Mitral Annular Disjunction and Its Progression during Childhood in Marfan Syndrome.

BACKGROUND: Data on mitral annular disjunction (MAD) in children with Marfan syndrome (MFS) are sparse. OBJECTIVES: To investigate the diagnostic yield of MAD by echocardiography and cardiac magnetic resonance imaging (CMR), its prevalence and progression during childhood. METHODS: We included patients <21 years old with MFS, defined by 2010 Ghent criteria and a pathogenic FBN1 variant or ectopia lentis. Two readers measured systolic separation between the mitral valve (MV) posterior hinge point and left ventricular (LV) myocardium on initial and subsequent imaging. MAD was defined as MV-LV separation ≥2 mm, MV prolapse (MVP) as atrial displacement ≥2 mm. Kappa coefficients evaluated echocardiogram-CMR agreement. Bland-Altman and intraclass correlation coefficients (ICC) assessed interrater and intermodality reliability. Univariable mixed-effects linear regression was used to evaluate longitudinal changes of MAD. RESULTS: MAD was detected in 60% (110/185) eligible patients. MVP was present in 48% (53/110) of MAD and MAD in 90% (53/59) of MVP. MAD detection by CMR and echocardiography had 96% overall agreement (Kappa = 0.89, p < 0.001) and a 0.32-mm estimate bias (95%CI 0.00, 0.65). ICC by echocardiography, CMR, and between modalities were 0.97 (95%CI 0.93, 0.98), 0.92 (95%CI 0.79, 0.97), and 0.91 (95%CI 0.85, 0.94), respectively. MAD was associated with aortic root dilation (p < 0.001). MAD was found in children of all ages, increased +0.18 mm/year (95%CI +0.14, + 0.22) during a median duration of 5.5 years (IQR 3.1, 7.5 years). MAD indexed by height yielded a constant value +0.0002 mm/m/year (95%CI -0.0002, + 0.0005 mm/m/year). CONCLUSIONS: MAD was common in pediatric MFS and was associated with aortic root dilation. MAD detection by echocardiography and CMR was highly reliable, suggesting that routine assessment in MFS is feasible. MAD was present in neonates and progressed over time but remained constant when indexing by height. Further studies are needed to evaluate MAD as a biomarker for clinical outcomes in pediatric MFS.

Left ventricular non-compaction in paediatrics: a novel semi-automated imaging technique bridging imaging findings and clinical outcomes.

AIMS: We set out to design a reliable, semi-automated, and quantitative imaging tool using cardiac magnetic resonance (CMR) imaging that captures LV trabeculations in relation to the morphologic endocardial and epicardial surface, or perimeter-derived ratios, and assess its diagnostic and prognostic utility. METHODS AND RESULTS: We queried our institutional database between January 2008 and December 2018. Non-compacted (NC)-to-compacted (C) (NC/C) myocardium ratios were calculated and our tool was used to calculate fractal dimension (FD), total mass ratio (TMR), and composite surface ratios (SRcomp). NC/C, FD, TMR, and SRcomp were assessed in relation to LVNC diagnosis and outcomes. Univariate hazard ratios with cut-offs were performed using clinically significant variables to find 'at-risk' patients and imaging parameters were compared in 'at-risk' patients missed by Petersen Index (PI). Ninety-six patients were included. The average time to complete the semi-automated measurements was 3.90 min (SEM: 0.06). TMR, SRcomp, and NC/C were negatively correlated with LV ejection fraction (LVEF) and positively correlated with indexed LV end-systolic volumes (iLVESVs), with TMR showing the strongest correlation with LVEF (-0.287; P = 0.005) and SRcomp with iLVESV (0.260; P = 0.011). We found 29 'at-risk' patients who were classified as non-LVNC by PI and hence, were missed. When compared with non-LVNC and 'low-risk' patients, only SRcomp differentiated between both groups (1.91 SEM 0.03 vs. 1.80 SEM 0.03; P = 0.019). CONCLUSION: This method of semi-automatic calculation of SRcomp captured changes in at-risk patients missed by standard methods, was strongly correlated with LVEF and LV systolic volumes and may better capture outcome events.

Imaging of pediatric cardiac tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

Cardiac tumors in children are rare and the majority are benign. The most common cardiac tumor in children is rhabdomyoma, usually associated with tuberous sclerosis complex. Other benign cardiac masses include fibromas, myxomas, hemangiomas, and teratomas. Primary malignant cardiac tumors are exceedingly rare, with the most common pathology being soft tissue sarcomas. This paper provides consensus-based imaging recommendations for the evaluation of patients with cardiac tumors at diagnosis and follow-up, including during and after therapy.

Global Longitudinal Strain Analysis of the Single Right Ventricle: Leveling the Playing Field.

BACKGROUND: All available echocardiographic methods to assess single systemic right ventricular systolic function have limitations. Subjective grading is prone to bias and varies among readers. Quantitative methods that require significant manual input, such as fractional area change (FAC), are often not reproducible. The aim of this study was to determine whether global longitudinal strain (GLS) is more reproducible than FAC and subjective grading in patients with systemic right ventricle among individual readers and across different levels of experience. METHODS: Clinically indicated echocardiograms from 40 patients with functional systemic right ventricles were assessed by five readers with varying reading experience: one sonographer, one cardiology fellow, and three attending cardiologists at different career stages. All readers were blinded to patient data and other reader responses. Each reader reviewed the same images for subjective grade (on a scale ranging from 1 [normal] to 8 [severely depressed]), right ventricular end-diastolic and end-systolic area measurements, and longitudinal strain analysis. A repeat analysis was performed under identical conditions after ≥2 weeks on all 40 patients. Inter- and intrareader reproducibility was assessed using intraclass correlation coefficients (ICCs). Correlations between responses were assessed using Spearman's correlation coefficient. RESULTS: The subjective method had fair to good reproducibility (ICC = 0.7; interquartile range [IQR], 0.60-0.72), while the FAC method was poor (ICC = 0.46; IQR, 0.39-0.51) among readers. Reproducibility for GLS was excellent (ICC = 0.88; IQR, 0.88-0.89). Intrareader reproducibility was excellent by subjective grading (ICC = 0.85; IQR, 0.73-0.88), poor by FAC (ICC = 0.63; IQR, 0.35-0.66), and excellent by GLS (ICC = 0.93; IQR, 0.88-0.96). Attending-level readers were more consistent with their subjective grading, while all readers were excellent with GLS. CONCLUSIONS: GLS is more reproducible than conventional methods at assessing systemic right ventricular systolic function among readers with different levels of experience. For most readers it was more consistent than their own subjective grades of right ventricular function. Laboratories staffed by multiple readers are likely to be more consistent in grading systemic right ventricular systolic function using GLS.

Dobutamine stress cardiac MRI is safe and feasible in pediatric patients with anomalous aortic origin of a coronary artery (AAOCA).

BACKGROUND: Risk stratification in anomalous aortic origin of a coronary artery (AAOCA) is challenged by the lack of a reliable method to detect myocardial ischemia. We prospectively studied the safety and feasibility of Dobutamine stress-cardiac magnetic resonance (DSCMR), a test with excellent performance in adults, in pediatric patients with AAOCA. METHODS: Consecutive DSCMR from 06/2014-12/2019 in patients≤20 years old with AAOCA were included. Hemodynamic response and major/minor events were recorded. Image quality and spatial/temporal resolution were evaluated. Rest and stress first-pass perfusion and wall motion abnormalities (WMA) were assessed. Inter-observer agreement was assessed using kappa coefficient. RESULTS: A total of 224 DSCMR were performed in 182 patients with AAOCA at a median age of 14 years (IQR 12, 16) and median weight of 58.0 kg (IQR 43.3, 73.0). Examinations were completed in 221/224 (98.9%), all studies were diagnostic. Heart rate and blood pressure increased significantly from baseline (p < 0.001). No patient had major events and 28 (12.5%) had minor events. Inducible hypoperfusion was noted in 31/221 (14%), associated with WMA in 13/31 (42%). Inter-observer agreement for inducible hypoperfusion was very good (Κ = 0.87). Asymptomatic patients with inducible hypoperfusion are considered high-risk and those with a negative test are of standard risk. CONCLUSIONS: DSCMR is feasible in pediatric patients with AAOCA to assess for inducible hypoperfusion and WMA. It can be performed safely with low incidence of major/minor events. Thus, DSCMR is potentially a valuable test for detection of myocardial ischemia and helpful in the management of this patient population.

Instantaneous Wave-Free Ratio (iFR) Correlates With Fractional Flow Reserve (FFR) Assessment of Coronary Artery Stenoses and Myocardial Bridges in Children.

OBJECTIVES: Instantaneous wave-free ratio (iFR) has been proven to correlate with coronary flow reserve better than fractional flow reserve (FFR) and is non-inferior to FFR in guiding coronary revascularization in ischemic heart disease. There has been no study validating the utility of iFR in children. METHODS: We performed a retrospective review of clinically indicated cases in which both FFR and iFR were obtained at Texas Children's Hospital from July, 2016 to March, 2019. FFR and iFR were obtained at baseline. Adenosine FFR (FFRa) was used for assessment of coronary artery (CA) stenoses and diastolic dobutamine FFR (dFFRd) for myocardial bridges (MBs). FFRa or dFFRd ≤0.8 and iFR ≤0.89 indicated significant flow impairment. RESULTS: A total of 22 coronary arteries (9 CA stenoses and 13 MBs) were assessed in 20 patients with median age of 13 years (range, 4-21 years) and median weight of 60 kg (range, 19-110 kg). iFR correlated with FFRa (Spearman's rho, 0.87; P<.01) in CA stenoses and with dFFRd (Spearman's rho, 0.74; P<.01) in MBs and agreed with FFR in 20/22 cases (90.9%). In 1 patient with CA stenosis and 1 MB with normal FFR, iFR was positive and both patients underwent coronary revascularization. CONCLUSIONS: iFR correlated with FFR in the assessment of CA stenoses in children. iFR does not require administration of pharmacological agents; thus, it may reduce procedural time, cost, and complications, and result in more widespread adoption of invasive assessment of CA lesions in young patients.

Regadenoson Stress Perfusion Cardiac Magnetic Resonance Imaging in Children With Kawasaki Disease and Coronary Artery Disease.

Coronary artery (CA) stenosis and occlusion in convalescent Kawasaki disease (KD) is progressive and may result in myocardial infarction. The use of regadenoson, a strong selective CA vasodilator with low side effect profile, for stress cardiac magnetic resonance (CMR) imaging has not been studied in children with KD. The safety, feasibility, and diagnostic utility of regadenoson stress CMR was assessed in children with KD and CA abnormalities. A retrospective review of regadenoson stress CMR in children with convalescent KD was performed. Hemodynamics changes after regadenoson administration and adverse effects were recorded. First-pass perfusion was evaluated at rest and during pharmacologic stress. The results were compared with anatomic CA imaging. Forty-one stress CMR (18 sedated examinations, 44%) were performed successfully in 32 patients. Median age was 11.2 years (range 2.2 to 18.6) and weight 41 kg (range 13 to 93.4). Heart rate increased 66 ± 25% (p <0.005) after regadenoson. Minor adverse events occurred in 6 sedated and 1 unsedated patients. Hypoperfusion during stress occurred in 16 of 41 (39%), including 5 inducible, 9 inducible and fixed, and 2 fixed lesions. Late gadolinium enhancement was present in 10 of 16 with hypoperfusion and in 1 without hypoperfusion. Stress CMR had 100% positive agreement and >90% negative and overall agreement with moderate-to-severe CA stenoses. Four patients with hypoperfusion underwent revascularization for severe CA stenoses. In conclusion, regadenoson stress CMR is hemodynamically safe and feasible in children with KD and CA disease. It has excellent agreement with CA angiography and aided decision-making to proceed with revascularization.

Myocardial Stress Perfusion MRI Using Regadenoson: A Weight-based Approach in Infants and Young Children.

PURPOSE: To determine the safety and feasibility of stress cardiac MRI by using weight-based dosing of regadenoson in patients less than 40 kg and whether stress cardiac MRI affects patient management. MATERIALS AND METHODS: All patients less than 40 kg undergoing stress cardiac MRI by using weight-based dosing (8 µg/kg) of regadenoson were included in this retrospective single-center study. Hemodynamic response, adverse events, and cardiac MRI abnormalities in myocardial perfusion, wall motion, and delayed enhancement were evaluated. Patient management based on the results of the stress cardiac MRI were evaluated. RESULTS: Forty-six consecutive stress cardiac MRI examinations were performed in 36 patients (median age, 9.0 years; age range, 2 months to 13.9 years) with congenital and acquired heart disease. Thirty-one of 46 (67.4%) studies were performed with the use of sedation. A myocardial perfusion defect was present in 20 of 46 (43.5%) studies, five with inducible defects only, and the remaining 15 with fixed or irreversible defects. In the 46 total studies, there were no major adverse events and nine (19.6%) minor adverse events including emesis (n = 1) and transient hypotension requiring pharmacologic intervention in eight patients who were all sedated. Sedation was an independent predictor for hypotension (P =.040). Twenty-six negative studies had no coronary interventions performed, and of the 20 positive studies, 15 were referred for catheterization, eight of which underwent coronary interventions. CONCLUSION: Weight-based dosing of regadenoson for stress cardiac MRI was safe and feasible in infants and young children and played an integral role in the outcome and treatment decisions for children with coronary artery disease.© RSNA, 2019.