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.

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.

Measurement of technical performance in surgery for congenital heart disease: the stage I Norwood procedure.

OBJECTIVE: No method of measuring technical performance exists for the stage I Norwood procedure. Hospital mortality is usually used as a surrogate for technical performance, but evidence is lacking to support this concept. A technical score was designed by expert consensus. METHODS: The technical score included the following steps: (1) Stage I was divided into subprocedures according to anatomic areas where an intervention is performed. (2) For each subprocedure, three score categories (optimal, adequate, and inadequate) were defined on the basis of echocardiography, catheterization, and/or clinical data. (3) Subprocedures were analyzed for the whole group and by surgeon. (4) Overall repair was also scored: optimal if all attempted subprocedures were optimal, inadequate if any was inadequate, and adequate for everything in between. (5) All patients undergoing the stage I procedure from January 2004 to December 2006 were retrospectively studied. RESULTS: One hundred ten patients were included (operated on by six surgeons), and 4 were excluded for lack of reliable postoperative data. Most subprocedures were scored as optimal. Subprocedures with the largest inadequate scores were distal arch reconstruction in 7 (6%) patients and aortopulmonary shunt in 3 (5%). No statistical differences were found among surgeons either by subprocedure or by overall outcome, although individual sample sizes were small. The overall score correlated with length of stay, extracorporeal membrane oxygenator support, and hospital mortality. CONCLUSIONS: Technical performance can be measured after the stage I procedure, and performance score correlates with early outcome. This score may also be useful as a self-assessment tool.

Design and rationale of a randomized trial comparing the Blalock-Taussig and right ventricle-pulmonary artery shunts in the Norwood procedure.

OBJECTIVE: The initial palliative procedure for patients born with hypoplastic left heart syndrome and related single right ventricle anomalies, the Norwood procedure, remains among the highest risk procedures in congenital heart surgery. The classic Norwood procedure provides pulmonary blood flow with a modified Blalock-Taussig shunt. Improved outcomes have been reported in a few small, nonrandomized studies of a modification of the Norwood procedure that uses a right ventricle-pulmonary artery shunt to provide pulmonary blood flow. Other nonrandomized studies have shown no differences between the two techniques. METHODS: The Pediatric Heart Network designed a randomized clinical trial to compare outcomes for subjects undergoing a Norwood procedure with either the right ventricle-pulmonary artery or modified Blalock-Taussig shunt. Infants with a diagnosis of single, morphologically right ventricle anomaly who are undergoing a Norwood procedure are eligible for inclusion in this study. The primary outcome is death or cardiac transplant 12 months after random assignment. Secondary outcomes include postoperative morbidity after Norwood and stage II palliation procedures, right ventricular function and pulmonary arterial growth at stage II palliation, and neurodevelopmental outcomes at 14 months old. Incidence of adverse events will also be compared between treatment groups. CONCLUSION: This study will make an important contribution to the care of patients with hypoplastic left heart syndrome and related forms of single, morphologically right ventricle. It also establishes a model with which other operative interventions for patients with congenital cardiovascular malformations can be evaluated in the future.

Measurement of technical performance in congenital heart surgery: a pilot study.

BACKGROUND: Although adequacy of repair after congenital heart surgery is a crucial determinant of clinical outcome, there is no current method of assessment. We sought to develop a process to measure the adequacy of repair for a diverse group of congenital heart procedures. METHODS: Selected surgical procedures, consisting of repair of ventricular septal defect (VSD), tetralogy of Fallot (TOF), complete common atrioventricular canal (CAVC), and arterial switch operation, were divided into component subprocedures, each of which was assessed separately. Three outcome categories of "optimal," "adequate," and "inadequate" were defined by consensus according to postprocedure echocardiographic assessment. Outcome categories for conduction disturbance were also created. All patients undergoing one of the four procedures in 2004 were identified, and each subprocedure was assessed. Other clinical data were obtained from medical records. Repairs were scored as "optimal" if all attempted subprocedures and conduction were optimal, and "inadequate" if any was inadequate. RESULTS: A total of 138 procedures were included. VSD repair was done in 46 patients (33%), TOF repair in 33 (24%), arterial switch operation in 36 (26%), and CAVC repair in 23 (17%). Optimal technical score was found in 28 (20%), adequate in 106 (77%), and inadequate in 4 (3%) (2 VSD, 1 TOF, 1 CAVC). Median length of stay was 8 days, and no patients died. CONCLUSIONS: Despite procedural diversity and complexity, technical adequacy of repair can be assessed for congenital heart surgery.