Previous studies have established an association between exercise intolerance and increased morbidity and mortality in congenital heart disease patients. We aimed to clarify if exercise intolerance is associated with poor outcome in Fontan patients and to identify risk factors for mortality, transplantation, and cardiac-related hospitalization. A total of 321 Fontan patients (57% male, mean age 20.9 ± 8.6 years) who underwent cardiopulmonary exercise testing (CPET) at four major European centres between 1997 and 2008 were included. During a median follow-up of 21 months, 22 patients died and 6 patients underwent cardiac transplantation (8.7%), resulting in an estimated 5-year transplant-free survival of 86%. Parameters of CPET were strongly related to increased risk of hospitalization, but—with the exception of heart rate reserve—unrelated to risk of death or transplantation. In contrast, patients with clinically relevant arrhythmia had a 6.0-fold increased risk of death or transplantation (P < 0.001). Furthermore, patients with atriopulmonary/-ventricular Fontan had a 3.7-fold increased risk of death or transplantation compared with total cavopulmonary connection patients (P= 0.009). The combination of clinically relevant arrhythmia, atriopulmonary/-ventricular Fontan, and signs of symptomatic or decompensated heart failure was associated with a particularly poor outcome (3-year mortality 25%). On short-term follow-up, most parameters of CPET are associated with increased risk of hospitalization but not death or transplantation in contemporary Fontan patients. Only decreased heart rate reserve and a history of clinically relevant arrhythmia, atriopulmonary/-ventricular Fontan, and/or heart failure requiring diuretic therapy are associated with poor prognosis, potentially identifying patients requiring medical and/or surgical attention.

Patients with congenital heart disease usually show diminished exercise capacity and quality of life. However, there is only little information about daily activity, a marker for lifestyle, exercise capacity, and the prevention of arteriosclerosis. This study investigated exercise capacity, quality of life, daily activity, and their interaction with univentricular heart physiology after total cavopulmonary connection (TCPC). Fifty-seven patients (18 females, 39 males, age 8–52 years) after TCPC (lateral tunnel 28, extra-cardiac conduit 29) who underwent surgery during 1994–2001 were examined in our institution. They performed a symptom-limited cardiopulmonary exercise test. Those patients 14 years of age and older filled in the health-related quality-of-life questionnaire SF-36, and those who were 8–13 years of age, the CF-87. Daily activity parameters were obtained by using a triaxial accelerometer over the next three consecutive days. Exercise capacity was severely reduced after TCPC (25.0 mL/min/kg corresponding to 59.7% of age- and sex-related reference values). Daily activity was within the recommendations of the United Kingdom Expert Consensus Group (≥60 min, ≥3 metabolic equivalent, ≥5 days/week) in 72% of the investigated patients. It was reduced in older patients (Spearman r = − 0.506, P < 0.001) and patients with a lower peak oxygen uptake (Spearman r = 0.432, P = 0.001). In children <14 years, mental health was related to daily activity. Despite their diminished exercise capacity, patients after TCPC show a fairly normal activity pattern. However, their activity depends not only on age, but also on exercise capacity, which, in contrast to healthy people, decreases already from early adolescence on.