Objectives We sought to identify risk factors for mortality and morbidity during the Norwood hospitalization in newborn infants with hypoplastic left heart syndrome and other single right ventricle ...anomalies enrolled in the Single Ventricle Reconstruction trial. Methods Potential predictors for outcome included patient- and procedure-related variables and center volume and surgeon volume. Outcome variables occurring during the Norwood procedure and before hospital discharge or stage II procedure included mortality, end-organ complications, length of ventilation, and hospital length of stay. Univariate and multivariable Cox regression analyses were performed with bootstrapping to estimate reliability for mortality. Results Analysis included 549 subjects prospectively enrolled from 15 centers; 30-day and hospital mortality were 11.5% (63/549) and 16.0% (88/549), respectively. Independent risk factors for both 30-day and hospital mortality included lower birth weight, genetic abnormality, extracorporeal membrane oxygenation (ECMO) and open sternum on the day of the Norwood procedure. In addition, longer duration of deep hypothermic circulatory arrest was a risk factor for 30-day mortality. Shunt type at the end of the Norwood procedure was not a significant risk factor for 30-day or hospital mortality. Independent risk factors for postoperative renal failure (n = 46), sepsis (n = 93), increased length of ventilation, and hospital length of stay among survivors included genetic abnormality, lower center/surgeon volume, open sternum, and post-Norwood operations. Conclusions Innate patient factors, ECMO, open sternum, and lower center/surgeon volume are important risk factors for postoperative mortality and/or morbidity during the Norwood hospitalization.
Objective For infants with single ventricle malformations undergoing staged repair, interstage mortality is reported at 2% to 20%. The Single Ventricle Reconstruction trial randomized subjects with a ...single morphologic right ventricle undergoing a Norwood procedure to a modified Blalock–Taussig shunt (MBTS) or a right ventricle-to-pulmonary artery shunt (RVPAS). The aim of this analysis was to explore the associations of interstage mortality and shunt type, and demographic, anatomic, and perioperative factors. Methods Participants in the Single Ventricle Reconstruction trial who survived to discharge after the Norwood procedure were included (n = 426). Interstage mortality was defined as death postdischarge after the Norwood procedure and before the stage II procedure. Univariate analysis and multivariable logistic regression were performed adjusting for site. Results Overall interstage mortality was 50 of 426 (12%)—13 of 225 (6%) for RVPAS and 37 of 201 (18%) for MBTS (odds ratio OR for MBTS, 3.4; P < .001). When moderate to severe postoperative atrioventricular valve regurgitation (AVVR) was present, interstage mortality was similar between shunt types. Interstage mortality was independently associated with gestational age less than 37 weeks (OR, 3.9; P = .008), Hispanic ethnicity (OR, 2.6; P = .04), aortic atresia/mitral atresia (OR, 2.3; P = .03), greater number of post-Norwood complications (OR, 1.2; P = .006), census block poverty level ( P = .003), and MBTS in subjects with no or mild postoperative AVVR (OR, 9.7; P < .001). Conclusions Interstage mortality remains high at 12% and is increased with the MBTS compared with the RVPAS if postoperative AVVR is absent or mild. Preterm delivery, anatomic, and socioeconomic factors are also important. Avoiding preterm delivery when possible and close surveillance after Norwood hospitalization for infants with identified risk factors may reduce interstage mortality.
Abstract Objectives The study objective was to determine the predictors of new-onset arrhythmia among infants with single-ventricle anomalies during the post-Norwood hospitalization and the ...association of those arrhythmias with postoperative outcomes (ventilator time and length of stay) and interstage mortality. Methods After excluding patients with preoperative arrhythmias, we used data from the Pediatric Heart Network Single Ventricle Reconstruction Trial to identify risk factors for tachyarrhythmias (atrial fibrillation, atrial flutter, supraventricular tachycardia, junctional ectopic tachycardia, and ventricular tachycardia) and atrioventricular block (second or third degree) among 544 eligible patients. We then determined the association of arrhythmia with outcomes during the post-Norwood hospitalization and interstage period, adjusting for identified risk factors and previously published factors. Results Tachyarrhythmias were noted in 20% of subjects, and atrioventricular block was noted in 4% of subjects. Potentially significant risk factors for tachyarrhythmia included the presence of modified Blalock–Taussig shunt ( P = .08) and age at Norwood ( P = .07, with risk decreasing each day at age 8-20 days); the only significant risk factor for atrioventricular block was undergoing a concomitant procedure at the time of the Norwood ( P = .001), with the greatest risk being in those undergoing a tricuspid valve procedure. Both tachyarrhythmias and atrioventricular block were associated with longer ventilation time and length of stay ( P < .001 for all analyses). Tachyarrhythmias were not associated with interstage mortality; atrioventricular block was associated with mortality among those without a pacemaker in the unadjusted analysis (hazard ratio, 2.3; P = .02), but not after adding covariates. Conclusions Tachyarrhythmias are common after the Norwood procedure, but atrioventricular block may portend a greater risk for interstage mortality.
Structural deterioration of allografts over time is believed to be at least partly related to an immune response mounted against human leukocyte antigen specific to the transplanted tissue. ...SynerGraft (SG) processing (CryoLife, Kennesaw, GA) is a technology that decellularizes an allograft leaving only connective tissue, therefore, reducing immunogenicity and potentially increasing durability of the implant.
We performed a retrospective review of 163 SG patients and 124 standard allograft controls from 3 medical centers. Patient demographics were tabulated, and conduit stenosis and insufficiency were measured by echocardiography.
There were 28 deaths (15 of 163 9% SG patients vs 13 of 124 11% standard patients; p = 0.72), but no deaths were attributed to structural failure of the conduit. The actuarial survival for SG vs standard cohorts was not different at 5 and 10 years. Among the 274 hospital survivors, 17% SG vs 42% standard had evidence for significant conduit dysfunction at the most recent follow-up or before conduit replacement. Freedom from conduit dysfunction was significantly worse at 10 years in the standard group (58%) than in the SG group (83%, p < 0.001).
This study represents a multiinstitutional retrospective comparison of SG and standard cryopreserved allografts used in right ventricular outflow tract reconstruction in a broad range of patient ages. Our results demonstrate that at an intermediate-term to long-term follow-up, conduit dysfunction and pulmonary insufficiency and stenosis are higher among patients receiving standard allografts. We postulate that the improved durability of SG is related to decreased immunogenicity of the SG technology.
There are limited data regarding long-term outcomes after the Ross procedure in children. We evaluated mortality and reintervention in a large pediatric cohort.
A retrospective analysis of all ...patients aged younger than 18 years who underwent the Ross procedure at our institution (1991 to 2013) was conducted. Kaplan-Meier curves and Cox proportion hazard models were used to evaluate long-term outcomes and associated risk factors.
Included were 240 consecutive patients undergoing a Ross/Ross-Konno procedure: 18% infants, 48% children, and 33% adolescents. Infants were more likely to have complex left heart disease (p = 0.005). Overall survival to hospital discharge was 96%; infants had the highest mortality (18%). Long-term survival status was known for 99.6% (median follow-up, 10.7 years). Overall 15-year survival was 87% (lowest in infants, 72%; p = 0.003). Reintervention status was known in 87%. Overall 15-year freedom from any left ventricular outflow tract reintervention was 59%; 85% still had their autograft valve at the latest follow-up. Left ventricular outflow tract reintervention was uncommon in infants (n = 2). Overall 15-year freedom from right ventricular outflow tract reintervention was 53%, and was lower in infants (19%) than in children (51%) and adolescents (76%; p < 0.0001).
Outcomes after the Ross procedure in children vary by age. Infants more commonly have complex left heart disease and experience higher mortality but have excellent long-term autograft durability. Children and adolescents have higher rates of left ventricular outflow tract reintervention, whereas infants are at highest risk of right ventricular outflow tract reintervention.
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.
Objective The study objective was to identify factors associated with death and cardiac transplantation in infants undergoing the Norwood procedure and to determine differences in associations that ...might favor the modified Blalock–Taussig shunt or a right ventricle-to-pulmonary artery shunt. Methods We used competing risks methodology to analyze death without transplantation, cardiac transplantation, and survival without transplantation. Parametric time-to-event modeling and bootstrapping were used to identify independent predictors. Results Data from 549 subjects (follow-up, 2.7 ± 0.9 years) were analyzed. Mortality risk was characterized by early and constant phases; transplant was characterized by only a constant phase. Early phase factors associated with death included lower socioeconomic status ( P = .01), obstructed pulmonary venous return ( P < .001), smaller ascending aorta ( P = .02), and anatomic subtype. Constant phase factors associated with death included genetic syndrome ( P < .001) and lower gestational age ( P < .001). The right ventricle-to-pulmonary artery shunt demonstrated better survival in the 51% of subjects who were full term with aortic atresia ( P < .001). The modified Blalock–Taussig shunt was better among the 4% of subjects who were preterm with a patent aortic valve ( P = .003). Lower pre-Norwood right ventricular fractional area change, pre-Norwood surgery, and anatomy other than hypoplastic left heart syndrome were independently associated with transplantation (all P < .03), but shunt type was not ( P = .43). Conclusions Independent risk factors for intermediate-term mortality include lower socioeconomic status, anatomy, genetic syndrome, and lower gestational age. Term infants with aortic atresia benefited from a right ventricle-to-pulmonary artery shunt, and preterm infants with a patent aortic valve benefited from a modified Blalock–Taussig shunt. Right ventricular function and anatomy, but not shunt type, were associated with transplantation.
Objective To measure neurodevelopment at 3 years of age in children with single right-ventricle anomalies and to assess its relationship to Norwood shunt type, neurodevelopment at 14 months of age, ...and patient and medical factors. Study design All subjects in the Single Ventricle Reconstruction Trial who were alive without cardiac transplant were eligible for inclusion. The Ages and Stages Questionnaire (ASQ, n = 203) and other measures of behavior and quality of life were completed at age 3 years. Medical history, including measures of growth, feeding, and complications, was assessed through annual review of the records and phone interviews. The Bayley Scales of Infant Development, Second Edition (BSID-II) scores from age 14 months were also evaluated as predictors. Results Scores on each ASQ domain were significantly lower than normal ( P < .001). ASQ domain scores at 3 years of age varied nonlinearly with 14-month BSID-II. More complications, abnormal growth, and evidence of feeding, vision, or hearing problems were independently associated with lower ASQ scores, although models explained <30% of variation. Type of shunt was not associated with any ASQ domain score or with behavior or quality-of-life measures. Conclusion Children with single right-ventricle anomalies have impaired neurodevelopment at 3 years of age. Lower ASQ scores are associated with medical morbidity, and lower BSID-II scores but not with shunt type. Because only a modest percentage of variation in 3-year neurodevelopmental outcome could be predicted from early measures, however, all children with single right-ventricle anomalies should be followed longitudinally to improve recognition of delays.
Objectives The Single Ventricle Reconstruction trial randomized 555 subjects with a single right ventricle undergoing the Norwood procedure at 15 North American centers to receive either a modified ...Blalock-Taussig shunt or right ventricle-to-pulmonary artery shunt. Results demonstrated a rate of death or cardiac transplantation by 12 months postrandomization of 36% for the modified Blalock-Taussig shunt and 26% for the right ventricle-to-pulmonary artery shunt, consistent with other publications. Despite this high mortality rate, little is known about the circumstances surrounding these deaths. Methods There were 164 deaths within 12 months postrandomization. A committee adjudicated all deaths for cause and recorded the timing, location, and other factors for each event. Results The most common cause of death was cardiovascular (42%), followed by unknown cause (24%) and multisystem organ failure (7%). The median age at death for subjects dying during the 12 months was 1.6 months (interquartile range, 0.6 to 3.7 months), with the highest number of deaths occurring during hospitalization related to the Norwood procedure. The most common location of death was at a Single Ventricle Reconstruction trial hospital (74%), followed by home (13%). There were 29 sudden, unexpected deaths (18%), although in retrospect, 12 were preceded by a prodrome. Conclusions In infants with a single right ventricle undergoing staged repair, the majority of deaths within 12 months of the procedure are due to cardiovascular causes, occur in a hospital, and within the first few months of life. Increased understanding of the circumstances surrounding the deaths of these single ventricle patients may reduce the high mortality rate.
Objectives In the Single Ventricle Reconstruction trial, infants undergoing the Norwood procedure were randomly allocated to undergo a right ventricle-to-pulmonary artery shunt or a modified ...Blalock-Taussig shunt. Apart from shunt type, subjects received the local standard of care. We evaluated variation in perioperative care during the Norwood hospitalization across 14 trial sites. Methods Data on preoperative, operative, and postoperative variables for 546 enrolled subjects who underwent the Norwood procedure were collected prospectively on standardized case report forms, and variation across the centers was described. Results Gestational age, birth weight, and proportion with hypoplastic left heart syndrome were similar across sites. In contrast, all recorded variables related to preoperative care varied across centers, including fetal diagnosis (range, 55%-85%), preoperative intubation (range, 29%-91%), and enteral feeding. Perioperative and operative factors were also variable across sites, including median total support time (range, 74-189 minutes) and other perfusion variables, arch reconstruction technique, intraoperative medication use, and use of modified ultrafiltration (range, 48%-100%). Additional variation across centers was seen in variables related to postoperative care, including proportion with an open sternum (range, 35%-100%), median intensive care unit stay (range, 9-44 days), type of feeding at discharge, and enrollment in a home monitoring program (range, 1%-100%; 5 sites did not have a program). Overall, in-hospital death or transplant occurred in 18% (range across sites, 7%-39%). Conclusions Perioperative care during the Norwood hospitalization varies across centers. Further analysis evaluating the underlying causes and relationship of this variation to outcome is needed to inform future studies and quality improvement efforts.
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