Residual shunt and stroke recurrence: When closure is not complete

Percutaneous closure of patent foramen ovale (PFO) using a double-disc device has been demonstrated in 4 clinical trials (CLOSE, REDUCE, extended follow-up of RESPECT, DEFENSE-PFO) to be superior to medical therapy alone in preventing recurrent cryptogenic stroke or transient ischemic attack (TIA) [1][2][3][4].Cryptogenic stroke, also referred to as embolic stroke of undetermined source, accounts for approximately one-quarter to one-third of all ischemic strokes [5,6].Among younger patients (<55 years) with cryptogenic stroke, the prevalence of PFO is approximately 50% [7,8].Collectively, these findings underscore the