Characterization and Z-score Calculation of Cardiac MRI parameters in patients after the Fontan operation. A Fontan Outcome Registry using CMR Examinations (FORCE) study

Tarek Alsaied; Runjia Li; Adam Christopher; Mark Fogel; Timothy C Slesnick; Rajesh Krishnamurthy; Vivek Muthurangu; Adam L Dorfman; Christopher Z Lam; Justin Weigand; Jong-Hyeon Jeong; Joshua D Robinson; Laura J Olivieri; Rahul H Rathod; FORCE Investigators

doi:10.1016/j.jocmr.2024.101113

Characterization and Z-score Calculation of Cardiac MRI parameters in patients after the Fontan operation. A Fontan Outcome Registry using CMR Examinations (FORCE) study

J Cardiovasc Magn Reson. 2024 Oct 21:101113. doi: 10.1016/j.jocmr.2024.101113. Online ahead of print.

Authors

Collaborators

FORCE Investigators:
Yue-Hin Loke¹³, Kenan Stern¹⁴, Jonathan H Soslow¹⁵, Thomas P Graham¹⁵, Manish Aggarwal¹⁶, Tiffanie Johnson¹⁷, Markus Renno¹⁸, Amee Shah¹⁹, Michael Quail²⁰, Shelby Kutty²¹, Ruchira Garg²², Jeremy Steele²³, Pierangelo Renella²⁴, Madhuradhar Chegondi²⁵, Aswathy Vaikom House²⁶, Alison Marsden²⁷, Francesca Raimondi²⁸

Affiliations

¹ The Heart and Vascular Institute, UPMC Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA. Electronic address: alsaiedt@upmc.edu.
² Department of Biostatistics, University of Pittsburgh, Pittsburgh, PA, USA.
³ The Heart and Vascular Institute, UPMC Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
⁴ Division of Cardiology, Department of Pediatrics, The Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
⁵ Departments of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA, USA.
⁶ The Department of Radiology, Nationwide Children's Hospital, Columbus, OH, USA.
⁷ UCL Centre for Cardiovascular Imaging, Institute of Cardiovascular Science, University College London, London, UK.
⁸ Department of Pediatrics, University of Michigan Medical School, Ann Arbor, MI, USA.
⁹ Department of Diagnostic Imaging, The Hospital for SickKids and Medical Imaging, University of Toronto, Toronto, Canada.
¹⁰ Division of Pediatric Cardiology, Department of Pediatrics, Baylor College of Medicine, Texas Children's Hospital, Houston, TX, USA.
¹¹ Department of Pediatrics, Ann & Robert H. Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
¹² Department of Cardiology, Boston Children's Hospital; Department of Pediatrics, Harvard Medical School, Boston, MA, USA.
¹³ Division of Pediatric Cardiology, George Washington University School of Medicine & Health Sciences, Washington, DC, USA.
¹⁴ Division of Pediatric Cardiology, Icahn School of Medicine at Mount Sinai, Kravis Children's Hospital, New York, NY, USA.
¹⁵ Division of Pediatric Cardiology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA.
¹⁶ Division of Pediatric Cardiology, Department of Pediatrics, Washington University School of Medicine, St. Louis Children's Hospital, St. Louis, MO, USA.
¹⁷ Department of Pediatrics, Indiana University School of Medicine, Riley Children's Hospital, Indianapolis, IN, USA.
¹⁸ Department of Pediatrics, University of Arkansas, Arkansas Children's Hospital, Little Rock, AR, USA.
¹⁹ Division of Pediatric Cardiology, Department of Pediatrics, Columbia University Irving Medical Center, New York, NY, USA.
²⁰ Division of Pediatric Cardiology, Department of Pediatrics, University College London, Great Ormond Street Children's Hospital, London, UK.
²¹ Helen Taussig Division of Pediatric Cardiology, Department of Pediatrics, Johns Hopkins University, Johns Hopkins Children's Hospital, Baltimore, MD, USA.
²² Division of Pediatric Cardiology, Department of Pediatrics, Cedars-Sinai Children's Hospital, Los Angeles, CA, USA.
²³ Division of Pediatric Cardiology, Department of Pediatrics, School of Medicine, Yale University, New Haven, CT, USA.
²⁴ Division of Pediatric Cardiology, Department of Pediatrics, Children's Hospital of Orange County, Orange, CA, USA.
²⁵ Division of Pediatric Cardiology, Department of Pediatrics, University of Iowa, Iowa City, IA, USA.
²⁶ Division of Pediatric Cardiology, Department of Pediatrics, University of Oklahoma, Oklahoma City, OK, USA.
²⁷ Division of Pediatric Cardiology, Department of Pediatrics and Bioengineering, Stanford University, Palo Alto, CA, USA.
²⁸ Division of Pediatric Cardiology, Papa Giovanni XXIII Hospital, Bergamo, Italy.

PMID: 39442671
DOI: 10.1016/j.jocmr.2024.101113

Abstract

Background: Cardiac magnetic resonance (CMR) offers valuable hemodynamic insights post-Fontan, but is limited by the absence of normative single ventricle data. The Fontan Outcomes Registry using CMR Examinations (FORCE) is a large international Fontan-specific CMR registry. This study used FORCE registry data to evaluate expected CMR ventricular size/function and create Fontan-specific z-scores adjusting for ventricular morphology (VM) in healthier Fontan patients.

Methods: "Healthier" Fontan patients were defined as patients free of adverse outcomes, who are New York Heart Association Class I, have mild or less valve disease, and <30% aortopulmonary collateral burden. General linear modeling was performed on 70% of the dataset to create z-scores for volumes and function. Models were tested using the remainder (30%) of the data. The z-scores were compared between children and adults. The z-scores were also compared between "healthier" Fontan and patients with adverse outcomes (death, listing for transplantation or multiorgan disease).

Results: The "healthier" Fontan population included 885 patients (15.0 ± 7.6 years) from 18 institutions with 1,156 CMR examinations. Patients with left ventricle morphology had lower volume, mass and higher ejection fraction (EF) compared to right or mixed (two-ventricles) morphology (p<0.001 for all pairwise comparisons). Gender, BSA and VM were used in z-scores. Of the "healthier" Fontan patients, 647 were children <18 years and 238 were adults. Adults had lower ascending aorta flow (2.9 ± 0.7 vs 3.3 ± 0.8L/min/m2, p<0.001) and ascending aorta flow z-scores (-0.16 ± 1.23 vs 0.05 ± 0.95, 0.02) compared to children. Additionally, there were 1595 patients with adverse outcomes who were older (16.1 ± 9.3 vs 15.0 ± 7.6, p<0.001) and less likely to have LV morphology (35 vs 47%, p<0.001). Patients with adverse outcomes had higher z-scores for ventricular volume and mass and lower z-scores for EF and ascending aorta flow compared to the "healthier" Fontan cohort.

Conclusion: This is the first study to generate CMR z-scores post-Fontan. Importantly the z-scores were generated and tested in "healthier" Fontan patients and both pediatric and adult Fontan patients. These equations may improve CMR-based risk stratification after the Fontan operation.

Keywords: Fontan; Z-scores; congenital heart disease; normal values.