BACKGROUND: Atrial fibrillation is an undesirable event following percutaneous patent fossa ovalis (PFO) closure with metallic occluders, suggesting that implanting a rigid closure device could alter atrial function. Suture-mediated PFO closure is a new technique, achieving closure of the PFO by means of a simple suture. Aim of this study was to evaluate left atrial function after closure of PFO by direct suture and traditional occluders.METHODS: We studied 40 age and sex homogeneous patients, 20 undergoing PFO closure by device (OCL) and 20 by suturing (NS). Twenty healthy sex-age matched subjects made up the control group (CT). Left atrial function was evaluated by using volumetric and speckle-tracking analysis assessing the following parameters: total emptying fraction (EF), Expansion Index (EI), active emptying fraction (AEF), strain values of the reservoir (r-ED), conduit (cd-ED) and contraction phase (ct-ED).RESULTS: Compared to CT and NS, OCL patients had significantly worst indices of left atrial reservoir function (EF P=0.001, EI P=0.003, r-ED P<0.001), conduit function (cd-ED P=0.018) and contraction function (AEF P=0.010; ct-ED P<0.001). No significant differences were observed in left atrial function indices between CT and NS patients. CONCLUSIONS: Suture-mediated PFO closure does not alter left atrial function. Conversely, metallic occluder is as-sociated with worse left atrium function. This detrimental effect on atrial function could favor the development of atrial arrhythmias.