Background: Patent foramen ovale (PFO) is associated with perioperative stroke in noncardiac surgery. The magnitude of this association was assessed in a systematic review and meta-analysis.

Methods: Electronic databases were searched up to June 2022 for studies assessing the association between patent foramen ovale and perioperative stroke in adult patients undergoing noncardiac surgery. The primary analysis was limited to studies reporting effect estimates adjusted for significant clinical confounders. We calculated the adjusted odds ratio (aOR) and 95% confidence interval (CI).

Results: We included nine retrospective and two prospective observational studies, including 21 257 082 patients. The presence of a patent foramen ovale was independently associated with stroke at 30 days after surgery (aOR=6.68 [95% CI: 3.51-12.73]; P<0.001) and at longest follow-up available (aOR=7.36 [95% CI: 3.56-15.21]; P<0.001). The odds of stroke at 30 days varied according to surgical specialty: neurosurgery (aOR=4.52 [95% CI: 3.17-6.43]), vascular surgery (aOR=7.15 [95% CI: 2.52-20.22]), thoracic surgery (aOR=10.64 [95% CI: 5.97-18.98]), orthopaedic surgery (aOR=11.85 [95% CI: 5.38-26.08]), general surgery (aOR=14.40 [95% CI: 10.88-19.06]), and genitourinary surgery (aOR=17.28 [95% CI: 10.36-28.84]).

Conclusions: The presence of a patent foramen ovale is associated with a large and consistent increase in odds of stroke across all explored surgical settings. Prospective trials should further explore this association by systematically assessing patent foramen ovale and stroke prevalence and identifying a specific population at risk. This is crucial for the elaboration of prevention plans and may improve perioperative outcomes.