Left atrial enlargement as a maker of significant high-risk patent foramen ovale

Left atrial (LA) enlargement is a marker of LA cardiopathy and, in patients with patent foramen ovale (PFO), is associated with an increased risk of ischemic stroke. The primary study outcome was the comparison of LA diameter between patients undergoing percutaneous PFO closure versus those treated conservatively. The secondary endpoints were the association of LA diameter with the Risk of Paradoxical Emboli (ROPE) score and the presence of Atrial septal aneurysm (ASA) and Right-To-Left Shunt (RLS). Retrospective analysis of clinical and instrumental data of 1040 subjects referred to a single tertiary center for PFO evaluation and treatment. Seven hundred and nineteen patients were enrolled: 495 patients (closure group, mean RoPE score 7.6 ± 0.8) underwent PFO closure while 224 patients (control group, mean RoPE score 4.1 ± 0.9. p < 0.001) were left to medical therapy. Preoperative LA diameter was significantly larger in closure group and reduced from 44.3 ± 9.1 to 37.3 ± 4.1 mm (p = 0.01) 1 year after the procedure to the size of controls. A larger LA diameter was associated with permanent RLS, RLS curtain pattern, ASA presence and multiple ischemic brain lesions pattern at neuroimaging. A LA diameter ≥ 43 mm was a predictor a RoPEscore > 7. In our patients' cohort, LA diameter was associated with the clinic severity of PFO and RLS. The reversal of LA enlargement after PFO closure suggests a role for RLS to induce LA cardiopathy. LA enlargement has the potential to be considered per se as an indication to transcatheter PFO repair.