3-Year Outcomes of the Edwards SAPIEN Transcatheter Heart Valve for Conduit Failure in the Pulmonary Position From the COMPASSION Multicenter Clinical Trial

OBJECTIVES

This study provides the 3-year follow-up results of the COMPASSION (Congenital Multicenter Trial of Pulmonic Valve Regurgitation Studying the SAPIEN Transcatheter Heart Valve) trial. Patients with moderate to severe pulmonary regurgitation and/or right ventricular outflow tract conduit obstruction were implanted with the SAPIEN transcatheter heart valve (THV).

BACKGROUND

Early safety and efficacy of the Edwards SAPIEN THV in the pulmonary position have been established through a multicenter clinical trial.

METHODS

Eligible patients were included if body weight was >35 kg and in situ conduit diameter was ≥16 and ≤24 mm. Adverse events were adjudicated by an independent clinical events committee. Three-year clinical and echocardiographic outcomes were evaluated in these patients.

RESULTS

Fifty-seven of the 63 eligible patients were accounted for at the 3-year follow-up visit from a total of 69 implantations in 81 enrolled patients. THV implantation was indicated for pulmonary stenosis (7.6%), regurgitation (12.7%), or both (79.7%). Twenty-two patients (27.8%) underwent implantation of 26-mm valves, and 47 patients received 23-mm valves. Functional improvement in New York Heart Association functional class was observed in 93.5% of patients. Mean peak conduit gradient decreased from 37.5 ± 25.4 to 17.8 ± 12.4 mm Hg (p < 0.001), and mean right ventricular systolic pressure decreased from 59.6 ± 17.7 to 42.9 ± 13.4 mm Hg (p < 0.001). Pulmonary regurgitation was mild or less in 91.1% of patients. Freedom from all-cause mortality at 3 years was 98.4%. Freedom from reintervention was 93.7% and from endocarditis was 97.1% at 3 years. There were no observed stent fractures.

CONCLUSIONS

Transcatheter pulmonary valve replacement using the Edwards SAPIEN THV demonstrates excellent valve function and clinical outcomes at 3-year follow-up.

Longitudinal measures of deformation are associated with a composite measure of contractility derived from pressure-volume loop analysis in children

Aims

The relationship between echocardiographic measures of left ventricular (LV) systolic function and reference-standard measures have not been assessed in children. The objective of this study was to assess the validity of echocardiographic indices of LV systolic function via direct comparison to a novel composite measure of contractility derived from pressure-volume loop (PVL) analysis.

Methods and results

Children with normal loading conditions undergoing routine left heart catheterization were prospectively enrolled. PVLs were obtained via conductance catheters. A composite invasive composite contractility index (ICCI) was developed using data reduction strategies to combine four measures of contractility derived from PVL analysis. Echocardiograms were performed immediately after PVL analysis under the same anesthetic conditions. Conventional and speckle-tracking echocardiographic measures of systolic function were measured. Of 24 patients, 18 patients were heart transplant recipients, 6 patients had a small patent ductus arteriosus or small coronary fistula. Mean age was 9.1 ± 5.6 years. Upon multivariable regression, longitudinal strain was associated with ICCI (β = -0.54, P = 0.02) while controlling for indices of preload, afterload, heart rate, and LV mass under baseline conditions. Ejection fraction and shortening fraction were associated with LV mass and load indices, but not contractility.

Conclusion

Speckle-tracking derived longitudinal strain is associated ICCI in children with normal loading conditions. Longitudinal measures of deformation appear to accurately assess LV contractility in children.

Echocardiographic Detection of Increased Ventricular Diastolic Stiffness in Pediatric Heart Transplant Recipients: A Pilot Study

BACKGROUND

Pediatric heart transplant recipients are at risk for increased left ventricular (LV) diastolic stiffness. However, the noninvasive evaluation of LV stiffness has remained elusive in this population. The objective of this study was to compare novel echocardiographic measures of LV diastolic stiffness versus gold-standard measures derived from pressure-volume loop (PVL) analysis in pediatric heart transplant recipients.

METHODS

Patients undergoing left heart catheterization were prospectively enrolled. PVLs were obtained via conductance. The end-diastolic pressure-volume relationship was obtained via balloon occlusion. The stiffness constant, β, was calculated. Echocardiographic measures of diastolic function were derived from spectral and tissue Doppler and two-dimensional speckle-tracking. Ventricular volumes were measured using three-dimensional echocardiography. The novel echocardiographic estimates of ventricular stiffness included E:e'/end-diastolic volume (EDV) and E:early diastolic strain rate/EDV.

RESULTS

Of 24 children, 18 were heart transplant recipients. Six control patients had hemodynamically insignificant patent ductus arteriosus or coronary fistula. The mean age was 9.1 ± 5.6 years. Median end-diastolic pressure was 9 mm Hg (interquartile range, 8-13 mm Hg). Lateral E:e'/EDV (r = 0.59, P < .01), septal E:e'/EDV (r = 0.57, P < .01), and (E:circumferential early diastolic strain rate)/EDV (r = 0.54, P < .01) correlated with β. Lateral E:e'/EDV displayed a C statistic of 0.93 in detecting patients with abnormal LV stiffness (β > 0.015 mL^-1). A lateral E:e'/EDV of >0.15 mL^-1 had 89% sensitivity and 93% specificity in detecting an abnormal β.

CONCLUSIONS

Echocardiographic estimates of ventricular stiffness may be accurate compared with the gold standard in pediatric heart transplant recipients. The clinical usefulness of these noninvasive measures in assessing LV stiffness merits further study in children.

Speckle-Tracking Echocardiographic Measures of Right Ventricular Diastolic Function Correlate with Reference Standard Measures Before and After Preload Alteration in Children

The accuracy of echocardiographic measures of right ventricular (RV) diastolic function has been sparsely studied. Our objective was to evaluate the correlation between echocardiographic and reference standard measures of RV diastolic function derived from micromanometer pressure analysis before and after preload alteration in children. Echocardiograms and micromanometer pressure analyses were prospectively performed before and after fluid bolus in children undergoing right heart catheterization. The isovolumic relaxation time constant (τ) and end-diastolic pressure (EDP) were measured. Conventional and speckle-tracking echocardiographic (STE) parameters of RV systolic and diastolic function were assessed. Normal saline bolus was given to increase RV EDP by 20 %. Twenty-eight studies were performed in 22 patients with congenital heart disease or postheart transplantation. Mean age was 8.7 ± 6.1 years. RV longitudinal early diastolic strain rate (EDSR) correlated with τ before (r = 0.57, p = 0.001) and after fluid bolus (r = 0.48, p = 0.008). No conventional echocardiographic measures correlated with τ both before and after fluid bolus. Multiple regression analysis revealed RV EDSR and LV circumferential EDSR as independent predictors of RV τ. There were no independent predictors of EDP. RV EDSR appears to correlate with the reference standard measure of early active ventricular relaxation in children at baseline and after changes in preload. Conventional echocardiographic measures of diastolic function were not predictive of diastolic function after preload alteration. Future studies should assess the prognostic significance of STE measures of diastolic function in this population.

Validation of Noninvasive Measures of Left Ventricular Mechanics in Children: A Simultaneous Echocardiographic and Conductance Catheterization Study

BACKGROUND

The accuracy of echocardiography in evaluating left ventricular contractility has not been validated in children. The objective of this study was to compare echocardiographic measures of contractility with those derived from pressure-volume loop (PVL) analysis in children.

METHODS

Patients with relatively normal loading conditions undergoing routine left heart catheterization were prospectively enrolled. PVLs were obtained via conductance catheters. The gold-standard measure of contractility, end-systolic elastance (Ees), was obtained via balloon occlusion of one or both vena cavae. Echocardiograms were performed immediately after PVL analysis under the same anesthetic conditions. Single-beat estimations of echocardiographic Ees were calculated using four different methods. These estimates were calculated using a combination of noninvasive blood pressure readings, ventricular volumes derived from three-dimensional echocardiography, and Doppler time intervals.

RESULTS

Of 24 patients, 18 patients were heart transplant recipients, and six patients had small patent ductus arteriosus or small coronary fistulae. The mean age was 9.1 ± 5.6 years. The average invasive Ees was 3.04 ± 1.65 mm Hg/mL. Invasive Ees correlated best with echocardiographic Ees by the method of Tanoue (r = 0.85, P < .01), with a mean difference of -0.07 mm Hg/mL (95% limits of agreement, -2.0 to 1.4 mm Hg/mL).

CONCLUSIONS

Echocardiographic estimates of Ees correlate well with gold-standard measures obtained via conductance catheters in children with relatively normal loading conditions. The use of these noninvasive measures in accurately assessing left ventricular contractility appears promising and merits further study in children.

Impact of Variability in Echocardiographic Interpretation on Assessment of Adequacy of Repair Following Congenital Heart Surgery: A Pilot Study

Technical Performance Score (TPS) is based largely on the presence and magnitude of residual lesions on postoperative echocardiograms; this score correlates with outcomes following repair of congenital heart defects. We evaluated reader variability for echocardiographic components of TPS for complete repair of tetralogy of Fallot (TOF) and arterial switch operation (ASO) in two centers and measured its effect on TPS. Postoperative echocardiograms were evaluated in 67 children (39 TOF and 28 ASO). Two readers (one per center) interpreted each echocardiogram. Reader variability in image quality assessments and measurements was compared using weighted kappa (κ), percent agreement, and intra-class correlation. TPS class (1 optimal-no residua, 2 adequate-minor residua, 3 inadequate-major residua) was assigned for each echocardiographic review by an independent investigator. The effect of reader interpretation variability on TPS classification was measured. There was strong agreement for TPS between the two readers (κ = 0.88). The readers were concordant for TPS classes for 57 children (85%) and discordant for classes 2 (minor residua) versus 3 (major residua) in six (9%). Coronary arteries and branch pulmonary arteries were frequently suboptimally visualized. Although inter-reader agreement for TPS was strong, inter-reader variation in echocardiographic interpretations had a small, but important effect on TPS for TOF and ASO, particularly for the distinction between minor and major residua. Further studies of generalizability and reproducibility of TPS and refinement of scoring modules may be needed before it can be used as a tool to assess pediatric cardiac surgical performance and outcomes.

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.

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

BACKGROUND

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.

METHODS

Echocardiograms were evaluated at baseline, discharge, 1 and 6 months after TPV placement in 24 patients from 4 centers. Speckle tracking measures of function included peak longitudinal strain, strain rate, and early diastolic strain rate. RV fractional area change, tricuspid annular plane systolic excursion, and left ventricular LV ejection fraction were assessed. Routine Doppler and tissue Doppler velocities were measured.

RESULTS

At baseline, all patients demonstrated moderate to severe pulmonary regurgitation; this improved following TPV placement. No significant changes were detected in conventional measures of RV or LV function at 6 months. RV longitudinal strain (-16.9% vs. -19.6%, P < 0.01), strain rate (-0.87 s(-1) vs. -1.16 s(-1) , P = 0.01), and LV longitudinal strain (-16.2% vs. -18.2%, P = 0.01) improved between baseline and 6 month follow-up. RV early diastolic strain rate, LV longitudinal strain rate and early diastolic strain rate showed no change.

CONCLUSION

Improvements in RV longitudinal strain, strain rate, and LV longitudinal strain are seen at 6 months post-TPV. Diastolic function does not appear to change at 6 months. Speckle tracking echocardiography may be more sensitive than traditional measures in detecting changes in systolic function after TPV implantation.

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.

Three-dimensional echocardiography in congenital heart disease

Complex intracardiac anatomy and spatial relationships are inherent to congenital heart defects (CHDs). Recognition of the limitations of two-dimensional echocardiography has stimulated clinical interest in three-dimensional imaging. The current review examines contemporary studies in the following areas where three-dimensional echocardiography has provided additive value in CHD: (1) visualization of morphology, (2) quantitation of chamber sizes and ventricular function, and (3) image-guided interventions.

Does initial shunt type for the Norwood procedure affect echocardiographic measures of cardiac size and function during infancy?: the Single Vventricle Reconstruction trial

BACKGROUND

The Pediatric Heart Network trial comparing outcomes in 549 infants with single right ventricle undergoing a Norwood procedure randomized to modified Blalock-Taussig shunt or right ventricle-pulmonary artery shunt (RVPAS) found better 1-year transplant-free survival in those who received RVPAS. We sought to compare the impact of shunt type on echocardiographic indices of cardiac size and function up to 14 months of age.

METHODS AND RESULTS

A core laboratory measured indices of cardiac size and function from protocol exams: early after Norwood procedure (age 22.5 ± 13.4 days), before stage II procedure (age 4.8 ± 1.8 months), and at 14 months (age 14.3 ± 1.2 months). Mean right ventricular ejection fraction was <50% at all intervals for both groups and was higher in the RVPAS group after Norwood procedure (49 ± 7% versus 44 ± 8%; P<0.001) but was similar by 14 months. Tricuspid and neoaortic regurgitation, diastolic function, and pulmonary artery and arch dimensions were similar in the 2 groups at all intervals. Neoaortic annulus area (4.2 ± 1.2 versus 4.9 ± 1.2 cm(2)/m(2)), systolic ejection times (214.0 ± 29.4 versus 231.3 ± 28.6 ms), neoaortic flow (6.2 ± 2.4 versus 9.4 ± 3.4 L/min per square meter), and peak arch velocity (1.9 ± 0.7 versus 2.2 ± 0.7 m/s) were lower at both interstage examinations in the RVPAS compared with the modified Blalock-Taussig shunt group (P<0.001 for all), but all were similar at 14 months.

CONCLUSIONS

Indices of cardiac size and function after the Norwood procedure are similar for modified Blalock-Taussig shunt and RVPAS by 14 months of age. Interstage differences between shunt types can likely be explained by the physiology created when the shunts are in place rather than by intrinsic differences in cardiac function.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00115934.

Clinico-morphological correlations in the categorization of holes between the ventricles

Controversy still exists in the categorization of holes between the ventricles, although they are the most common congenital cardiac malformation. Advanced imaging techniques such as three-dimensional echocardiography and computed tomographic angiography offer superb anatomical details of these defects. In this review, we have sought to collate the features highlighted in different categorizations and identify their similarities, but also emphasize their differences. We hope that an analysis of this type, now achievable during life, using advanced imaging, might lead to the appearance of a unified system for diagnosis and description of holes between the ventricles.

Three dimensional echocardiography in congenital heart defects

Three dimensional echocardiography (3DE) is a new, rapidly evolving modality for cardiac imaging. Important technological advances have heralded an era where practical 3DE scanning is becoming a mainstream modality. We review the modes of 3DE that can be used. The literature has been reviewed for articles that examine the applicability of 3DE to congenital heart defects to visualize anatomy in a spectrum of defects ranging from atrioventricular septal defects to mitral valve abnormalities and Ebstein's anomaly. The use of 3DE color flow to obtain echocardiographic angiograms is illustrated. The state of the science in quantitating right and left ventricular volumetrics is reviewed. Examples of novel applications including 3DE transesophageal echocardiography and image-guided interventions are provided. We also list the limitations of the technique, and discuss potential future developments in the field.

Predictors of coronary artery visualization in Kawasaki disease

BACKGROUND

Echocardiography is the imaging modality of choice for the evaluation of coronary artery (CA) abnormalities in Kawasaki disease. Small series have established high specificity and sensitivity for detecting abnormalities, yet visualization rates of individual CA segments and factors associated with success are unknown.

METHODS

In the Pediatric Heart Network's randomized trial of primary steroid treatment for Kawasaki disease, echocardiograms were interpreted locally and by a core laboratory. Univariate and multivariate predictors of CA visualization by the local lab as determined by the core lab were explored, and agreement of CA size measured locally and by the core lab was assessed.

RESULTS

A total of 589 echocardiograms from 199 patients were obtained over 27 months. Visualization rates for the left main, proximal and distal left anterior descending, and proximal right CAs ranged from 91% to 98% but were lower for the distal right (65%), circumflex (86%), and posterior descending (54%) CAs. For the distal right and circumflex CAs, visualization rates improved over the course of the study (P<.05). In multivariate analysis, local center, CA segment, and time from study start to echocardiography were independent predictors of visualization (all P values<.001). For segments for which visualization rates varied by center, higher percentage visualization was associated with larger center volume (P=.001). Routine sedation use was also associated with higher visualization rates.

CONCLUSIONS

Successful CA visualization in Kawasaki disease is associated with the segment being evaluated and is influenced by center volume and sedation use. Increased visualization rates over time suggest a learning curve and underscore the value of core lab oversight in pediatric multicenter trials.

Internal right ventricular band for multiple ventricular septal defects in a neonate undergoing arterial switch and aortic arch repair

A neonate presented with d-transposition of the great arteries, aortic arch hypoplasia, aortic coarctation, and multiple ventricular septal defects. During the arterial switch procedure and the aortic arch repair, a fenestrated Gore-Tex disk (W.L. Gore & Assoc, Flagstaff, AZ) was sewn into the right ventricular outflow tract to restrict pulmonary blood flow. The internal right ventricular band successfully controlled the pulmonary blood flow, maintaining a systemic oxygen saturation of 88% to 92%, and allowing growth from 3.5 to 10.5 kg. At 8 months of age, the internal band in the patient was removed, and the ventricular septal defects were successfully closed.

Comparison of Norwood shunt types: do the outcomes differ 6 years later?

BACKGROUND

A modification to the Norwood procedure involving a right ventricle-to-pulmonary artery (RV-PA) shunt may improve early postoperative outcomes. Concerns remain about the effect of the right ventriculotomy required with this shunt on long-term ventricular function.

METHODS

Between January 2000 and April 2005, 76 patients underwent the Norwood procedure, 35 with a modified Blalock-Taussig shunt (mBTS) and 41 with a RV-PA shunt. Patients were monitored until death or September 1, 2009, with an average follow-up of 6.8 years. Cardiac catheterization, echocardiograms, perioperative Fontan courses, and need for cardiac transplantation were compared between groups.

RESULTS

Cumulative survival was 63% (22 of 35) in the mBTS group vs 78% (32 of 41) in the RV-PA group (p = 0.14). Pre-Fontan echocardiography revealed poorer ventricular function in RV-PA patients (p = 0.03). Cardiac transplantation was required in 6 of 32 (19%) patients with a prior RV-PA shunt vs 1 of 23 (4%) in the mBTS group (p = 0.06). This results in an almost identical cumulative transplant-free survival between groups; 60% (21 of 35) in the mBTS group and 63% (26 of 41) in the RV-PA group (p = 0.95).

CONCLUSIONS

Neither shunt offers a clear survival advantage through an average follow-up of 6.8 years. The RV-PA shunt results in impaired late ventricular function that may result in an increased need for cardiac transplantation.

Universal screening for extracardiac abnormalities in neonates with congenital heart disease

Extracardiac or genetic abnormalities (EGA) represent a factor in the morbidity of patients with congenital heart disease. We evaluated the way neonates with CHD are screened at our institution and determined the yield for the screening tests. We reviewed the charts of 223 neonates with structural CHD. Subjects were categorized into 6 groups: univentricular, left-sided obstructive lesions, right-sided obstructive lesions, septal defects, conotruncal defects (CTD), and other. We reviewed which patients underwent cranial ultrasonogram (CUS), abdominal ultrasonogram (AUS), and/or genetic studies (GS) as well as their results. There was a high prevalence of EGA in each group by CUS (32% to 42%), AUS (32% to 69%), and GS (10% to 60%). There was considerable variability in the proportion within each group that underwent screening tests, and the consistency of screening often was not congruent with the likelihood of abnormal results. Approximately 50% of our patients had >/=1 EGA identified, resulting in a cost-yield ratio of $4,508/patient with EGA. Screening for EGA at our institution is not uniform and is often at odds with the prevalence of such patients. Given the high prevalence of EGA, we advocate for a universal screening program for neonates with CHD using cranial/abdominal ultrasonography and genetic testing.

Transseptal left heart catheterization for a patient with a prosthetic mitral valve using live three-dimensional transesophageal echocardiography

The images and videos presented in this article illustrate a diagnostic transseptal left heart catheterization for a patient with a prosthetic mitral valve guided by live three-dimensional (3D) transesophageal echocardiography. This method provided high-quality 3D imaging that was useful in guiding transseptal puncture and demonstrating prosthetic valve function during this evaluation.

Left Ventricular Dysfunction is Associated with Intraventricular Dyssynchrony by 3-Dimensional Echocardiography in Children

INTRODUCTION

We used 3-dimensional (3D) echocardiography to identify and quantify left ventricular (LV) dyssynchrony in children with LV dysfunction compared with control subjects.

METHODS

The 3D echocardiography LV full volumes were acquired in 18 children, 9 with LV dysfunction and 9 control subjects. The LV was subdivided into 16 segments (apex excluded). Time from end diastole to the minimal systolic volume for each segment was expressed as a percent of the R-R interval. The SD of these times provided a 16-segment dyssynchrony index (16-SDI). The second index (12-SDI) was similarly calculated using 6 basal and 6 mid segments. The third index consisted of 6 basal segments (6-SDI).

RESULTS

The dysfunction group exhibited significantly increased 16-SDI (P = .008) and 12-SDI (P = .01). The 16-SDI was negatively correlated with 3D ejection fraction and 2-dimensional fractional shortening.

CONCLUSIONS

Children with LV dysfunction demonstrate increased intraventricular LV dyssynchrony by 3D echocardiography, in a pattern that is negatively correlated with LV systolic function.

Survival after bidirectional cavopulmonary anastomosis: Analysis of preoperative risk factors

OBJECTIVE

Prognostic factors for survival after bidirectional cavopulmonary anastomosis for functionally single ventricle are not well defined. We analyzed preoperative hemodynamic and echocardiographic data to determine risk factors for death or transplantation at least 1 year after bidirectional cavopulmonary anastomosis.

METHODS

Data for all patients who underwent bidirectional cavopulmonary anastomosis before 5 years of age at our institution from September 1995 through June 2005 were analyzed. Available preoperative echocardiograms and catheterizations were reviewed. Survivors were compared with those who died or underwent transplantation. Bivariable associations between demographic and clinical risk factors and survival status (alive without transplantation vs dead or transplanted) were assessed with Wilcoxon rank sum test and chi2 or Fisher exact tests. Survival functions were constructed with Kaplan-Meier estimates, and event times compared between subgroups with log-rank tests. Cox proportional hazard modeling was used for multivariable modeling of risk of death or transplantation.

RESULTS

One hundred sixty-seven patients underwent bidirectional cavopulmonary anastomosis with hemi-Fontan (n = 62) or bidirectional Glenn (n = 105) operations. Three patients died before discharge, 11 died later, and 1 has undergone transplantation. Freedom from death or transplantation after bidirectional cavopulmonary anastomosis was 96% at 1 year and 89% at 5 years. Multivariable analysis of preoperative variables showed atrioventricular valve regurgitation to be an independent risk factor for death or transplantation (hazard ratio 2.8, 95% confidence interval 1.1-7.1, P = .02).

CONCLUSION

Although survival after bidirectional cavopulmonary anastomosis is high, preoperative atrioventricular valve regurgitation is an important risk factor for death or transplantation.

Quantitative Three-dimensional Echocardiography in Congenital Heart Disease

Collapse

Does a ventriculotomy have deleterious effects following palliation in the Norwood procedure using a shunt placed from the right ventricle to the pulmonary arteries?

INTRODUCTION

A recent modification to the Norwood procedure involving a shunt placed directly from the right ventricle to the pulmonary arteries may improve postoperative haemodynamics. Concerns remain, however, about the potential problems produced by the required ventriculotomy.

METHODS

We compared 76 patients with hypoplastic left heart syndrome who underwent the Norwood procedure, 35 receiving a modified Blalock-Taussig shunt and the remaining 41 a shunt placed directly from the right ventricle to the pulmonary arteries. We reviewed their subsequent progress through the second stage of palliation. A single observer graded right ventricular function, and the severity of tricuspid regurgitation, based on blinded review of the most recent echocardiograms prior to the second stage of palliation.

RESULTS

At the time of catheterization prior to the second stage, patients with a shunt placed from the right ventricle to the pulmonary arteries, rather than a modified Blalock-Taussig shunt, had higher arterial diastolic blood pressure, at 44 versus 40 millimetres of mercury, p equal to 0.02, lower ventricular end diastolic pressures, at 8 versus 11 millimetres of mercury, p equal to 0.0002, and larger pulmonary arteries as judged using the Nakata index, at 270 versus 188 millimetres squared per metres squared, p equal to 0.009. There was no difference in qualitative ventricular systolic function or tricuspid regurgitation between groups. No differences were found between groups during the hospitalization following the second stage of palliation. A trend towards improved survival to the second stage was seen following the construction of a shunt from the right ventricle to the pulmonary arteries.

CONCLUSIONS

Construction of a shunt from the right ventricle to the pulmonary arteries is associated with lower right ventricular end diastolic pressures, larger pulmonary arterial size, and higher systemic arterial diastolic pressures. No apparent deleterious effects of the right ventriculotomy were observed in terms of qualitative ventricular systolic function or tricuspid regurgitation.

Early Experience with a Miniaturized Three-dimensional Matrix Transducer in Children

Collapse

Echo-morphological correlates in patients with atrioventricular septal defect and common atrioventricular junction

It is now well recognized that patients fulfilling the diagnostic criterions for the group of hearts usually described as atrioventricular canal malformations, or atrioventricular septal defects, can present with shunting at atrial level, at both atrial and ventricular levels, and on occasion, with shunting only at ventricular level.1,2It is also well recognized that, in most instances, the patients with shunting exclusively at atrial level have separate atrioventricular valvar orifices for the right and left ventricles, this arrangement often described as the “ostium primum” variant of atrial septal defect.3Morphological and echocardiographic studies, however, have shown that, in this variant presumed to represent deficient atrial septation, it is the atrioventricular septal structures, rather than the atrial septum, which are deficient, the phenotypic feature being the presence of a common atrioventricular junction.4,5In this review, we will show how, using modern day echocardiographic techniques, particularly the newly developed potential for three-dimensional display, it is an easy matter to identify the presence or absence of the common atrioventricular junction, and then to demonstrate the various relationships between the valvar leaflets, the septal structures, and the common junction itself which determine the options for clinical presentation within the group.

Real-Time Three-Dimensional Echocardiography Is Useful in the Evaluation of Patients with Atrioventricular Septal Defects

OBJECTIVE

We sought to determine whether three-dimensional echocardiography (3DE) is useful in the evaluation of patients with atrioventricular septal defect (AVSD).

BACKGROUND

Recent advances in 3DE have enhanced its practicality. We assessed whether 3DE provided new information compared to 2DE among patients with AVSD.

METHODS

We retrospectively reviewed 52 3DE datasets from 51 patients (median age: 4.6 years, range 0-30 years; median BSA: 0.6 m2, range 0.2-1.9 m2) with any type of AVSD during a 1-year period. 3DE findings were compared to 2DE and surgical reports. For each study, AVSD was classified by 2DE as one of the following: unrepaired balanced defect, repaired balanced defect with residual lesions, repaired balanced defect without residual lesions, or unbalanced defect. 3DE was graded as (1) Additive: 3DE resulted in a new finding or changed diagnosis; (2) Useful: While useful, 3DE did not result in new findings or changed diagnosis; or (3) Not useful.

RESULTS

3DE on unrepaired balanced AVSD and repaired AVSD with residual lesions was more often additive/useful (33/36; 92%) than on repaired AVSD without residual lesions or unbalanced AVSD (9/16 (56%), P=0.009). 3DE was additive or useful in all three patients with unbalanced AVSD being considered for biventricular repair. Useful information obtained by 3DE included: precise characterization of mitral regurgitation and cleft leaflet, substrate for subaortic stenosis, valve anatomy, and presence and location of additional septal defects.

CONCLUSION

3DE provides useful and additive information in unrepaired balanced AVSD, repaired AVSD with residual lesions, and unbalanced AVSD under consideration for biventricular repair.

Characteristics of the Interatrial Communication in Patients Undergoing Transcatheter Device Closure of Atrial Septal Defects for Cryptogenic Stroke

BACKGROUND

Prior studies suggest that patent foramen ovale (PFO) diameter >4 mm is associated with a high probability of cryptogenic ischemic stroke (CIS).

METHODS

We evaluated all patients diagnosed with CIS who underwent closure of intra-atrial communication (IAC) using the Amplatzer atrial septal defect (ASD) occluder in our institution between August 1997 and March 2004. For each IAC, echocardiographic diameters and balloon-stretched diameters were recorded. Stretchability index was calculated as the ratio of stretched diameter to unstretched diameter.

RESULTS

Fifty-six patients met the inclusion criteria for this study. There was an inverse logarithmic relationship between unstretched IAC diameter and stretchability index. For the 28 smaller defects, the median IAC diameter was 2 mm, and median stretchability index was 5.58 (range 2.6-15). For the 28 larger defects, median diameter was 6 mm, and median stretchability index was 2.38 (range 1.05-5). The difference in stretchability index between the two groups was significant (P < 0.0001).

CONCLUSION

Our data bring into question the concept that the diameter of the defect would singularly predict the probability of stroke.

Hemodynamic status after the Norwood procedure: A comparison of right ventricle–to–pulmonary artery connection versus modified blalock-taussig shunt

BACKGROUND

The aim of this study is to compare hemodynamic status, in particular systemic oxygen delivery, in patients undergoing a Norwood procedure with a right ventricle-to-pulmonary artery (RV-PA) versus a modified Blalock-Taussig (mBT) shunt.

METHODS

From June 2000 to November 2003, 44 consecutive neonates with hypoplastic left heart syndrome underwent a Norwood procedure. The first 25 patients received an mBT shunt; the subsequent 19 an RV-PA shunt. Hemodynamic data, including mixed venous oxygen saturation, was determined during the first 48 hours after surgery.

RESULTS

The mBT and RV-PA shunt patients had no significant differences in systemic oxygen saturation, mixed venous oxygen saturation, arteriovenous oxygen saturation difference, or oxygen excess factor during the first 48 hours. Mixed venous saturation declined to a nadir in both groups at 6 to 12 hours. The RV-PA patients had significantly higher diastolic and mean blood pressures, and lower systolic blood pressure. Mean heart rate, common atrial pressure, and inotrope score did not differ between the two groups. The RV-PA patients received higher fraction of inspired oxygen and minute ventilation to achieve partial pressures of arterial oxygen and carbon dioxide, and pH, similar to mBT patients. Durations of mechanical ventilation, intensive care unit stay, and hospital stay did not differ between mBT and RV-PA patients. Operative survival in the mBT versus RV-PA group was 20 of 25 (80%) versus 17 of 19 (89%; p = 0.7).

CONCLUSIONS

Indicators of postoperative systemic oxygen delivery are equivalent in neonates who have undergone a Norwood procedure with an mBT or RV-PA shunt. Both mBT and RV-PA patients undergo similar declines in hemodynamic status 6 to 12 hours after surgery. Any advantages of one approach over the other lie in areas other than systemic oxygen delivery, such as resistance to physiologic insults, or preservation of ventricular function.

Implications and limitations of an abnormal fetal echocardiogram

This study evaluates the accuracy of fetal echocardiograms in terms of anatomic diagnosis and predicted neonatal management over a 7-year period. Although an abnormal fetal echocardiogram is a highly reliable predictor of postnatal structural heart defects, challenges persist in the areas of conotruncal malformations, aortic arch, and pulmonary venous anomalies.

Effectiveness of cardiac surgery in trisomies 13 and 18 (from the Pediatric Cardiac Care Consortium)

Because of severely reduced lifespan in children with trisomies 13 and 18, surgical repair of congenital heart lesions has rarely been offered. With data from a multicenter registry, we report 35 cases of cardiac surgery in infants and children with trisomy 13 or 18 with a 91% hospital survival rate. Those patients without an extended preoperative ventilatory requirement did not require prolonged mechanical ventilation after surgery.

Outcome following, and impact of, prenatal identification of the candidates for the Norwood procedure

OBJECTIVES

Our study evaluates hospital survival following prenatal identification of candidates for the Norwood procedure, and the impact of prenatal diagnosis on survival, preoperative stability, and postoperative morbidity.

METHODS

We reviewed records of all patients who were identified prenatally as candidates for the Norwood procedure, and compared them to all postnatally diagnosed patients who underwent the Norwood procedure between August 1995 and May 2002.

RESULTS

Of the 98 patients studied, 45 (46%) were diagnosed prenatally. Of these, 35 underwent the Norwood procedure, 29 (83%) of who survived. Thus, 29 of 45 (64%) patients survived from prenatal diagnosis to discharge following the Norwood procedure. Of the 53 postnatally diagnosed patients who underwent the Norwood procedure, 42 (79%) survived. Prenatal diagnosis was not associated with improvement in survival, preoperative stability, or postoperative morbidity. By multivariate analysis, ascending aortic diameter equal to or greater than 2 mm (p = 0.01), and gestational age 36 weeks or greater (p = 0.01) independently predicted survival. Based on this, patients were stratified into groups at low risk, consisting of 69 patients, and at high risk, consisting of 19 patients. Prenatal diagnosis was unassociated with improved survival in either group. Results were unchanged when the analysis was restricted to patients with hypoplasia of the left heart.

CONCLUSION

From the time of prenatal diagnosis, 64% of patients survived to discharge following the Norwood procedure. Prenatal diagnosis did not affect preoperative stability, survival or postoperative morbidity. This remained the case after stratifying patients by risk, or restricting analysis to patients with hypoplasia of the left heart. Ascending aortic diameter and gestational age independently predicted survival.

Predictors of residual defects following closure of defects in the oval fossa using the Amplatzer device: echocardiography recapitulates morphometry

OBJECTIVES

This study was designed to identify predictors of residual defects following deployment of the Amplatzer device to close septal defects within the oval fossa.

METHODS

Between February 1997 and February 2000, we used the Amplatzer device to close defects in the oval fossa in 89 patients. Of these patients, 18 (20%) had residual defects. At 6 or 12 months following placement of the device, 13 defects (14.6%) had persisted. We evaluated several variables derived from clinical features, transesophageal echocardiography and catheterization to establish predictors for residual shunting.

RESULTS

Multivariate analysis identified a shorter superior rim of less than 8 mm (Odds ratio = 10.1; 95% confidence intervals = 2.64-38.72; p = 0.001), and a smaller interatrial septum in the 30-degree transesophageal echocardiographic plane of less than 30 mm (Odds ratio = 5.5; 95% confidence intervals = 1.17-26.14; p = 0.03) as independent predictors of residual defects. When the analysis was repeated defining only those 13 patients with persisting residual defects at 6 or 12 months as failures, a short superior rim (p = 0.004) remained a predictor for residual shunting.

CONCLUSIONS

Defects with a short superior rim and smaller interatrial septum in the 30-degree transesophageal echocardiographic plane independently and additively predict an increased probability of residual shunting following closure of defects in the oval fossa using the Amplatzer device.

Experience with use of multiplane transesophageal echocardiography to guide closure of atrial septal defects using the amplatzer device

By providing unlimited imaging planes, multiplane transesophageal echocardiography (MTEE) should improve real-time guidance of interventional procedures. The potential advantages of MTEE in this scenario have not been systematically evaluated. We retrospectively reviewed our experience with MTEE-guided Amplatzer device closure of atrial septal defects (ASDs) MTEE angles used to obtain images for guiding all measurements and maneuvers were recorded. These angles were compared to the range of MTEE angles that are postulated to be available from biplane TEE. Images obtained using MTEE angles from 21 degrees to 70 degrees and from 111 degrees to l59 degrees were defined as only obtainable by MTEE. The MTEE probe was successfully introduced in all (89) patients. Thirteen patients (15%) had multiple defects. Ninety-five devices (5-32 mm in diameter) were deployed. In 66% of patients, balloon sizing and device deployment necessitated imaging planes that are only obtainable by MTEE. All devices were well positioned, with no impingement on inflows or outflows. At follow-up, 79 of 89 (88.7%) patients had no residual ASDs. Each of the remaining 10 patients (11.3%) had a small (<3 mm) residual defect. MTEE played an important role in guiding device closure of ASD, particularly during the phases of balloon sizing and device deployment.

Echocardiographic diagnosis of partial obstruction of Blalock-Taussig shunts

While echocardiography has previously been used to differentiate between patency and complete occlusion of aortopulmonary shunts, the echocardiographic diagnosis of partial obstruction of a shunt has not been reported. We describe a unique color flow Doppler finding that quickly and accurately diagnosed three cases of partial distal obstruction of aortopulmonary shunts.

Functional pulmonary atresia in neonatal Marfan's syndrome: successful treatment with inhaled nitric oxide

Functional pulmonary atresia is characterized by a structurally normal pulmonary valve not opening during right ventricular ejection. We report this rare condition in a premature newborn of a twin pregnancy, in which fetal echocardiography findings were consistent with critical pulmonary stenosis. After birth, features of neonatal Marfan's syndrome were noted. Echocardiography showed a morphologically normal but immobile pulmonary valve with continuous regurgitation. Right ventricular pressure was subsystemic. In this case, initial treatment with nitric oxide, followed by pharmacological duct closure, was successful. Differentiating between anatomic and functional pulmonary valve atresia may be difficult. The echocardiographic criteria are discussed.

Noninvasive diagnosis of partial anomalous left pulmonary artery

The branching patterns of the pulmonary arteries may vary, with one or more lobes of the left lung being supplied by a branch originating from the right pulmonary artery-a condition termed partial anomalous left pulmonary artery. If this anomalous branch courses anterior and inferior to the trachea, it is unlikely to result in airway obstruction. It is important that this anomaly not be confused with pulmonary artery sling, where the anomalous branch courses posterior to the trachea, encircling it almost completely. Partial anomalous left pulmonary artery has previously been diagnosed with angiography or by direct visualization during surgery. We present the first cases of noninvasive diagnosis of this anomaly with the use of echocardiography and magnetic resonance imaging. The complementary roles of these two modalities in detecting the anomaly and defining the spatial relationship of the anomalous pulmonary artery to the trachea are emphasized.

Association of viral genome with graft loss in children after cardiac transplantation

BACKGROUND

The survival of recipients of cardiac allografts is limited by rejection, lymphoproliferative disease, and coronary vasculopathy. The purpose of this study in children who had received heart transplants was to evaluate the cardiac allografts for myocardial viral infections and to determine whether the presence of viral genome in the myocardium correlates with rejection, coronary vasculopathy, or graft loss.

METHODS

We enrolled heart-transplant recipients 1 day to 18 years old who were undergoing evaluation for possible rejection and coronary vasculopathy. Endomyocardial-biopsy specimens were evaluated for evidence of rejection with the use of standard criteria and were analyzed for the presence of virus by the polymerase chain reaction (PCR).

RESULTS

PCR analyses were performed on 553 consecutive biopsy samples from 149 transplant recipients. Viral genome was amplified from 48 samples (8.7 percent) from 34 patients (23 percent); adenovirus was found in 30 samples, enterovirus in 9 samples, parvovirus in 5 samples, cytomegalovirus in 2 samples, herpes simplex virus in 1 sample, and Epstein-Barr virus in 1 sample. In 29 of the 34 patients with positive results on PCR (85 percent), an adverse cardiac event occurred within three months after the positive biopsy, and 9 of the 34 patients had graft loss due to coronary vasculopathy, chronic graft failure, or acute rejection. In 39 of the 115 patients with negative results on PCR (34 percent), an adverse cardiac event occurred within three months of the negative PCR finding; graft loss did not occur in any of the patients in this group. The odds of graft loss were 6.5 times as great among those with positive results on PCR (P=0.006). The detection of adenovirus was associated with considerably reduced graft survival (P=0.002).

CONCLUSIONS

Identification of viral genome, particularly adenovirus, in the myocardium of pediatric transplant recipients is predictive of adverse clinical events, including coronary vasculopathy and graft loss.

Posttransplant recoarctation of the aorta: a twelve year experience

OBJECTIVES

This study was undertaken to investigate the incidence of posttransplant recoarctation of the aorta, delineate the mode of presentation, identify risk factors that predict recoarctation and examine the results of intervention for posttransplant recoarctation.

BACKGROUND

Patients with aortic arch hypoplasia require extended arch reconstruction at transplant, with an inherent possibility of subsequent recoarctation of the aorta.

METHODS

This was a retrospective review of all children (age <18 years) who underwent cardiac transplantation over a 10-year period. Collected data included pretransplant diagnosis, details of the transplant procedure and posttransplant data including development of recoarctation of the aorta, interventions for recoarctation and the most recent follow-up assessment of the aortic arch.

RESULTS

Two hundred eighty-eight transplants were performed on 279 children (follow-up = 1,075 patient-years; range 0 to 133 months, median 43.7). Thirty-two of 152 patients (21%) who underwent extended aortic arch reconstruction subsequently developed recoarctation. All but one patient developed recoarctation within 2 years after transplant; 87% were hypertensive at presentation. Of 30 patients who underwent intervention for recoarctation (balloon angioplasty [n = 26] and surgical repair of recoarctation [n = 4]), 26 (87%) have remained recurrence-free (follow-up = 133 patient-years; range 8 to 106 months, median 47).

CONCLUSIONS

The high frequency of recoarctation after cardiac transplantation with extended aortic arch reconstruction mandates serial echocardiographic evaluation of the aortic arch. Patients typically present with systemic hypertension within the first two years after transplantation. Balloon angioplasty is a safe, effective and durable method of treatment.