Causes and factors associated with late mortality after the Fontan operation are summarised in this study. The presented information will aid in identifying patients at highest risk for mortality and guide our risk stratification efforts in this patient population.

In TOF patients who had undergone PVR, the best preoperative threshold to achieve mid-to-late RV normalization was RV ESV < 80 mL/m(2). Patients with preoperative RV ESV > 95 mL/m(2) were at increased risk for suboptimal haemodynamic outcome and adverse clinical events. Our findings may assist in timing of PVR.

In patients with repaired TOF, biventricular dysfunction on CMR imaging was associated with major adverse clinical outcomes. The quantified thresholds (RV EF <30% and LV EF <45%) may be implemented in noninvasive risk stratification.