilateral and unilateral branch pulmonary artery stenosis was associated with a greater main pulmonary artery regurgitant fraction and smaller RV end-diastolic volume than those in patients without stenosis, likely owing to the development of restrictive physiology. Branch pulmonary artery stenosis might effectively delay the referral for pulmonary valve replacement.

A 25‐year experience of endomyocardial biopsy safety in infants

To analyze the outcomes and risk factors associated with endomyocardial biopsy (EMB) in children less than one year of age.

Early catheterization after initiation of extracorporeal membrane oxygenation support in children is associated with improved survival

The study evaluated the institutional experience with cardiac catheterization on extracorporeal membrane oxygenation (ECMO) support.