Extracorporeal life support: experience with 2,000 patients.

This is a review of the University of Michigan experience with extracorporeal life support (ECLS) also known as extracorporeal membrane oxygenation (ECMO). Two thousand patients were managed with ECMO from 1973 to 2010. The first 1,000 patients were reported previously. Of the 2,000 patients, 74% were weaned from ECLS, and 64% survived to hospital discharge. In patients with respiratory failure, survival to hospital discharge was 84% in 799 neonates, 76% in 239 children, and 50% in 353 adults. Survival in patients with cardiac failure was 45% in 361 children and 38% in 119 adults. ECLS during extracorporeal cardiopulmonary resuscitation was performed in 129 patients, with 41% surviving to discharge. Survival decreased from 74 to 55% between the first and second 1,000 patients. The most common complication was bleeding at sites other than the head, with an incidence of 39%, and the least frequent complication was pump malfunction, with a 2% incidence. Intracranial bleeding or infarction occurred in 8% of patients, with a 43% survival rate. This is the largest series of ECLS at one institution reported in the world to date. Our experience has shown that ECLS saves lives of moribund patients with acute pulmonary and cardiac failure in all age groups.

Utility of a clinical practice guideline in treatment of chylothorax in the postoperative congenital heart patient.

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

Contemporary outcomes in infants with congenital heart disease and bochdalek diaphragmatic hernia.

BACKGROUND: Fifteen percent of infants with congenital diaphragmatic hernia (CDH) are born with a coexisting cardiac anomaly. The purpose of this study was to evaluate contemporary outcomes in this patient population and to identify potential risk factors for in-hospital mortality. METHODS: Data from all CDH neonates with congenital heart disease managed at a single pediatric tertiary care referral center between 1997 and 2011 were retrospectively analyzed. RESULTS: Forty (18%) of 216 CDH patients had a cardiac anomaly. This group was associated with a significant decrease in overall survival when compared with patients without cardiac anomaly (55% versus 81%; p = 0.001). There was no association between type of cardiac anomaly and mortality based on risk stratification according to the Risk Adjustment for Congenital Heart Surgery and The Society of Thoracic Surgeons-European Association for Cardiothoracic Surgery scoring systems (p = 0.86 and p = 0.87, respectively). Birth weight was similarly no different between survivors and nonsurvivors (2.8 ± 0.6 kg versus 2.8 ± 0.9 kg, respectively; p = 0.98). There was a trend toward increased extracorporeal membrane oxygenation use among nonsurvivors (p = 0.13). Infants with hemodynamic stability enabling subsequent cardiac repair were associated with lower mortality (p = 0.04). Survivors had a wide spectrum of long-term morbidity, but most had some evidence of neurodevelopmental impairment. CONCLUSIONS: This large single-institution series suggests that the overall prognosis of infants with concomitant CDH and congenital heart disease can be quite variable, regardless of the type of heart anomaly. Hemodynamic instability and need for extracorporeal membrane oxygenation correlate with higher mortality. Although some long-term survivors have excellent outcomes, most suffer from chronic, long-term morbidities.

Use of a pressure guidewire to assess pulmonary artery band adequacy in the hybrid stage I procedure for high-risk neonates with hypoplastic left heart syndrome and variants.

OBJECTIVE: The hybrid stage I procedure is an alternative palliative strategy for patients with hypoplastic left heart syndrome who traditionally have undergone the Norwood operation. At our institution, the hybrid stage I procedure is employed only for patients with high operative risk. Our objective was to describe our use of a pressure guidewire during the hybrid stage I procedure to assess quantitatively pulmonary artery band adequacy. DESIGN: After reviewing the charts on all high-risk patients who underwent a hybrid stage I procedure at our institution, we compared two groups of patients: those who underwent the standard hybrid stage I palliation (standard cohort) and those with pressure wire-facilitated assessment of distal branch pulmonary artery pressure (pressure wire cohort) to evaluate the impact of pressure guidewire use on procedural risk, radiation time, patient outcomes, and need for reoperation for pulmonary artery band adjustment. RESULTS: The pressure guidewire was used in 8 of 14 patients at the time of hybrid stage I procedure and was successful and without complication in all attempts. In the standard cohort, 67% of patients needed reoperation for pulmonary artery band adjustment, compared to 12.5% of patients in the pressure wire cohort (P =.09). Procedure time, radiation exposure, and survival to hospital discharge were not different between groups. CONCLUSIONS: This novel use of a pressure guidewire to assess quantitatively pulmonary artery band adequacy at the time of placement is feasible, safe and may decrease the need for reoperation for pulmonary artery band adjustment.

Demographic characteristics and estimated prevalence of Fontan-associated plastic bronchitis.

Plastic bronchitis (PB) is a poorly understood disease that can complicate any underlying pulmonary disease. However, it appears to most often occur in patients with surgically palliated congenital heart disease, particularly after the Fontan procedure. Few data exist about the prevalence and etiology of PB in this population. In an effort to establish data about prevalence, we conducted a retrospective study of an existing Fontan surgery database (n = 654) comprised of data, including sex, age at date of surgery, alive/dead status, New York Heart Association classification at last follow-up, right-ventricular end-diastolic pressure and pulmonary artery pressure before Fontan surgery, and the presence of a Fontan fenestration. An initial medical record review of 173 patients in the database who were followed at the University of Michigan identified seven patients with PB resulting in an estimated prevalence of 4 %. Subsequently, 14 % of 211 surveyed patients reported that they presently expectorate mucus or fibrin plugs (casts). Demographic and clinical variables did not differ between patients with or without possible PB. Collectively, these findings suggest that Fontan patients presently with PB may range from 4 to 14 %, indicating potential under-diagnosis of the disease. There were no remarkable physical or hemodynamic indicators that differentiated patients with or without possible PB. These data also highlight the need for more elaborate, prospective studies to improve our understanding of PB pathogenesis so that more definitive diagnostic criteria for this devastating disease can be established and its prevalence more accurately determined.

Differential case ascertainment in clinical registry versus administrative data and impact on outcomes assessment for pediatric cardiac operations.

BACKGROUND: Administrative datasets are often used to assess outcomes and quality of pediatric cardiac programs; however their accuracy regarding case ascertainment is unclear. We linked patient data (2004-2010) from the Society of Thoracic Surgeons Congenital Heart Surgery (STS-CHS) Database (clinical registry) and the Pediatric Health Information Systems (PHIS) database (administrative database) from hospitals participating in both to evaluate differential coding/classification of operations between datasets and subsequent impact on outcomes assessment. METHODS: Eight individual benchmark operations and the Risk Adjustment in Congenital Heart Surgery, version 1 (RACHS-1) categories were evaluated. The primary outcome was in-hospital mortality. RESULTS: The cohort included 59,820 patients from 33 centers. There was a greater than 10% difference in the number of cases identified between data sources for half of the benchmark operations. The negative predictive value (NPV) of the administrative (versus clinical) data was high (98.8%-99.9%); the positive predictive value (PPV) was lower (56.7%-88.0%). Overall agreement between data sources in RACHS-1 category assignment was 68.4%. These differences translated into significant differences in outcomes assessment, ranging from an underestimation of mortality associated with truncus arteriosus repair by 25.7% in the administrative versus clinical data (7.01% versus 9.43%; p = 0.001) to an overestimation of mortality associated with ventricular septal defect (VSD) repair by 31.0% (0.78% versus 0.60%; p = 0.1). For the RACHS-1 categories, these ranged from an underestimation of category 5 mortality by 40.5% to an overestimation of category 2 mortality by 12.1%; these differences were not statistically significant. CONCLUSIONS: This study demonstrates differences in case ascertainment between administrative and clinical registry data for children undergoing cardiac operations, which translated into important differences in outcomes assessment.

Risk factors for surgical site infection in pediatric cardiac surgery patients undergoing delayed sternal closure.

OBJECTIVES: To determine the incidence of surgical site infections (SSIs) in congenital heart surgery (CHS) patients undergoing delayed sternal closure (DSC) and to evaluate risk factors for SSI. METHODS: A nested case-control study was performed within a cohort of CHS patients undergoing DSC at our institution between 2005 and 2009. Cases met 2008 Centers for Disease Control and Prevention criteria for SSI; control subjects were matched based on year of surgery. Uni- and multivariate logistic regressions were performed to identify SSI risk factors. RESULTS: Of 375 patients who underwent DSC, 43 (11%) developed an SSI. The analysis included 172 patients (43 cases, 129 controls); 118 (69%) were neonates, 80 (47%) had undergone Norwood procedure, and 150 (87%) had DSC initiated in the operating room. Case and control subjects were similar based on pre- and intraoperative characteristics. Duration of mechanical ventilation, intensive care unit and hospital length of stay, and mortality were significantly greater in patients with an SSI. Multiple periods of DSC, longer duration of DSC, greater dependence on parenteral nutrition, and extracorporeal membrane oxygenation were significantly associated with SSI in univariate analyses. Multivariate analysis demonstrated that multiple periods of DSC (adjusted odds ratio, 5.9; 95% confidence interval, 1.7-20.1) and extracorporeal membrane oxygenation (adjusted odds ratio, 2.9; 95% confidence interval, 1.1-7.6) remained independent risk factors for SSI. CONCLUSIONS: For CHS patients undergoing DSC, extracorporeal membrane oxygenation and multiple periods of DSC are independent risk factors for SSI. New strategies for prevention and prophylaxis of SSI may be indicated for these high-risk patients who have worse outcomes and greater health care resource utilization.

Outcomes of infants weighing three kilograms or less requiring extracorporeal membrane oxygenation after cardiac surgery.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) is the most common form of cardiac support for postcardiotomy cardiac failure in children. While its benefits have been thoroughly explored in infants weighing more than 3 kg, similar analyses are lacking in lower weight neonates. This single-center study investigated outcomes and risks for poor survival among infants weighing 3 kg or less. METHODS: A retrospective review of infants 3 kg or less who required postcardiotomy ECMO support was performed (January 1, 1999 to December 31, 2010). Primary outcome was 30-day survival after decannulation. Factors analyzed for association with poor outcome included demographics, cardiac anatomy, bypass and circulatory arrest times, total ECMO support time, postoperative lactate, inotrope use, and need for renal replacement therapy. RESULTS: During the study period, 64 patients weighing 3 kg or less required postcardiotomy ECMO. Median gestational age and age at ECMO initiation were 38 weeks (interquartile range, 36 to 39) and 7 days (interquartile range, 4 to 9), respectively, with median ECMO support time of 164 hours (interquartile range, 95 to 231). Overall 30-day survival after decannulation was 33%. Factors associated with poor outcome were longer duration of support (231 hours or more, 12% survival, versus less than 231 hours, 40% survival; p = 0.05) and renal replacement therapy (n = 36, survival 17% versus 54%; p = 0.002). Multivariable regression analysis identified renal replacement therapy as the only independent factor associated with poor survival (odds ratio 4.3, 95% confidence interval: 1.3 to 14.9, p = 0.02). CONCLUSIONS: For infants weighing 3 kg or less, 30-day survival after decannulation after cardiac ECMO is poor. Factors associated with poor prognosis were need for renal replacement therapy and longer duration of ECMO support. These findings may provide a useful guide for medical decision making among this unique, high-risk patient group.

Pattern of recovery for transient complete heart block after open heart surgery for congenital heart disease: duration alone predicts risk of late complete heart block.

Transient complete heart block (TCHB) is defined as complete interruption of atrioventricular conduction (AVC) after cardiac surgery followed by return of conduction. This study aimed to assess the risk for the development of late complete heart block (LCHB) after recovery of TCHB and to examine the electrocardiographic and electrophysiologic properties of the AVC system after TCHB. Of the 44 patients in this study who experienced TCHB, 37 recovered completely. Seven patients progressed from TCHB to intermittent CHB or LCHB requiring pacemaker implantation. Preoperative, early postoperative, and late postoperative electrocardiograms as well as postoperative atrial stimulation were obtained. The results showed that the median duration of TCHB was 5 days in the TCHB group compared with 9 days in the LCHB group (p = 0.01). All 37 subjects with TCHB recovered AVC within 12 days, but only two with LCHB did so (p = 0.02). The risk of LCHB for the patients with 7 days of postoperative TCHB or longer was 13 times greater than for the patients with fewer than 7 days of TCHB (p = 0.01). The median late postoperative PR interval was slightly but significantly longer in the LCHB group than in the TCHB group (p = 0.02). In contrast, the electrophysiologic properties between the two groups did not differ significantly. From those findings, we concluded that delayed recovery of AVC after surgical TCHB (≥7 days), but not electrophysiologic properties of recovered AVC assessed early in the postoperative period strongly, predicts risk of LCHB. Follow-up evaluation of AVC is particularly indicated for the delayed recovery group.

Protecting the infant brain during cardiac surgery: a systematic review.

Prevention of brain injury during congenital heart surgery has focused on intraoperative and perioperative neuroprotection and neuromonitoring. Many strategies have been adopted as "standard of care." However, the strength of evidence for these practices and the relationship to long-term outcomes are unknown. We performed a systematic review (January 1, 1990 to July 30, 2010) of neuromonitoring and neuroprotection strategies during cardiopulmonary bypass (CPB) in infants of age 1 year or less. Papers were graded individually and as thematic groups, assigning evidence-based medicine and American College of Cardiology/American Heart Association (ACC/AHA) level of evidence grades. Consensus scores were determined by adjudication. Literature search identified 527 manuscripts; 162 met inclusion criteria. Study designs were prospective observational cohort (53.7%), case-control (21.6%), randomized clinical trial (13%), and retrospective observational cohort (9.9%). Median sample size was 43 (range 3 to 2,481). Primary outcome was evidence of structural brain injury or functional disability (neuroimaging, electroencephalogram, formal neurologic examination, or neurodevelopmental testing) in 43%. Follow-up information was reported in only 29%. The most frequent level of evidence was evidence-based medicine level 4 (33.3%) or ACC/AHA class IIB: level B (42%). The only intervention with sufficient evidence to recommend "the procedure or treatment should be performed" was avoidance of extreme hemodilution during CPB. Data supporting use of current neuromonitoring and neuroprotective techniques are limited. The level of evidence is insufficient to support effectiveness of most of these strategies. Well-designed studies with correlation to clinical outcomes and long-term follow-up are needed to develop guidelines for neuromonitoring and neuroprotection during CPB in infants.

Effect of sex and race on outcome in patients undergoing congenital heart surgery: an analysis of the society of thoracic surgeons congenital heart surgery database.

BACKGROUND: Previous studies on the impact of race and sex on outcome in children undergoing cardiac operations were based on analyses of administrative claims data. This study uses clinical registry data to examine potential associations of sex and race with outcomes in congenital cardiac operations, including in-hospital mortality, postoperative length of stay (LOS), and complications. METHODS: The Society of Thoracic Surgeons Congenital Heart Surgery Database (STS-CHSD) was queried for patients younger than 18 years undergoing cardiac operations from 2007 to 2009. Preoperative, operative, and outcome data were collected on 20,399 patients from 49 centers. In multivariable analysis, the association of race and sex with outcome was examined, adjusting for patient characteristics, operative risk (Society of Thoracic Surgeons-European Association for Cardiothoracic Surgery [STAT] mortality category), and operating center. RESULTS: Median age at operation was 0.4 years (interquartile range 0.1-3.4 years), and 54.4% of patients were boys. Race/ethnicity included 54.9% white, 17.1% black, 16.4% Hispanic, and 11.7% "other." In adjusted analysis, black patients had significantly higher in-hospital mortality (odds ratio [OR], 1.67; 95% confidence interval [CI], 1.37-2.04; p<0.001) and complication rate (OR, 1.15; 95% CI, 1.04-1.26; p<0.01) in comparison with white patients. There was no significant difference in mortality or complications by sex. Girls had a shorter LOS than boys (-0.8 days; p<0.001), whereas black (+2.4 days; p<0.001) and Hispanic patients (0.9 days; p<0.01) had longer a LOS compared with white patients. CONCLUSIONS: These data suggest that black children have higher mortality, a longer LOS, and an increased complication rate. Girls had outcomes similar to those of boys but with a shorter LOS of almost a day. Further study of potential causes underlying these race and sex differences is warranted.

Junctional ectopic tachycardia after infant heart surgery: incidence and outcomes.

Junctional ectopic tachycardia (JET) is an arrhythmia observed almost exclusively after open heart surgery in children. Current literature on JET has not focused on patients at the highest risk of both developing and being negatively impacted by JET. The purpose of this study was to determine the overall incidence of JET in an infant patient cohort undergoing open cardiac surgery, to identify patient- and procedure-related factors associated with developing JET, and to assess the clinical impact of JET on patient outcomes. We performed a nested case-control study from the complete cohort of patients at our institution younger than 1 year of age who underwent open heart surgery between 2005 and 2010. JET patients were compared with an age matched control group undergoing open heart surgery without JET regarding potential risk factors and outcomes. The overall incidence of JET in infants after open cardiac surgery was 14.3 %. From multivariate analyses, complete repair of tetralogy of Fallot [adjusted odds ratio (AOR) 2.0, 95 % CI 1.12-3.57] and longer aortic cross clamp times (AOR 1.02, 95 % CI 1.01-1.03) increased the risk of developing JET. Patients with JET had longer length of intubation, intensive care unit stays, and total length of hospitalization, and were more likely to require extracorporeal membrane oxygenation support (13 vs. 4.3 %). JET is a common postoperative arrhythmia in infants after open heart operations. Both anatomic substrate and surgical procedure contribute to the overall risk of developing JET. Developing JET is associated with worse clinical outcomes.

Extended single-patch repair of supravalvar aortic stenosis: a simple and effective technique.

BACKGROUND: The optimal surgical procedure for repair of supravalvar aortic stenosis (SVAS) remains uncertain. Proponents of multisinus repair techniques suggest improved outcomes compared with the single-patch technique. We evaluated the outcomes after an extended single-patch technique for relief of SVAS. METHODS: A cross-sectional retrospective analysis was performed of all SVAS patients who underwent repair from 1996 to 2009. Patient, procedural, and hospital course data were obtained through a review of the medical records. At follow-up, patients were evaluated for residual SVAS gradient, valvar aortic stenosis, aortic insufficiency, and need for reintervention. RESULTS: Twenty-two patients (mean age, 2.4 ± 2.4 years) underwent repair of SVAS (discrete form, 59%). Mean preoperative peak gradient was 77 ± 27 mm Hg (range, 20 to 139 mm Hg). There were no hospital deaths. Median postoperative length of stay was 5 days (range, 3 to 68 days). Mean follow-up was 4.1 ± 3.5 years (range, 0.7 to 13 years). Follow-up Doppler echocardiography revealed a peak left ventricular outflow tract gradient of 10 ± 12 mm Hg (range, 0 to 41 mm Hg). No patient had significant valvar aortic stenosis or insufficiency. Two patients (9%) required catheter-based reintervention that was unrelated to the SVAS repair. CONCLUSIONS: This study demonstrates that a simple, extended single-patch technique for repair of SVAS provides excellent medium-term results. A durable reduction in gradient with low complication and recurrence rates can be achieved without the need for more complicated multisinus patch repairs.

Personnel and unit factors impacting outcome after cardiac arrest in a dedicated pediatric cardiac intensive care unit.

OBJECTIVE: To assess the impact of personnel and unit factors on outcome from cardiac arrest in a dedicated pediatric cardiac intensive care unit. DESIGN: Retrospective medical record review. SETTING: Dedicated cardiac intensive care unit at a quaternary academic children's hospital. PATIENTS: Children and young adults who had cardiac arrest while cared for in the pediatric cardiac intensive care unit from January 1, 2006, to December 31, 2008. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: One hundred two index cardiac arrests over a 3-yr period in our pediatric cardiac intensive care unit were reviewed. We defined successful resuscitation as either return of spontaneous circulation or successful cannulation to extracorporeal membrane oxygenation. Differences in resuscitation rates were assessed across categorical systems variables using logistic regression. The rate of successful resuscitation was 84% (return of spontaneous circulation 74%, extracorporeal membrane oxygenation 10%). Survival to hospital discharge was 48% for patients who had a cardiac arrest. 11% of arrests during the week and 31% during weekends (odds ratio 3.8; 95% confidence interval 1.2-11.5) were not successfully resuscitated. Unsuccessful resuscitation was significantly more likely when the primary nurse had <1 yr of experience in the pediatric cardiac intensive care unit (50% <1 yr vs. 13% >1 yr; odds ratio 6.8; confidence interval 1.5-31.0). Cardiac arrest on a weekend day and <1-yr pediatric cardiac intensive care unit nursing experience were also associated with unsuccessful resuscitation in a multivariable model. Resuscitation outcomes were similar when senior intensive care unit attending physicians were on-call at the time of arrest compared with other intensive care unit staff (17% unsuccessful vs. 15%; odds ratio 1.2; confidence interval 0.4-3.7). Arrests where the attending physician was present at the onset resulted in unsuccessful resuscitation 18% of the time vs. 14% for events where the attending was not present (odds ratio 1.3; confidence interval 0.5-3.9). CONCLUSIONS: Our data suggest that personnel and unit factors may impact outcome after cardiac arrest in a pediatric cardiac intensive care unit. Weekend arrests and less experience of the primary nurse were risk factors for unsuccessful resuscitation. Neither presence at arrest onset nor experience of the attending cardiac intensivist was associated with outcome.

Risk factor analysis for second-stage palliation of single ventricle anatomy.

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

Quality measures for congenital and pediatric cardiac surgery.

This article presents 21 "Quality Measures for Congenital and Pediatric Cardiac Surgery" that were developed and approved by the Society of Thoracic Surgeons (STS) and endorsed by the Congenital Heart Surgeons' Society (CHSS). These Quality Measures are organized according to Donabedian's Triad of Structure, Process, and Outcome. It is hoped that these quality measures can aid in congenital and pediatric cardiac surgical quality assessment and quality improvement initiatives.

Retrospective database research in pediatric cardiology and congenital heart surgery: an illustrative example of limitations and possible solutions.

BACKGROUND: Secondary use of data, whether from clinical information systems or registries, for carrying out clinical research in rare diseases is a common practice but is fraught with potential errors. We sought to elucidate some of the limitations of database research and describe possible solutions to overcome these limitations. METHODS: Using a disease model of a rare postsurgical outcome, we evaluated the ability of four different data sources to correctly identify patients who had that outcome both as individual databases and also when used in conjunction with each other. These results were compared with manual chart review. RESULTS: The sensitivity of the various databases to pick up a rare and specific outcome was poor (9.9%-37%), while the specificities were fairly good (91%-96.7%). By combining the databases, the sensitivity was increased to as much as 56.8% without a large decrease in the specificity (85.2%-91.6%). The electronic medical record (EMR) search engine had the highest sensitivity (96.9%) and a high specificity (89.3%) with a very high negative predictive value (99.4%). CONCLUSION: For rare and specific diseases or outcomes, a single data source search methodology can miss large numbers of patients and potentially bias study results. Combining overlapping databases can improve the ability to capture these rare diseases or outcomes. While chart review remains the most accurate way to obtain complete case capture, new tools like EMR search engines can facilitate the efficiency of this process without sacrificing search quality.

Prospective, longitudinal study of plastic bronchitis cast pathology and responsiveness to tissue plasminogen activator.

Plastic bronchitis (PB) is a rare disease that often occurs in patients with congenital heart disease (CHD) who have undergone staged single-ventricle palliation. It is characterized by the formation of rubbery "casts" in the airways. PB treatment frequently includes inhaled tissue plasminogen activator (tPA). However, the efficacy of tPA to reduce cast burden is unknown. This is further complicated by our lack of knowledge of cast composition. We obtained spontaneously expectorated PB casts from children (n = 4) with CHD and one adult patient with idiopathic PB. Pathological assessment was made from paraffin-preserved samples. Casts were treated with phosphate-buffered saline (PBS) or tPA. Cast response to tPA was assessed by changes in cast weight and the production of fibrin D-dimer. Independent of dose, tPA reduced cast weight compared with PBS-treatment (P = 0.001) and increased D-dimer levels. Histological staining showed that PB casts from all patients were composed of fibrin and contained notable numbers of lymphocytes. Cast composition did not change over time. Collectively, these data support that in our PB patients, casts are composed of fibrin and are responsive to tPA treatment. This makes inhaled tPA a potentially viable option for symptomatic relief of PB while we work to unravel the complexity of PB pathogenesis.

Population-based analysis of survival for hypoplastic left heart syndrome.

OBJECTIVE: To analyze survival patterns among infants with hypoplastic left heart syndrome (HLHS) in the State of Michigan. STUDY DESIGN: Cases of HLHS prevalent at live birth were identified and confirmed within the Michigan Birth Defects Registry from 1992 to 2005 (n=406). Characteristics of infants with HLHS were compared with a 10:1 random control sample. RESULTS: Compared with 4060 control subjects, the 406 cases of HLHS were more frequently male (62.6% vs 51.4%), born prematurely (<37 weeks gestation; 15.3% vs 8.7%), and born at low birth weight (LBW) (<2.5 kg; 16.0% vs 6.6%). HLHS 1-year survival rate improved over the study period (P=.041). Chromosomal abnormalities, LBW, premature birth, and living in a high poverty neighborhood were significantly associated with death. Controlling for neighborhood poverty, term infants versus preterm with HLHS or LBW were 3.2 times (95% CI: 1.9-5.3; P<.001) more likely to survive at least 1 year. Controlling for age and weight, infants from low-poverty versus high-poverty areas were 1.8 times (95% CI: 1.1-2.8; P=.015) more likely to survive at least 1 year. CONCLUSIONS: Among infants with HLHS in Michigan, those who were premature, LBW, had chromosomal abnormalities, or lived in a high-poverty area were at increased risk for early death.

Tricuspid valve repair in hypoplastic left heart syndrome.

Tricuspid valve regurgitation (TR) remains an obstacle for staged palliation of hypoplastic left heart syndrome (HLHS). Because previous results from our institution suggested that posterior leaflet obliteration (PLO) is effective in tricuspid valve repair (TVR), we preferentially used this method. This report analyzes the effect of this preference on repair success and patient survival. All HLHS patients with 3-4+ preoperative TR undergoing TVR between 2002 and 2007 were retrospectively analyzed. Clinical and echocardiographic data were used to determine outcomes. Seventy-one percent (17 of 24) of patients had success at early outcome; the remaining 29% experienced early failure. Sixty-three percent (15 of 24) of patients demonstrated success at late outcome. Early outcome status was found to be a predictor of late outcome status (OR 22.9, P = 0.0037). Overall survival was 71% (17 of 24). Survival could not be shown to be associated with early or late outcome status (odds ratio = 0.96). A preference for PLO was found to give improved, long-lasting results for HLHS patients. Success at immediate outcome was predictive of success with time. PLO has the advantage of being simple and reproducible and produces good outcomes in this challenging group. Continued follow-up will be necessary to confirm long-term outcomes.