Atrial function in Fontan patients assessed by CMR: Relation with exercise capacity and long-term outcomes.

van der Ven JPG, Alsaied T, Juggan S, Bossers SSM, van den Bosch E, Kapusta L, Kuipers IM, Kroft LJM, Ten Harkel ADJ, van Iperen GG, Rathod RH, Helbing WA.

Int J Cardiol. 2020 Feb 24. pii: S0167-5273

OBJECTIVE: To assess the role of atrial function on exercise capacity and
clinical events in Fontan patients.
DESIGN: We included 96 Fontan patients from 6 tertiary centers, aged 12.8 (IQR
10.1-15.6) years, who underwent cardiac magnetic resonance imaging and
cardiopulmonary exercise testing within 12 months of each other from 2004 to
2017. Intra-atrial lateral tunnel (ILT) and extracardiac conduit (ECC) patients
were matched 1:1 with regard to age, gender and dominant ventricle. The pulmonary
venous atrium was manually segmented in all phases and slices. Atrial function
was assessed by volume-time curves. Furthermore, atrial longitudinal and
circumferential feature tracking strain was assessed. We determined the relation
between atrial function and exercise capacity, assessed by peak oxygen uptake and
VE/VCO2 slope, and events (mortality, listing for transplant, re-intervention,
arrhythmia) during follow-up.
RESULTS: Atrial maximal and minimal volumes did not differ between ILT and ECC
patients. ECC patients had higher reservoir function (21.1 [16.4-28.0]% vs 18.2
[10.9-22.2]%, p = .03), lower conduit function and lower total circumferential
strain (13.8 ± 5.1% vs 18.0 ± 8.7%, p = .01), compared to ILT patients. Only for
ECC patients, a better late peak circumferential strain rate predicted better
VE/VCO2 slope. No other parameter of atrial function predicted peak oxygen uptake
or VE/VCO2 slope. During a median follow-up of 6.2 years, 42 patients reached the
composite end-point. No atrial function parameters predicted events during
CONCLUSIONS: ECC patients have higher atrial reservoir function and lower conduit
function. Atrial function did not predict exercise capacity or events during