The neo-aortic valve in patients with hypoplastic left heart syndrome is largely preserved: a serial follow-up CMR study.

Background: In hypoplastic left heart syndrome (HLHS) patients, neo-aortic valve regurgitation can negatively impact right ventricular (RV) function. We assessed neo-aortic valve function and RV volumetric parameters by analysing serial cardiovascular magnetic resonance (CMR) studies in HLHS patients after completion of total cavopulmonary connection (TCPC).

Methods: Consecutive CMR examinations of 80 patients (female: 22) with two ( = 80) or three ( = 45) examinations each were retrospectively analysed. RV volumetry was performed using short-axis cine images. RV end-diastolic and end-systolic volumes normalised to body surface area (BSA, RVEDVi, RVESVi), ejection fraction (RVEF) and stroke volume (RVSV) were measured. Neo-aortic flow, regurgitant fraction (RF) and peak velocity were quantified from phase-contrast cine images.

Results: Median neo-aortic regurgitation was mild at all three examinations (RF <20%) and there was no significant increase in RF over time ( > 0.05). None of the patients had significant neo-aortic valve stenosis (peak velocity >3 m/s). RF correlated with RVESVi and RVEF at the second examination. At the third examination, RF correlated with RVESVi and RVEDVi even in patients with RF <15% (RVESVi:  = 0.40,  = 0.001; RVEDVi:  = 0.34,  = 0.031).

Conclusion: Assessment of serial CMR studies in HLHS patients after TCPC completion demonstrates a preserved neo-aortic valve function. Nevertheless, thorough follow-up is mandatory as even mild neo-aortic dysfunction might impact RV size and function over a longer term.