Perspective:

This study raises important clinical questions, especially given the large number of patients with intracardiac devices and leads, and the common occurrence of PFOs. Even after adjusting for risk factors, patients with a PFO had an over threefold increased risk of stroke or TIA, and this difference persisted despite adjustment for risk factors including baseline aspirin and warfarin use. While intriguing, this study raises several questions. As saline contrast studies were not uniformly performed, and as transesophageal echocardiography was performed only in a small subset of patients, it is likely that many PFOs were missed during this study. It is unclear whether routine performance of saline contrast studies and transesophageal echocardiography would identify an additional cohort of patients with intracardiac leads and a PFO at increased risk of stroke or TIA. Further, while adjustment was made for baseline aspirin and warfarin use, it is not clear whether there were differences between groups at the time of the index event or follow-up. Most importantly, while this study identifies a relationship between PFO and risk of stroke or TIA, it is not clear whether a medical or procedural intervention would change this risk, and future studies are therefore needed.