Ascending aortic and main pulmonary artery areas derived from cardiovascular magnetic resonance as reference values for normal subjects and repaired tetralogy of Fallot.

BACKGROUND: Cardiac magnetic resonance (CMR) imaging is an important clinical tool for serial follow-up of patients with congenital heart disease, but normative data for great vessel dimensions in pediatric subjects are scarce. We investigated the ascending aortic (AO) and main pulmonary artery dimensions in normal children and young adults in comparison with a cohort of patients with repaired tetralogy of Fallot (TOF).

METHODS AND RESULTS: Subjects were prospectively enrolled for cardiac magnetic resonance after a standardized protocol in 14 participating centers of the German Competence Network for Congenital Heart Defects. All studies were performed in 1.5-T scanners and used single-slice multiphase acquisitions steady-state free precession and velocity-encoded cine. AO and main pulmonary artery areas were measured. The cohort consisted of 483 subjects: 105 normal controls (55 men; 50 women; and median age, 14 years) and 378 patients with repaired TOF (210 men; 168 women; and median age, 16 years). Among TOF, 35 (9%) had pulmonary atresia, 98 (26%) had a palliative procedure before repair, the mean age at repair was 2.9 years, and 82 (23%) used a transannular patch repair. Great vessel areas correlated well with body surface area and age in controls and reference Z-score values were derived. Z scores for ascending AO areas were larger in TOF compared with controls (mean Z score =1.95, P=0.001). In TOF, pulmonary atresia (P=0.003), male sex (P=0.01) and previous palliations (P=0.046) were associated with larger AO areas. Main pulmonary artery area Z scores in surgically modified TOF were smaller on an average than controls (mean Z score =-0.293 P=0.001) but not small to the same extent as the AO was large.

CONCLUSIONS: This study provides cardiac magnetic resonance reference Z scores for great vessel areas in normal children and adolescents in comparison with a large contemporary cohort of repaired TOF. Male sex, pulmonary atresia, and previous palliations emerged as predictors for larger AO dimensions in TOF.