Super-Fontan (SF) is an excellent phenotype of patients with Fontan circulation and normal exercise capacity. This study aimed to clarify the prevalence and clinical correlates and characteristics of SF.

We reviewed 404 Fontan patients who had undergone cardiopulmonary exercise testing, and the results were compared with clinical profiles.

Seventy-seven (19%) patients had SF, and the postoperative prevalence at 5, 10, 15, 20, and ≥ 25 years was 16 (35%), 30 (39%), 18 (19%), 13 (14%), and 0 (0%), respectively. Compared with non-SF, SF patients were younger (P < .001) and were mostly men (P < .05). SF was characterized by a current high arterial blood pressure and oxygen saturation (SaO₂), low systemic ventricle (SV) end-diastolic pressure, favorable body composition, superior pulmonary function, preserved hepatorenal and hemostatic functions, and better glucose tolerance (P < .05-.001). Pre-Fontan better SV function, low pulmonary artery resistance, and high SaO₂ were associated with current SF (P < .05-.01). Furthermore, positive trajectory of exercise capacity and high daily activity during childhood were associated with current adult SF (P < .05). During the follow-up, 25 patients died, and 74 patients were unexpectedly hospitalized. There was no death in the SF group, and the rate of hospitalization was 67% lower than that of the non-SF group (P < .01-.001).

The prevalence of SF gradually decreased over time. SF was characterized by preserved multi-end-organ function and an excellent prognosis. Pre-Fontan hemodynamics and post-Fontan childhood daily activity were associated with being adult SF.