Structural and functional atrial remodelling after transcatheter closure of patent foramen ovale

Abstract Introduction Patent foramen ovale (PFO) is a common abnormality affecting more than 20% of the adult population. For most people they are accidental findings; however, in some the PFO can open widely enabling paradoxical embolisation. Randomised controlled trials have demonstrated in patients with cryptogenic stroke that transcatheter closure of PFO with a septal occluder device is associated with reduced rates of recurrent stroke. However, the impact of atrial septal closure on left atrial (LA) and right atrial (RA) structural and functional remodelling is less known. Methods We prospectively enrolled 53 patients with cryptogenic ischemic stroke and PFO eligible for transcatheter PFO closure (mean age 46±11 years, 44% females). National Institute of Health Stroke Score (NIHSS), and the modified Rankin score (mRS) were calculated as markers of clinical severity of the index stroke. Presence of any shunt, atrial volumes and functional parameters were evaluated including LA reservoir, conduit and contraction function before PFO closure and 12 months after procedure. Beyond conventional transthoracic echocardiography (Philips Epiq CVx Ultrasound), two dimensional speckle tracking method was used to assess body surface area-indexed LA maximal volume (LAVmaxi), LA minimal volume (LAVmini), LA volume before left atrial contraction (LApreAi), LA ejection fraction (LAEF), LA reservoir strain (LASres), LA conduit strain (LAScond), LA contraction strain (LAScontr), LA peak systolic strain rates (LASRs), LA peak early diastolic strain rate (LASRe) and LA peak late diastolic strain rate (LASRa) using dedicated software on separate workstation (Cardiac Performance; TomTec Imaging, Unterschleissheim, Germany). Results The index stroke was modest and non-disabling, with an NIHSS 3.37±2.63 and mRS 1.67±1.06. Baseline LA, RA volumes and dimensions were in normal range (LAVi 25.5±9.6 ml/m2; LA length 37.6±6.2 mm; LA width 40.4±7.1 mm; RA length 36.6±6.7 mm; RA width 39.5±8.6 mm). Thirty-seven patient had 12 month clinical follow-up examinations revealing no significant differences (all p values >0.05) in atrial volumes, ejection fraction and strain parameters. LASRa was significantly lower after 12 month (p=0.03; baseline LASRa −1.7±0.7 s–1 vs follow-up LASRa −1.3±0.9 s–1) No new cerebral ischaemic events, aortic erosions, atrial fibrillation, significant residual shunts or device thrombosis and displacement were recorded during the follow-up. Conclusion PFO-associated strokes in young individuals are mainly non-disabling. Our study suggests that transcatheter interatrial closure is effective without promoting unfavourable atrial anatomical remodelling during short-term follow-up, however, it may affect active atrial contraction. Long-term follow-up examinations are needed to investigate the potential late impact of occluders on atrial anatomical, functional remodelling. Funding Acknowledgement Type of funding source: None