Abstract 1173: Risk of Recurrent Cerebrovascular Events in Patients with Cryptogenic Cerebral Ischemia and Patent Foramen Ovale: A Meta-Analysis of Observational Studies

Abstract

In patients with a patent foramen ovale (PFO) and a prior cryptogenic ischemic stroke or transient ischemic attack (TIA), the risk of recurrent events is unclear. To conduct a systematic review and meta-analysis of studies assessing the risk of recurrent cerebrovascular events in patients with cryptogenic cerebral ischemia and PFO. MEDLINE (1950 to February 2008) and EMBASE (1980 to February 2008) databases were searched to identify studies in any language. Searches were supplemented by scanning bibliographies of key articles. Studies reporting original data on recurrent cerebrovascular events in patients with prior cryptogenic stroke or TIA and PFO, with or without a non-PFO comparison group, were included. Uncontrolled case series evaluating device or surgical closure of PFO were excluded. Two authors independently extracted the data from included studies and evaluated study quality. For studies with a non-PFO comparison group, relative risks were pooled using a fixed effects model after confirming homogeneity of results. For all studies, the pooled absolute rate of recurrent events was calculated using a random effects model due to heterogeneity of results. Fifteen studies published between 1994 and 2007, following 2377 patients over a mean of 37 months were included. In the four studies with a non-PFO comparison group, the pooled relative risk of recurrent stroke or TIA associated with the presence of a PFO was 1.1 (95% CI 0.8 to 1.5), while for recurrent ischemic stroke the pooled relative risk associated with the presence of a PFO was 0.8 (95% CI 0.5 to 1.3). The pooled absolute rate of recurrent ischemic stroke or TIA in patients with PFO was 4.0 events per 100 person-years (95% CI 3.0 to 5.1) while the rate of recurrent ischemic stroke was 1.6 events per 100 person years (95% CI 1.1 to 2.1). No clinical or imaging features are reliably associated with increased risk of recurrent events. In medically treated patients with prior cryptogenic stroke, available evidence does not support an increased risk of recurrent ischemic events in those with vs. without a PFO. Routine PFO closure in these patients may not be warranted, outside of ongoing clinical trials.