Ranjit Aiyagari

Decompression of the left atrium during extracorporeal membrane oxygenation using a transseptal cannula incorporated into the circuit.

Objectives:When extracorporeal membrane oxygenation (ECMO) is used in the setting of severe myocardial dysfunction, left ventricular end-diastolic and left atrial pressure can rise to extremely high levels. Decompression of the left atrium in this setting is essential for resolution of pulmonary edema and recovery of left ventricular function. We sought to evaluate whether adequate left atrial decompression can be achieved via percutaneous placement of a transseptal left atrial drain incorporated in the ECMO venous circuit. Design:Retrospective case series. Setting:Tertiary care center pediatric intensive care unit and cardiac catheterization laboratory. Patients:Seven patients (age 8 months to 28 yrs) with cardiac failure on venoarterial ECMO with left atrial hypertension. Interventions:All patients underwent left atrial decompression with transseptal puncture and placement of a drain (8- to 15-Fr) incorporated into the ECMO venous circuit. Catheterization and ECMO records and echocardiograms were reviewed, as were the clinical course and outcome for each patient. Measurements and Main Results:The median time from ECMO cannulation to left atrial decompression was 11 hrs. Average initial left atrial pressure was 31 mm Hg. Successful drain placement was achieved in seven patients with no major procedural complications. Echocardiographic improvement in left atrial dilation was achieved in five patients (71%). Inability to decompress the left atrium was fatal in two patients. Four patients were decannulated (57%), and three survived to hospital discharge (43%). Larger sheath size and higher flow rate correlated with a greater likelihood of success. Conclusions:Adequate decompression of the left atrium can be achieved by transseptal placement of a left atrial drain incorporated into the ECMO circuit. This technique represents a reasonable alternative to blade or balloon atrial septostomy for patients requiring left atrial decompression.

Long‐Term Follow Up of Secundum Atrial Septal Defect Closure with the Amplatzer Septal Occluder

BACKGROUND During the past 15 years, closure of a secundum atrial septal defect (ASD) has moved from a surgical to a percutaneous transcatheter approach. Few long-term studies of the efficacy and safety of closure of an ASD by an Amplatzer septal occluder (ASO) exist. METHODS To examine the long-term results of secundum ASD closure using the ASO, data on 94 patients who underwent secundum ASD closure with the ASO between 1998 and 2002 were available and reviewed. Data regarding residual shunt, chest pain, palpitations, arrhythmias, headaches, transient ischemic attacks, cerebrovascular accidents, and mortality were collected. RESULTS Seven (7.4%) subjects had residual shunts immediately following ASO placement. During follow-up, 4 residual shunts closed for a complete closure rate of 97%. Eighteen (19%) patients reported chest pain during the follow-up period. Twenty-three patients (24%) reported palpitations during the follow up period, 7 were documented arrhythmias, including supraventricular tachycardia, atrial fibrillation, and premature ventricular beats. Migraine headaches were new-onset in 4 patients. Migraine cessation occurred in 2 patients after secundum ASD closure. One child died from a cerebral vascular event 18 months following device placement. Only 1 patient developed mild aortic insufficiency. CONCLUSION These data indicate that for up to 120 months of patient follow-up, the ASO continues to be a safe device. Residual shunts and arrhythmias have low incidence post-ASO placement. Given the mortality in one high-risk patient, further investigation into anti-platelet therapy after device placement is warranted.

Risk Factor Analysis for Second-Stage Palliation of Single Ventricle Anatomy

BACKGROUND Single ventricle hearts can be surgically palliated by a series of operations culminating in the Fontan procedure, which establishes a total cavopulmonary connection. The second-stage procedure creates a physiologic connection between the superior vena cava and the pulmonary artery. METHODS From 1998 to 2010, 557 patients with single ventricle heart disease underwent second-stage surgical palliation. This cohort was retrospectively analyzed to assess patient outcome by a number of anatomic, physiologic, and procedural factors. The analysis excluded patients undergoing hybrid first-stage procedures. RESULTS The median age at operation was 165 days (range, 59 days to 49 years). The most common anatomic subtypes were hypoplastic left heart syndrome (52%), tricuspid atresia (12%), unbalanced atrioventricular septal defect (10%), double inlet left ventricle (9%), or other (17%). Left ventricular hypoplasia was present in 70%. A hemi-Fontan procedure was done in 89%, and 11% received a bidirectional Glenn. Concomitant atrioventricular valve repair was necessary in 9%. Early mortality was 4.7%, and 5.9% died after discharge but before Fontan. No early or late deaths occurred in patients with tricuspid atresia and double inlet left ventricle. Multivariate analysis demonstrated ventricular dysfunction, atrioventricular valve regurgitation, and unbalanced atrioventricular septal defect were significant adverse risk factors for survival to Fontan. CONCLUSIONS Second-stage palliation can be performed at low risk for patients with left ventricular dominance, but significant risk remains for patients with left ventricular hypoplasia and unbalanced atrioventricular septal defect. Atrioventricular valve insufficiency is a persistent problem that has not been neutralized by repair strategies.

Radiofrequency Ablation for Supraventricular Tachycardia in Children ≤15 kg Is Safe and Effective

Risks associated with radiofrequency ablation (RFA) have been reported to be increased in children ≤15 kg. We sought to compare the safety and efficacy of RFA in children <15 kg with those between 15.1 and 20 kg. Clinical, electrophysiologic, and RFA data for all patients ≤20 kg who underwent RFA for supraventricular tachycardia between January 1994 and January 2003 were reviewed. Patients were divided into those ≤15 kg (group 1, n = 25) and those between 15.1 and 20 kg (group 2, n = 44). The two groups differed significantly in age and weight by design (group 1: mean weight, 11.9 ± 3.0 kg; age, 2.8 ± 1.9 years; group 2: weight, 18.0 ± 1.5 kg; age, 5.1 ± 1.1 years). There were no significant differences in other baseline characteristics except for incidence of structural heart disease (28% group 1 vs 7% group 2, p < 0.01). No significant differences in mechanism of tachycardia, arrhythmia cycle length, number of total and brief RFA applications, total RFA time, average and maximum RFA temperatures, total procedure duration, short-term success rate (96% group 1 vs 86% group 2, p = 0.17), long-term success rate (91% group 1 vs 89% group 2, p = 0.76), or major complications (8.0% group 1 vs 2.3% group 2, p = 0.39) were found. There were no procedure-related deaths in either group. These data suggest that, in two large volume electrophysiology centers, the procedural risks and outcomes of RFA are similar between patients weighing less than 15 kg and those between 15.1 and 20 kg.

Parental perspectives on suffering and quality of life at end-of-life in children with advanced heart disease: an exploratory study*.

Objective: To describe parent perspectives regarding the end-of-life experience of children with advanced heart disease. Design: Cross-sectional multicenter survey study of bereaved parents. Setting: Two tertiary care pediatric hospitals. Subjects: Parents of children younger than 21 years with primary cardiac diagnoses who died in the hospital 9 months to 4 years before the survey date. Parents were excluded if they were non-English speakers or had previously denied permission to contact. Intervention: The Survey for Caring for Children with Advanced Heart Disease was developed, piloted, and then sent to parents of all children who died at two sites. Measurements and Main Results: Fifty bereaved parents responded (39% response rate) a mean of 2.7 years after their child’s death. Median age at death was 6 months (3.6 d to 20.4 yr). At end-of-life, 86% of children were intubated and 46% were receiving mechanical circulatory support. Seventy-eight percent died during withdrawal of life-sustaining interventions and 16% during resuscitative efforts. Parents realized that their child had no realistic chance of survival a median of 2 days prior to death (0–30 d). According to parents, 47% of children suffered “a great deal,” “a lot,” or “somewhat” during the end-of-life period. The symptoms parents perceived to be causing the most suffering were breathing and feeding difficulties in children under 2 years and fatigue and sleeping difficulties in older children. Seventy-one percent of parents described the quality of life of their child during the last month of life as “poor” or “fair.” Most parents (84%) described the quality of care delivered as “very good” or “excellent.” Conclusions: According to their parents, many children with advanced heart disease experience suffering in the end-of-life care period. For most, realization that their child has no realistic chance of survival does not occur until late, some not until death is imminent. Once this realization occurs, however, parents perceive peacefulness, a “good death,” and excellent quality of care. Strategies for improved communication around symptom management, quality of life, prognosis, and advance care planning are needed for families of children with advanced heart disease.

Intervention for Recoarctation in the Single Ventricle Reconstruction Trial Incidence, Risk, and Outcomes

Background— Recoarctation after the Norwood procedure increases risk for mortality. The Single Ventricle Reconstruction (SVR) trial randomized subjects with a single right ventricle undergoing a Norwood procedure to a modified Blalock-Taussig shunt or a right ventricle–pulmonary artery shunt. We sought to determine the incidence of recoarctation, risk factors, and outcomes in the SVR trial. Methods and Results— Recoarctation was defined by intervention, either catheter based or surgical. Univariate analysis and multivariable Cox proportional hazard models were performed with adjustment for center. Of the 549 SVR subjects, 97 (18%) underwent 131 interventions (92 balloon aortoplasty, 39 surgical) for recoarctation at a median age of 4.9 months (range, 1.1–10.5 months). Intervention typically occurred at pre–stage II catheterization (n=71, 54%) or at stage II surgery (n=38, 29%). In multivariable analysis, recoarctation was associated with the shunt type in place at the end of the Norwood procedure (hazard ratio, 2.0 for right ventricle–pulmonary artery shunt versus modified Blalock-Taussig shunt; P=0.02), and Norwood discharge peak echo-Doppler arch gradient (hazard ratio, 1.07 per 1 mm Hg; P<0.01). Subjects with recoarctation demonstrated comorbidities at pre–stage II evaluation, including higher pulmonary arterial pressures (15.4±3.0 versus 14.5±3.5 mm Hg; P=0.05), higher pulmonary vascular resistance (2.6±1.6 versus 2.0±1.0 Wood units·m2; P=0.04), and increased echocardiographic volumes (end-diastolic volume, 126±39 versus 112±33 mL/BSA1.3, where BSA is body surface area; P=0.02). There was no difference in 12-month postrandomization transplantation-free survival between those with and without recoarctation (P=0.14). Conclusions— Recoarctation is common after Norwood and contributes to pre–stage II comorbidities. Although with intervention there is no associated increase in 1-year transplantation/mortality, further evaluation is warranted to evaluate the effects of associated morbidities. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00115934.

Impact of pre-stage II hemodynamics and pulmonary artery anatomy on 12-month outcomes in the Pediatric Heart Network Single Ventricle Reconstruction trial.

OBJECTIVE To compare the interstage cardiac catheterization hemodynamic and angiographic findings between shunt types for the Pediatric Heart Network Single Ventricle Reconstruction trial. The trial, which randomized subjects to a modified Blalock-Taussig shunt (MBTS) or right ventricle-to-pulmonary artery shunt (RVPAS) for the Norwood procedure, demonstrated the RVPAS was associated with a smaller pulmonary artery diameter but superior 12-month transplant-free survival. METHODS We analyzed the pre-stage II catheterization data for the trial subjects. The hemodynamic variables and shunt and pulmonary angiographic data were compared between shunt types; their association with 12-month transplant-free survival was also evaluated. RESULTS Of 549 randomized subjects, 389 underwent pre-stage II catheterization. A smaller size, lower aortic and superior vena cava saturation, and higher ventricular end-diastolic pressure were associated with worse 12-month transplant-free survival. The MBTS group had a lower coronary perfusion pressure (27 vs 32 mm Hg; P<.001) and greater pulmonary blood flow/systemic blood flow ratio (1.1 vs 1.0, P=.009). A greater pulmonary blood flow/systemic blood flow ratio increased the risk of death or transplantation only in the RVPAS group (P=.01). The MBTS group had fewer shunt (14% vs 28%, P=.004) and severe left pulmonary artery (0.7% vs 9.2%, P=.003) stenoses, larger mid-main branch pulmonary artery diameters, and greater Nakata indexes (164 vs 134, P<.001). CONCLUSIONS Compared with the RVPAS subjects, the MBTS subjects had more hemodynamic abnormalities related to shunt physiology, and the RVPAS subjects had more shunt or pulmonary obstruction of a severe degree and inferior pulmonary artery growth at pre-stage II catheterization. A lower body surface area, greater ventricular end-diastolic pressure, and lower superior vena cava saturation were associated with worse 12-month transplant-free survival.

Survival Through Staged Palliation: Fate of Infants Supported by Extracorporeal Membrane Oxygenation After the Norwood Operation

BACKGROUND Infants supported by extracorporeal membrane oxygenation (ECMO) after a Norwood operation face in-hospital mortality rates of 60% to 70%. There are limited data on completion of staged palliation for the subset of patients who survive to hospital discharge. METHODS We performed a retrospective case-control study of 64 sequential patients at a single institution supported by ECMO after a Norwood operation. Primary endpoints were survival to hospital discharge, stage II palliation, and stage III palliation. Predictors of non-survival to each endpoint were identified with logistic regression. Survival was compared with a 3:1 era-matched group of control patients who underwent a Norwood operation but did not require ECMO. RESULTS Survival to hospital discharge, stage II palliation, and stage III palliation was 43.8%, 35.9%, and 25.4%, respectively for ECMO cases. Factors independently associated with non-survival to hospital discharge included female gender, ECMO 7 days or greater, and need for renal replacement therapy on ECMO. Non-Caucasian race and ECMO 7 days or greater were independently associated with non-survival to stage II, while non-Caucasian race, lower birth weight, and ECMO 7 days or greater were independently associated with non-survival to stage III. Extracorporeal membrane oxygenation was associated with decreased survival at each endpoint. Patients who survived ECMO had increased interstage mortality between hospital discharge and stage II palliation. CONCLUSIONS Extracorporeal membrane oxygenation after a Norwood operation can be life-saving but ultimate survival through staged palliation remains suboptimal. The elevated mortality risk for patients supported by ECMO persists after hospital discharge. Both socioeconomic factors and ECMO-related morbidity may contribute to midterm mortality.

Utility of a Clinical Practice Guideline in Treatment of Chylothorax in the Postoperative Congenital Heart Patient

BACKGROUND Chylothorax after congenital heart surgery is a common complication with associated morbidities, but consensus treatment guidelines are lacking. Variability exists in the duration of medical treatment and timing for surgical intervention. METHODS After institution of a clinical practice guideline for management of postoperative chylothorax at a single center, pediatric cardiothoracic intensive care unit (ICU) in June 2010, we retrospectively analyzed 2 cohorts of patients: those with chylothorax from January 2008 to May 2010 (early cohort; n=118) and from June 2010 to August 2011 (late cohort; n=45). Data collected included demographics, cardiac surgical procedure, treatments for chylothorax, bloodstream infections, hospital mortality, length of hospitalization, duration of mechanical ventilation, and device utilization. RESULTS There were no demographic differences between the cohorts. No differences were found in octreotide use or surgical treatments for chylothorax. Significant differences were found in median times to chylothorax diagnosis (9 in early cohort versus 6 days in late cohort, p=0.004), ICU length of stay (18 vs 9 days, p=0.01), hospital length of stay (30 vs 23 days, p=0.005), and total durations of mechanical ventilation (11 vs 5 days, p=0.02), chest tube use (20 vs 14 days, p=0.01), central venous line use (27 vs 15 days, p=0.001), and NPO status (9.5 vs 6 days, p=0.04). CONCLUSIONS Institution of a clinical practice guideline for treatment of chylothorax after congenital heart surgery was associated with earlier diagnosis, reduced hospital length of stay, mechanical ventilation, and device utilization for these patients.

Effects of N-acetylcysteine on renal dysfunction in neonates undergoing the arterial switch operation.

OBJECTIVE We evaluated N-acetylcysteine, a potent antioxidant, as prevention for renal dysfunction in infants undergoing cardiac surgery for dextro-transposition of the great arteries. METHODS Twenty-one neonates undergoing the arterial switch operation were randomized to receive either placebo or intravenous N-acetylcysteine. Serial data were collected on fluid balance, serum creatinine, inotropic support, cardiac output, and length of stay. RESULTS Hospital and 30-day survival was 100%. No serious adverse events were attributable to the drug. Subjects treated with N-acetylcysteine had a higher urine output at 24 hours (175 mL vs 96 mL; P < .01) and a shorter median time to first negative fluid balance (27 hours vs 39.5 hours; P = .02). There were no differences between groups in diuretic therapy, inotropic support, fluid intake, or chest tube output. Serum creatinine increased at 24 hours after the operation by a mean of 0.27 mg/dL with placebo (P < .01) but was unchanged with N-acetylcysteine treatment. By postoperative day 3, serum creatinine increased by 92% in the placebo group but only 38% in the N-acetylcysteine group (P = .04). Length of intensive care unit stay was shorter by an average of 5 days (P = .04) with N-acetylcysteine treatment. CONCLUSIONS In this pilot study, perioperative treatment with N-acetylcysteine resulted in improved urine output, shorter time to negative fluid balance, and attenuation of the rise in creatinine. These effects of N-acetylcysteine may translate to improved outcomes for infants undergoing complex cardiac operations.