Introduction and objective: Corrective surgery for tetralogy of Fallot (TF) has led to excellent survival. However; several years after surgery, the majority of patients have right ventricular (RV) dilatation, and 10% will need reoperation of the RV outflow tract due to limited exercise capacity, ventricular arrhythmias or symptoms of heart failure (HF). Our aim was to identify predictive factors of adverse outcome: moderate to severe RV dilatation, HF, reoperation of the RV outflow tract and cardiac death.
Methods: Eighty-eight adult patients with TF were operated between January 1977 and July 2001; 22 were lost to follow-up and 66 were followed for 18 +/- 6 years. We analyzed clinical, electrocardiographic and echocardiographic variables. RV dilatation was considered to exist if the inlet measurement at end-diastole in 4-chamber apical view was more than 35 mm, being classified as moderate when > or = 50 and < 60 mm and severe when > or = 60 mm.
Results: Of the 66 patients, 25 (37.9%) had undergone previous palliative shunt (PS) at the age of 4 +/- 5 years. Mean age at surgical correction was 10 +/- 8 years (range: < 1 to 38 years; median: 6.5 years). Transannular patching was used in 65% of patients, patch closure of a right ventriculotomy in 91%, and in 53% of patients a pulmonary commissurotomy was performed. At the end of follow-up, 3 patients were in NYHA class III-IV and one patient was successfully reoperated with implantation of a biological pulmonary valve. Prevalence of RV dilatation was 97% (57/59), being moderate to severe in 69% (36/52). In patients with moderate to severe RV dilatation we found previous PS (18.8 vs. 50.0%; p = 0.03), transannular patching (37.5 vs. 75.0%; p 0.01) and wide QRS (160 ms) (6.7 vs. 45.7%, p = 0.01) to be more frequent. These patients reported more palpitations (0 vs. 22.2%; p 0.05), but there were no differences in arrhythmic events (18.8 vs. 33.3%; p = 0.28); maximal heart rate on exercise was lower (86.2 +/- 10.9 vs. 79.9 +/- 8.6; p = 0.04), but exercise time and functional capacity were similar between the groups. Follow-up time and use of RV patching were similar. Transannular patching was associated with previous PS at an older age (0.9 +/- 0.7 vs. 4.9 +/- 5.7 years; p = 0.01), a higher grade of pulmonary regurgitation (III-IV) (22.7 vs. 57.5%; p = 0.01), wide QRS (160 ms) (9.5 vs. 41.0%, p = 0.01), and greater RV dilatation. No mortality was reported.
Conclusion: Transannular patching and performance of previous PS were predictive factors of severe RV dilatation, and pulmonary regurgitation seems to be its physiological mechanism. Despite this, long-term prognosis is favorable and patients have good functional capacity.