Machine Learning Quantification of Pulmonary Regurgitation Fraction from Echocardiography.

Assessment of pulmonary regurgitation (PR) guides treatment for patients with congenital heart disease. Quantitative assessment of PR fraction (PRF) by echocardiography is limited. Cardiac MRI (cMRI) is the reference-standard for PRF quantification. We created an algorithm to predict cMRI-quantified PRF from echocardiography using machine learning (ML). We retrospectively performed echocardiographic measurements paired to cMRI within 3 months in patients with ≥ mild PR from 2009 to 2022. Model inputs were vena contracta ratio, PR index, PR pressure half-time, main and branch pulmonary artery diastolic flow reversal (BPAFR), and transannular patch repair. A gradient boosted trees ML algorithm was trained using k-fold cross-validation to predict cMRI PRF by phase contrast imaging as a continuous number and at > mild (PRF ≥ 20%) and severe (PRF ≥ 40%) thresholds. Regression performance was evaluated with mean absolute error (MAE), and at clinical thresholds with area-under-the-receiver-operating-characteristic curve (AUROC). Prediction accuracy was compared to historical clinician accuracy. We externally validated prior reported studies for comparison. We included 243 subjects (median age 21 years, 58% repaired tetralogy of Fallot). The regression MAE = 7.0%. For prediction of > mild PR, AUROC = 0.96, but BPAFR alone outperformed the ML model (sensitivity 94%, specificity 97%). The ML model detection of severe PR had AUROC = 0.86, but in the subgroup with BPAFR, performance dropped (AUROC = 0.73). Accuracy between clinicians and the ML model was similar (70% vs. 69%). There was decrement in performance of prior reported algorithms on external validation in our dataset. A novel ML model for echocardiographic quantification of PRF outperforms prior studies and has comparable overall accuracy to clinicians. BPAFR is an excellent marker for > mild PRF, and has moderate capacity to detect severe PR, but more work is required to distinguish moderate from severe PR. Poor external validation of prior works highlights reproducibility challenges.

PPA2 Deficiency in 2 Sisters: A Rare Cause of Sudden Cardiac Death.

Inorganic pyrophosphatase 2 (PPA2) deficiency is a genetic cause of sudden cardiac death, often triggered by viral infection or alcohol consumption. Literature on management is limited because most cases are diagnosed post mortem. We report lethal and nonlethal cardiac presentations of PPA2 deficiency in 2 adolescent sisters that resulted from a novel pathogenic PPA2 variant. (Level of Difficulty: Advanced.).

Aneurysms of the fetal arterial duct are usually benign.

INTRODUCTION: Fetal arterial duct aneurysm, saccular, or fusiform enlargement of the arterial duct affect > 8% of pregnancies. It is uncommonly associated with serious sequelae postnatally, including thromboembolic events such as stroke and left pulmonary artery obstruction, rupture with demise, and vocal cord compression. Risk factors include maternal diabetes, late maternal age, maternal blood type A, large size for gestational age, and connective tissue disorders. The clinical importance remains unknown, making it difficult to determine how to monitor this finding postnatally. METHODS: This is a retrospective echocardiogram study assessing the outcomes of fetally diagnosed arterial duct aneurysm. Images and records were reviewed to confirm the diagnosis and assess risk factors and outcomes. Descriptive statistics were performed. RESULTS: Fifty-three affected fetuses were identified. The median gestational age at diagnosis was 34.9 weeks (IQR 32.6, 36.6). The median maternal age was 31 years (IQR 27.3-34.1). Eight (15%) had maternal diabetes. The most common blood type was type O. The median maximal dimension of the aneurysm was 7.6 mm (IQR 6.1, 8.7). The aortic end was the maximal dimension in 67.9%. Median postnatal follow-up period was 76 days (IQR 7.5, 368). No patients sustained postnatal demise related to the duct, rupture of the ductal aneurysm, cerebral infarction, or other sequelae. No newborn had associated connective tissue disorders. No patients underwent ductal intervention. CONCLUSION: In our experience, no adverse outcomes related to the ductal aneurysm were identified. This should be considered when counselling families about the need for postnatal follow-up.

Juxtaposition of the Atrial Appendages: A Large Echocardiographic Series.

Juxtaposition of the atrial appendages is known to occur in specific congenital heart lesions. Recognition of these variants is critical in balloon atrial septostomy and atrial switch operations. There remains little clinical data on the prevalence and associations of these lesions. This is the largest echocardiographic study of juxtaposition of the atrial appendages. This is a retrospective study using the Mt. Sinai echocardiogram database (EchoLAN), which contains echocardiogram reports performed or reviewed at Mt. Sinai Hospital (New York, NY) between 1992 and 2019. Each report was reviewed for associated intracardiac and extracardiac anomalies and the prevalence of juxtaposed atrial appendage among specific diagnosis, including tricuspid atresia, transposition of the great arteries, and double outlet right ventricle, was calculated. Descriptive and analytical statistics were performed as applicable, including Fisher's exact test, with p value < 0.05 considered statistically significant. Forty-nine patients had juxtaposed atrial appendages (1.2/1000 patients): Thirty-eight had LJRAA (0.9 per 1000 patients) and eleven had RJLAA (0.3 per 1000 patients). LJRAA was seen in 22% of tricuspid atresia, 6% of d-TGA, 1% of l-TGA, and 5% of DORV. RJLAA was seen in 2% of DORV, and none of the other lesions. Of associated lesions, dextrocardia, mesocardia, transposition, tricuspid atresia, double inlet left ventricle, and pulmonary valve stenosis were more likely to be present in LJRAA, while bicuspid aortic valve and left ventricular hypoplasia were more likely to be present in RJLAA. This study reaffirms our understanding of juxtaposition of the atrial appendages, its prevalence, and clinical importance.

Left heart hypoplasia in the fetus: Echocardiographic predictors of outcome.

INTRODUCTION: Fetal left heart hypoplasia (LHH) with an apex-forming left ventricle may require neonatal intervention but it is difficult to predict. METHODS: We performed a retrospective study of fetuses with LHH defined as normal segmental anatomy, apex-/near-apex forming left ventricle, and ≥1 left-sided z-score ≤ -2 between 1997 and 2014. Fetuses with mitral or aortic atresia, critical aortic stenosis, extracardiac anomalies, or fetal intervention were excluded. Classification and regression tree analyses (CART) were performed to construct algorithms to predict postnatal circulation: no surgery versus biventricular surgery versus single ventricle (SV) palliation. RESULTS: Among 138 included fetuses, 52 (37%) underwent neonatal surgery, with 10 (7%) undergoing SV palliation. The strongest single outcome discriminator was exclusively left-to-right flow foramen ovale (FO) flow ≥32 weeks gestational age (GA) (seen in 0% with no surgery, 22% with biventricular surgery, 88% with SV palliation). On CART analysis >32 weeks GA, fetuses with right-to-left FO flow and aortopulmonary ratio >0.76 had 0% probability of neonatal surgery, while those with left-to-right FO flow and mitral valve z-score < -3.6 had a 70% probability of SV palliation. CONCLUSION: SV palliation is an uncommon outcome of fetal LHH. Fetal FO flow and other echocardiographic measures can help determine risk and type of postnatal intervention.

Stereoscopic virtual reality does not improve knowledge acquisition of congenital heart disease.

Advances in virtual reality have made it possible for clinicians and trainees to interact with 3D renderings of hearts with congenital heart disease in 3D stereoscopic vision. No study to date has assessed whether this technology improved instruction compared to standard 2D interfaces. The purpose of this study was to assess whether stereoscopic virtual reality improves congenital heart disease anatomy education. Subjects in a prospective, blinded, randomized trial completed a pre-test assessing factual and visuospatial knowledge of common atrioventricular canal and were randomized to an intervention or control group based on their score. The intervention group used a 3D virtual reality (VR) headset to visualize a lecture with 3D heart models while the control group used a desktop (DT) computer interface with the same models. Subjects took a post-test and provided subjective feedback. 51 subjects were enrolled, 24 in the VR group & 27 in the DT group. The median score difference for VR subjects was 12 (IQR 9-13.3), compared to 10 (IQR 7.5-12) in the DT group. No difference in score improvement was found (p = 0.11). VR subjects' impression of the ease of use of their interface was higher than DT subjects (median 8 vs 7, respectively, p = 0.01). VR subjects' impression of their understanding of the subject matter was higher than desktop subjects (median 7 vs 5, respectively, p = 0.01). There was no statistically significant difference in the knowledge acquisition observed between the stereoscopic virtual reality group and the monoscopic desktop-based group. Participants in virtual reality reported a better learning experience and self-assessment suggesting virtual reality may increase learner engagement in understanding congenital heart disease.

Diastolic velocity half time is associated with aortic coarctation gradient at catheterization independent of echocardiographic and clinical blood pressure gradients.

OBJECTIVE: The most accurate noninvasive parameter to predict whether a patient with aortic coarctation will meet interventional criteria at catheterization remains elusive. We aim to determine the best independent echocardiographic predictors of a coarctation peak-to-peak pressure gradient ≥20 mm Hg at catheterization, the accepted threshold for intervention. DESIGN: Retrospective query of our catheterization database from 1/2007 to 7/2016 for the diagnostic code of aortic coarctation was performed. Multiple echocardiographic measurements and blood pressure gradients prior to cardiac catheterization were collected. Univariate correlation of variables with the continuous catheterization peak were calculated using Spearman's rho. Univariate association with peak-to-peak gradient at catheterization ≥20 mm Hg was tested using Mann-Whitney U test and the Pearson chi-square test or Fisher's exact test. Multivariable logistic regression assessed the independent association of the clinically relevant metrics with gradient at catheterization ≥20 mm Hg. RESULTS: Sixty-eight patients met study criteria (median age 9.25 years), of whom 84% underwent intervention at catheterization. Echocardiographic peak and mean coarctation velocity, indexed systolic and diastolic velocity half times (SVHTi, DVHTi), and blood pressure gradient all had moderate correlation (Spearman's rho = 0.529-0.617, P < .001) with the continuous catheterization gradient and were significantly associated with the binary outcome of catheterization peak ≥20 mm Hg (P < .001). Logistic regression found echocardiographic mean systolic gradient (OR 1.213 [95% CI 1.041-1.414]) and DVHTi (OR 1.039 [95% CI 1.004-1.074]) independently associate with catheterization peak ≥20 mm Hg after controlling for blood pressure gradient (OR 1.066 [0.987-1.150]). CONCLUSIONS: Most echocardiographic estimates show moderate correlation with arch gradient at catheterization. Noninvasive four extremity blood pressure gradient is significantly associated with peak-to-peak gradient ≥20 mm Hg. DVHTi may provide a unique independently associated echocardiographic estimate of coarctation severity. Further study of these variables with larger cohorts may allow for development of predictive models to direct catheterization.

Barth Syndrome with Late-Onset Cardiomyopathy: A Missed Opportunity for Diagnosis.

A male infant presented with neutropenia, growth delay, and death of a maternal uncle at age 2 years. Despite extensive evaluation over 10 years, Barth syndrome was not diagnosed until he presented in acute heart failure. Although late-onset cardiomyopathy is rare, persistence of common Barth features should have enabled earlier diagnosis.

Echocardiographic Parameters and Outcomes in Primary Fetal Cardiomyopathy.

OBJECTIVES: Primary fetal cardiomyopathy is a rare entity, with a poor prognosis. We sought to describe its echocardiographic characteristics and outcomes. METHODS: We performed a 12-year retrospective review of fetuses with primary cardiomyopathy. RESULTS: Of more than 6000 fetuses evaluated, 25 met criteria for primary cardiomyopathy, and 18 had sufficient echocardiographic and pregnancy outcome data for inclusion. At echocardiography, the median gestational age was 29.6 weeks (range, 21.0-36.4 weeks); median cardiovascular profile score was 6 (range, 1-9); median right ventricular Tei index was 0.52 (range, 0.32-0.94); and median left ventricular Tei index was 0.40 (range, 0.15-0.88). Two had fetal demise, and 16 survived to delivery. The median cardiovascular profile score in those with fetal demise was 3.0 and in those who survived to delivery was 6.5 (range, 3-9; P = .14). The median right ventricular Tei index in those with fetal demise was 0.39 and in those surviving to delivery was 0.53 (range, 0.38-0.94; P = .49). The median left ventricular Tei index in those with fetal demise was 0.29 and in those surviving to delivery was 0.42 (range, 0.15-0.88; P = .50). Sixty-day survival was available in 11 of 16 fetuses. In addition to the 2 with fetal demise, 4 had postnatal demise, and 5 were alive at a median follow-up of 39 months. Hydrops (P = .01), skin edema (P = .01), and mild or greater mitral regurgitation (P = .02) were associated with fetal or postnatal demise, with a trend toward an association between moderate or greater tricuspid regurgitation (P = .07) and fetal or postnatal demise. CONCLUSIONS: Hydrops and atrioventricular valvar regurgitation are ominous signs in primary fetal cardiomyopathy. Although other commonly used methods for assessing cardiovascular performance may help in diagnosing primary cardiomyopathy, these data suggest limited predictive value.

Tissue Doppler Imaging Measures Correlate Poorly with Left Ventricular Filling Pressures in Pediatric Cardiomyopathy.

SETTING: In adults with cardiomyopathy, tissue Doppler imaging (TDI) has been shown to correlate with left ventricular filling pressures (LVFPs) and has been advocated as a surrogate to catheterization. However, this has not been validated in children. DESIGN: This is a retrospective review of children ≤18 years old with dilated, hypertrophic, restrictive, and left ventricular noncompaction cardiomyopathy who underwent cardiac catheterization within 3 months of an echocardiogram. Spearman's correlation coefficients were calculated to assess a correlation between LVFP and mitral inflow E/A ratio, lateral mitral E/E', and septal E/E'. RESULTS: Thirty-eight patients were included in the study; median age was 8.6 years old. The median LVFP was 19 mm Hg, median mean pulmonary artery pressure was 25 mm Hg, and median pulmonary vascular resistance index (PVRi) was 2.4 Wu. There was no significant correlation between LVFP or PVRi with lateral mitral E/E' or septal E/E'. There was a positive correlation between LVFP and mitral inflow E/A ratio (rs = 0.59, P < .01). In a subgroup analysis of patients with hypertrophic or restrictive cardiomyopathy, there was a negative correlation (rs = 0.56, P = .02) between the mean pulmonary artery pressure and septal A'. CONCLUSIONS: TDI measures of diastolic function are not reliable surrogates for LVFP, mean pulmonary artery pressures, and PVRi at catheterization in children.

Pediatric ventricular assist device use as a bridge to transplantation does not affect long-term quality of life.

OBJECTIVE: The present study sought to determine the long-term quality of life (QOL) of children who required long-term ventricular assist device (VAD) support as a bridge to transplantation (BTT) compared with children who underwent heart transplantation without VAD support. Currently, 20% of children undergoing heart transplantation have required a VAD as a BTT. Few data have been published assessing how children requiring a VAD as a BTT will fair in terms of their long-term QOL. METHODS: The present study used a cross-sectional design, using the Core and Cardiac modules of the Pediatric Quality of Life Inventory survey. In a secondary analysis, the factors associated with worse QOL outcomes among the VAD patients were also investigated. RESULTS: At follow-up (median, 4.2 years), between the 21 children who required a VAD as a BTT and 42 who went straight to transplantation, no significant differences were found in the QOL as measured using the Psychosocial Health Summary Score, Physical Health Summary Score, or Total Score in the survey's Core Module, nor were any differences found in the outcomes assessed using the survey's Cardiac Module. Of the patients who required a VAD, only the presence of a neurologic complication was associated with worse QOL, which was demonstrated by decreased Physical Health Summary and Cardiac Communication scores. CONCLUSIONS: Over the long term, surviving children who required a long-term VAD as a BTT experience a similar QOL as those who went straight to transplantation.

Fixed subaortic stenosis: a clinical dilemma for clinicians and patients.

Subaortic stenosis carries considerable morbidity and mortality. In most cases, patients have an underlying left ventricular outflow tract morphology that promotes turbulence at the outflow tract, which induces the development of subaortic fibromuscular tissue. A subset of patients will progress to develop severe stenosis and aortic regurgitation, but it has been difficult to determine which patients are at risk. While resection of the subaortic tissue improves immediate outcome, many patients have recurrence of both stenosis and regurgitation, questioning the efficacy of surgical intervention in asymptomatic patients. This review article describes the current understanding of the etiology, treatment, and prognosis of subaortic stenosis.