Pathological antibody-mediated rejection in pediatric heart transplant recipients: Immunologic risk factors, hemodynamic significance, and outcomes

Biopsy-diagnosed pAMR has been observed in over half of pediatric HT recipients within 6 years of transplantation. We report the incidence and outcomes of pAMR at our center. All endomyocardial biopsies for all HT recipients transplanted between 2010 and 2015 were reviewed and classified using contemporary ISHLT guidelines. Graft dysfunction was defined as a qualitative decrement in systolic function by echocardiogram or an increase of ≥3 mm Hg in atrial filling pressure by direct measurement. Among 96 patients, pAMR2 occurred in 7 (7%) over a median follow-up period of 3.1 years, while no cases of pAMR3 occurred. A history of CHD, DSA at transplant, and elevated filling pressures were associated with pAMR2. Five-sixths (83%) of patients developed new C1q+ DSA at the time of pAMR diagnosis. There was a trend toward reduced survival, with 43% of patients dying within 2.3 years of pAMR diagnosis.

Haemodynamic profiles of children with end-stage heart failure

Aims

To evaluate associations between haemodynamic profiles and symptoms, end-organ function and outcome in children listed for heart transplantation.

Methods and results

Children <18 years listed for heart transplant between 1993 and 2013 with cardiac catheterization data [pulmonary capillary wedge pressure (PCWP), right atrial pressure (RAP), and cardiac index (CI)] in the Pediatric Heart Transplant Study database were included. Outcomes were New York Heart Association (NYHA)/Ross classification, renal and hepatic dysfunction, and death or clinical deterioration while on waitlist. Among 1059 children analysed, median age was 6.9 years and 46% had dilated cardiomyopathy. Overall, 58% had congestion (PCWP >15 mmHg), 28% had severe congestion (PCWP >22 mmHg), and 22% low cardiac output (CI < 2.2 L/min/m2). Twenty-one per cent met the primary outcome of death (9%) or clinical deterioration (12%). In multivariable analysis, worse NYHA/Ross classification was associated with increased PCWP [odds ratio (OR) 1.03, 95% confidence interval (95% CI) 1.01-1.07, P = 0.01], renal dysfunction with increased RAP (OR 1.04, 95% CI 1.01-1.08, P = 0.007), and hepatic dysfunction with both increased PCWP (OR 1.03, 95% CI 1.01-1.06, P < 0.001) and increased RAP (OR 1.09, 95% CI 1.06-1.12, P < 0.001). There were no associations with low output. Death or clinical deterioration was associated with severe congestion (OR 1.6, 95% CI 1.2-2.2, P = 0.002), but not with CI alone. However, children with both low output and severe congestion were at highest risk (OR 1.9, 95% CI 1.1-3.5, P = 0.03).

Conclusion

Congestion is more common than low cardiac output in children with end-stage heart failure and correlates with NYHA/Ross classification and end-organ dysfunction. Children with both congestion and low output have the highest risk of death or clinical deterioration.

Assessing Statewide All-Cause Future One-Year Mortality: Prospective Study With Implications for Quality of Life, Resource Utilization, and Medical Futility

Background

For many elderly patients, a disproportionate amount of health care resources and expenditures is spent during the last year of life, despite the discomfort and reduced quality of life associated with many aggressive medical approaches. However, few prognostic tools have focused on predicting all-cause 1-year mortality among elderly patients at a statewide level, an issue that has implications for improving quality of life while distributing scarce resources fairly.

Objective

Using data from a statewide elderly population (aged ≥65 years), we sought to prospectively validate an algorithm to identify patients at risk for dying in the next year for the purpose of minimizing decision uncertainty, improving quality of life, and reducing futile treatment.

Methods

Analysis was performed using electronic medical records from the Health Information Exchange in the state of Maine, which covered records of nearly 95% of the statewide population. The model was developed from 125,896 patients aged at least 65 years who were discharged from any care facility in the Health Information Exchange network from September 5, 2013, to September 4, 2015. Validation was conducted using 153,199 patients with same inclusion and exclusion criteria from September 5, 2014, to September 4, 2016. Patients were stratified into risk groups. The association between all-cause 1-year mortality and risk factors was screened by chi-squared test and manually reviewed by 2 clinicians. We calculated risk scores for individual patients using a gradient tree-based boost algorithm, which measured the probability of mortality within the next year based on the preceding 1-year clinical profile.

Results

The development sample included 125,896 patients (72,572 women, 57.64%; mean 74.2 [SD 7.7] years). The final validation cohort included 153,199 patients (88,177 women, 57.56%; mean 74.3 [SD 7.8] years). The c-statistic for discrimination was 0.96 (95% CI 0.93-0.98) in the development group and 0.91 (95% CI 0.90-0.94) in the validation cohort. The mortality was 0.99% in the low-risk group, 16.75% in the intermediate-risk group, and 72.12% in the high-risk group. A total of 99 independent risk factors (n=99) for mortality were identified (reported as odds ratios; 95% CI). Age was on the top of list (1.41; 1.06-1.48); congestive heart failure (20.90; 15.41-28.08) and different tumor sites were also recognized as driving risk factors, such as cancer of the ovaries (14.42; 2.24-53.04), colon (14.07; 10.08-19.08), and stomach (13.64; 3.26-86.57). Disparities were also found in patients’ social determinants like respiratory hazard index (1.24; 0.92-1.40) and unemployment rate (1.18; 0.98-1.24). Among high-risk patients who expired in our dataset, cerebrovascular accident, amputation, and type 1 diabetes were the top 3 diseases in terms of average cost in the last year of life.

Conclusions

Our study prospectively validated an accurate 1-year risk prediction model and stratification for the elderly population (≥65 years) at risk of mortality with statewide electronic medical record datasets. It should be a valuable adjunct for helping patients to make better quality-of-life choices and alerting care givers to target high-risk elderly for appropriate care and discussions, thus cutting back on futile treatment.

Association of dead space ventilation and prolonged ventilation after repair of tetralogy of Fallot with pulmonary atresia

BACKGROUND

We set out to determine whether patients with tetralogy of Fallot with pulmonary atresia and major aortopulmonary collateral arteries (TOF/PA/MAPCA) are at risk for elevated dead space ventilation fraction (VD/VT), and whether this is associated with prolonged mechanical ventilation. We hypothesized that elevated VD/VT (>20%) in the first 24 hours after unifocalization surgery is associated with increased risk for prolonged mechanical ventilation (>7 days).

METHODS

All patients with TOF/PA/MAPCA undergoing unifocalization surgery between January 2003 and December 2015 were included in this study. Average VD/VT was calculated over the first 24 hours after surgery. Demographic and surgical data were collected. Outcome data included duration of mechanical ventilation. Patients were separated into 2 groups: elevated VD/VT and normal DVSF. Groups were compared using the Student t test, Wilcoxon rank-sum test, and χ² test. Univariable and multivariable regression analyses were performed with VD/VT as a continuous variable to test for association.

RESULTS

Of the 265 included patients, 127 (48%) had an elevated VD/VT. The 2 groups did not differ significantly in any demographic characteristic. Patients with an elevated VD/VT had longer cardiopulmonary bypass times (P = .03), were more likely to have delayed sternal closure, and more likely to have prolonged respiratory failure (odds ratio, 2.2; 95% confidence interval, 1.2-4.0; P = .007). The percent VD/VT was associated with duration of mechanical ventilation in univariable (P < .001) and multivariable (P < .001) regression analyses when controlled for age, weight and bypass time.

CONCLUSIONS

Elevated postoperative VD/VT is associated with prolonged mechanical ventilation in patients with TOF/PA/MAPCA following unifocalization. Elevated postoperative VD/VT may be an early indicator of patients who will require prolonged duration of mechanical ventilation, allowing optimization of medical management to promote better outcomes.

Longitudinal Assessment of the Doppler-Estimated Maximum Gradient in Patients With Congenital Valvar Aortic Stenosis Pre- and Post-Balloon Valvuloplasty

BACKGROUND

Aortic stenosis has been reported to manifest a slow rate of progression in mild disease, with a greater likelihood of progression in patients with moderate-severe disease. The natural history of the Doppler-estimated maximum gradient (DEMG) in patients after balloon aortic valvuloplasty (BAVP) has not previously been studied on a large scale.

METHODS AND RESULTS

A retrospective review was performed of 360 patients from 1984 to 2012 with aortic stenosis, providing a total of 2059 echocardiograms both before and after BAVP. Patients were excluded if they had an intervention within the first 30 days of life. The relationships between the aortic stenosis DEMG and several predictors (age at initial study, body surface area, valve morphology, and initial DEMG) were explored using linear mixed effect models. Patients with a unicommissural aortic valve had a significantly higher rate of progression compared with those with a bicommissural aortic valve (0.81 and 0.45 mm Hg/year; P<0.001). The median rate of progression in the post-BAVP group was significantly lower than the median pre-BAVP rate of progression (n=34; pre-BAVP 3.97 [1.69-8.7] mm Hg/year; post-BAVP 0.40 [-1.80 to 3.88] mm Hg/year; P<0.008). When adjusted for body surface area, there was no significant increase in the DEMG (-0.03 mm Hg/m² per year; P<0.001).

CONCLUSIONS

There is a statistically significant increase in the DEMG over time in patients with aortic stenosis. After balloon dilation, the DEMG rate of change is reduced compared with that pre-dilation. Given the effect of body surface area on DEMG progression, more frequent observation should be made during periods of rapid somatic growth.

Anesthetic Management During Surgery for Tetralogy of Fallot With Pulmonary Atresia and Major Aortopulmonary Collateral Arteries

Tetralogy of Fallot with pulmonary atresia and major aortopulmonary collaterals (TOF/PA/MAPCAs) is a heterogeneous disease with varying degrees of severity, requiring complex anesthetic management. Our institution has adopted the approach of early complete repair with incorporation of all lung segments, extensive lobar and branch segmental pulmonary artery reconstruction, and ventricular septal defect closure. While the surgical management of TOF/PA/MAPCAs has been extensively described and varies depending on the institution, there is a paucity of literature on the anesthetic management for such procedures. Herein, we describe our anesthetic management based on our own institution’s surgical approach at Lucile Packard Children’s Hospital/Stanford University.

Outcomes of Transcatheter Tricuspid Valve-in-Valve Implantation in Patients With Ebstein Anomaly

We sought to describe the acute results and short- to medium-term durability of transcatheter tricuspid valve-in-valve (TVIV) implantation within surgical bioprostheses among patients with Ebstein anomaly (EA). Cases were identified from a voluntary, multicenter, international registry of 29 institutions that perform TVIV. Demographic, clinical, procedural, and follow-up data were analyzed. Eighty-one patients with EA underwent TVIV from 2008 to 2016. Thirty-four patients (42%) were New York Heart Association (NYHA) class 3/4 at time of TVIV. The most common indication for TVIV was the presence of moderate or severe tricuspid regurgitation (40%). Most patients received a Melody valve (64%). TVIV was ultimately successful in all patients, and there was no procedural mortality. Four patients (5%) developed acute valve thrombosis, 4 patients (5%) developed endocarditis, and 9 patients (11%) developed valve dysfunction not related to thrombosis or endocarditis. Eight patients (10%) underwent reintervention (2 transcatheter, 6 surgical) due to thrombosis (3), endocarditis (2), other valve dysfunction (2), and patient-prosthesis mismatch without valve dysfunction (1). Among 69 patients who were alive without reintervention at latest follow-up, 96% of those with NYHA status reported were class 1/2, a significant improvement from baseline (62% NYHA class 1/2, p <0.001). In conclusion, transcatheter TVIV offers a low-risk, minimally invasive alternative to surgical tricuspid valve re-replacement in patients with EA and a failing tricuspid valve bioprosthesis.

Bronchoscopy in children with tetralogy of fallot, pulmonary atresia, and major aortopulmonary collaterals

OBJECTIVE

Children with Tetralogy of Fallot, Pulmonary Atresia, and Major Aortopulmonary Collaterals (TOF/PA/MAPCAs) undergoing unifocalization surgery are at risk for developing more postoperative respiratory complications than children undergoing other types of congenital heart surgery. Bronchoscopy is used in the perioperative period for diagnostic and therapeutic purposes. In this study, we describe bronchoscopic findings and identify factors associated with selection for bronchoscopy.

DESIGN

Retrospective case-control.

PATIENTS AND METHODS

All patients with TOF/PA/MAPCAs who underwent unifocalization surgery from September 2005 through March 2016 were included. Patients who underwent bronchoscopy in the perioperative period were compared to a randomly selected cohort of 172 control patients who underwent unifocalization without bronchoscopy during the study period.

RESULTS

Forty-three children underwent perioperative bronchoscopy at a median of 9 days postoperatively. Baseline demographics were similar in bronchoscopy patients and controls. Patients who underwent bronchoscopy were more likely to have a chromosome 22q11 deletion and were more likely have undergone unifocalization surgery without intracardiac repair. These patients had a longer duration of mechanical ventilation, ICU duration, and length of hospitalization. Abnormalities were detected on bronchoscopy in 35 patients (81%), and 20 (35%) of bronchoscopy patients underwent a postoperative intervention related to abnormalities identified on bronchoscopy.

CONCLUSION

Bronchoscopy is a useful therapeutic and diagnostic instrument for children undergoing unifocalization surgery, capable of identifying abnormalities leading to an additional intervention in over one third of patients. Special attention should be given to children with a 22q11 deletion to expedite diagnosis and intervention for possible airway complications.

Cerebral Oxygen Saturation in Children With Congenital Heart Disease and Chronic Hypoxemia

BACKGROUND

Increased hemoglobin (Hb) concentration accompanying hypoxemia is a compensatory response to maintain tissue oxygen delivery. Near infrared spectroscopy (NIRS) is used clinically to detect abnormalities in the balance of cerebral tissue oxygen delivery and consumption, including in children with congenital heart disease (CHD). Although NIRS-measured cerebral tissue O2 saturation (ScO2) correlates with arterial oxygen saturation (SaO2), jugular bulb O2 saturation (SjbO2), and Hb, little data exist on the interplay between these factors and cerebral O2 extraction (COE). This study investigated the associations of ScO2 and ΔSaO2-ScO2 with SaO2 and Hb and verified the normal range of ScO2 in children with CHD.

METHODS

Children undergoing cardiac catheterization for CHD were enrolled in a calibration and validation study of the FORE-SIGHT NIRS monitor. Two pairs of simultaneous arterial and jugular bulb samples were drawn for co-oximetry, calculation of a reference ScO2 (REF CX), and estimation of COE. Pearson correlation and linear regression were used to determine relationships between O2 saturation parameters and Hb. Data were also analyzed according to diagnostic group defined as acyanotic (SaO2 ≥ 90%) and cyanotic (SaO2 < 90%).

RESULTS

Of 65 children studied, acceptable jugular bulb samples (SjbO2 absolute difference between samples ≤10%) were obtained in 57 (88%). The ΔSaO2-SjbO2, ΔSaO2-ScO2, and ΔSaO2-REF CX were positively correlated with SaO2 and negatively correlated with Hb (all P < .001). Although by diagnostic group ScO2 differed statistically (P = .002), values in the cyanotic patients were within the range considered normal (69% ± 6%). COE estimated by the difference between arterial and jugular bulb O2 content (ΔCaO2-CjbO2, mL O2/100 mL) was not different for cyanotic and acyanotic patients (P = .10), but estimates using ΔSaO2-SjbO2, ΔSaO2-ScO2, or ΔSaO2-ScO2/SaO2 were significantly different between the cyanotic and acyanotic children (P < .001).

CONCLUSIONS

Children with adequately compensated chronic hypoxemia appear to have ScO2 values within the normal range. The ΔSaO2-ScO2 is inversely related to Hb, with the implication that in the presence of reduced Hb, particularly if coupled with a decreased cardiac output, the ScO2 can fall to values associated with brain injury in laboratory studies.

Estimating One-Year Risk of Incident Chronic Kidney Disease: Retrospective Development and Validation Study Using Electronic Medical Record Data From the State of Maine

Background

Chronic kidney disease (CKD) is a major public health concern in the United States with high prevalence, growing incidence, and serious adverse outcomes.

Objective

We aimed to develop and validate a model to identify patients at risk of receiving a new diagnosis of CKD (incident CKD) during the next 1 year in a general population.

Methods

The study population consisted of patients who had visited any care facility in the Maine Health Information Exchange network any time between January 1, 2013, and December 31, 2015, and had no history of CKD diagnosis. Two retrospective cohorts of electronic medical records (EMRs) were constructed for model derivation (N=1,310,363) and validation (N=1,430,772). The model was derived using a gradient tree-based boost algorithm to assign a score to each individual that measured the probability of receiving a new diagnosis of CKD from January 1, 2014, to December 31, 2014, based on the preceding 1-year clinical profile. A feature selection process was conducted to reduce the dimension of the data from 14,680 EMR features to 146 as predictors in the final model. Relative risk was calculated by the model to gauge the risk ratio of the individual to population mean of receiving a CKD diagnosis in next 1 year. The model was tested on the validation cohort to predict risk of CKD diagnosis in the period from January 1, 2015, to December 31, 2015, using the preceding 1-year clinical profile.

Results

The final model had a c-statistic of 0.871 in the validation cohort. It stratified patients into low-risk (score 0-0.005), intermediate-risk (score 0.005-0.05), and high-risk (score ≥ 0.05) levels. The incidence of CKD in the high-risk patient group was 7.94%, 13.7 times higher than the incidence in the overall cohort (0.58%). Survival analysis showed that patients in the 3 risk categories had significantly different CKD outcomes as a function of time (P<.001), indicating an effective classification of patients by the model.

Conclusions

We developed and validated a model that is able to identify patients at high risk of having CKD in the next 1 year by statistically learning from the EMR-based clinical history in the preceding 1 year. Identification of these patients indicates care opportunities such as monitoring and adopting intervention plans that may benefit the quality of care and outcomes in the long term.

Impact of the 18th birthday on waitlist outcomes among young adults listed for heart transplant: A regression discontinuity analysis

BACKGROUND

Patients listed for heart transplant after their 18th birthday purportedly wait longer to receive a donor heart compared with patients listed before their 18th birthday. It is unclear whether there is an actual difference in wait times and whether any difference in wait time is associated with lower likelihood of transplant and/or higher risk of mortality.

METHODS

Organ procurement and transplant network data were used to identify all patients listed for heart transplant between 2006 and 2014 within a 1-year period before and after their 18th birthday. The primary study end-point was the waiting time to receive a donor heart. Secondary end-points included the probability of transplant and waitlist mortality. Regression discontinuity analysis was used to analyze the effect of age on either side of the sharp cut-off value of age 18 years (6,574 days of life), when allocation of donor hearts transitions from the pediatric to adult allocation system.

RESULTS

A total of 360 patients met the study inclusion criteria, including 207 (57.5%) listed during the 12-month period before their 18th birthday under the pediatric allocation system, and 153 (42.5%) listed during the 12 months after their 18th birthday under the adult allocation system. The pediatric cohort was more likely to be listed Status 1A. Otherwise, the 2 groups shared similar baseline characteristics. Overall, patients listed after their 18th birthday waited 8.5 months longer to receive a transplant than adolescents listed before their 18th birthday (p = 0.01) and had a 47% lower probability of receiving a transplant (p = 0.001), but there was no difference in waitlist mortality (p = 0.37).

CONCLUSIONS

Patients listed for heart transplant shortly after their 18th birthday have significantly longer wait-times compared with patients listed shortly before their 18th birthday and a lower probability of transplant, but no significant difference in waitlist mortality. For medically fragile adolescents at high risk of death, birth date may be a relevant factor in the timing of heart transplant listing.

Programmatic Approach to Management of Tetralogy of Fallot With Major Aortopulmonary Collateral Arteries

Background—

Tetralogy of Fallot with major aortopulmonary collateral arteries is a complex and heterogeneous condition. Our institutional approach to this lesion emphasizes early complete repair with the incorporation of all lung segments and extensive lobar and segmental pulmonary artery reconstruction.

Methods and Results—

We reviewed all patients who underwent surgical intervention for tetralogy of Fallot and major aortopulmonary collateral arteries at Lucile Packard Children’s Hospital Stanford (LPCHS) since November 2001. A total of 458 patients underwent surgery, 291 (64%) of whom underwent their initial procedure at LPCHS. Patients were followed for a median of 2.7 years (mean 4.3 years) after the first LPCHS surgery, with an estimated survival of 85% at 5 years after first surgical intervention. Factors associated with worse survival included first LPCHS surgery type other than complete repair and Alagille syndrome. Of the overall cohort, 402 patients achieved complete unifocalization and repair, either as a single-stage procedure (n=186), after initial palliation at our center (n=74), or after surgery elsewhere followed by repair/revision at LPCHS (n=142). The median right ventricle:aortic pressure ratio after repair was 0.35. Estimated survival after repair was 92.5% at 10 years and was shorter in patients with chromosomal anomalies, older age, a greater number of collaterals unifocalized, and higher postrepair right ventricle pressure.

Conclusions—

Using an approach that emphasizes early complete unifocalization and repair with incorporation of all pulmonary vascular supply, we have achieved excellent results in patients with both native and previously operated tetralogy of Fallot and major aortopulmonary collateral arteries.

A multicenter study of the impella device for mechanical support of the systemic circulation in pediatric and adolescent patients

OBJECTIVES

The objective was to review the use of Impella devices (Abiomed Inc, Danvers, MA) for temporary circulatory support in pediatric and adolescent patients (age ≤ 21 yrs).

BACKGROUND

Options for minimally invasive circulatory support in children are limited, and published data are confined to case reports and small case series.

METHODS

This was a retrospective, multicenter review of Impella implants in pediatric and adolescent patients from 2009-15, using standardized data collection and INTERMACS definitions.

RESULTS

A total of 39 implants were performed in 38 patients from 16 centers. Median age and weight were 16 yrs (4-21 yrs) and 62 kg (15-134 kg). The primary indication for implant was cardiogenic shock in 28 patients (72%). Cardiac allograft rejection, myocarditis, or cardiomyopathy were the underlying diagnosis in 23 patients (59%); 11 patients had congenital heart disease. The median duration of support was 45 hr (1-1224 hr). Indications for explant included ventricular recovery in 16 patients, transition to another device in 12, death in 5, and transplant in 1. Survival was 85% at 7 days and 68% at 30 days. Major adverse events occurred in 8 patients: hemolysis in 3, bleeding in 2, stroke in 1 (unclear if related to Impella), sepsis in 1, and critical leg ischemia in 1. An increase in aortic regurgitation was noted in three patients, with no evidence of valve injury.

CONCLUSION

Temporary circulatory support with Impella devices is feasible in pediatric and adolescent patients, with acceptable risk profiles. More experience and follow up is needed to improve technical performance and patient selection. © 2017 Wiley Periodicals, Inc.

Functional status of United States children supported with a left ventricular assist device at heart transplantation

BACKGROUND

As survival with pediatric left ventricular assist devices (LVADs) has improved, decisions regarding the optimal support strategy may depend more on quality of life and functional status (FS) rather than mortality alone. Limited data are available regarding the FS of children supported with LVADs. We sought to compare the FS of children supported with LVADs vs vasoactive infusions to inform decision making around support strategies.

METHODS

Organ Procurement and Transplant Network data were used to identify all United States children aged between 1 and 21 years at heart transplant (HT) between 2006 and 2015 for dilated cardiomyopathy and supported with an LVAD or vasoactive infusions alone at HT. FS was measured using the 10-point Karnofsky and Lansky scale.

RESULTS

Of 701 children who met the inclusion criteria, 430 (61%) were supported with vasoactive infusions, and 271 (39%) were supported with an LVAD at HT. Children in the LVAD group had higher median FS scores at HT than children in the vasoactive infusion group (6 vs 5, p < 0.001) but lower FS scores at listing (4 vs 6, p < 0.001). The effect persisted regardless of patient location at HT (home, hospital, intensive care) or device type. Discharge by HT occurred in 46% of children in the LVAD group compared with 26% of children in the vasoactive infusion cohort (p = 0.001). Stroke was reported at HT in 3% of children in the LVAD cohort and in 1% in the vasoactive infusion cohort (p = 0.04).

CONCLUSIONS

Among children with dilated cardiomyopathy undergoing HT, children supported with LVADs at HT have higher FS than children supported with vasoactive infusions at HT, regardless of device type or hospitalization status. Children supported with LVADs at HT were more likely to be discharged from the hospital but had a higher prevalence of stroke at HT.

Rehospitalization after pediatric heart transplantation: Incidence, indications, and outcomes

We report the patterns of rehospitalization after pediatric heart transplant (Htx) at a single center. Retrospective review of 107 consecutive pediatric Htx recipients between January 22, 2007, and August 28, 2014, who survived their initial transplant hospitalization. The frequency, duration, and indications for all hospitalizations between transplant hospitalization discharge and September 30, 2015, were analyzed. A total of 444 hospitalization episodes occurred in 90 of 107 (84%) patients. The median time to first rehospitalization was 59.5 (range 1-1526) days, and the median length of stay was 2.5 (range 0-81) days. There were an average of two hospitalizations per patient in the first year following transplant hospitalization, declining to about 0.8 per patient per year starting at 3 years post-transplant. Admissions for viral infections were most common, occurring in 93 of 386 (24%), followed by rule out sepsis in 61 of 386 (16%). Admissions for suspected or confirmed rejection were less frequent, accounting for 41 of 386 (11%) and 31 of 386 (8%) of all admissions, respectively. Survival to discharge after rehospitalization was 97%. Hospitalization is common after pediatric Htx, particularly in the first post-transplant year, with the most frequent indications for hospitalization being viral illness and rule out sepsis. After the first post-transplant year, the risk for readmission falls significantly but remains constant for several years.

Practice Patterns in Postoperative Echocardiographic Surveillance after Congenital Heart Surgery in Children: A Single Center Experience

OBJECTIVES

To review current institutional practice and describe factors contributing to variation in inpatient postoperative imaging surveillance after congenital heart surgery.

STUDY DESIGN

We reviewed records of all children who underwent congenital heart surgery from June to December 2014. Number and primary indications for postoperative transthoracic echocardiograms (TTEs), providers involved, cardiovascular intensive care unit (CVICU) and total hospital length of stay, and Risk-Adjustment for Congenital Heart Surgery-1 scores were recorded.

RESULTS

A total of 253 children (age at surgery: 8 months [2 days-19 years]) received 556 postoperative TTEs (median 1 TTE/patient [1-14]), and 23% had ≥3 TTEs. Fifteen of 556 TTEs (2.7%) revealed a new abnormal finding. The majority of TTEs (59%) were performed in the CVICU (1.5 ± 1.1 TTEs/week/patient), with evaluation of function as the most common indication (44%). Attending physician practice >10 years was not associated with fewer TTEs (P = .12). Patients with ≥3 TTEs had higher Risk-Adjustment for Congenital Heart Surgery-1 scores (P = .001), longer CVICU lengths of stay (22 vs 3 days; P < .0001), longer overall hospitalizations (28 vs 7 days; P < .0001), and a higher incidence of mechanical circulatory support (10% vs 0%; P < .0001) than those with <3 TTEs. Eight patients with ≥3 TTEs did not survive, compared with 3 with <3 TTEs (P = .0004).

CONCLUSIONS

There was wide intra-institutional variation in echocardiographic use among similar complexity surgeries. Frequency of postoperative echocardiographic surveillance was associated with degree of surgical complexity and severity of postoperative clinical condition. Few studies revealed new abnormal findings. These results may help establish evidence-based guidelines for inpatient echocardiographic surveillance after congenital heart surgery.

Utility and Scope of Rapid Prototyping in Patients with Complex Muscular Ventricular Septal Defects or Double-Outlet Right Ventricle: Does it Alter Management Decisions?

Rapid prototyping facilitates comprehension of complex cardiac anatomy. However, determining when this additional information proves instrumental in patient management remains a challenge. We describe our experience with patient-specific anatomic models created using rapid prototyping from various imaging modalities, suggesting their utility in surgical and interventional planning in congenital heart disease (CHD). Virtual and physical 3-dimensional (3D) models were generated from CT or MRI data, using commercially available software for patients with complex muscular ventricular septal defects (CMVSD) and double-outlet right ventricle (DORV). Six patients with complex anatomy and uncertainty of the optimal management strategy were included in this study. The models were subsequently used to guide management decisions, and the outcomes reviewed. 3D models clearly demonstrated the complex intra-cardiac anatomy in all six patients and were utilized to guide management decisions. In the three patients with CMVSD, one underwent successful endovascular device closure following a prior failed attempt at transcatheter closure, and the other two underwent successful primary surgical closure with the aid of 3D models. In all three cases of DORV, the models provided better anatomic delineation and additional information that altered or confirmed the surgical plan. Patient-specific 3D heart models show promise in accurately defining intra-cardiac anatomy in CHD, specifically CMVSD and DORV. We believe these models improve understanding of the complex anatomical spatial relationships in these defects and provide additional insight for pre/intra-interventional management and surgical planning.

Risk Estimates for Atherosclerotic Cardiovascular Disease in Adults With Congenital Heart Disease

The adult with congenital heart disease (CHD) is at risk of developing atherosclerotic cardiovascular disease (ASCVD). We performed a cross-sectional study to describe established ASCVD risk factors and estimate 10-year and lifetime risk of ASCVD in adults over age 18 with CHD of moderate or great complexity using 3 validated risk assessment tools-the Framingham Study Cardiovascular Disease Risk Assessment, the Reynolds Risk Score, and the ASCVD Risk Estimator. We obtained extensive clinical and survey data on 178 enrolled patients, with average age 37.1 ± 12.6 years, 51% men. At least 1 modifiable ASCVD risk factor was present in 70%; the 2 most common were overweight/obesity (53%) and systemic hypertension (24%). Laboratory data were available in 103 of the 178 patients. Abnormal levels of glycated hemoglobin, high-sensitivity C-reactive protein, and high-density lipoprotein were each found in around 30% of patients. The 10-year ASCVD predicted risk using all 3 tools was relatively low (i.e., at least 90% of patients <10% risk), yet the median estimated lifetime risk was 36%. In conclusion, ASCVD risk factors are prevalent in adults with CHD. The risk estimation tools suggest that this population is particularly vulnerable to ASCVD with aging and should undergo guideline-based screening and management of modifiable risk factors.

Web-based Real-Time Case Finding for the Population Health Management of Patients With Diabetes Mellitus: A Prospective Validation of the Natural Language Processing-Based Algorithm With Statewide Electronic Medical Records

Background

Diabetes case finding based on structured medical records does not fully identify diabetic patients whose medical histories related to diabetes are available in the form of free text. Manual chart reviews have been used but involve high labor costs and long latency.

Objective

This study developed and tested a Web-based diabetes case finding algorithm using both structured and unstructured electronic medical records (EMRs).

Methods

This study was based on the health information exchange (HIE) EMR database that covers almost all health facilities in the state of Maine, United States. Using narrative clinical notes, a Web-based natural language processing (NLP) case finding algorithm was retrospectively (July 1, 2012, to June 30, 2013) developed with a random subset of HIE-associated facilities, which was then blind tested with the remaining facilities. The NLP-based algorithm was subsequently integrated into the HIE database and validated prospectively (July 1, 2013, to June 30, 2014).

Results

Of the 935,891 patients in the prospective cohort, 64,168 diabetes cases were identified using diagnosis codes alone. Our NLP-based case finding algorithm prospectively found an additional 5756 uncodified cases (5756/64,168, 8.97% increase) with a positive predictive value of .90. Of the 21,720 diabetic patients identified by both methods, 6616 patients (6616/21,720, 30.46%) were identified by the NLP-based algorithm before a diabetes diagnosis was noted in the structured EMR (mean time difference = 48 days).

Conclusions

The online NLP algorithm was effective in identifying uncodified diabetes cases in real time, leading to a significant improvement in diabetes case finding. The successful integration of the NLP-based case finding algorithm into the Maine HIE database indicates a strong potential for application of this novel method to achieve a more complete ascertainment of diagnoses of diabetes mellitus.

Progressive intermediate-term improvement in ventricular and atrioventricular interaction after transcatheter pulmonary valve replacement in patients with right ventricular outflow tract obstruction

BACKGROUND

Relief of postoperative right ventricular outflow tract (RVOT) obstruction with transcatheter pulmonary valve replacement (TPVR) results in functional improvement in the short term which we investigated at baseline (BL), early follow-up (FU), and midterm FU after TPVR.

METHODS

Echocardiography and cardiopulmonary exercise testing were performed at BL and at early (median 6 months) and midterm FU (median 2.5years) after TPVR.

RESULTS

Patients with RVOT obstruction (n=22, median age 17years) were studied. The max RVOT Doppler gradient fell from BL to early FU (60±24 to 26±8mm Hg, P<.001). Left ventricular (LV) end-diastolic and stroke volume increased at early FU (both P<.001) without further change, whereas LV ejection fraction improved throughout FU (P<.001). LV end-systolic and diastolic eccentricity (leftward septal displacement) improved early (both P≤.003), and end-diastolic eccentricity improved further at midterm FU (P=.02). Furthermore, whereas mitral inflow A wave velocity increased (P=.003), the LV A' velocity declined early (P=.007) without further change at midterm. RV systolic and early diastolic function was impaired at BL. Whereas RV strain improved partially at early and midterm FU (P≤.02), RV E' velocity did not improve throughout FU. Mildly impaired LV strain at BL fully recovered by midterm FU (P≤.002). Peak oxygen uptake improved at early and midterm FU (all P≤.003).

CONCLUSIONS

Patients with RVOT obstruction had biventricular systolic and diastolic dysfunction at BL. Relieving RVOT obstruction with TPVR reduced adverse ventricular and compensatory atrioventricular interaction, resulting in progressive biventricular functional improvement and remodeling at early and midterm FU.

Subacute left ventricular outflow tract obstruction after transapical closure of a mitral paravalvular leak in the region of the aortomitral curtain

We report a rare case of progressive left ventricular outflow tract (LVOT) obstruction after percutaneous device closure of a mechanical prosthetic mitral valve (MV) paravalvular leak (PVL) in the region of aortomitral curtain in a patient who also had small mechanical aortic valve prosthesis with patient-prosthesis mismatch.

Management Strategies for Complex Bronchopleural Fistula

The management of complex bronchopleural fistula remains a major therapeutic challenge for the thoracic surgeon. Although the incidence of bronchopleural fistula following lung resection has decreased in recent years to 1% to 2%, when it occurs, it is associated with significant morbidity and mortality. Using illustrative cases, the epidemiology and pathophysiology of bronchopleural fistula are reviewed and operative strategies are discussed. Algorithms for the diagnosis and treatment are suggested on the basis of cases described in the literature. The best way to prevent a fistula is to rigorously follow the surgical techniques described, with minimal devascularization of the bronchus and prophylactic coverage of the stump in high-risk patients. Successful management of a fistula is combined with treatment of the associated empyema cavity. Definitive repair should be accomplished expeditiously, minimizing the number of procedures performed. When treatment is protracted, secondary complications are more likely and survival is adversely affected. The first step should be control of active infection and adequate drainage of the hemithorax, followed by timely repair of the bronchopleural fistula when possible and reinforcement of the stump with vascularized tissue. If a residual cavity is present it must also be obliterated with a pedicled muscle flap.

Transcatheter Tricuspid Valve-in-Valve Implantation for the Treatment of Dysfunctional Surgical Bioprosthetic Valves

Background—

Off-label use of transcatheter aortic and pulmonary valve prostheses for tricuspid valve-in-valve implantation (TVIV) within dysfunctional surgical tricuspid valve (TV) bioprostheses has been described in small reports.

Methods and Results—

An international, multicenter registry was developed to collect data on TVIV cases. Patient-related factors, procedural details and outcomes, and follow-up data were analyzed. Valve-in-ring or heterotopic TV implantation procedures were not included. Data were collected on 156 patients with bioprosthetic TV dysfunction who underwent catheterization with planned TVIV. The median age was 40 years, and 71% of patients were in New York Heart Association class III or IV. Among 152 patients in whom TVIV was attempted with a Melody (n=94) or Sapien (n=58) valve, implantation was successful in 150, with few serious complications. After TVIV, both the TV inflow gradient and tricuspid regurgitation grade improved significantly. During follow-up (median, 13.3 months), 22 patients died, 5 within 30 days; all 22 patients were in New York Heart Association class III or IV, and 9 were hospitalized before TVIV. There were 10 TV reinterventions, and 3 other patients had significant recurrent TV dysfunction. At follow-up, 77% of patients were in New York Heart Association class I or II ( P <0.001 versus before TVIV). Outcomes did not differ according to surgical valve size or TVIV valve type.

Conclusions—

TVIV with commercially available transcatheter prostheses is technically and clinically successful in patients of various ages across a wide range of valve size. Although preimplantation clinical status was associated with outcome, many patients in New York Heart Association class III or IV at baseline improved. TVIV should be considered a viable option for treatment of failing TV bioprostheses.

Intentional Fracture of Maximally Dilated Balloon-Expandable Pulmonary Artery Stents Using Ultra–High-Pressure Balloon Angioplasty

Background—

Treatment with endovascular stents has become increasingly common for the management of vascular stenosis in congenital heart disease. The use of stents in smaller patients has been tempered by concerns about the potential for stent expansion to accommodate somatic growth. One solution to limited stent diameter is the intentional fracture of maximally dilated stents, which can be accomplished using ultra–high-pressure (UHP) balloons.

Methods and Results—

This retrospective cohort study compared procedural characteristics and adverse events between a cohort of patients with branch pulmonary artery (PA) stents who underwent stent fracture using UHP balloons and control patients who underwent UHP redilation of previously placed PA stents without stent fracture between 2004 and 2014. Two control patients were selected for every case. Thirty-three PA stents were fractured in 31 patients with a median of 10 years after initial stent placement. The median balloon:waist ratio was 1.17 (1–1.71), and the median inflation pressure was 20 (8–30) atm. There were significant reductions in pressure gradient after angioplasty, with no difference in postangioplasty gradients between cases and controls. There were no major PA complications in the stent fracture group and no difference in the number of adverse events between the 2 groups.

Conclusions—

In this small series, PA stent fracture using UHP balloon angioplasty was feasible and did not result in major complications although predictors of successful fracture were not identified. Intentional fracture with UHP balloon angioplasty may be considered when treating stents that have become restrictive despite maximal dilation.

Aortic Root Distortion and Aortic Insufficiency During Balloon Angioplasty of the Right Ventricular Outflow Tract Prior to Transcatheter Pulmonary Valve Replacement

OBJECTIVE

To describe the significance of aortic root distortion (AD) and/or aortic valve insufficiency (AI) during balloon angioplasty of the right ventricular outflow tract (RVOT) performed to rule out coronary artery compression prior to transcatheter pulmonary valve (TPV) implantation.

METHODS

AD/AI was assessed by retrospective review of all procedural aortographies performed to evaluate coronary anatomy prior to TPV implantation. AD/AI was also reviewed in all pre-post MPV implant echocardiograms to assess for progression.

RESULTS

From 04/2007 to 3/2015, 118 pts underwent catheterization with intent for TPV implant. Mean age and weight were 24.5 ± 12 years and 64.3 ± 20 kg, respectively. Diagnoses were: TOF (53%), D-TGA/DORV (18%), s/p Ross (15%), and Truncus (9%). Types of RV-PA connections were: conduits (96), bioprosthetic valves (14), and other (7). Successful TPV implant occurred in 91 pts (77%). RVOT balloon angioplasty was performed in 43/118 pts (36%). Aortography was performed in 18/43 pts with AD/AI noted in 6/18 (33%); 2 with D-TGA (1 s/p Lecompte, 1 s/p Rastelli), 2 with TOF, 1 Truncus and 1 s/p Ross. Procedure was aborted in the 2 who developed severe AD/AI. TPV was implanted in 3/4 patients with mild AD/AI. Review of pre-post TPV implantation echocardiograms in 83/91 pts (91%) revealed no new/worsened AI in any patient.

CONCLUSION

AD/AI is relatively common on aortography during simultaneous RVOT balloon angioplasty. Lack of AI progression by echocardiography post-TPV implant suggests these may be benign findings in most cases. However, AD/AI should be carefully evaluated in certain anatomic subtypes with close RVOT/aortic alignments.

Retrograde transcatheter device closure of a complex paravalvular leak after bioprosthetic pulmonary valve replacement in a pediatric patient

We report a case of retrograde transcatheter device closure of a complex paravalvular leak (PVL) after bioprosthetic pulmonary valve replacement (PVR) in a 13-year-old patient with congenital pulmonary valve stenosis. There are prior reports of pulmonary PVL closure after PVR in adults (Seery and Slack, Congenit Heart Dis 2014;9:E19-F22), but indications for and technical considerations in PVL closure after bioprosthetic PVR, particularly in children, are not well defined. © 2015 Wiley Periodicals, Inc.

Exploring Value in Congenital Heart Disease: An Evaluation of Inpatient Admissions

OBJECTIVES

Understanding value provides an important context for improvement. However, most health care models fail to measure value. Our objective was to categorize inpatient encounters within an academic congenital heart program based on clinical outcome and the cost to achieve the outcome (value). We aimed to describe clinical and nonclinical features associated with value.

DESIGN

We defined hospital encounters based on outcome per resource utilized. We performed principal component and cluster analysis to classify encounters based on mortality, length of stay, hospital cost and revenue into six classes. We used nearest shrunken centroid to identify discriminant features associated with the cluster-derived classes. These features underwent hierarchical clustering and multivariate analysis to identify features associated with each class.

STUDY SETTING/PATIENTS

We analyzed all patients admitted to an academic congenital heart program between September 1, 2009, and December 31, 2012.

OUTCOME MEASURES/RESULTS

A total of 2658 encounters occurred during the study period. Six classes were categorized by value. Low-performing value classes were associated with greater institutional reward; however, encounters with higher-performing value were associated with a loss in profitability. Encounters that included insertion of a pediatric ventricular assist device (log OR 2.5 [95% CI, 1.78 to 3.43]) and acquisition of a hospital-acquired infection (log OR 1.42 [95% CI, 0.99 to 1.87]) were risk factors for inferior health care value.

CONCLUSIONS

Among the patients in our study, institutional reward was not associated with value. We describe a framework to target quality improvement and resource management efforts that can benefit patients, institutions, and payers alike.