Wall motion assessment by feature tracking in pediatric patients with coronary anomalies undergoing dobutamine stress CMR.

Background: Left ventricular (LV) wall motion assessment is an important adjunct in addition to perfusion defects in assessing ischemic changes. This study aims to investigate the feasibility and utility of performing feature tracking (FT) in pediatric patients with coronary anomalies undergoing dobutamine stress CMR to assess wall motion abnormalities (WMA) and perfusion defects. Method: This is a retrospective study where 10 patients with an inducible first-pass perfusion (FPP) defect and 10 without were selected. Global LV circumferential strain/strain rate (GCS/GCSR) was measured at rest and at peak stress (systole and diastole) using a commercially available feature tracking software. Peak GCS and GCSR were compared to indexed wall motion score (WMSI) between groups with and without FPP defect and in subjects with and without WMA. Results: The median age of patients was 13.5 years (Q1, 11 years; Q3, 15 years). Five subjects had qualitatively WMA at peak stress. A moderate correlation of GCS with WMSI at peak stress (0.48, p = 0.026) and a significant difference between GCS at rest and stress in patients with no inducible WMA (p = 0.007) were seen. No significant difference was noted in GCS between rest and stress in patients with WMA (p = 0.13). There was a larger absolute GCS/GCSR at peak stress in subjects with no inducible FPP defect or WMA. Conclusion: Smaller absolute GCS and a lack of significant change in GCS at peak stress in those with inducible WMA or perfusion defect are suggestive of compromised LV deformation in subjects with inducible WMA. Given these findings, GCS derived from CMR-FT may be used to objectively assess WMA in pediatric patients undergoing stress CMR.

Invasive Coronary Assessment in a 9-Year-Old With Anomalous Aortic Origin of the Left Coronary Artery.

A previously healthy nine-year-old boy with anomalous aortic origin of the left coronary artery (AAOLCA) with high-risk anatomy demonstrated negative stress on magnetic resonance imaging. Invasive cardiac catheterization for intracoronary flow measurement was performed and demonstrated compromised coronary flow during pharmacologic stress and significant stenosis on angiography. The patient underwent surgical intervention with normalization of coronary flow upon postoperative evaluation. Invasive intracoronary flow determination with angiography under provocative stress is emerging as a critical data point for risk stratification and management decision-making in high-risk AAOLCA patients with negative noninvasive perfusion studies.

Assessment of transfer of morphological characteristics of Anomalous Aortic Origin of a Coronary Artery from imaging to patient specific 3D Printed models: A feasibility study.

BACKGROUND AND OBJECTIVE: This study aims to determine the accuracy of patient specific 3D printed models in capturing pathological anatomical characteristics derived from CT angiography (CTA) in children with anomalous aortic origin of a coronary artery (AAOCA). METHODS & MATERIALS: Following institutional regulatory approval, a standardized protocol for CTA of AAOCA was utilized for imaging. Blood volume of the aorta and coronaries were segmented from the DICOM images. A total of 10 models from 8 AAOCA patients were created, including 2 post-operative models. Mechanical properties of Agilus30 a flexible photopolymer coated with a thin layer of parylene, polyurethane (PU) and silicone and native aortic tissue from a postmortem specimen were compared. AAOCA models with wall thicknesses of 2mm aorta and 1.5mm coronaries were 3D printed in Agilus30 and coated with PU. CT of the printed models was performed, and 3D virtual models were generated. Transfer of anatomical characteristics and geometric accuracy were compared between the patient model virtual models. RESULTS: Dynamic modulus of Agilus30 at 2mm thickness was found to be close to native aortic tissue. Structured reporting of anatomical characteristics by imaging experts showed good concordance between patient and model CTA Comparative patient and virtual model measurements showed Pearson's correlation (r) of 0.9959 for aorta (n=70) and 0.9538 for coronaries (n=60) linear, and 0.9949 for aorta (n=30) and 0.9538 for coronaries (n=30) cross-sectional, dimensions. Surface contour map mean difference was 0.08 ± 0.29mm. CONCLUSIONS: Geometrically accurate AAOCA models preserving morphological characteristics, essential for risk stratification and decision-making, can be 3D printed from a patient's CTA.

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.

Sports Cardiology: Core Curriculum for Providing Cardiovascular Care to Competitive Athletes and Highly Active People.

The last few decades have seen substantial growth in the populations of competitive athletes and highly active people (CAHAP). Although vigorous physical exercise is an effective way to reduce the risk of cardiovascular (CV) disease, CAHAP remain susceptible to inherited and acquired CV disease, and may be most at risk for adverse CV outcomes during intense physical activity. Traditionally, multidisciplinary teams comprising athletic trainers, physical therapists, primary care sports medicine physicians, and orthopedic surgeons have provided clinical care for CAHAP. However, there is increasing recognition that a care team including qualified CV specialists optimizes care delivery for CAHAP. In recognition of the increasing demand for CV specialists competent in the care of CAHAP, the American College of Cardiology has recently established a Sports and Exercise Council. An important primary objective of this council is to define the essential skills necessary to practice effective sports cardiology.

Decision analysis to define the optimal management of athletes with anomalous aortic origin of a coronary artery.

OBJECTIVES: The goal of this study was to use decision analysis to evaluate the impact of varying uncertainties on the outcomes of patients with anomalous aortic origin of a coronary artery. METHODS: Two separate decision analysis models were created: one for anomalous left coronary artery (ALCA) and one for anomalous right coronary artery (ARCA). Three strategies were compared: observation, exercise restriction, and surgery. Probabilities and health utilities were estimated on the basis of existing literature. Deterministic and probabilistic sensitivity analyses were performed. RESULTS: Surgery was the optimal management strategy for patients <30 years of age with ALCA. As age increased, observation became an equivalent strategy and eventually surpassed surgery as the treatment of choice. The advantage on life expectancy for surgery over observation ranged from 2.6 ± 1.7 years for a 10-year-old patient to -0.03 ± 0.1 for a 65-year old patient. In patients with ARCA, observation was the optimal strategy for most patients with a life expectancy advantage over surgery of 0.1 ± 0.1 years to 0.2 ± 0.4 years, depending on age. Surgery was the preferred strategy only for patients <25 years of age when the perceived risk of sudden cardiac death was high and the perioperative mortality was low. Exercise restriction was a suboptimal strategy for both ALCA and ARCA in all scenarios. CONCLUSIONS: The optimal management in anomalous aortic origin of a coronary artery depends on multiple factors, including individual patient characteristics. Decision analysis provides a tool to understand how these characteristics affect the outcomes with each management strategy and thus may aid in the decision making process for a particular patient.