Percutaneous Closure of Patent Foramen Ovale - Data from Randomized Clinical Trials and Meta-Analyses.

Data from epidemiologic studies have indicated a close association between the presence of a patent foramen ovale (PFO) and cryptogenic stroke that is suggestive of paradoxical embolism as the underlying cause. Percutaneous closure of PFO has been proposed for the secondary prevention among patients suffering from paradoxical embolism. While observational data support this strategy, three randomized trials investigating percutaneous PFO closure with medical therapy have failed to detect a statistically significant reduction of the primary endpoint of recurrent ischemic cerebrovascular events, peripheral embolism, and death in the intention-to-treat analysis. Several reasons have been discussed as basis for the negative primary study results, including long recruitment rates, low number of recurrent events, and the use of different devices. In order to provide an answer to these unresolved factors, several meta-analyses have been published that have provided conflicting results. This article will review the available evidence of percutaneous PFO closure, will provide an overview on randomized clinical trials, and summarize the evidence from meta-analyses.