Pulmonary artery size is associated with functional clinical status in the Fontan circulation

Objective In the Fontan circulation, non-pulsatile pulmonary blood flow is suggested to negatively affect pulmonary artery growth. The pulmonary vasculature is regarded a key determinant of outcome after Fontan completion. We hypothesised that in Fontan patients pulmonary artery size correlates with follow-up and functional clinical status. Methods This is a single-centre, cross-sectional cohort study. Thirty-nine paediatric and adult Fontan patients with a concomitant cardiac magnetic resonance (CMR) scan and a cardiopulmonary exercise test between 2012 and 2013 were included. CMR-derived left and right pulmonary artery cross-sectional areas were expressed as Nakata index. Functional status was defined as peak oxygen consumption (pVO(2)) indexed for weight, as percentage of predicted (pred) and as New York Heart Association Functional Class (NYHA-FC). Results Age at CMR was 18 +/- 7.2 years. Time since Fontan completion was 11.9 +/- 7.4 years. Nakata index was lower versus the reference values (238.6 +/- 78.5 vs 330 +/- 30 mm(2)/m(2), p