EXERCISE CAPACITY AND MIDTERM SURVIVAL IN PATIENTS WITH TRICUSPID-ATRESIA AND COMPLEX CONGENITAL CARDIAC-MALFORMATIONS AFTER MODIFIED FONTAN-OPERATION

Objective: Continued follow-up of the Fontan population group is manda tory in order to evaluate the best approach for long term treatment. W e studied exercise capacity and survival in patients with either right atrial to right ventricular (Fontan-Bjoerk, RA-RV) anastomosis or rig ht atrial to pulmonary artery (RA-PA) connection. Methods: Between Jan uary 1980 and December 1995 Fontan-Bjoerk modifications were performed in 73 patients with tricuspid atresia. A RA-PA anastomosis (performed either with direct atrio-pulmonary connection or with a lateral tunne l of autologous atrial tissue) was used in 118 patients with single ve ntricle or complex cardiac malformations. Using bicycle ergospirometry and impedance cardiography standard variables of exercise testing wer e measured in 15 patients with RA-RV and in 18 patients with RA-PA con nection. A group of 23 healthy pupils served as controls. Results: Fol low-up was complete for 97.9% (n = 187) of all operated patients. Surv ival (% mean +/- SEM) at 5, 10 and 15 years was 89.3 +/- 3.6, 76.8 +/- 0.6 and 63.6 +/- 10.5 for RA-RV connection and 80.2 +/- 4.0, 75.3 +/- 4.5 and 64.6 +/- 10.7 for RA-PA connection (P = 0.12) respectively. E xercise capacity was tested after a median time of 6.0 (0.8-19.8) year s after Fontan operation in RA-RV and of 7.8 (4.3-18.2) years in RA-PA patients. Total work load was equal in the two Fontan groups, but it was below normal. Heart ratel respiratory rate, oxygen uptake and vent ilatory equivalent for oxygen were not different between the two Fonta n groups. Cardiac index and stroke volume index were consistently lowe r at anaerobic threshold and at maximal exercise in RA-PA patients com pared with controls. Conclusion: Survival analysis between RA-RV and R A-PA Fontan connection failed to demonstrate a better outcome for pati ents with either Fontan modification. Although there was a tendency fo r RA-RV connection to adapt cardiac output more efficient to exercise compared with RA-PA patients, total workload and ventilatory equivalen t was not significantly different between the two Fontan modifications , We conclude, that by incorporation of a residual subpulmonary ventri cular chamber within the Fontan circulation no additional benefit for exercise capacity could be observed. (C) 1997 Elsevier Science B.V.