Proteomics discovery in children and young adults with HIV identifies fibrosis, inflammatory, and immune biomarkers associated with myocardial impairment

People with HIV are at increased risk of cardiac dysfunction; however, limited tools are available to identify patients at highest risk for future cardiac disease. We performed proteomic profiling using plasma samples from children and young adults with perinatally acquired HIV without clinical cardiac disease, comparing samples from participants with and without an abnormal myocardial performance index (MPI). We identified four proteins independently associated with subclinical cardiac dysfunction: ST2, CA1, EN-RAGE, and VSIG2.

Correlating Severity of Pulmonary Hypertension by Echocardiogram with Mortality in Premature Infants with Bronchopulmonary Dysplasia

OBJECTIVE

 Bronchopulmonary dysplasia (BPD) is the most common complication of preterm birth. Infants with BPD are at increased risk for pulmonary hypertension (PH). Cardiac catheterization is the gold standard for diagnosing PH, but cardiac catheterization is challenging to perform in small, sick, premature infants. The utility of echocardiography for diagnosing PH and predicting outcomes in extremely premature infants has not been clearly defined. Therefore, we sought to use predefined criteria to diagnose PH by echocardiogram and relate PH severity to mortality in extremely premature infants with BPD.

STUDY DESIGN

 Echocardiograms from 46 infants born ≤28 weeks' postmenstrual age with a diagnosis of BPD were assessed for PH by three pediatric cardiologists using predefined criteria, and survival times among categories of PH patients were compared. A total of 458 echocardiograms were reviewed, and 15 (33%) patients were found to have at least moderate PH. Patients with at least moderate PH had similar demographic characteristics to those with no/mild PH.

RESULTS

 Ninety percent of infants without moderate to severe PH survived to hospital discharge, compared with 67% of infants with at least moderate PH (p = 0.048). Patients with severe PH had decreased survival to hospital discharge (38%) compared with moderate (100%) and no/mild PH (90%) groups. Kaplan-Meier survival curves also differed among PH severity groups (Wilcoxon p < 0.001).

CONCLUSION

 Using predefined criteria for PH, premature infants with BPD can be stratified into PH severity categories. Patients diagnosed with severe PH by echocardiogram have significantly reduced survival.

KEY POINTS

· A composite score definition of PH by echocardiogram showed high inter- and intrarater reliability.. · Infants with severe PH by echocardiogram had decreased survival rates.. · Early diagnosis of PH by echocardiogram dictates treatment which may improve outcomes..

Detection of occult thrombosis in individuals with Fontan circulation by cardiac MRI

OBJECTIVE

Identifying thrombus formation in Fontan circulation has been highly variable, with reports between 17 and 33%. Initially, thrombus detection was mainly done through echocardiograms. Delayed-enhancement cardiac MRI is emerging as a more effective imaging technique for thrombus identification. This study aims to determine the prevalence of occult cardiac thrombosis in patients undergoing clinically indicated cardiac MRI.

METHODS

A retrospective chart review of children and adults in the Duke University Hospital Fontan registry who underwent delayed-enhancement cardiac MRI. Individuals were excluded if they never received a delayed-enhancement cardiac MRI or had insufficient data. Demographic characteristics, native heart anatomy, cardiac MRI measurements, and thromboembolic events were collected for all patients.

RESULTS

In total, 119 unique individuals met inclusion criteria with a total of 171 scans. The median age at Fontan procedure was 3 (interquartile range 1, 4) years. The majority of patients had dominant systemic right ventricle. Cardiac function was relatively unchanged from the first cardiac MRI to the third cardiac MRI. While 36.4% had a thrombotic event by history, only 0.5% (1 patient) had an intracardiac thrombus detected by delayed-enhancement cardiac MRI.

CONCLUSIONS

Despite previous echocardiographic reports of high prevalence of occult thrombosis in patients with Fontan circulation, we found very low prevalence using delayed-enhancement cardiac MRI. As more individuals are reaching adulthood after requiring early Fontan procedures in childhood, further work is needed to develop thrombus-screening protocols as a part of anticoagulation management.

Obesity Predisposes Anthracycline-Treated Survivors of Childhood and Adolescent Cancers to Subclinical Cardiac Dysfunction

Anthracyclines are effective chemotherapeutics used in approximately 60% of pediatric cancer cases but have a well-documented risk of cardiotoxicity. Existing cardiotoxicity risk calculators do not include cardiovascular risk factors present at the time of diagnosis. The goal of this study is to leverage the advanced sensitivity of strain echocardiography to identify pre-existing risk factors for early subclinical cardiac dysfunction among anthracycline-exposed pediatric patients. We identified 115 pediatric patients with cancer who were treated with an anthracycline between 2013 and 2019. Peak longitudinal left ventricular strain was retroactively calculated on 495 surveillance echocardiograms via the TOMTEC AutoSTRAIN software. Cox proportional hazards models were employed to identify risk factors for abnormal longitudinal strain (> - 16%) following anthracycline treatment. High anthracycline dose (≥ 250 mg/m2 doxorubicin equivalents) and obesity at the time of diagnosis (BMI > 95th percentile-for-age) were both significant predictors of abnormal strain with hazard ratios of 2.79, 95% CI (1.07-7.25), and 3.85, 95% CI (1.42-10.48), respectively. Among pediatric cancer survivors, patients who are obese at the time of diagnosis are at an increased risk of sub-clinical cardiac dysfunction following anthracycline exposure. Future studies should explore the incidence of symptomatic cardiomyopathy 10-15 years post-treatment among patients with early subclinical cardiac dysfunction.

Diffuse myocardial fibrosis is uncommon in people with perinatally acquired human immunodeficiency virus infection

BACKGROUND

Cardiovascular disease (CVD) remains a leading cause of death in people living with HIV. Myocardial fibrosis is well-described in HIV infection acquired in adulthood. We evaluate the burden of fibrosis by cardiac magnetic resonance in people with perinatal HIV infection.

METHODS

Individuals with perinatally acquired HIV (pnHIV) diagnosed before 10 years-old and on antiretroviral treatment for ≥ 6 months were matched with uninfected controls. Patients with significant cardiometabolic co-morbidities and pregnancy were excluded. Diffuse fibrosis was assessed by cardiac magnetic resonance (CMR) with native T1 mapping for calculation of extracellular volume fraction (ECV). Viability was assessed with late gadolinium enhancement. The normality of fibrosis was assessed using the Komogrov-Smirnov test. Fibrosis between the groups was analyzed using a Mann-Whitney U test, as the data was not normally distributed. Statistical significance was defined as a p-valve < 0.05.

RESULTS

Fourteen adults with pnHIV group and 26 controls (71% female and 86% Black race) were assessed. The average (± standard deviation) age in the study group was 29 (± 4.3) years-old. All pnHIV had been on ART for decades. Demographic data, CMR functional/volumetric data, and pre-contrast T1 mapping values were similar between groups. Diastolic function was normal in 50% of pnHIV patients and indeterminate in most of the remainder (42%). There was no statistically significant difference in ECV between groups; p = 0.24.

CONCLUSION

Perinatally-acquired HIV was not associated with diffuse myocardial fibrosis. Larger prospective studies with serial examinations are needed to determine whether pnHIV patients develop abnormal structure or function more often than unaffected controls.

Textbook Outcome for Superior Cavopulmonary Connection: A Metric for Single Ventricle Heart Surgery

Background: To develop a more holistic measure of congenital heart center performance beyond mortality, we created a composite "textbook outcome" (TO) for the Glenn operation. We hypothesized that meeting TO would have a positive prognostic and financial impact. Methods: This was a single center retrospective study of patients undergoing superior cavopulmonary connection (bidirectional Glenn or Kawashima ± concomitant procedures) from 2005 to 2021. Textbook outcome was defined as freedom from operative mortality, reintervention, 30-day readmission, extracorporeal membrane oxygenation, major thrombotic complication, length of stay (LOS) >75th percentile (17d), and mechanical ventilation duration >75th percentile (2d). Multivariable logistic regression and Cox proportional hazards modeling were used. Results: Fifty-one percent (137/269) of patients met TO. Common reasons for TO failure were prolonged LOS (78/132, 59%) and ventilator duration (67/132, 51%). In multivariable analysis, higher weight [odds ratio, OR: 1.44 (95% confidence interval, CI: 1.15-1.84), P = .002] was a positive predictor of TO achievement while right ventricular dominance [OR 0.47 (0.27-0.81), P = .007] and higher preoperative pulmonary vascular resistance [OR 0.58 (0.40-0.82), P = .003] were negative predictors. After controlling for preoperative factors and excluding operative mortalities, TO achievement was independently associated with a decreased risk of death over long-term follow-up [hazard ratio: 0.50 (0.25-0.99), P = .049]. Textbook outcome achievement was also associated with lower direct cost of care [$137,626 (59,333-167,523) vs $262,299 (114,200-358,844), P < .0001]. Conclusion: Achievement of the Glenn TO is associated with long-term survival and lower costs and can be predicted by certain risk factors. As outcomes continue to improve within congenital heart surgery, operative mortality will become a less informative metric. Textbook outcome analysis may represent a more balanced measure of a successful outcome.

Development and Temporal Validation of a Machine Learning Model to Predict Clinical Deterioration

OBJECTIVES

Early warning scores detecting clinical deterioration in pediatric inpatients have wide-ranging performance and use a limited number of clinical features. This study developed a machine learning model leveraging multiple static and dynamic clinical features from the electronic health record to predict the composite outcome of unplanned transfer to the ICU within 24 hours and inpatient mortality within 48 hours in hospitalized children.

METHODS

Using a retrospective development cohort of 17 630 encounters across 10 388 patients, 2 machine learning models (light gradient boosting machine [LGBM] and random forest) were trained on 542 features and compared with our institutional Pediatric Early Warning Score (I-PEWS).

RESULTS

The LGBM model significantly outperformed I-PEWS based on receiver operating characteristic curve (AUROC) for the composite outcome of ICU transfer or mortality for both internal validation and temporal validation cohorts (AUROC 0.785 95% confidence interval [0.780-0.791] vs 0.708 [0.701-0.715] for temporal validation) as well as lead-time before deterioration events (median 11 hours vs 3 hours; P = .004). However, LGBM performance as evaluated by precision recall curve was lesser in the temporal validation cohort with associated decreased positive predictive value (6% vs 29%) and increased number needed to evaluate (17 vs 3) compared with I-PEWS.

CONCLUSIONS

Our electronic health record based machine learning model demonstrated improved AUROC and lead-time in predicting clinical deterioration in pediatric inpatients 24 to 48 hours in advance compared with I-PEWS. Further work is needed to optimize model positive predictive value to allow for integration into clinical practice.

Center-level factors associated with shorter length of stay following stage 1 palliation: An analysis of the national pediatric cardiology quality improvement collaborative registry

BACKGROUND

Stage 1 single ventricle palliation (S1P) has the longest length of stay (LOS) of all benchmark congenital heart operations. Center-level factors contributing to prolonged hospitalization are poorly defined.

METHODS

We analyzed data from infants status post S1P included in the National Pediatric Cardiology Quality Improvement Collaborative Phase II registry. Our primary outcome was patient-level LOS with days alive and out of hospital before stage 2 palliation (S2P) used as a balancing measure. We compared patient and center-level characteristics across quartiles for median center LOS, and used multivariable regression to calculate center-level factors associated with LOS after adjusting for case mix.

RESULTS

Of 2,510 infants (65 sites), 2037 (47 sites) met study criteria (61% male, 61% white, 72% hypoplastic left heart syndrome). There was wide intercenter variation in LOS (first quartile centers: median 28 days [IQR 19, 46]; fourth quartile: 62 days [35, 95], P < .001). Mortality prior to S2P did not differ across quartiles. Shorter LOS correlated with more pre-S2P days alive and out of hospital, after accounting for readmissions (correlation coefficient -0.48, P < .001). In multivariable analysis, increased use of Norwood with a right ventricle to pulmonary artery conduit (aOR 2.65 [1.1, 6.37]), shorter bypass time (aOR 0.99 per minute [0.98,1.0]), fewer additional cardiac operations (aOR 0.46 [0.22, 0.93]), and increased use of NG tubes rather than G tubes (aOR 7.03 [1.95, 25.42]) were all associated with shorter LOS centers.

CONCLUSIONS

Modifiable center-level practices may be targets to standardize practice and reduce overall LOS across centers.

Risk of in-hospital Deterioration for Children with Single Ventricle Physiology

Children with single ventricle physiology (SV) are at high risk of in-hospital morbidity and mortality. Identifying children at risk for deterioration may allow for earlier escalation of care and subsequently decreased mortality.We conducted a retrospective chart review of all admissions to the pediatric cardiology non-ICU service from 2014 to 2018 for children < 18 years old. We defined clinical deterioration as unplanned transfer to the ICU or inpatient mortality. We selected children with SV by diagnosis codes and defined infants as children < 1 year old. We compared demographic, vital sign, and lab values between infants with and without a deterioration event. We evaluated vital sign and medical therapy changes before deterioration events.Among infants with SV (129 deterioration events over 225 admissions, overall 25% with hypoplastic left heart syndrome), those who deteriorated were younger (p = 0.001), had lower baseline oxygen saturation (p = 0.022), and higher baseline respiratory rate (p = 0.022), heart rate (p = 0.023), and hematocrit (p = 0.008). Median Duke Pediatric Early Warning Score increased prior to deterioration (p < 0.001). Deterioration was associated with administration of additional oxygen support (p = 0.012), a fluid bolus (p < 0.001), antibiotics (p < 0.001), vasopressor support (p = 0.009), and red blood cell transfusion (p < 0.001).Infants with SV are at high risk for deterioration. Integrating baseline and dynamic patient data from the electronic health record to identify the highest risk patients may allow for earlier detection and intervention to prevent clinical deterioration.

Ultrasound Visualization and Recording of Transient Myocardial Vibrations

OBJECTIVE

A new visualization and recording method used to assess and quantitate autogenic high-velocity motions in myocardial walls to provide a new description of cardiac function is described.

METHODS

The regional motion display (RMD) is based on high-speed difference ultrasound B-mode images and spatiotemporal processing to record propagating events (PEs). Sixteen normal participants and one patient with cardiac amyloidosis were imaged at rates of 500-1000/s using the Duke Phased Array Scanner, T5. RMDs were generated using difference images and spatially integrating these to display velocity as function of time along a cardiac wall.

RESULTS

In normal participants, RMDs revealed four discrete PEs with average onset timing with respect to the QRS complex of -31.7, +46, +365 and +536 ms. The late diastolic PE propagated apex to base in all participants at an average velocity of 3.4 m/s by the RMD. The RMD of the amyloidosis patient revealed significant changes in the appearance of PEs compared with normal participants. The late diastolic PE propagated at 5.3 m/s from apex to base. All four PEs lagged the average timing of normal participants.

CONCLUSION

The RMD method reliably reveals PEs as discrete events and successfully allows reproducible measurement of PE timing and the velocity of at least one PE. The RMD method is applicable to live, clinical high-speed studies and may offer a new approach to characterization of cardiac function.

Sustained Total All-Region Perfusion During the Norwood Operation and Postoperative Recovery

We developed a technique for the Norwood operation utilizing continuous perfusion of the head, heart, and lower body at mild hypothermia named Sustained Total All-Region (STAR) perfusion. We hypothesized that STAR perfusion would be associated with shorter operative times, decreased coagulopathy, and expedited post-operative recovery compared to standard perfusion techniques. Between 2012 and 2020, 80 infants underwent primary Norwood reconstruction at our institution. Outcomes for patients who received successful STAR perfusion (STAR, n = 37) were compared to those who received standard Norwood reconstruction utilizing regional cerebral perfusion only (SNR, n = 33), as well as to Norwood patients reported in the PC⁴ national database during the same timeframe (n = 1238). STAR perfusion was performed with cannulation of the innominate artery, descending aorta, and aortic root at 32-34°C. STAR patients had shorter median CPB time compared to SNR (171 vs 245 minutes, P < 0.0001), shorter operative time (331 vs 502 minutes, P < 0.0001), and decreased intraoperative pRBC transfusion (100 vs 270 mL, P < 0.0001). STAR patients had decreased vasoactive-inotropic score on ICU admission (6 vs 10.8, P = 0.0007) and decreased time to chest closure (2 vs 4.5 days, P = 0.0004). STAR patients had lower peak lactate (8.1 vs 9.9 mmol/L, P = 0.03) and more rapid lactate normalization (18.3 vs 27.0 hours, P = 0.003). In-hospital mortality in STAR patients was 2.7% vs 15.1% with SNR (P = 0.06) and 10.3% in the PC⁴ aggregate (P = 0.14). STAR perfusion is a novel approach to Norwood reconstruction associated with excellent survival, decreased transfusions, shorter operative time, and improved convalescence in the early post-operative period.

Tricuspid regurgitation and left ventricular eccentricity as a measure of heart failure in the newborn patient with a vein of Galen malformation: illustrative case

BACKGROUND

Successful management of a vein of Galen malformation (VoGM) in the newborn patient requires a highly coordinated team approach involving neonatologists, pediatric cardiologists, pediatric neurologists, neurosurgeons, and interventionalists. Indication and timing of catheter intervention are topics of ongoing debate.

OBSERVATIONS

The authors highlighted two key echocardiographic markers believed to be practical indicators regarding the need for urgent catheter embolization in neonates with a VoGM. The first and preferred parameter was the tricuspid valve regurgitation (TR) gradient, an estimate of pulmonary artery hypertension. If the TR gradient exceeds systolic blood pressure (suprasystemic pulmonary hypertension [PH], i.e., >60 mm Hg), urgent intervention should be considered in eligible newborns. The second parameter was the left ventricular end-systolic eccentricity index (EI), a newly emerging echocardiographic marker and indirect correlate of PH. As an alternative to the TR gradient, an increased eccentricity index (>1.6) suggests severe right heart compromise, requiring emergency catheter embolization of the malformation. Postoperatively, the progressive reduction of both the TR gradient and the EI correlated with recovery.

LESSONS

In eligible newborns, urgent embolization of a VoGM is recommended in the presence of suprasystemic TR gradients and/or increased EI >1.6.

Post-operative Renal Failure, Shunt Type and Mortality after Norwood Palliation

BACKGROUND

The Single Ventricle Reconstruction (SVR) trial demonstrated increased risk of death or heart transplant one year post-Norwood in subjects randomized to Blalock-Taussig shunts (mBTS) compared to right ventricle-to-pulmonary artery (RV-PA) shunts. We used the SVR public use database to evaluate incidence and risk factors for post-operative renal failure and relationships between renal failure, shunt type and outcomes post-Norwood.

METHODS

Post-operative renal failure was defined a-priori as a 3-fold rise in creatinine from baseline, or dialysis use, within 7 days of Norwood. We used multivariate logistic regression to evaluate risk factors for post-operative renal failure and Cox hazard regression to determine the association between post-operative renal failure and one-year post-Norwood mortality.

RESULTS

Overall, post-operative renal failure occurred in 8.4% (46/544) with risk factors including receipt of a mBTS (aOR 3.3, p=0.02), low center volume (aOR 2.7, p=0.005), presence of ≥2 pre-op complications (aOR 4.0, p<0.001), low birth weight (aOR 3.2, p=0.002), post-operative heart block (aOR 8.5, p=0.001), and delayed sternal closure (aOR 5.3, p=0.026). Renal failure was an independent risk factor for one-year mortality (aHR 1.9, p=0.019). Assessing interaction by shunt type, mortality risk associated with renal failure was greatest in the RV-PA shunt group (aHR 3.3 versus RV-PA shunt without renal failure, p=0.001), but was also increased in the mBTS group (aHR 1.9, p=0.03).

CONCLUSIONS

Post-operative renal failure is common after Norwood and is independently associated with mortality. Although renal failure is more common after mBTS, the highest mortality risk with renal failure occurs after RV-PA shunt.

Workforce Cost Model for Expanding Congenital and Rheumatic Heart Disease Services in Kenya

BACKGROUND

Cardiovascular disease is the number one global killer, with over three quarters of these deaths arising from the populations of low- and middle-income countries (LMICs). Addressing the burden of cardiovascular disease in LMICs must include medical and surgical services for these patients. In this article, we model the needs and costs to scale up the cardiac provider workforce in Kenya, which can be adapted to other LMICs based on country-specific workforce hours and workforce salaries.

METHODS

Using published epidemiological reports from sub-Saharan Africa, we structured the model based on the expected disease burden of congenital and rheumatic disease in a simulated 1,000-person population. Services modeled include clinic visits, echocardiograms, diagnostic cardiac catheterizations, interventional catheterizations, and heart surgery. Costs were modeled based on Kenyan public sector salaries. After scaling the model, we created a sensitivity analysis of change in service duration and salaries.

RESULTS

Based on a 1,000-person Kenyan population, we estimate that 2.5 heart surgeries will be needed every year, with a corresponding annual workforce cost of US$526. Including accompanying services of clinic visits, echocardiograms, and both diagnostic and interventional cardiac catheterizations, the total annual workforce cost is US$899. Based on estimated productive hours for public sector workforce, 196 full-time equivalent cardiac surgeons will be needed for the entire population of Kenya (2017 figure).

CONCLUSIONS

We present a model for appropriate cardiovascular service staffing based on disease burden and workforce costs. This model can be scaled up as needed to plan for local capacity building.

Radiofrequency Ablation in the Sinus of Valsalva for Ventricular Arrhythmia in Pediatric Patients

The need to perform catheter ablation of ventricular arrhythmia from within the sinuses of Valsalva in a pediatric patient is uncommon. This has been reported in adults, but there are little data about the feasibility, safety or efficacy of catheter ablation in the sinuses of Valsalva in the pediatric patients. This is a retrospective review of all patients aged 18 years or less, at two separate institutions with no structural heart disease that underwent an ablation procedure for ventricular arrhythmia mapped to the sinus of Valsalva from 2010 to 2015. We identified 8 total patients meeting inclusion criteria. Median age was 16 years and the median weight was 61 kg. All patients were symptomatic or had developed arrhythmia-induced ventricular dysfunction. Ablation was performed in the left sinus in 4 patients and the right sinus in 4 patients. No ablations were required in the non-coronary sinus. All 8 patients had an acutely successful ablation using radiofrequency energy. There were no complications. At a mean follow-up of 7 months (4-15 months), all patients were known to be living. Follow-up data regarding arrhythmia were available in 6 of the 8 patients, and none had recurrence of their ventricular arrhythmia off of all antiarrhythmic medications. Radiofrequency catheter ablation of ventricular arrhythmia in the sinus of Valsalva can be done safely and effectively in pediatric patients.

Differences in Eccentricity Index and Systolic-Diastolic Ratio in Extremely Low-Birth-Weight Infants with Bronchopulmonary Dysplasia at Risk of Pulmonary Hypertension

OBJECTIVE

To compare the left ventricular eccentricity index (EI) and tricuspid valve systolic-diastolic (SD) ratio in infants at risk of bronchopulmonary dysplasia (BPD) and pulmonary hypertension (PH).

STUDY DESIGN

Review of echocardiograms performed on infants born at ≤ 28 weeks' postmenstrual age, categorized into the following three cohorts: BPD and PH (n = 13); BPD only (n = 16); and controls (n = 59). EI was measured from a parasternal short axis 2D image. The SD ratio was measured from the continuous wave Doppler tracing. Groups were compared using Kruskal-Wallis and Wilcoxon rank sum tests.

RESULT

EI and SD ratios were successfully measured in all infants. There were no differences between controls and BPD cohort. In contrast, the BPD and PH cohort had increased systolic EI (1.46 vs. 1.00-1.01), diastolic EI (1.47 vs. 1.00), and SD ratio (1.12 vs. 0.97-1.00) compared with controls and BPD only cohort (p ≤ 0.01 for all).

CONCLUSION

The EI and SD ratio may be useful as a screening tool for PH in this population.