Critical Care Therapies Pre and Post Heart Transplant and Their Impact: Analysis from The Pediatric Cardiac Critical Care Consortium.

BACKGROUND: Few studies highlighting the critical care management of patients after heart HTx (HTx) have been published to date. This analysis provides a contemporary representation of critical care burden pre- and post-HTx, describes care differences based on pre-transplant diagnosis and outlines the impact of intensive care unit (ICU) therapies on outcomes. METHODS: Data from PC4 Collaborative Registry was analyzed for pediatric patients undergoing HTx between 08/2014-04/2022. RESULTS: 1877 HTx in 1857 patients were reported from 42 centers; 56.5% had congenital heart disease (CHD). Patients with CHD were younger, smaller, more likely male, White race, and publicly insured. Their pre-HTx ICU course was characterized by a higher need for catheterization, increased likelihood of inotropic support and mechanical ventilation with lower VAD rates. Their operative courses were significant for longer bypass and cross-clamp times. Postoperatively, CHD patients required more CPR and utilized more ICU therapies such as inotropes, ECMO and renal replacement. Those with CHD had a longer duration of ventilatory support (68.6 vs. 27.3 hours), total hospital stays (37.1 vs. 22.9 days) and higher hospital mortality (7.8% vs. 1.8%); all p<0.0001. Longer cardiopulmonary bypass and longer deep hypothermic circulatory arrest times and delayed sternal closure were independent risk factors for hospital mortality. Lastly, there was no association between total surgical volume for a center and outcomes but there was a significant relationship between center transplant volume and outcomes with higher volume centers demonstrating significantly lower mortality. CONCLUSION: A diagnosis of CHD prior to HTx is associated with a greater use of ICU specific therapies compared non-CHD cohort. Operative factors, particularly in CHD patients, are independently associated with higher hospital mortality as was low transplant volume at the center. The study provides basis for further investigating ICU and operative factors that can be modified to improve transplant outcomes.

DQB1 antigen matching improves rejection-free survival in pediatric heart transplant recipients.

BACKGROUND: Presence of donor-specific antibodies (DSAs), particularly to class II antigens, remains a major challenge in pediatric heart transplantation. Donor-recipient human leukocyte antigen (HLA) matching is a potential strategy to mitigate poor outcomes associated with DSAs. We evaluated the hypothesis that antigen mismatching at the DQB1 locus is associated with worse rejection-free survival. METHODS: Data were collected from Scientific Registry of Transplant Recipients for all pediatric heart transplant recipients 2010-2021. Only transplants with complete HLA typing at the DQB1 locus for recipient and donor were included. Primary outcome was rejection-free graft survival through 5 years. RESULTS: Of 5,115 children, 4,135 had complete DQB1 typing and were included. Of those, 503 (12%) had 0 DQB1 donor-recipient mismatches, 2,203 (53%) had 1, and 1,429 (35%) had 2. Rejection-free survival through 5 years trended higher for children with 0 DQB1 mismatches (68%), compared to those with 1 (62%) or 2 (63%) mismatches (pairwise p = 0.08 for both). In multivariable analysis, 0 DQB1 mismatches remained significantly associated with improved rejection-free graft survival compared to 2 mismatches, while 1 DQB1 mismatch was not. Subgroup analysis showed the strongest effect in non-Hispanic Black children and those undergoing retransplant. CONCLUSIONS: Matching at the DQB1 locus is associated with improved rejection-free survival after pediatric heart transplant, particularly in Black children, and those undergoing retransplant. Assessing high-resolution donor typing at the time of allocation may further corroborate and refine this association. DQB1 matching may improve long-term outcomes in children stabilized either with optimal pharmacotherapy or supported with durable devices able to await ideal donors.

Successful implementation of telehealth visits in the paediatric heart failure and heart transplant population.

The Advanced Cardiac Therapies Improving Outcomes Network (ACTION) and Pediatric Heart Transplant Society (PHTS) convened a working group at the beginning of 2020 during the COVID-19 pandemic, with the aim of using telehealth as an alternative medium to provide quality care to a high-acuity paediatric population receiving advanced cardiac therapies. An algorithm was developed to determine appropriateness, educational handouts were developed for both patients and providers, and post-visit surveys were collected. Telehealth was found to be a viable modality for health care delivery in the paediatric heart failure and transplant population and has promising application in the continuity of follow-up, medication titration, and patient education/counselling domains.

Three decades of collaboration through the Pediatric Heart Transplant Society Registry: A journey through registry data with a highlight on children with single ventricle anatomy.

BACKGROUND: The Pediatric Heart Transplant Society (PHTS) Registry was founded 30 years ago as a collaborative effort among like-minded providers of this novel life-saving technique for children with end-stage heart failure. In the intervening decades, the data from the Registry have provided invaluable knowledge to the field of pediatric heart transplantation. This report of the PHTS Registry provides a comprehensive look at the data, highlighting both the longevity of the registry and one unique aspect of the PHTS registry, allowing for exploration into children with single ventricle anatomy. METHODS: The PHTS database was queried from January 1, 1993 to December 31, 2019 to include pediatric (age < 18 years) patients listed for HT. For our analysis, we primarily analyzed patients by era. The early era was defined as children listed for HT from January 1, 1993 to December 31, 2004; middle era January 1, 2005 to December 31, 2009; and recent era January 1, 2010 to December 31, 2019. Outcomes after listing and transplant, including mortality and morbidities, are presented as unadjusted for risk, but compared across eras. RESULTS: Since 1993, 11 995 children were listed for heart transplant and entered into the PHTS Registry with 9755 listed during the study period. The majority of listings occurred within the most recent era. Waitlist survival improved over the decades as did posttransplant survival. Other notable changes over time include fewer patients experiencing allograft rejection or infection after transplant. Waitlist and posttransplant survival have changed dramatically in patients with single ventricle physiology and significantly differ by stage of single ventricle palliation. SUMMARY: Key points from this PHTS Registry summary and focus on patients with single ventricle congenital heart disease in particular, include the changing landscape of candidates and recipients awaiting heart transplant. There is clear improvement in waitlist and transplant outcomes for children with both cardiomyopathy and congenital heart disease alike.

Novel uses for implanted haemodynamic monitoring in adults with subaortic right ventricles.

BACKGROUND: Pulmonary hypertension (PH) is a common complication in patients with complete dextro-transposition of the great arteries (TGA) after atrial switch (D-TGA/AS) and congenitally corrected TGA (ccTGA). In this population with subaortic right ventricles (sRVs), echocardiography is a poor screening tool for PH; implantable invasive haemodynamic monitoring (IHM) could be used for this purpose, but data are limited. The aim of this study is to report on novel uses of IHM in patients with sRV. METHODS: This retrospective study describes the uses of IHM, impact of IHM on heart failure hospitalisation (HFH) and device-related complications in adults with sRV from a single centre (2015-2022). RESULTS: IHM was placed in 18 patients with sRV (median age 43 (range 30-54) years, 8 female, 16 with D-TGA/AS, 2 with ccTGA); 16 had moderate or severe sRV systolic dysfunction, 13 had PH on catheterisation. IHM was used for (1) Medical therapy titration, (2) Medical management after ventricular assist device in patients with transplant-limiting PH and (3) Serial monitoring of pulmonary artery pressures without repeat catheterisations to help identify the optimal time for heart transplant referral. In follow-up (median 23 months), HFHs/year were similar to the year prior to IHM (median 0 (IQR 0-1.0) before vs 0 (0-0.8) after, p=0.984). Device migration occurred in one, without long-term sequelae. CONCLUSIONS: Uses of IHM in patients with sRV are described which may minimise the need for serial catheterisations in a population where PH is prevalent. HFHs were low overall but not impacted by IHM. One device-related complication occurred without long-term consequence.

An in vitro comparison of intra-operative isohemagglutinin and human leukocyte antigen removal techniques in pediatric heart transplantation.

BACKGROUND: Highly sensitized pediatric patients awaiting heart transplantation experience longer wait times and thus higher waitlist mortality. Similarly, children less than 2 years of age have increased waitlist times and mortality when compared to their older peers. To improve the likelihood of successful transplantation in these patients, various strategies have been utilized, including peri-operative plasmapheresis. However, limited data exists comparing plasmapheresis techniques for antibody reduction. This study's aim was to compare the in vitro magnitude of isohemagglutinin titers (IT) and human leukocyte antigen (HLA) antibody removal and the time required between membrane-based plasmapheresis (MP) and centrifuge-based plasmapheresis (CP) incorporated into the extracorporeal (EC) circuit. METHODS: Two MP (Prismaflex) and two CP (Spectra Optia, Terumo BCT) circuits were incorporated into four separate EC circuits primed with high titer, highly sensitized type O donor whole blood. Assays were performed to determine baseline IT and anti-HLA antibodies and then at 30-minute increments until completion of the run (two plasma volume exchanges) at two hours. RESULTS: There was a decrease in anti-A and anti-B IgM and IgG titers with both MP and CP. Mean anti-A and anti-B titer reduction was by 4.625 titers (93.7% change) and 4.375 titers (93.8% change) using MP and CP, respectively. At 2 h of apheresis, CP reduced 62.5% of all ITs to ≤ 1:4, while MP reduced 50% of ITs to ≤ 1:4. Additionally, reduction of anti-HLA class II antibody to mean fluorescence intensity (MFI) <3000 was achieved with both MP and CP. At 2 h of apheresis, CP reduced MFI by 2-3.5 fold and MP reduced MFI by 1.7-2.5 fold. Both demonstrated similar hemolytic and thrombotic profiles. CONCLUSIONS: In this in vitro plasmapheresis model of IT and anti-HLA antibody reduction, both MP and CP incorporated into the EC circuit can be used quickly and effectively to reduce circulating antibodies. While CP may have some greater efficiency, further study is necessary to verify this in vivo.

Improving Situational Awareness to Decrease Emergency ICU Transfers for Hospitalized Pediatric Cardiology Patients.

Introduction: Failure to recognize and mitigate critical patient deterioration remains a source of serious preventable harm to hospitalized pediatric cardiac patients. Emergency transfers (ETs) occur 10-20 times more often than code events outside the intensive care unit (ICU) and are associated with morbidity and mortality. This quality improvement project aimed to increase days between ETs and code events on an acute care cardiology unit (ACCU) from a baseline median of 17 and 32 days to ≥70 and 90 days within 12 months. Methods: Institutional leaders, cardiology-trained physicians and nurses, and trainees convened, utilizing the Institution for Healthcare Improvement model to achieve the project aims. Interventions implemented focused on improving situational awareness (SA), including a "Must Call List," evening rounds, a visual management board, and daily huddles. Outcome measures included calendar days between ETs and code events in the ACCU. Process measures tracked the utilization of interventions, and cardiac ICU length of stay was a balancing measure. Statistical process control chart methodology was utilized to analyze the impact of interventions. Results: Within the study period, we observed a centerline shift in primary outcome measures with an increase from 17 to 56 days between ETs and 32 to 62 days between code events in the ACCU, with sustained improvement. Intervention utilization ranged from 87% to 100%, and there was no observed special cause variation in our balancing measure. Conclusions: Interventions focused on improving SA in a particularly vulnerable patient population led to sustained improvement with reduced ETs and code events outside the ICU.

Proactive risk mitigation for cardiac arrest prevention in high-risk patients with congenital heart disease.

Objective: The prevalence of postoperative cardiac arrest (CA) increases with cardiothoracic surgical case complexity and is associated with a 40% to 50% mortality. Despite having a low overall surgical mortality rate at our center, our postoperative CA rates were higher than expected, with an observed-to-expected ratio of 2.6. Utilizing quality improvement methodology, we evaluated the influence of proactive risk mitigation on postprocedure CA in a high-risk cohort of pediatric cardiac patients. Methods: This single-center study utilized the Institute for Healthcare Improvement model. We created and implemented our Proactive Mitigation to Decrease Serious Adverse Events program in July 2020, prospectively enrolling preidentified high-risk patients. Enrolled patients underwent scheduled multidisciplinary reviews via virtual platform at 2 periprocedural time points with discussion of patient-specific risks and the subsequent development of proactive risk mitigation plans. Primary outcome measures were derived from the Pediatric Cardiac Critical Care Consortium national registry and included rate of postprocedure CA within 7 days and an institution-specific observed-to-expected ratio for postoperative CA. Results: Our baseline median number of high-risk cases between postprocedure CAs was 3. Following project initiation, median high-risk cases between events increased to 7. Our observed-to-expected ratio for postoperative CA decreased from 2.56 during the 12 months before Proactive Mitigation to Decrease Serious Adverse Events program implementation to 1.01 during the 12 months after Proactive Mitigation to Decrease Serious Adverse Events program implementation, and hospital length of stay decreased by ∼10 days. Conclusions: Implementation of periprocedure-related proactive risk mitigation strategies in high-risk pediatric cardiac patients led to improvement in postprocedure CA with a 133% increase in high-risk cases between events.

Increasing the Percentage of Neonates Consuming Human Milk in a Pediatric Cardiothoracic Intensive Care Unit: A Quality Improvement Initiative.

OBJECTIVE: To address a known nutritional deficit and enhance the overall health of critically ill babies, this project sought to increase the percentage of cardiothoracic intensive care unit (CTICU) neonates consuming human milk from a 2019 baseline of 55% to 75% by December 2020 and 90% by December 2021. STUDY DESIGN: This was a quality improvement initiative targeted to all neonates admitted to the CTICU, with baseline data obtained from January 2019 through February 2020. We implemented 11 interventions from March 2020 to January 2022 to address the key drivers of "education of parents and providers," "environment/equipment," and "process." We tracked the monthly percentage of neonates who were human milk fed with a statistical process control p-chart. The balancing measure of critical human milk feeding errors was also monitored. RESULTS: The baseline percentage of CTICU neonates consuming human milk was 55%. This percentage increased to 73% by the end of 2020 and 92% by the year end 2021. Most neonates who received human milk were fed mother's milk with a minority receiving donor human milk. The number of aborted, critical human milk administration errors decreased during the intervention period. CONCLUSIONS: In this quality improvement initiative, we significantly increased the percentage of CTICU neonates consuming human milk without an increase in critical human milk errors. Interventions directly increasing the ease with which lactating mothers can provide/store their milk were likely the most effective.

Racial and socioeconomic disparities in status exceptions for pediatric heart transplant candidates under the current U.S. Pediatric Heart Allocation Policy.

BACKGROUND: The 2016 revision of the US Pediatric Heart Allocation Policy developed stringent rules for priority status creating impetus for clinicians to seek status exceptions. We hypothesized there may be differential status exceptions based on race and socioeconomic status (SES) contributing to disparities in waitlist outcomes. METHODS: The Scientific Registry for Transplant Recipients was queried for children listed for heart transplant from 2012 to 2020. Waitlist status & mortality with regards to race and neighborhood SES were stratified by listing before (Era 1) or after (Era 2) the policy change. RESULTS: The use of both 1A and 1B exceptions (E) increased in Era 2. In Era 1, there was no association between patient race or neighborhood SES on use of 1A(E) or 1B(E) when controlling for age and diagnosis. In Era 2, neither race nor neighborhood SES were associated with 1A(E), but both were associated with 1B(E): non-Hispanic (NH) Black children and those from low- and middle-SES neighborhoods were significantly less likely to be listed 1B(E). In Era 1, there were no significant differences in waitlist mortality based on race at any waitlist status; in Era 2, NH Black children had higher waitlist mortality when initially listed 1B or 2. CONCLUSIONS: Since the 2016 policy change, racial disparities in waitlist mortality have worsened among children initially listed with lower priority status. Unequal use of 1B exceptions, which lower waitlist mortality, may explain some of these disparities. Recently implemented standardized pediatric exception guidance has the potential to improve equity.

Considerations for Advanced Heart Failure Consultation in Individuals With Fontan Circulation: Recommendations From ACTION.

Individuals with Fontan circulation are at risk of late mortality from both cardiac and noncardiac causes. Despite the known risk of mortality, referral indications for advanced heart failure care vary between centers, and many individuals die from Fontan circulation-related complications either after late consideration for advanced heart failure therapies or having never seen a heart failure specialist. There is a critical need for guidelines to direct appropriately timed referral for advanced heart failure consultation. The Advanced Cardiac Therapies Improving Outcomes Network (ACTION) Fontan Committee has developed recommended thresholds for advanced heart failure referral to guide primary cardiologists. These recommendations are divided into 4 categories of clinical Fontan circulatory dysfunction including (1) cardiac/systemic ventricular dysfunction, (2) Fontan pathway dysfunction, (3) lymphatic dysfunction, and (4) extracardiac dysfunction.

Worsening racial disparity in waitlist mortality for pediatric heart transplant candidates since the 2016 Pediatric Heart Allocation Policy revision.

BACKGROUND: The US Pediatric Heart Allocation Policy (PHAP) was revised in March 2016, with the goal of reducing waitlist mortality. We evaluated the hypothesis that these changes, which increased status exceptions, have worsened racial disparities in waitlist outcomes. METHODS: Children in the Pediatric Heart Transplant Study database listed for first heart transplant from January 2012 - June 2020 were included and stratified by listing before (Era 1) or after (Era 2) the PHAP revision. RESULTS: A total of 4,089 children were listed during the study period. Compared with white children (n = 2648), non-white children (n = 1441) were more likely to have an underlying diagnosis of cardiomyopathy in both eras. Waitlist mortality was similar in white and non-white children in Era 1, but comparatively worse for non-white children in Era 2. In multivariable analysis controlling for diagnosis, age, and severity markers, non-white children had a significantly higher waitlist mortality only in Era 2 (Era 1: sHR 1.22 [95%CI 0.90 - 1.66] vs. Era 2: sHR 1.57 [95%CI 1.17 - 2.10]). CONCLUSIONS: Widening racial disparities in waitlist mortality may be an unintended consequence of the 2016 PHAP revision. Additional analyses may inform the degree to which this policy vs. unrelated changes in care differentially contribute to these disparities.

Evidence-Based Guidelines for Acute Stabilization and Management of Neonates with Persistent Pulmonary Hypertension of the Newborn.

Persistent pulmonary hypertension of the newborn, or PPHN, represents a challenging condition associated with high morbidity and mortality. Management is complicated by complex pathophysiology and limited neonatal specific evidence-based literature, leading to a lack of universal contemporary clinical guidelines for the care of these patients. To address this need and to provide consistent high-quality clinical care for this challenging population in our neonatal intensive care unit, we sought to develop a comprehensive clinical guideline for the acute stabilization and management of neonates with PPHN. Utilizing cross-disciplinary expertise and incorporating an extensive literature search to guide best practice, we present an approachable, pragmatic, and clinically relevant guide for the bedside management of acute PPHN. KEY POINTS: · PPHN is associated with several unique diagnoses; the associated pathophysiology is different for each unique diagnosis.. · PPHN is a challenging, dynamic, and labile process for which optimal care requires frequent reassessment.. · Key management goals are adequate tissue oxygen delivery, avoiding harm..

Data-driven computational models of ventricular-arterial hemodynamics in pediatric pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a complex disease involving increased resistance in the pulmonary arteries and subsequent right ventricular (RV) remodeling. Ventricular-arterial interactions are fundamental to PAH pathophysiology but are rarely captured in computational models. It is important to identify metrics that capture and quantify these interactions to inform our understanding of this disease as well as potentially facilitate patient stratification. Towards this end, we developed and calibrated two multi-scale high-resolution closed-loop computational models using open-source software: a high-resolution arterial model implemented using CRIMSON, and a high-resolution ventricular model implemented using FEniCS. Models were constructed with clinical data including non-invasive imaging and invasive hemodynamic measurements from a cohort of pediatric PAH patients. A contribution of this work is the discussion of inconsistencies in anatomical and hemodynamic data routinely acquired in PAH patients. We proposed and implemented strategies to mitigate these inconsistencies, and subsequently use this data to inform and calibrate computational models of the ventricles and large arteries. Computational models based on adjusted clinical data were calibrated until the simulated results for the high-resolution arterial models matched within 10% of adjusted data consisting of pressure and flow, whereas the high-resolution ventricular models were calibrated until simulation results matched adjusted data of volume and pressure waveforms within 10%. A statistical analysis was performed to correlate numerous data-derived and model-derived metrics with clinically assessed disease severity. Several model-derived metrics were strongly correlated with clinically assessed disease severity, suggesting that computational models may aid in assessing PAH severity.

Outcomes of infants with pulmonary atresia with intact ventricular septum listed for heart transplantation: A multi-institutional study.

BACKGROUND: Management of infants with pulmonary atresia/intact ventricular septum (PA/IVS) is variable. Because of higher mortality in more severe forms, heart transplant (HT) is an acceptable approach, but waitlist and post-transplant outcomes are unclear. This study compared outcomes of infants with PA/IVS vs. other single ventricle (SV) anatomies listed for HT. METHODS: Data from the Pediatric Heart Transplant Society (1993-2018) were analyzed for survival and risk factors for mortality. RESULTS: Of 1617 SV infants, 300 had PA/IVS (19%) and 1317 had other SV (81%). Overall, 1-, 5-, and 10-year survival was higher among PA/IVS (74%, 65%, 61%) versus other SV infants (62%, 54%, 50%, p = .004). While waitlist mortality was similar between groups (p = .09), PA/IVS was an independent predictor of improved waitlist survival (HR 0.68, p = .03), and PA/IVS infants had higher incidence of waitlist removal (8% vs. 5.5%, p = .03), most commonly for being "too well." Post-transplant survival was superior among PA/IVS versus other SV infants (1- and 5-year survival 93% and 81% vs. 80% and 71%, p < .0001). Risk factors for PA/IVS waitlist mortality (2008-2018) included extracorporeal membrane oxygenation and mechanical ventilation. Prior aortopulmonary (AP) shunt among PA/IVS infants was associated with improved waitlist survival. CONCLUSIONS: Overall survival among PA/IVS infants listed for HT exceeds that of other SV infants with PA/IVS identified as an independent predictor of improved waitlist and post-transplant survival. Prior AP shunt among listed PA/IVS infants was associated with improved waitlist outcomes, though, which may reflect a listing selection bias.

Decreased Risk of Strokes in Children with Ventricular Assist Devices Within ACTION.

We sought to characterize strokes in children with ventricular assist devices. Of 407 patients in the ACTION registry (4/1/18-5/3/2021), 45 (11%) experienced 52 strokes (45 ischemic and 7 hemorrhagic). Median time to stroke was 23.5 days and 19/52 (37%) occurred ≤ 10 days. Stroke rate was 0.09 and 0.63 strokes per patient-year for implantable continuous and paracorporeal devices, respectively. Patients with stroke were younger, more likely to have congenital heart disease and have been on extracorporeal membrane oxygenation at time of VAD. Based on these data, ACTION is now focused on decreasing strokes in these higher-risk patients with particular attention to the peri-implant period.

Standardization of Care Reduces Length of Stay for Postoperative Congenital Heart Disease Patients.

Congenital heart disease (CHD), the most common congenital malformation, often requires surgical correction. As surgical mortality rates are low, a common quality marker linked with surgical outcomes is hospital length of stay (LOS). Reduced LOS is associated with better long-term outcomes, reduced hospital-acquired complications, and improved patient-family satisfaction. This project aimed to reduce aggregate median postoperative LOS for four CHD lesions from a baseline of 6.2 days by 10%. METHODS: This single-center study utilized the Institute for Healthcare Improvement model to achieve the project aim. A diuretic wean protocol implemented in April 2018 entailed weaning to a homegoing diuretic regimen upon transfer from the cardiac intensive care unit to the inpatient step-down unit. A discharge milestone checklist implemented in September 2018 contained milestones necessary for discharge and an anticipated date of discharge. Outcome measures included aggregate median postoperative LOS and ∆LOS. Balancing measures included cardiac intensive care unit bounce back, pleural chest tube replacement, and readmission rates. RESULTS: Our baseline aggregate median postoperative LOS for the lesions studied was 6.2 days. Following diuretic protocol implementation, the aggregate median LOS decreased to 4.4 days. Baseline ∆LOS decreased from 5.5 to 0.42 days. Postoperative cost fell by an average of $11,874. Balancing measures demonstrated no unintended consequences. CONCLUSIONS: Implementation of a diuretic wean protocol led to sustained improvement in postoperative LOS, and ∆LOS in a subset of CHD patients with no unintended consequences supporting that standardization of postoperative care is effective for improvement efforts and can reduce overall practice variation.

The Diagnostic Error Index: A Quality Improvement Initiative to Identify and Measure Diagnostic Errors.

OBJECTIVE: To develop a diagnostic error index (DEI) aimed at providing a practical method to identify and measure serious diagnostic errors. STUDY DESIGN: A quality improvement (QI) study at a quaternary pediatric medical center. Five well-defined domains identified cases of potential diagnostic errors. Identified cases underwent an adjudication process by a multidisciplinary QI team to determine if a diagnostic error occurred. Confirmed diagnostic errors were then aggregated on the DEI. The primary outcome measure was the number of monthly diagnostic errors. RESULTS: From January 2017 through June 2019, 105 cases of diagnostic error were identified. Morbidity and mortality conferences, institutional root cause analyses, and an abdominal pain trigger tool were the most frequent domains for detecting diagnostic errors. Appendicitis, fractures, and nonaccidental trauma were the 3 most common diagnoses that were missed or had delayed identification. CONCLUSIONS: A QI initiative successfully created a pragmatic approach to identify and measure diagnostic errors by utilizing a DEI. The DEI established a framework to help guide future initiatives to reduce diagnostic errors.