Predictors of mid-term event-free survival in adults with corrected tetralogy of Fallot

Objectives Patients who underwent corrective surgery for tetralogy of Fallot (TOF) have increased long-term risk of cardiovascular morbidity and mortality. Yet, limited information is available on how to evaluate the risk in this population. Therefore, the aim of this study was to investigate the prognostic value of aerobic exercise capacity, along with other related parameters, at medium-term follow-up in adult patients with tetralogy of Fallot. Methods and results Between 2000 and 2003, 92 adults (age 26.2 +/- 7.8 years; 63 male) with corrected TOF or TOF-type morphology underwent a cardiopulmonary exercise test (CPET) until exhaustion and echocardiography. During a mean follow-up of 7.3 +/- 1.2 years (range 0.9 to 9.3 years), 2 patients died and 26 patients required at least 1 cardiac-related intervention at a mean age of 28.9 +/- 7.9 years. Event-free survival tended to be higher in patients with the classical type of TOF (P=0.061). At multivariate Cox analysis, age at CPET [hazard ratio (HR): 1.13, P=0.006], age at correction (HR: 0.82, P=0.037), right ventricular (RV) function (HR: 4.94, P=0.001), QRS duration (HR: 1.02, P=0.007), percentage of predicted peak oxygen uptake (peak VO2%) (HR: 0.96, P=0.029) and ventilatory efficiency slope (VE/VCO2 slope) (HR: 1.13, P=0.021) were significantly related to the incidence of death/cardiac-related intervention during medium follow-up. Conclusions Early corrective surgery and a well-preserved RV are associated with a better outcome in adults with corrected TOF. Furthermore, CPET provides important prognostic information; peak VO2% and VE/VCO2 slope are independent predictors for event-free survival in patients with corrected TOF.