Objective Recently it has been suggested that,in patients with large patent foramen ovale (PFO) and atrial septal aneurysms (ASA),a certain amount of left atrial (LA) dysfunction may be active as an alternate mechanism promoting arterial embolism-Following this hypothesis,elderly patients,being more susceptible to atrial chambers stiffness,should present a more severe LA dysfunction profile.We sought to evaluate the grade of LA dysfunction in elderly patients submitted to transcatheter PFO closure.Methods We retrospectively enrolled 28 consecutive patients with previous stroke (mean age 67±12.5 years,18 females) referred to our centre for catheter-based PFO closure after recurrent stroke.Baseline values of LA passive and active emptying,LA conduit function,LA ejection fraction,and spontaneous echocontrast (SEC) in the LA and LA appendage were compared with those of 50 atrial fibrillation patients,as well as a sex/age/cardiac risk matched population of 70 healthy controls.Results Pre-closure elderly subjects demonstrated significantly greater reservoir function as well as passive and active emptying,with reduced conduit function and LA ejection fraction,when compared to healthy and younger patients.After closure in elderly patients,LA parameters did not return completely to the levels of healthy patients,whereas LA dysfunction in younger subjects returned normal.Conclusions This study suggests that elderly patients have more severe LA dysfunction than younger patients,which affects the LA remodelling after closure.