Shahryar M. Chowdhury

Early Echocardiographic Changes After Percutaneous Implantation of the Edwards SAPIEN Transcatheter Heart Valve in the Pulmonary Position

To evaluate echocardiographic changes after SAPIEN valve implantation in the pulmonary position.

Intraoperative Steroid Use and Outcomes Following the Norwood Procedure: An Analysis of the Pediatric Heart Network's Public Database.

Objective: Data supporting the use of perioperative steroids during cardiac surgery are conflicting, and most pediatric studies have been limited by small sample sizes and/or diverse cardiac diagnoses. The objective of this study was to determine if intraoperative steroid administration improved outcomes following the Norwood procedure. Design: A retrospective analysis was performed on the 549 neonates who underwent a Norwood procedure in the publicly available datasets from the Pediatric Heart Network’s Single Ventricle Reconstruction trial. Groups were compared to determine if outcomes differed between intraoperative steroid recipients (n = 498, 91%) and nonrecipients (n = 51, 9%). Setting: Fifteen North American centers. Subjects: Infants enrolled in the Single Ventricle Reconstruction trial. Interventions: None. Measurements and Main Results: Baseline characteristics and intraoperative variables were similar between groups with the exception of a shorter duration of cross clamp and cardiopulmonary bypass time in the group that received steroids. Subjects who did not receive intraoperative steroids had improved hospital survival (94% vs 83%, p = 0.03) but longer ICU stays (16 d; interquartile range, 12–33 vs 14 d; interquartile range, 9–28; p = 0.04) and hospital stays (29 d; interquartile range, 21–50 vs 23 d; interquartile range, 15–40; p = 0.01) than steroid recipients. In multivariate analysis, lengths of stay associations were no longer significant, but hospital survival trended toward favoring the nonsteroid group with an odds ratio of 3.52 (95% CI, 0.98–12.64; p = 0.054). Conclusions: In the large multicentered Single Ventricle Reconstruction trial, there was widespread use of intraoperative steroids. Intraoperative steroid administration was not associated with an improvement in outcomes and may be associated with a reduction in hospital survival in neonates undergoing the Norwood procedure. This study highlights the need for a randomized control trial.

Lean Body Mass May Explain Apparent Racial Differences in Carotid Intima-Media Thickness in Obese Children

BACKGROUND Racial differences in carotid intima-media thickness (cIMT) have been suggested to be associated with the disproportionally high prevalence of cardiovascular disease in black adults. The objective of this study was to evaluate the effects of cardiovascular risk factors on the racial differences seen in cIMT in obese children. METHODS Obese subjects aged 4 to 21 years were recruited prospectively. Height, weight, blood pressure, fasting insulin, glucose, lipid panel, high-sensitivity C-reactive protein, and body composition by dual-energy x-ray absorptiometry were obtained. B-mode carotid imaging was analyzed by a single blinded physician. RESULTS A total of 120 subjects (46 white, 74 black) were enrolled. Black subjects exhibited greater cIMT (0.45 ± 0.03 vs 0.43 ± 0.02 cm, P < .01) and higher lean body mass index (19.3 ± 3.4 vs 17.3 ± 3.2 kg/m², P = .02) than white subjects. Simple linear regression revealed modest associations between mean cIMT and race (R = 0.52, P < .01), systolic blood pressure (R = 0.47, P < .01), and lean body mass (R = 0.51, P < .01). On multivariate regression analysis, lean body mass remained the only measure to maintain a statistically significant relationship with mean cIMT (P < .01). CONCLUSIONS Black subjects demonstrated greater cIMT than white subjects. The relationship between race and cIMT disappeared when lean body mass was accounted for. Future studies assessing the association of cardiovascular disease risk factors to cIMT in obese children should include lean body mass in the analysis.

Cardiovascular manifestations of heterotaxy and related situs abnormalities assessed with CT angiography

Heterotaxy and situs abnormalities describe an abnormal arrangement of visceral organs in the thoracoabdominal cavity across the normal left-right axis of the body. It is associated with a high occurrence of congenital heart and abdominal defects, including anomalous pulmonary venous connections, systemic venous abnormalities, asplenia, and intestinal malrotation. Without proper diagnosis and surgical intervention, the prognosis of patients with heterotaxy syndrome and associated congenital defects is extremely poor. Complex intracardiac and extracardiac lesions are common in heterotaxy and can be difficult to assess by echocardiography. CT angiography (CTA) is a useful tool in this setting to accurately assess intracardiac and extracardiac abnormalities in this population for medical or surgical management. The intention of this pictorial essay is to review the most common cardiovascular defects involved with heterotaxy syndrome in addition to emphasizing the utility of CTA in the identification and classification of anomalies seen in these patients. This review briefly defines most common terminology used in situs abnormalities as well as presents CT images and 3-dimensional reconstructions of common anomalies associated with situs abnormalities. In summary, this review should prepare radiologists and pediatric cardiologists to describe heterotaxy and situs abnormalities in addition to recognizing the utility of CTA in these patients.

Speckle-Tracking Echocardiographic Measures of Right Ventricular Function Correlate With Improvement in Exercise Function After Percutaneous Pulmonary Valve Implantation

BACKGROUND Speckle-tracking echocardiographic (STE) measures of right ventricular (RV) function appear to improve after transcatheter pulmonary valve implantation (TPVI). Measures of exercise function, such as ventilatory efficiency (the minute ventilation [VE]/carbon dioxide production [VCO2] slope), have been shown to be prognostic of mortality in patients who may require TPVI. The aim of this study was to evaluate the correlation between STE measures of RV function and changes in VE/VCO2 after TPVI. METHODS Speckle-tracking echocardiography and cardiopulmonary exercise testing were performed at baseline and 6 months after TPVI in 24 patients from four centers. Conventional echocardiographic measures of RV function were also assessed. Echocardiographic and exercise stress test results were interpreted by single blinded observers at separate core laboratories. RESULTS All patients demonstrated relief of pulmonary regurgitation and stenosis after TPVI. Improvements in RV longitudinal strain (-16.9 ± 3.5% vs -19.7 ± 4.3%, P < .01) and strain rate (-0.9 ± 0.4 vs. -1.2 ± 0.4 s(-1), P < .01) were noted. The VE/VCO2 slope improved (32.4 ± 5.7 vs 31.5 ± 8.8, P = .03). No other significant echocardiographic or exercise changes were found. On multivariate regression, the change in VE/VCO2 was independently associated with change in RV longitudinal early diastolic strain rate (P < .001) and tricuspid A velocity (P < .001). Preintervention RV longitudinal strain was found to be a predictor of change in VE/VCO2 after TPVI (r = -0.60, P < .001). CONCLUSIONS STE measures of RV function appear to hold the potential for use as predictors of improved outcomes in patients requiring TPVI. Future studies should directly assess the prognostic significance of STE measures of RV function in this population.

Multidetector computed tomography pulmonary angiography in childhood acute pulmonary embolism

Pulmonary embolism is a life-threatening condition affecting people of all ages. Multidetector row CT pulmonary angiography has improved the imaging of pulmonary embolism in both adults and children and is now regarded as the routine modality for detection of pulmonary embolism. Advanced CT pulmonary angiography techniques developed in recent years, such as dual-energy CT, have been applied as a one-stop modality for pulmonary embolism diagnosis in children, as they can simultaneously provide anatomical and functional information. We discuss CT pulmonary angiography techniques, common and uncommon findings of pulmonary embolism in both conventional and dual-energy CT pulmonary angiography, and radiation dose considerations.

Changes in speckle tracking echocardiography measures of ventricular function after percutaneous implantation of the Edwards SAPIEN transcatheter heart valve in the pulmonary position.

Patients with free pulmonary regurgitation or mixed pulmonary stenosis and regurgitation and severely dilated right ventricles (RV) show little improvement in ventricular function after pulmonary valve replacement when assessed by traditional echocardiographic markers. We evaluated changes in right and left ventricular (LV) function using speckle tracking echocardiography in patients after SAPIEN transcatheter pulmonary valve (TPV) placement.

Current Practice and Utility of Chromosome Microarray Analysis in Infants Undergoing Cardiac Surgery

OBJECTIVE Traditionally, karyotype and fluorescence in situ hybridization (FISH) were used for cytogenetic testing of infants with congenital heart disease (CHD) who underwent cardiac surgery at our institution. Recently, chromosome microarray analysis (CMA) has been performed in lieu of the traditional tests. A standardized approach to cytogenetic testing does not exist in this population. The purpose of this study was to assess the utility of CMA based on our current ordering practice. DESIGN We reviewed the records of all infants (<1 year old) who underwent cardiac surgery at our institution from January 2010 to June 2013. Data included results of all cytogenetic testing performed. Diagnostic yield was calculated as the percentage of significant abnormal results obtained by each test modality. Patients were grouped by classification of CHD. RESULTS Two hundred seventy-five (51%) of 535 infants who underwent cardiac surgery had cytogenetic testing. Of those tested, 154 (56%) had multiple tests performed and at least 18% were redundant or overlapping. The utilization of CMA has increased each year since its implementation. The diagnostic yield for karyotype, FISH and CMA was 10%, 12%, and 14%, respectively. CMA yield was significantly higher in patients with septal defects (33%, P = .01) compared with all other CHD classes. CMA detected abnormalities of unknown clinical significance in 13% of infants tested. CONCLUSIONS In our center, redundant cytogenetic testing is frequently performed in infants undergoing cardiac surgery. The utilization of CMA has increased over time and abnormalities of unknown clinical significance are detected in an important subset of patients. A screening algorithm that risk-stratifies based on classification of CHD and clinical suspicion may provide a practical, data-driven approach to genetic testing in this population and limit unnecessary resource utilization.

Preoperative echocardiographic measures of left ventricular mechanics are associated with postoperative vasoactive support in preterm infants undergoing patent ductus arteriosus ligation

Objective: Preoperative risk factors associated with poor outcomes after patent ductus arteriosus ligation in preterm infants have not been well defined. The aim of this study was to determine the association between preoperative echocardiographic measures of left ventricular mechanics and postoperative clinical outcomes after patent ductus arteriosus ligation. Methods: Preterm infants less than 90 days of age with no other significant congenital anomalies who underwent patent ductus arteriosus ligation between 2007 and 2015 were considered for retrospective analysis. The primary outcome was peak postoperative vasoactive inotropic score. Conventional echocardiographic measures of ventricular size, function, and patent ductus arteriosus size were performed. Echocardiographic single‐beat, pressure‐volume loop analysis estimates of contractility (end‐systolic elastance) and afterload (arterial elastance) were calculated. Ventriculoarterial coupling was assessed using the arterial elastance/end‐systolic elastance ratio. Multivariable linear regression was performed using clinical and echocardiographic data. Results: Echocardiograms from 101 patients (42.5% male) were analyzed. We found a statistically significant association between vasoactive inotropic score and both end‐systolic elastance and arterial elastance. No patient with arterial elastance/end‐systolic elastance greater than 0.78 (n = 32) had a vasoactive inotropic score 20 or greater. Analysis of our secondary outcomes found associations between preoperative end‐systolic elastance and postoperative urine output less than 1 mL/kg/h at 24 hours, creatinine change greater than 0.5 mg/dL, and time to first extubation. Conclusions: End‐systolic elastance and arterial elastance were the only predictors of postoperative vasoactive inotropic score after patent ductus arteriosus ligation in preterm infants. Those neonates with increased contractility and low afterload were at highest risk for elevated inotropic support. These findings suggest a role for echocardiographic end‐systolic elastance and arterial elastance in the preoperative assessment of preterm infants undergoing patent ductus arteriosus ligation.

Validation of a Simple Score to Determine Risk of Hospital Mortality After the Norwood Procedure

The ability to quantify patient-specific hospital mortality risk before the Norwood procedure remains elusive. This study aimed to develop an accurate and clinically feasible score to assess the risk of hospital mortality in neonates undergoing the Norwood procedure. All patients (n = 549) in the publically available Pediatric Heart Network Single Ventricle Reconstruction trial database were included in the analysis. Patients were randomly divided into a derivation (75%) and validation (25%) cohort. Preoperative factors found to be associated with mortality upon univariable analysis (P < 0.2) were included in the logistic regression model. The score was derived by including variables independently associated with mortality (P < 0.05). A 20-point score using 6 variables (birth weight, clinical syndrome or abnormal karyotype, surgeon Norwood volume or year, anatomic subtype, ascending aorta size, and obstructed pulmonary venous return) was developed using relative magnitudes of the covariates׳ odds ratio. The score was then tested in the validation cohort. In weighted regression analysis, model predicted risk of mortality correlated closely with actual rates of mortality in the derivation (R2 = 0.87, P < 0.01) and validation cohorts (R2 = 0.82, P < 0.01). Patients were classified as low (score: 0-5), medium (6-10), or high risk (>10). Mortality differed significantly between risk groups in both the derivation (6% vs 22% vs 77%, P < 0.01) and validation (4% vs 30% vs 53%, P < 0.01) cohorts. This mortality score is accurate in determining risk of hospital mortality in neonates undergoing planned Norwood operations. The score has the potential to be used in clinical practice to aid in risk assessment before surgery. Clinical trial registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT00115934.