Clinical question: Are patients with patent foramen ovale (PFO) at increased risk of perioperative ischemic stroke?
Background: Prior research has identified an association between PFO and risk of stroke. However, little is known about the effect of a preoperatively diagnosed PFO on perioperative stroke risk.
Study design: Retrospective cohort study.
Setting: Three Massachusetts hospitals, from January 2007 to December 2015.
Synopsis: The charts of 150,198 adult patients who underwent noncardiac surgery were reviewed for ICD codes for PFO. The primary outcome was perioperative ischemic stroke within 30 days of surgery, as identified via ICD code and subsequent chart review. After they adjusted for confounding variables, the study authors found that patients with PFO had an increased risk of perioperative ischemic stroke (odds ratio, 2.66; 95% confidence interval, 1.96-3.63; P less than .001) compared with patients without PFO. These findings were replicated in a propensity score–matched cohort to adjust for baseline differences between PFO and non-PFO groups. Patients with PFO also had a significantly increased risk of large-vessel territory ischemia and more severe neurologic deficits.
Given the observational design, this study could not establish a causal relationship between presence of a PFO and perioperative stroke. While the results support the consideration of PFO as a risk factor for perioperative stroke, research into whether this risk can be mitigated is needed.
Bottom line: Patients with PFO undergoing noncardiac surgery may be at increased risk of perioperative ischemic stroke.
Citation: Ng PY et al. Association of preoperatively diagnosed patent foramen ovale with perioperative ischemic stroke..
Dr. Roy is a hospitalist at Beth Israel Deaconess Medical Center, and instructor in medicine, Harvard Medical School, Boston.