Browsing by Author "Johnson, Tiffanie R."

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    Design and implementation of multicenter pediatric and congenital studies with cardiovascular magnetic resonance: Big data in smaller bodies
    (Elsevier, 2024) DiLorenzo, Michael P.; Lee, Simon; Rathod, Rahul H.; Raimondi, Francesca; Farooqi, Kanwal M.; Jain, Supriya S.; Samyn, Margaret M.; Johnson, Tiffanie R.; Olivieri, Laura J.; Fogel, Mark A.; Lai, Wyman W.; Renella, Pierangelo; Powell, Andrew J.; Buddhe, Sujatha; Stafford, Caitlin; Johnson, Jason N.; Helbing, Willem A.; Pushparajah, Kuberan; Voges, Inga; Muthurangu, Vivek; Miles, Kimberley G.; Greil, Gerald; McMahon, Colin J.; Slesnick, Timothy C.; Fonseca, Brian M.; Morris, Shaine A.; Soslow, Jonathan H.; Grosse-Wortmann, Lars; Beroukhim, Rebecca S.; Grotenhuis, Heynric B.; Pediatrics, School of Medicine
    Cardiovascular magnetic resonance (CMR) has become the reference standard for quantitative and qualitative assessment of ventricular function, blood flow, and myocardial tissue characterization. There is a preponderance of large CMR studies and registries in adults; However, similarly powered studies are lacking for the pediatric and congenital heart disease (PCHD) population. To date, most CMR studies in children are limited to small single or multicenter studies, thereby limiting the conclusions that can be drawn. Within the PCHD CMR community, a collaborative effort has been successfully employed to recognize knowledge gaps with the aim to embolden the development and initiation of high-quality, large-scale multicenter research. In this publication, we highlight the underlying challenges and provide a practical guide toward the development of larger, multicenter initiatives focusing on PCHD populations, which can serve as a model for future multicenter efforts.
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    Height Versus Body Surface Area to Normalize Cardiovascular Measurements in Children Using the Pediatric Heart Network Echocardiographic Z-Score Database
    (Springer, 2021) Mahgerefteh, Joseph; Lai, Wyman; Colan, Steven; Trachtenberg, Felicia; Gongwer, Russel; Stylianou, Mario; Bhat, Aarti H.; Goldberg, David; McCrindle, Brian; Frommelt, Peter; Sachdeva, Ritu; Shuplock, Jacqueline Marie; Spurney, Christopher; Troung, Dongngan; Cnota, James F.; Camarda, Joseph A.; Levine, Jami; Pignatelli, Ricardo; Altmann, Karen; van der Velde, Mary; Thankavel, Poonam Punjwani; Chowdhury, Shahryar; Srivastava, Shubhika; Johnson, Tiffanie R.; Lopez, Leo; Pediatric Heart Network Investigators; Pediatrics, School of Medicine
    Normalizing cardiovascular measurements for body size allows for comparison among children of different ages and for distinguishing pathologic changes from normal physiologic growth. Because of growing interest to use height for normalization, the aim of this study was to develop height-based normalization models and compare them to body surface area (BSA)-based normalization for aortic and left ventricular (LV) measurements. The study population consisted of healthy, non-obese children between 2 and 18 years of age enrolled in the Pediatric Heart Network Echo Z-Score Project. The echocardiographic study parameters included proximal aortic diameters at 3 locations, LV end-diastolic volume, and LV mass. Using the statistical methodology described in the original project, Z-scores based on height and BSA were determined for the study parameters and tested for any clinically significant relationships with age, sex, race, ethnicity, and body mass index (BMI). Normalization models based on height versus BSA were compared among underweight, normal weight, and overweight (but not obese) children in the study population. Z-scores based on height and BSA were calculated for the 5 study parameters and revealed no clinically significant relationships with age, sex, race, and ethnicity. Normalization based on height resulted in lower Z-scores in the underweight group compared to the overweight group, whereas normalization based on BSA resulted in higher Z-scores in the underweight group compared to the overweight group. In other words, increasing BMI had an opposite effect on height-based Z-scores compared to BSA-based Z-scores. Allometric normalization based on height and BSA for aortic and LV sizes is feasible. However, height-based normalization results in higher cardiovascular Z-scores in heavier children, and BSA-based normalization results in higher cardiovascular Z-scores in lighter children. Further studies are needed to assess the performance of these approaches in obese children with or without cardiac disease.
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    Myocardial Perfusion Reserve in Children with Friedreich Ataxia
    (Springer, 2021-12) Hutchens, Jeffrey A.; Johnson, Tiffanie R.; Payne, R. Mark; Medical and Molecular Genetics, School of Medicine
    Children with Friedreich's ataxia (FA) are at risk of perioperative morbidity and mortality from severe unpredictable heart failure. There is currently no clear way of identifying patients at highest risk. We used myocardial perfusion reserve (MPR), an MRI technique used to assess the maximal myocardial blood flow above baseline, to help determine potential surgical risk in FA subjects. In total, seven children with genetically confirmed FA, ages 8-17 years, underwent MPR stress testing using regadenoson. Six of the seven demonstrated impaired endocardial perfusion during coronary hyperemia. The same six were also found to have evidence of ongoing myocardial damage as illustrated by cardiac troponin I leak (range 0.04-0.17 ng/mL, normal < 0.03 ng/mL). None of the patients had a reduced ejection fraction (range 59-74%) or elevated insulin level (range 2.46-14.23 mCU/mL). This retrospective study shows that children with FA develop MPR defects early in the disease process. It also suggests MPR may be a sensitive tool to evaluate underlying cardiac compromise and could be of use in directing surgical management decisions in children with FA.