Fontan Fenestration and the Role of the Covered Stent

Key Points : • Interventional therapies directed at fenestration closure in the Fontan patient must rely on good hemodynamic data • The Large Optimus-CVSTM stent is an additional armamentarium for fenestration closure however, longer term follow up is needed • Multi institutional studies defining the long-term benefits of fenestration closure and outlining fenestration management guidelines may help improve the long-term morbidity and mortality in this group of patients.

Planned reduction in Fontan fenestration size using the Atrial Flow Regulator

Fontan fenestration allows right-to-left shunting increasing cardiac output and oxygen delivery. Increased shunting occurs as cardiac function and ventricular end-diastolic pressures improve, potentially decreasing oxygen saturation. Complete closure may result in impaired Fontan haemodynamics and low cardiac output; however, there are no dedicated devices to reduce fenestration size. We describe Fontan fenestration size reduction using the Atrial Flow Regulator.

Abstract 13502: Impact of Udenafil on Echocardiographic Indices of Single Ventricle Size and Function in Fuel Study Participants

Introduction: The Pediatric Heart Network’s Fontan Udenafil Exercise Longitudinal (FUEL) Trial (Mezzion Pharma Co. Ltd., NCT 02741115) demonstrated improvements in exercise capacity following 6 months of treatment with udenafil (87.5 mg po BID). The effect of udenafil on echocardiographic measures of single ventricle (SV) function in this cohort has not been studied. Methods: Protocol echocardiograms were obtained at baseline and 26 weeks after initiation of udenafil/placebo. Linear regression compared change from baseline in indices of SV systolic, diastolic and global function, atrioventricular valve (AVV) regurgitation and mean Fontan fenestration gradient in the udenafil cohort vs placebo, controlling for ventricular morphology (LV vs. RV/other). Effects of ventricular morphology on echo measures and its interaction over time was also evaluated. Difficult imaging windows limited consistent capture of all measures. Results: The 191 udenafil participants had significantly improved myocardial performance index (p=0.03), AVV inflow peak E and A velocities (p = 0.007 and 0.03), and annular DTI-derived peak e’ velocity (p = 0.008) compared to 195 placebo participants (Table). There were no significant differences in change in SV size, systolic function, AVV regurgitation severity or mean fenestration gradient. Although LV morphology participants had significantly more favorable indices of SV size and function (lower volumes and areas, E/e’ ratio, systolic:diastolic time and AVV regurgitation, and higher annular s’ and e’ velocity) at baseline, there was no differential effect of udenafil by ventricular morphology at 26 weeks. Conclusions: FUEL participants who received udenafil demonstrated a significant improvement in global and diastolic echo indices. The changes in diastolic function suggest improvement in pulmonary venous return and/or augmented ventricular relaxation, which may help explain improved exercise performance in that cohort.