Increased Short- and Long-term Mortality at Low-volume Pediatric Heart Transplant Centers

Analysis of UNOS: Pediatric Heart Transplantation Over 36 Years and Contemporary Volume-Outcome Relationship

BACKGROUND

This study examines 36 years of national pediatric heart transplantation data to (1) identify trends in transplant volume, centers, and 1-year graft survival and (2) assess how center transplant volume affects outcomes over a contemporary 11-year period.

METHODS

Study investigators utilized the United Network for Organ Sharing database and performed a retrospective review of pediatric patients (aged <18 years) who underwent heart transplantation between January 1, 1987 and December 31, 2022, inclusive. Trend analyses included the whole cohort, whereas volume-outcome analyses included a contemporary cohort (January 1, 2012 through December 31, 2022) to account for the temporal changes observed in transplant survival. Highest-volume centers were defined by the number of heart transplantations performed per center per year.

RESULTS

Over 36 years, 11,828 pediatric heart transplantations were performed. Transplant volume steadily rose, the number of centers remained stable, and 1-year graft survival improved significantly. In the contemporary era (2012-2022), 89 centers conducted 4959 pediatric heart transplantations. The top 15% high-volume centers (13 centers) accounted for 48.3% (n = 2393) of transplantations, with an average of 16.7 ± 3.8 transplantations per center annually, compared with 3.9 ± 3.1 for lower-volume centers (P < .001). Despite performing transplantations in higher-risk patients, high-volume centers achieved similar postoperative outcomes and improved long-term survival compared with low-volume centers.

CONCLUSIONS

Although the number of US pediatric heart transplant centers has remained stable, pediatric heart transplant volume has steadily increased, as has 1-year graft survival. In a contemporary cohort, the top 15th percentile highest-volume centers accounted for 48.3% of US pediatric heart transplants and performed transplantations in higher-risk patients with similar postoperative outcomes and improved longitudinal survival.

Decoding surgical skill: an objective and efficient algorithm for surgical skill classification based on surgical gesture features -experimental studies

BACKGROUND

Various surgical skills lead to differences in patient outcomes and identifying poorly skilled surgeons with constructive feedback contributes to surgical quality improvement. The aim of the study was to develop an algorithm for evaluating surgical skills in laparoscopic cholecystectomy based on the features of elementary functional surgical gestures (Surgestures).

MATERIALS AND METHODS

Seventy-five laparoscopic cholecystectomy videos were collected from 33 surgeons in five hospitals. The phase of mobilization hepatocystic triangle and gallbladder dissection from the liver bed of each video were annotated with 14 Surgestures. The videos were grouped into competent and incompetent based on the quantiles of modified global operative assessment of laparoscopic skills (mGOALS). Surgeon-related information, clinical data, and intraoperative events were analyzed. Sixty-three Surgesture features were extracted to develop the surgical skill classification algorithm. The area under the receiver operating characteristic curve of the classification and the top features were evaluated.

RESULTS

Correlation analysis revealed that most perioperative factors had no significant correlation with mGOALS scores. The incompetent group has a higher probability of cholecystic vascular injury compared to the competent group (30.8 vs 6.1%, P =0.004). The competent group demonstrated fewer inefficient Surgestures, lower shift frequency, and a larger dissection-exposure ratio of Surgestures during the procedure. The area under the receiver operating characteristic curve of the classification algorithm achieved 0.866. Different Surgesture features contributed variably to overall performance and specific skill items.

CONCLUSION

The computer algorithm accurately classified surgeons with different skill levels using objective Surgesture features, adding insight into designing automatic laparoscopic surgical skill assessment tools with technical feedback.

Survival does not differ by annual center transplant volume-A Pediatric Heart Transplant Society Registry study

BACKGROUND

There are conflicting data regarding the relationship between center volume and outcomes in pediatric heart transplantation. Previous studies have not fully accounted for differences in case mix, particularly in high-risk congenital heart disease (CHD) groups. We aimed to evaluate the relationship between center volume and outcomes using the Pediatric Heart Transplant Society (PHTS) Registry and explore how case mix may affect outcomes.

METHODS

A retrospective cohort study of all pediatric patients in the PHTS Registry who received a heart transplant from 2009 to 2018 was performed. Centers were divided into 5 groups based on average yearly transplant volume. The primary outcome was time to death or graft loss and outcomes were compared using Kaplan-Meier analysis.

RESULTS

There were 4583 cases among 55 centers included. There was no difference in time to death or graft loss by center volume in the entire cohort (p = .75), in patients with CHD (p = .79) or in patients with cardiomyopathy (p = .23). There was also no difference in time to death or graft loss by center size in patients undergoing transplant after Norwood, Glenn or Fontan (log rank p = .17, p = .31, and p = .10 respectively). There was a statistically significant difference in outcomes by center size in the positive crossmatch group (p < .0001), though no discernible pattern related to high or low center volume.

CONCLUSIONS

Outcomes are similar among transplant centers of all sizes, including for high-risk patient groups with CHD. Future work is needed to understand how patient-specific risk factors may vary among centers of various sizes and whether this influences patient outcomes.

Quality care close to home: Objectives and early outcomes of a second paediatric heart transplant service in Australia

AIM

We describe the experience of a new paediatric heart transplant (HT) centre in Australia. New South Wales offers quaternary paediatric cardiac services including comprehensive care pre- and post-HT; however, perioperative HT care has previously occurred at the national paediatric centre or in adult centres. Internationally, perioperative HT care is highly protocol-driven and a majority of HT occurs in low volume centres. Establishing a low volume paediatric HT centre in New South Wales offers potential for quality HT care close to home.

METHODS

Retrospective review of programme data for the first 12 months was undertaken. Patient selection was audited against the programme's intended initiation criteria. Longitudinal patient data on outcomes and complications were obtained from patient medical records.

RESULTS

The programme's initial phase offered HT to children with non-congenital heart disease and no requirement for durable mechanical circulatory support. Eight patients met criteria for HT referral. Three underwent interstate transfer to the national paediatric centre. Five children (13-15 years, weight 36-85 kg) underwent HT in the new programme. Individual predicted 90-day mortality was 1.3-11.6%, with increased risk for recipients transplanted from veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and with restrictive/hypertrophic cardiomyopathies. Survival at 90 days and for duration of follow-up is 100%. Observed programme benefits include mitigation of family dislocation and improved continuity of care within a family-centred programme.

CONCLUSION

Audit of the first 12 months' activity of a second paediatric HT centre in Australia demonstrates adherence to proposed patient selection criteria and excellent 90-day patient outcomes. The programme demonstrates feasibility of care close to home, providing continuity for all patients including those requiring increased rehabilitation and psychosocial support post-transplantation.

Association of Operative Volume and Odds of Surgical Complication for Patients Undergoing Repair of Pectus Excavatum at Children's Hospitals

OBJECTIVE

To determine whether procedure-specific provider volume is associated with outcomes for patients undergoing repair of pectus excavatum at tertiary care children's hospitals.

STUDY DESIGN

We performed a cohort study of patients undergoing repair of pectus excavatum between January 1, 2013 and December 31, 2019, at children's hospitals using the Pediatric Health Information System database. The main exposures were the pectus excavatum repair volume quartile of the patient's hospital and the pectus excavatum repair volume category of their surgeon. Our primary outcome was surgical complication, identified using International Classification of Diseases, Ninth Revision, Clinical Modification, and International Classification of Diseases, Tenth Revision, Clinical Modification codes from Pediatric Health Information System. Secondary outcomes included high-cost admission and extended length of stay.

RESULTS

In total, 7183 patients with an average age of 15.2 years (SD 2.0), 83% male, 74% non-Hispanic White, 68% no comorbidities, 72% private insurance, and 82% from metro areas were analyzed. Compared with the lowest-volume (≤10 cases/year) quartile of hospitals, patients undergoing repair of pectus excavatum at hospitals in the second (>10-18 cases/year), third (>18-26 cases/year), and fourth (>26 cases/year) volume quartiles had decreased odds of complication of OR 0.52 (CI 0.34-0.82), 0.51 (CI 0.33-0.78), and 0.41 (CI 0.27-0.62), respectively. Patients with pectus excavatum who underwent repair by surgeons in the second (>1-5 cases/year), third (>5-10 cases/year), and fourth (>10 cases/year) volume categories had decreased odds of complication of OR 0.91 (CI 0.68-1.20), OR 0.73 (CI 0.51-1.04), and OR 0.55 (CI 0.39-0.76), respectively, compared with the lowest-volume (≤1 case/year) category of surgeons.

CONCLUSIONS

Procedure-specific case volume is an important factor when considering providers for elective surgery, even among specialized centers providing comprehensive patient care.

Center Variation in Indication and Short-Term Outcomes after Pediatric Heart Transplantation: Analysis of a Merged United Network for Organ Sharing - Pediatric Health Information System Cohort

The relationship between center-specific variation in indication for pediatric heart transplantation and short-term outcomes after heart transplantation is not well described. We used merged patient- and hospital-level data from the United Network for Organ Sharing and the Pediatric Health Information Systems to analyze outcomes according to transplant indication for a cohort of children (≤ 21 years old) who underwent heart transplantation between 2004 and 2015. Outcomes included 30-day mortality, transplant hospital admission mortality, and hospital length of stay, with multivariable adjustment performed according to patient and center characteristics. The merged cohort reflected 2169 heart transplants at 20 U.S. centers. The median number of transplants annually at each center was 11.6, but ranged from 3.5 to 22.6 transplants/year. Congenital heart disease was the indication in the plurality of cases (49.2%), with cardiomyopathy (46%) and myocarditis (4.8%) accounting for the remainder. There was significant center-to-center variability in congenital heart disease as the principal indication, ranging from 15% to 66% (P < 0.0001). After adjustment, neither center volume nor proportion of indications for transplantation were associated with 30-day or transplant hospital admission mortality. In this large, merged pediatric cohort, variation was observed at center level in annual transplant volume and prevalence of indications for heart transplantation. Despite this variability, center volume and proportion of indications represented at a given center did not appear to impact short-term outcomes.

Characteristics Associated With High-Performing Pediatric Heart Transplant Centers in the United States From 2006 to 2015

IMPORTANCE

Differences among pediatric transplant centers in long-term survival of pediatric recipients of heart transplants can be mostly explained by differences in 90-day mortality.

OBJECTIVE

To understand characteristics associated with high-performing pediatric HT centers by comparing key outcomes among centers stratified by 90-day risk-adjusted mortality.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study included recipients of HT aged younger than 18 years in the US. Analyses included 44 US centers during 2006 to 2015 using the Organ Procurement and Transplant Network database. A risk model for 90-day mortality was developed using data from all recipients to estimate expected 90-day mortality and 90-day standardized mortality ratio (SMR; calculated as observed mortality divided by expected mortality) for each center. Centers were stratified into tertiles by SMR and compared for key outcomes. Data were analyzed from January to March 2020.

EXPOSURES

High-, medium-, and low-performing centers (SMR tertile).

MAIN OUTCOMES AND MEASURES

Posttransplant 90-day mortality across recipient risk spectrum and incidence of and mortality following early posttransplant complications.

RESULTS

Of 3211 children analyzed, 1016 (31.6%) were infants younger than 1 year and 1459 (45.4%) were girls. The median (interquartile range) age was 4 (0-12) years. Centers were stratified by SMR tertile, and SMR was 0 to 0.71 among 15 high-performing centers, 0.79 to 1.12 among 14 medium-performing centers, and 1.19 to 3.33 among 15 low-performing centers. High-performing centers had 90-day mortality of 0.8% (95% CI, 0.3%-1.8%) in children with low risk and expected mortality of 2.0%, 2.3% (95% CI, 0.6%-5.7%) in children with intermediate risk and expected mortality of 6.5%, and 16.7% (95% CI, 7.9%-29.3%) in children with high risk and expected mortality of 30.8%. Incidence of acute rejection during transplant hospitalization was 10.3% at high-performing centers, 10.3% at medium-performing centers, and 9.7% at low-performing centers (P for trend = .68), and incidence of post-HT kidney failure requiring dialysis was 4.1% at high-performing centers, 5.2% at medium-performing centers, and 8.5% at low-performing centers (P for trend = .001). Ninety-day mortality was significantly lower at high-performing centers among children treated for rejection (high-performing: 2.0%; medium-performing: 6.9%; low-performing: 11.7%; P for trend = .006) and among recipients receiving dialysis for post-HT kidney failure (high-performing: 17.5%; medium-performing: 39.4%; low-performing: 47.6%; P for trend < .001).

CONCLUSIONS AND RELEVANCE

This cohort study found that high-performing pediatric HT centers had lower 90-day mortality across the recipient risk spectrum and lower mortality among recipients who develop rejection or post-HT kidney failure during transplant hospitalization. These findings suggest presence of superior processes and systems of care at high-performing pediatric HT centers.

An Overview of Contemporary Outcomes in Fetal Cardiac Intervention: A Case for High-Volume Superspecialization?

Fetal cardiac interventions (FCI) offer the opportunity to rescue a fetus at risk of intrauterine death, or more ambitiously to alter disease progression. Most of these fetuses require multiple additional postnatal procedures, and it is difficult to disentangle the effect of the fetal procedure from that of the postnatal management sequence. The true clinical impact of FCI may only be discernible in large-volume institutions that can commit to a standardized postnatal approach and have sufficient case volume to overcome their FCI learning curve.

The reality of limping to pediatric heart transplantation

OBJECTIVE

Improvements in surgical technique, critical care, and early repair for congenital heart disease (CHD) have led to improved outcomes with heart transplantation, often used as a salvage procedure after failed palliation, especially in infants. These patients, however, often have several risk factors for poor posttransplant survival. We aimed to identify the reality of survival after heart transplantation in patients "limping to transplant" with common risk factors.

METHODS

All heart transplant recipients younger than 18 years were identified from the UNOS data set from 2000 to 2017. Modifiable risk factors (MRFs) of mechanical ventilation, renal dysfunction, and liver dysfunction at transplant and nonmodifiable risk factors of infancy at listing or CHD were examined. One-year posttransplant survival was analyzed with logistic regression.

RESULTS

Of 4101 transplants, 1459 patients (36%) had 1 or more MRFs. There was a decrease in 1-year survival with additional MRFs up to a 9.1-times increased risk of death in an infant with CHD. A noninfant without CHD and no MRFs had a 95% 1-year survival, in contrast to an intubated patient with CHD without other end-organ dysfunction, who had 1-year survival of 76%, which decreased to 58% if they were an infant and also had renal dysfunction.

CONCLUSIONS

Patients "limping to transplant" with multiple risk factors demonstrates decreasing early survival relative to those without other end-organ dysfunction. It is imperative that we have transparent discussions about expected outcomes with these families and identify ways to optimize patients' conditions through other supportive avenues to improve posttransplant outcomes.

A model for geographic and sociodemographic access to care disparities for adults with congenital heart disease

BACKGROUND

Follow-up at a regional adult congenital heart disease (ACHD) center is recommended for all ACHD patients at least once per the 2018 ACC/AHA guidelines. Other specialties have demonstrated poorer follow-up and outcomes correlating with increased distance from health care providers, but driving time to regional ACHD centers has not been examined in the US population.

OBJECTIVE

To identify and characterize potential disparities in access to ACHD care in the US based on drive time to ACHD centers and compounding sociodemographic factors.

METHODS

Mid- to high-volume ACHD centers with ≥500 outpatient ACHD visits and ≥20 ACHD surgeries annually were included based on self-reported, public data. Geographic Information System mapping was used to delineate drive times to ACHD centers. Sociodemographic data from the 2012-2016 American Community Survey (US Census) and the Environmental Systems Research Institute were analyzed based on drive time to nearest ACHD center. Previously established CHD prevalence estimates were used to estimate the similarly located US ACHD population.

RESULTS

Nearly half of the continental US population (45.1%) lives >1 hour drive to an ACHD center. Overall, 39.7% live 1-4 hours away, 3.4% live 4-6 hours away, and 2.0% live >6 hours away. Hispanics were disproportionately likely to live a >6 hour drive to a center (p < .001). Compared to people with <1 hour drive, those living >6 hours away have higher proportions of uninsured adults (29% vs. 18%; p < .001), households below the federal poverty level (19% vs. 13%; p < .001), and adults with less than college education (18% vs. 12%; p < .001).

CONCLUSIONS

We estimate that ~45% of the continental US population lives >1 hour to an ACHD center, with 5.4% living >4 hours away. Compounding barriers exist for Hispanic, uninsured, lower socioeconomic status, and less-educated patients. These results may help drive future policy changes to improve access to ACHD care.

Heart Failure in Adult Congenital Heart Disease: From Advanced Therapies to End-of-Life Care

There is mounting recognition that some of the most urgent problems of adult congenital heart disease (ACHD) are the prevention, diagnosis, and management of heart failure (HF). Recent expert consensus and position statements not only emphasize a specific and pressing need to tackle HF in ACHD (ACHD-HF) but also highlight the difficulty of doing so given a current sparsity of data. Some of the challenges will be addressed by this review. The authors are from 3 different centres; each centre has an established subspeciality ACHD-HF clinic and is able to provide heart transplant, multiorgan transplant, and mechanical support for patients with ACHD. Appropriate care of this complex population requires multidisciplinary ACHD-HF teams evaluate all possible treatment options. The risks and benefits of nontransplant ACHD surgery, percutaneous structural and electrophysiological intervention, and ongoing conservative management must be considered alongside those of transplant strategies. In our approach, advanced care planning and palliative care coexist with the consideration of advanced therapies. An ethos of shared decision making, guided by the patient's values and preferences, strengthens clinical care, but requires investment of time as well as skilled communication. In this review, we aim to offer practical real-world advice for managing these patients, supported by scientific data where it exists.

Impact of pediatric cardiac surgery regionalization on health care utilization and mortality

OBJECTIVE

Regionalization directs patients to high-volume hospitals for specialized care. We investigated regionalization trends and outcomes in pediatric cardiac surgery.

DATA SOURCES/STUDY SETTING

Statewide inpatient data from eleven states between 2000 and 2012.

STUDY DESIGN

Mortality, length of stay (LOS), and cost were assessed using multivariable hierarchical regression with state and year fixed effects. Primary predictor was hospital case-volume, categorized into low-, medium-, and high-volume tertiles.

DATA COLLECTION/EXTRACTION METHODS

We used Risk Adjustment for Congenital Heart Surgery-1 (RACHS-1) to select pediatric cardiac surgery discharges.

PRINCIPAL FINDINGS

In total, 2841 (8.5 percent), 8348 (25.1 percent), and 22 099 (66.4 percent) patients underwent heart surgeries in low-, medium-, and high-volume hospitals. Mortality decreased over time, but remained higher in low- and medium-volume hospitals. High-volume hospitals had lower odds of mortality and cost than low-volume hospitals (odds ratio [OR] 0.59, P < 0.01, and relative risk [RR] 0.91, P < 0.01, respectively). LOS was longer for high- and medium-volume hospitals, compared to low-volume hospitals (high-volume: RR 1.18, P < 0.01; medium-volume: RR 1.05, P < 0.01).

CONCLUSIONS

Regionalization reduced mortality and cost, indicating fewer complications, but paradoxically increased LOS. Further research is needed to explore the full impact on health care utilization.

Center effect on posttransplant survival among currently active United States pediatric heart transplant centers

The official analysis of posttransplant survival considers only recently transplanted patients and suggests absence of outcome differences among pediatric heart transplant (HT) centers. We sought to compare posttransplant survival among currently active pediatric HT centers in the United States over 15 years of activity. We identified all children <18 years old who underwent their first HT during 2000-2014 at US centers active during 2013-14. Recipients were followed until March 2016. A mixed-effects survival model with center as a random effect was used to assess center differences in patient and graft survival. Center case-mix and standardized mortality ratio (SMR) for 90-day mortality were assessed by applying an internally validated risk-model. Overall, 4271 children transplanted at 46 centers were analyzed. There was a significant center effect on risk-adjusted patient (P = .01) and graft survival (P < .001). Adjusting for 90-day SMR or center-volume, but not for case-mix, was associated with a significant reduction in center effect on long-term survival. There was no center effect on conditional survival in 90-day survivors. In conclusion, there are significant differences in posttransplant survival among pediatric HT centers in the United States. Centers with better short-term performance (lower SMR for 90-day mortality) maintain their outcome advantage on follow-up and have superior longer-term outcomes.

Successful merging of data from the United Network for Organ Sharing and the Pediatric Health Information System databases

Data routinely collected through United Network for Organ Sharing (UNOS) lack the detailed information on medical resource utilization and treatment costs required to accomplish for center-level comparisons of quality of care and cost for pediatric heart transplantation. We aimed to overcome this limitation by merging UNOS with the Pediatric Health Information System (PHIS) database, an administrative database containing inpatient, emergency department, ambulatory surgery, and observation unit information from over 40 not-for-profit, tertiary care pediatric hospitals. Utilizing a probabilistic match based on center, date of birth, recipient gender, and transplant date within ±2 days, more than 90% of eligible UNOS patients (N = 2264) were successfully merged to their corresponding PHIS records. Thirty-day and 1-year mortality rates observed for the merged cohort (3.2% and 9.0%, respectively) were compared with those previously reported for pediatric heart transplants, as were the significant predictors of increased mortality. These results demonstrate that the established UNOS-PHIS cohort will provide a valid platform for subsequent research aimed at identifying center-level differences that could be exploited to optimize quality of care while minimizing cost across institutions.

Resource utilization at the time of prostacyclin initiation in children in pulmonary arterial hypertension: a multicenter analysis

There are limited data investigating the epidemiology and resource utilization associated with parenteral prostacyclin use in children. We sought to examine national trends in treatment practices and resource utilization during prostacyclin initiation for pulmonary arterial hypertension (PAH) at children’s hospitals in the United States. Patients with PAH initiated on parenteral epoprostenol and treprostinil (2004–2014) were identified using a nationwide administrative database. Demographics, clinical characteristics, and resource utilization were compared between epoprostenol and treprostinil groups. Costs were indexed in 2014 US dollars. Among 1448 children admitted with a primary or secondary diagnosis of PAH, 280 (19%) were initiated on parenteral prostacyclins (epoprostenol n = 195 and treprostinil n = 85). Epoprostenol predominated early (97% of initiations in 2005); however, treprostinil predominated recently (52–67% of initiations/year). Children initiated on treprostinil had shorter ICU stays (1 [IQR = 0–4] vs. 4 [0–10] days, P < 0.001), shorter total lengths of stay (4 [2–9] vs. 8 [4–18] days, P = 0.001), and lower in-hospital mortality (1 vs. 12%, P = 0.001) with no difference in 30-day (13 vs. 19%, P = 0.19) or one-year readmission rates (56 vs. 61%, P = 0.41). Inpatient costs were lower for treprostinil initiation ($23,779 [11,830–39,535] vs. $32,976 [11,904–94,082], P = 0.03), with a greater difference in the recent era (2009–2013). Though significant variation exists regarding prostacyclin use for PAH across US centers, prostacyclins are common among children with PAH. Treprostinil initiation has been increasing and is associated with less resource utilization and lower cost compared to epoprostenol initiation. Post-discharge outcome data are needed to fully inform decision-making about the relative benefits of parental prostacyclin drug choice.

Inferior Outcomes on the Waiting List in Low-Volume Pediatric Heart Transplant Centers

Low case volume has been associated with poor outcomes in a wide spectrum of procedures. Our objective was to study the association of low case volume and worse outcomes in pediatric heart transplant centers, taking the novel approach of including waitlist outcomes in the analysis. We studied a cohort of 6482 candidates listed in the Organ Procurement and Transplantation Network for pediatric heart transplantation between 2002 and 2014; 4665 (72%) of the candidates underwent transplantation. Candidates were divided into groups according to the average annual transplantation volume of the listing center during the study period: more than 10, six to 10, three to five, or fewer than three transplantations. We used multivariate Cox regression analysis to identify independent risk factors for waitlist and posttransplantation mortality. Of the 6482 candidates, 24% were listed in low-volume centers (fewer than three annual transplantations). Of these listed candidates in low-volume centers, only 36% received a transplant versus 89% in high-volume centers (more than 10 annual transplantations) (p < 0.001). Listing at a low-volume center was the most significant risk factor for waitlist death (hazard ratio [HR] 4.5, 95% confidence interval [CI] 3.5-5.7 in multivariate Cox regression and HR 5.6, CI 4.4-7.3 in multivariate competing risk regression) and was significant for posttransplantation death (HR 1.27, 95% CI 1.0-1.6 in multivariate Cox regression). During the study period, one-fourth of pediatric transplant candidates were listed in low-volume transplant centers. These children had a limited transplantation rate and a much greater risk of dying while on the waitlist.

Influence of Transplant Center Procedural Volume on Survival Outcomes of Heart Transplantation for Children Bridged with Mechanical Circulatory Support

Transplant center expertise improves survival after heart transplant (HTx) but it is unknown whether center expertise ameliorates risk associated with mechanical circulatory support (MCS) bridge to transplantation. This study investigated whether center HTx volume reduced survival disparities among pediatric HTx patients bridged with extracorporeal membrane oxygenation (ECMO), left ventricular assist device (LVAD), or no MCS. Patients ≤18 years of age receiving first-time HTx between 2005 and 2015 were identified in the United Network of Organ Sharing registry. Center volume was the total number of HTx during the study period, classified into tertiles. The primary outcome was 1 year post-transplant survival, and MCS type was interacted with center volume in Cox proportional hazards regression. The study cohort included 4131 patients, of whom 719 were supported with LVAD and 230 with ECMO. In small centers (≤133 HTx over study period), patients bridged with ECMO had increased post-transplant mortality hazard compared to patients bridged with LVAD (HR 0.29, 95% CI 0.12, 0.71; p = 0.006) and patients with no MCS (HR 0.33, 95% CI 0.19, 0.57; p < 0.001). Interactions of MCS type with medium or large center volume were not statistically significant, and the same differences in survival by MCS type were observed in medium- or large-volume centers (136-208 or ≥214 HTx over the study period). Post-HTx survival disadvantage of pediatric patients bridged with ECMO persisted regardless of transplant program volume. The role of institutional ECMO expertise outside the transplant setting for improving outcomes of ECMO bridge to HTx should be explored.

Is there a relationship between surgical case volume and mortality in congenital heart disease services? A rapid evidence review

OBJECTIVE

To identify and synthesise the evidence on the relationship between surgical volume and patient outcomes for adults and children with congenital heart disease.

DESIGN

Evidence synthesis of interventional and observational studies.

DATA SOURCES

MEDLINE, EMBASE, CINAHL, Cochrane Library and Web of Science (2009-2014) and citation searching, reference lists and recommendations from stakeholders (2003-2014) were used to identify evidence.

STUDY SELECTION

Quantitative observational and interventional studies with information on volume of surgical procedures and patient outcomes were included.

RESULTS

31 of the 34 papers identified (91.2%) included only paediatric patients. 25 (73.5%) investigated the relationship between volume and mortality, 7 (20.6%) mortality and other outcomes and 2 (5.9%) non-mortality outcomes only. 88.2% were from the US, 97% were multicentre studies and all were retrospective observational studies. 20 studies (58.8%) included all congenital heart disease conditions and 14 (41.2%) single conditions or procedures. No UK studies were identified. Most studies showed a relationship between volume and outcome but this relationship was not consistent. The relationship was stronger for single complex conditions or procedures. We found limited evidence about the impact of volume on non-mortality outcomes. A mixed picture emerged revealing a range of factors, in addition to volume, that influence outcome including condition severity, individual centre and surgeon effects and clinical advances over time.

CONCLUSIONS

The heterogeneity of findings from observational studies suggests that, while a relationship between volume and outcome exists, this is unlikely to be a simple, independent and directly causal relationship. The effect of volume on outcome relative to the effect of other, as yet undetermined, health system factors remains a complex and unresolved research question.

The Effect of Institutional Volume on Complications and Their Impact on Mortality After Pediatric Heart Transplantation

BACKGROUND

This study evaluated the potential association of institutional volume with survival and mortality subsequent to major complications in a modern cohort of pediatric patients after orthotopic heart transplantation (OHT).

METHODS

The United Network of Organ Sharing database was queried for pediatric patients (aged ≤18 years) undergoing OHT between 2000 and 2010. Institutional volume was defined as the average number of transplants completed annually during each institution's active period and was evaluated as categoric and as a continuous variable. Logistic regression models were used to determine the effect of institutional volumes on postoperative outcomes, which included renal failure, stroke, rejection, reoperation, infection, and a composite complication outcome. Cox modeling was used to analyze the risk-adjusted effect of institutional volume on 30-day, 1-year, and 5-year mortality. Kaplan-Meier estimates were used to compare differences in unconditional survival.

RESULTS

A total of 3,562 patients (111 institutions) were included and stratified into low-volume (<6.5 transplants/year, 91 institutions), intermediate-volume (6.5 to 12.5 transplants/year, 12 institutions), and high-volume (>12.5 transplants/year, 8 institutions) tertiles. Unadjusted survival was significantly different at 30 days (p = 0.0087) in the low-volume tertile (94.2%; 95% confidence interval, 92.7% to 95.4%) compared with the high-volume tertile (96.8%; 95% confidence interval, 95.7% to 97.7%). No difference was observed at 1 or 5 years. Risk-adjusted Cox modeling demonstrated that low-volume institutions had an increased rate of mortality at 30 days (hazard ratio, 1.91; 95% confidence interval, 1.02 to 3.59; p = 0.044), but not at 1 or 5 years. High-volume institutions had lower incidences of postoperative complications than low-volume institutions (30.3% vs 38.4%, p < 0.001). Despite this difference in the rate of complications, survival in patients with a postoperative complication was similar across the volume tertiles.

CONCLUSIONS

No association was observed between institutional volume and adjusted or unadjusted long-term survival. High-volume institutions have a significantly lower rate of postoperative complications after pediatric OHT. This association does not correlate with increased subsequent mortality in low-volume institutions. Given these findings, strategies integral to the allocation of allografts in adult transplantation, such as regionalization of care, may not be as relevant to pediatric OHT.

Can linking databases answer questions about paediatric heart failure?

Numerous data sets collect information on patients with paediatric cardiovascular disease, including paediatric heart failure and transplant patients. This review discusses methodologies available for linking and integrating information across data sets, which may help facilitate answering important questions in the field of paediatric heart failure and transplant that cannot be answered with individual data sets or single-centre data alone.

Pediatric Liver Transplant Center Volume and the Likelihood of Transplantation

BACKGROUND

Low case volume has been associated with poorer surgical outcomes in a multitude of surgical procedures. We studied the association among low case volume, outcomes, and the likelihood of pediatric liver transplantation.

METHODS

We studied a cohort of 6628 candidates listed in the Organ Procurement and Transplantation Network for primary pediatric liver transplantation between 2002 and 2012; 4532 of the candidates went on to transplantation. Candidates were divided into groups according to the average volume of yearly transplants performed in the listing center over 10 years: >15, 10 to 15, 5 to 9, and <5. We used univariate and multivariate Cox regression analyses with bootstrapping on transplant recipient data and identified independent recipient and donor risk factors for wait-list and posttransplant mortality.

RESULTS

38.5% of the candidates were listed in low-volume centers, those in which <5 transplants were performed annually. These candidates had severely reduced likelihood of transplantation with only 41% receiving a transplant. For the remaining candidates, listed at higher volume centers, the transplant rate was 85% (P < .001). Being listed at a low-volume center was a significant risk factor in multivariate Cox regression analysis for both wait-list mortality (hazard ratio, 3.27; confidence interval, 2.53-4.23) and posttransplant mortality (hazard ratio, 2.21; confidence interval, 1.43-3.40).

CONCLUSIONS

38.5% of pediatric transplant candidates are listed in low-volume transplant centers and have lower likelihood of transplantation and poorer outcomes. If further studies substantiated these findings, we would advocate consolidating pediatric liver transplantation in higher volume centers.

What evidence is there for a relationship between organisational features and patient outcomes in congenital heart disease services? A rapid review

Background

The purpose of this rapid evidence synthesis is to support the current NHS England service review on organisation of services for congenital heart disease (CHD). The evidence synthesis team was asked to examine the evidence on relationships between organisational features and patient outcomes in CHD services and, specifically, any relationship between (1) volume of cases and patient outcomes and (2) proximity of colocated services and patient outcomes. A systematic review published in 2009 had confirmed the existence of this relationship, but cautioned this was not sufficient to make recommendations on the size of units needed.

Objectives

To identify and synthesise the evidence on the relationship between organisational features and patient outcomes for adults and children with CHD.

Data sources

A systematic search of medical- and health-related databases [MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), The Cochrane Library and Web of Science] was undertaken for 2009–14 together with citation searching, reference list checking and stakeholder recommendations of evidence from 2003 to 2014.

Review methods

This was a rapid review and, therefore, the application of the inclusion and exclusion criteria to retrieved records was undertaken by one reviewer, with 10% checked by a second reviewer. Five reviewers extracted data from included studies using a bespoke data extraction form which was subsequently used for evidence synthesis. No formal quality assessment was undertaken, but the usefulness of the evidence was assessed together with limitations identified by study authors.

Results

Thirty-nine papers were included in the review. No UK-based studies were identified and 36 out of 39 (92%) studies included only outcomes for paediatric patients. Thirty-two (82%) studies investigated the relationship between volume and mortality and seven (18%) investigated other service factors or outcomes. Ninety per cent were from the USA, 92% were multicentre studies and all were retrospective observational studies. Twenty-five studies (64%) included all CHD conditions and 14 (36%) included single conditions or procedures. Although the evidence does demonstrate a relationship between volume and outcome in the majority of studies, this relationship is not consistent. The relationship was stronger for single-complex conditions or procedures. A mixed picture emerged revealing a range of factors as well as volume that influence outcome, including condition severity, individual centre and surgeon effects and clinical advances over time. We found limited (seven studies) evidence about the impact of proximity and colocation of services on outcomes, and about volume on non-mortality outcomes.

Limitations

This was a rapid review that followed standard methods to ensure transparency and reproducibility. The main limitations of the included studies were the retrospective nature, reliance on routine data sets, completeness, selection bias and lack of data on key clinical and service-related processes.

Conclusions

This review identified a substantial number of studies reporting a positive relationship between volume and outcome, but the complexity of the evidence requires careful interpretation. The heterogeneity of findings from observational studies suggests that, while a relationship between volume and outcome exists, this is unlikely to be a simple, independent and directly causal relationship. The effect of volume on outcome relative to the effect of other as yet undetermined health system factors remains a complex and unresolved research question.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Creation of a quantitative score to predict the need for mechanical support in children awaiting heart transplant

BACKGROUND

Due to the availability of new devices, the use of ventricular assist devices (VADs) in children has been increasing; however, patient selection and optimal timing of device implantation in this population remains uncertain.

METHODS

A retrospective review of the United Network for Organ Sharing dataset identified 5,200 listings without mechanical circulatory support (MCS) for isolated pediatric heart transplant, 1995 to 2012. Patients were randomly divided into a derivation and validation cohort. A multivariable logistic regression model predicting the likelihood of death or need for MCS within 60 days was built using the derivation cohort and tested in the validation cohort. A simplified score (PedsMCS score) was developed and evaluated for accuracy.

RESULTS

The predictive model consisted of variables present at listing (age, albumin level, creatinine clearance, serum bilirubin, mechanical ventilation, and inotropic support). It had good predictive ability (C statistic 0.7304) within the validation cohort. The simplified PedsMCS score was also predictive (C statistic 0.7217) and there was a strong correlation between predicted and expected outcomes (r=0.91, p<0.0001). Patients with PedsMCS score 16 or greater had a significantly higher risk of death or MCS within 2 months (36.6%) than those with low scores (<6) (1.5%, p<0.0001). A single point increase in PedsMCS score was associated with a 16.7% increase in the risk of death or MCS with 2 months (p<0.0001).

CONCLUSIONS

We have developed and validated a simplified score to predict the need for MCS based on risk factors present at listing. This will provide more accurate prognostication in children awaiting heart transplant, and may improve patient selection.

The right stuff

We will discuss a new initiative of the American College of Surgeons and the American Pediatric Surgical Association to prospectively define optimal resource standards for children's surgical care.

Lower socioeconomic status is associated with worse outcomes after both listing and transplanting children with heart failure

The relationship between SES and outcomes surrounding pediatric cardiac transplantation is complex and influenced by recipient race. Broad-based studies of SES have not been performed. A retrospective review of all 5125 primary pediatric heart transplants performed in the United States between 2000 and 2011. Patients were stratified by SES based on zip code of residence and U.S. census data (low SES: 1637; mid-SES: 2253; high SES: 1235). Survival following listing and transplantation was compared across strata. Risk-adjusted long-term mortality on the waitlist was higher among low SES patients (hazard 1.32, CI 1.07-1.63). The relationship between SES and outcomes varied by race. Early risk-adjusted post-transplant outcomes were worst among high SES patients (10.8% vs. low SES: 8.9%, p < 0.05). The incidence of non-compliance was higher among low SES patients (p < 0.0001). Long-term risk-adjusted patient survival was poorer among low (hazard 1.41, CI 1.10-1.80) and mid-SES (1.29, 1.04-1.59) groups. Low SES is associated with worse outcomes on both the waitlist and late following transplantation. Higher SES patients had more complex transplants with higher early mortality. Further research should be directed at identifying and addressing underlying causal factors for these disparities.

Regional variation in survival before and after pediatric heart transplantation--an analysis of the UNOS database

Geographic variation occurs in a variety of health outcomes. Regional influences on outcomes before and after listing for pediatric heart transplantation have not been assessed. Review of the UNOS dataset identified 5398 pediatric (≤ 18 years) patients listed for heart transplantation 2000-2011. Patients were stratified based on the region of listing. Regional-level variables were correlated with individual risk-adjusted outcomes. Mean time spent on the waitlist varied from 91.0 ± 163 days (Region 6 [R6]) to 248.1 ± 493 days (R4, p < 0.0001). Regions with more transplant centers (p < 0.0001) and fewer transplants (p = 0.0015) had higher waitlist mortality. Risk-adjusted individual waitlist mortality varied from 6.9% (R1, CI 6.2-7.8) to 19.2% (R5, CI 18.0-20.6). Waitlist mortality was higher for individuals awaiting transplant in regions with more listings per center (OR 1.04, CI 1.01-1.08) and lower in regions with more donors per center (OR 0.95, CI 0.90-0.99 per donor). Posttransplant risk-adjusted survival varied across regions (R4: 5.4%, CI 4.2-7.4; R7: 18.0%, CI 12.4-32.5), but regional variables were not correlated with outcomes. Outcomes among children undergoing heart transplantation vary by region. Factors leading to increased competition for donor allografts are associated with poorer waitlist survival. Equitable allocation of cardiac allografts requires further investigation of these findings.

Effect of tonsillar fossa closure on postoperative pain and bleeding risk after tonsillectomy

OBJECTIVE

To determine if closing the tonsil fossa after tonsillectomy leads to less pain and bleeding.

STUDY DESIGN

Interventional, Randomized, Single Blind, Active Control, Single Group Assignment, Safety/Efficacy Study.

FOLLOW-UP

2 months.

METHODS

Generalized Estimating Equations (GEE) analyzed effects of tonsillar pillar closure, surgeon experience and interaction on outcomes.

SETTING

Primarily academic tertiary care referral center, institutional practice, primarily children, both ambulatory and hospitalized care.

SUBJECTS

763 subjects (age 8-264 months) undergoing tonsillectomy.

EXCLUSIONS

suspected malignancy or active peritonsillar abscess. At the discretion of the attending surgeon, patients undergoing tonsillectomy during the 4 year study period were offered participation. A computer selected the side closed. 131 subjects withdrew (complete lack of follow-up information) after the first 72 h.

INTERVENTION

3-0 chromic sutures on tapered needles to close one tonsillar fossa. The subject was not told which side was closed.

MAIN OUTCOME MEASURES

postoperative bleeding (at any time) and pain reported was sought on days 1, 7, 14, 21, and 28.

RESULTS

Closure of the tonsillar fossa did not change the risk of bleeding. Closing the tonsillar fossa had a 40% increase in the odds ratio of postoperative pain. In the tonsillar fossa sides left open, greater surgeon experience decreased the risk of bleeding. In closed sides, enriched surgeon experience increased the risk of bleeding (p<.0.05).

CONCLUSIONS

Suture closure of the tonsillar fossa after tonsillectomy does not reduce the risk of bleeding. Additionally, closing the tonsillar fossa increased postoperative pain.

LEVEL OF EVIDENCE

1b (individual randomized controlled trial).

Relationship between pediatric blood and marrow transplant center volume and day +100 mortality: Pediatric Blood and Marrow Transplant Consortium experience

The number of patients receiving a BMT is currently being used as a factor in the accreditation process in determining whether a center can provide a high-quality BMT. Such criteria particularly impact pediatric BMT centers as most of them perform a relatively small number of BMTs. To determine whether patient volume is a valid marker of pediatric BMT center's capabilities, the Pediatric Blood and Marrow Transplant Consortium (PBMTC) evaluated data from its registry to define the relationship between a pediatric transplant center's patient volume and day +100 mortality. The analyses evaluated 2575 transplants from 60 centers reporting to the PBMTC between the years 2002 and 2004. The volume-outcome relationship was evaluated while adjusting for 46 independent data categories divided between nine variables that were known- or suspected-mortality risk factors. We found no association between transplant center volume and day +100 mortality in several analyses. A calculated intraclass correlation coefficient also indicated that differences in individual transplant center volume contributed to only 1% of the variance in day +100 mortality within the PBMTC. The results of this study suggest that factors other than transplant center volume contribute to variation in day +100 mortality among pediatric patients.

Using the UNOS/SRTR and PHTS Databases to Improve Quality in Pediatric Cardiac Transplantation

Data collection and dissemination have been a part of the US transplant experience since its earliest days. As part of this process, the United Network for Organ Sharing (UNOS) has provided open access to its data. In addition, multiinstitutional groups such as the Pediatric Heart Transplant Study (PHTS) have collected data of particular interest to pediatric and congenital transplants. This wealth of data enables quality improvement along several pathways including individual program assessment and improvement and development of both structure and process measures for ongoing improvement. Extensive literature exists utilizing these data, but must be read critically, recognizing the limitations presented by missing variables (whether uncollected or collected but left blank), reproducibility, and small sample sizes among pediatric patients. However, despite these limitations, opportunity continues to exist to apply these data sets to ongoing questions of quality and optimize organ allocation and long-term survival among pediatric patients with heart failure.

Volume-outcome effects for children undergoing resection of renal malignancies

INTRODUCTION

Adults undergoing oncologic resections at low-volume centers experience increased perioperative morbidity and mortality. The volume-outcome effect has not been extensively studied in pediatric oncologic resections.

METHODS

To clarify volume-outcome effects in pediatric oncologic resections, we analyzed resection of renal malignancies in children less than 15 y of age. We conducted a cross-sectional analysis of hospital discharges included in the health care utilization project kids' inpatient database from 1997 to 2009, examining in-hospital operative complications, length of stay (LOS), and inflation-adjusted hospital charges. Hospital volume was expressed as low (n = 1-2), medium (n = 3-4), and high (n > 4) annual volume of resections.

RESULTS

One thousand five hundred thirty-eight patients underwent renal malignancy resection. Of these, 527 patients had resection in low-, 422 in medium-, and 589 in high-volume hospitals. Relative to low-volume hospitals, those resected in medium-volume hospitals had an odds ratio of 0.62 (95% confidence interval 0.39-0.99, P = 0.046) for operative complication and those in high-volume hospitals had an odds ratio of 1.02 (95% confidence interval 0.63-1.65, P = 0.95). There was no detectable association with LOS (P = 0.113) or inflation-adjusted charges (P = 0.331).

CONCLUSIONS

The number of complications, total charges, and LOS attributable to resection of a childhood renal malignancy did not differ among high-, medium-, or low-operative volume hospitals, although oncologic outcomes could not be determined because of the limited nature of this administrative database.

[Pediatric cardiology and congenital heart disease: from fetus to adult]

This article contains a review of some of the most important publications on congenital heart disease and pediatric cardiology that appeared in 2010 and up until September 2011. Of particular interest were studies on demographic changes reported in this patient population and on the need to manage the patients' transition from the pediatric to the adult cardiology department. This transition has given rise to the appearance of new areas of interest: for example, pregnancy in women with congenital heart disease, and the effect of genetic factors on the etiology and transmission of particular anomalies. In addition, this review considers some publications on fetal cardiology from the perspective of early diagnosis and, if possible, treatment. There follows a discussion on new contributions to Eisenmenger's syndrome and arrhythmias, as well as on imaging techniques, interventional catheterization and heart transplantation. Finally, there is an overview of the new version of clinical practice guidelines on the management of adult patients with congenital heart disease and of recently published guidelines on pregnancy in women with heart disease, both produced by the European Society of Cardiology.

Commentary: beyond educational initiatives: how can we change health care to improve the health of persons with disabilities?

Minihan and colleagues discuss necessary elements of an educational program to instruct generalist physicians in the care of individuals with disabilities. To support these physicians adequately in practice will require significant adaptations of health care financing, recognition of the unique medical needs of persons with disabilities, and efficient utilization of experienced clinical resources. The author outlines what remains to be addressed in the pursuit of better health for patients with disabilities as the U.S. health care system evolves.