Natural and modified history of single-ventricle physiology in adult patients

To define the evolution of the single-ventricle (SV) heart in adult patients in terms of morbidity, mortality and quality of life.

Sixty-two patients with SV physiology and aged older than 16 years were retrospectively reviewed. Three patients (5%) were in natural history, one had received a Blalock-Taussig shunt, one a Waterstone anastomosis, one a pulmonary artery banding, three a bidirectional cavopulmonary anastomosis, eight a classic Fontan procedure and 46 a total cavopulmonary connection (TCPC). The morphology of the SV was left in 48 patients (77%), right in nine (14%) and indeterminable in five (8%). Thirty-three patients underwent magnetic resonance imaging (MRI) to assess ventricular mass (VM), ventricular systolic function, pulmonary artery branch diameter and potential thrombosis of the conduit. Cardiopulmonary exercise testing (CPTE) was carried out to evaluate exercise tolerance. The quality of life was monitored with two different specific tests, the Short Form-36 (SF-36) and the congenital heart disease-TNO/AZL adult quality of life (CHD-TAAQOL). The mean follow-up time was 8.0 ± 9.1 years.

Two of the three patients in natural history underwent primary TCPC. Re-interventions were necessary in seven patients (11%). Three patients (5%) died during follow-up. Five patients (8%) underwent cardiac transplantation. Protein losing enteropathy appeared in six (10%), while the arrhythmic disorder was detected in 13 patients. On the MRI, the mean end-diastolic ventricular volume was 106 ± 448 ml/m(2), the mean ejection fraction (EF) was 52.3 ± 10% and VM was 56 ± 22.1 g/m(2). On CPTE, the peak of oxygen uptake (peak VO(2)) was moderately impaired in 92% of patients, while 4% presented a severely impaired and 4% a normal peak of VO(2). No correlations were found among the peak of VO(2) and the quality-of-life evaluation.

Adult patients with SV are at high risk of reoperations and need of transplant and complications. Nevertheless, in the presence of a moderately reduced peak of VO(2) and a moderate reduction in the EF detected at the MRI, the results of the evaluation of daily quality of life are incredibly high.