April 8, 2026Open Access
View Full PaperCombined CMR and Catheterization for Pre-Fontan Evaluation: Comparing Metrics and Clinical Correlations
Key Result
CMR yielded higher Qp/Qs values than catheterization, which underestimated Qp/Qs by a mean of 0.41, a difference strongly correlated with aortopulmonary collateral burden (p<0.0001).
Key Points
- This study aims to evaluate the effectiveness of combined CMR and catheterization for the pre-Fontan evaluation.
- Conducted a retrospective analysis in a single-center study
- Included 57 single-ventricle patients undergoing CMR and catheterization
- Compared Qp/Qs values between CMR and catheterization
- Assessed the relationship between APC burden, hemodynamics, and postoperative outcomes
- CMR provided higher Qp/Qs values than catheterization, with a mean underestimation of 0.41 from Cath
- Strong correlation found between CMR-derived APC burden and Qp/Qs (p<0.0001)
- CMR APC burden correlated with increased indexed ventricular volumes and lower ejection fractions
- Cath-based qualitative APC assessments poorly correlated with CMR findings
Structured PICO
Does CMR provide superior quantification of Qp/Qs and aortopulmonary collateral burden compared to cardiac catheterization in children undergoing pre-Fontan evaluation?
P
Population
57 children with single ventricle (SV) physiology undergoing pre-Fontan evaluation
I
Intervention
Cardiac magnetic resonance imaging (CMR) assessment
C
Comparator
Cardiac catheterization (Cath) assessment
O
Outcome
Comparison of pulmonary and systemic blood flow ratio (Qp/Qs) and aortopulmonary collateral (APC) assessmentssurrogate
Combined CMR and catheterization provides comprehensive pre-Fontan assessment, with CMR offering superior quantification of aortopulmonary collateral burden compared to catheterization alone.
Main Result
Absolute Event Rate: 0% vs 0%
Abstract
Cardiac magnetic resonance imaging (CMR) is increasingly used in combination with cardiac catheterization (Cath) for the pre-Fontan evaluation of children with single ventricle (SV) physiology. The aim of this study was to describe our institutional experience of this combined assessment. We conducted a retrospective, single-center study of 57 single-ventricle patients who underwent CMR and Cath under the same anesthesia prior to Fontan completion. CMR and Cath-based pulmonary and systemic blood flow ratio (Qp/Qs) and aortopulmonary collateral (APC) assessments were compared. In addition, we analyzed the association between significant APC burden (>30% of aortic flow) and preoperative hemodynamics, as well as postoperative outcomes, including chest tube duration and hospital length of stay. CMR consistently yielded higher Qp/Qs values compared to Cath, with a mean underestimation of 0.41 by the latter. This difference was strongly correlated with CMR-derived APC burden (p<0.0001). In comparison, Cath-based qualitative assessment of the APC had a poor correlation with the CMR APC burden and Qp/Qs. The CMR APC burden was also associated with increased indexed ventricular volumes and lower ejection fraction (EF). Combined CMR and Cath provide a comprehensive pre-Fontan assessment, with CMR offering superior quantification of aortopulmonary collateral burden and demonstrating larger Qp/Qs than calculated by Cath methods. These findings support the continued use of integrated imaging modalities for individualized care.