Risk of ischemic stroke in patients with pulmonary embolism and patent foramen ovale: A systematic review and meta-analysis

Objective: Patients with acute pulmonary hypertension during an acute pulmonary embolism (PE) can develop stroke due to paradoxical embolism in the presence of a patent foramen ovale (PFO). We evaluated the current evidence regarding the risk of ischemic stroke and mortality in patients with PE and a PFO.

Methods: We performed a systematic review and meta-analysis of studies found on PubMed, the Cochrane Library, Embase, SCOPUS, and the BVS portal. We included full-length reports, prospective observational cohorts, and clinical trials of adult patients (aged ≥18 years) diagnosed with PE and investigating the presence of PFO and new ischemic brain injuries. This study is registered with PROSPERO (CRD42023467133).

Results: The initial search identified 1398 articles. After applying exclusion criteria, only 8 articles remained, including a total of 1197 individuals with PE, among whom PFO was identified in 318 patients. Ischemic stroke occurred in 62/318 (19.5 %) individuals in the PFO group and in 40/879 (4.5 %) individuals in the non-PFO group. The prevalence of ischemic stroke in the PFO group was higher than in the non-PFO group in all eight studies. The meta-analysis showed that PFO was significantly associated with ischemic stroke in patients with PE compared to those without PFO (odds ratio 5.36, 95 % CI 3.20-8.99, p < 0.00001; I² = 0 %). Three studies also reported higher mortality in the PFO group.

Conclusion: Patent foramen ovale is a common condition in patients with acute PE and is associated with a higher incidence of ischemic stroke and increased mortality.