• Fontan
• cardiac magnetic resonance
• univentricular heart
• cardiac catheterization

Background: routine pre-Fontan cardiac catheterization has been the standard of care for the assessment of anatomic and hemodynamic data for many years. More recently, Cardiovascular Magnetic Resonance has emerged as a useful diagnostic tool and it has been proposed as a non-invasive imaging alternative to routine catheterization before intervention.
Aims: to investigate non-invasive predictors of pre-Fontan conventional risk factors and to identify predictors of early and mid-term follow up adverse outcomes in post-Fontan palliation patients.
Methods: From our cardiac magnetic resonance (CMR) database, we identified 53 patients (mean age 5,7 ± 4,3 years, 68% males) with a functionally univentricular heart and eventual indication for Fontan intervention. Their medical history, surgical and catheterization (CC) procedures, and clinical data were retrospectively abstracted from hospital records and analyzed. We investigated the association between non-invasive parameters and conventional pre-Fontan risk factors.
Results: Pulmonary branches hypoplasia was associated with McGoon and Nakata indexes at univariate and multivariate analysis. Regression Cox analysis identified a significant association between severe atrioventricular valve regurgitation and adverse cardiac events at follow up (HR: 9, p 0,04). No significant discrepancy was found between Pre-Fontan CMR and CC evaluation and no patient was excluded after CC evaluation.
Conclusions: in selected cases, CC could be avoided before Fontan intervention and accurate non-invasive evaluation, comprising trans-thoracic echocardiography (TTE) and CMR, could provide adequate pre-operative information.