Preoperatively Diagnosed PFO and Perioperative Stroke

Study Questions:

Is a preoperatively diagnosed PFO associated with increased risk of perioperative ischemic stroke?

Methods:

This was a large retrospective study of approximately 150,000 adult patients undergoing noncardiac surgery under general anesthesia with post-procedure extubation at three centers over 9 years. The main outcome measure was ischemic stroke occurring within 30 days after surgery. Presence of a PFO and occurrence of ischemic stroke were identified using International Classification of Diseases (ICD) diagnostic codes.

Results:

Of the ~150,000 patients, 1% had a diagnosis of PFO before surgery. Of the 850 subjects who had a stroke within 30 days after surgery (0.6% of the total cohort), 49 occurred among those with PFO and 801 occurred among those without PFO (3.2% vs. 0.5%). After adjustment for numerous potential confounders, the odds of perioperative stroke were higher in the PFO group than in the non-PFO group (adjusted odds ratio [OR], 2.66; 95% confidence interval [CI], 1.96-3.63). A subgroup analysis of only subjects with a presurgical echocardiogram found a somewhat attenuated association in unadjusted analysis (OR, 1.86; 95% CI, 1.28-2.72).

Conclusions:

These data suggest that presence of a PFO is associated with increased risk of stroke within 30 days after noncardiac surgery.

Perspective:

As the authors state in their introduction, the prevalence of PFO in the general population is approximately 25%. The prevalence of identified PFO in this cohort was 1%. Therefore, PFO was presumably underdiagnosed in this cohort. If patients with present but undiagnosed PFO had less frequent stroke than those with present and diagnosed PFO, the results may be biased. To help corroborate the results of this study, a large prospective cohort study of presurgical patients, all with baseline echocardiography with bubble study, would be indicated. However, given the low prevalence of stroke within 30 days after surgery in all-comers in this study (0.6%), the clinical relevance of an association between PFO and perioperative stroke may be limited.

Clinical Topics: Congenital Heart Disease and Pediatric Cardiology, Noninvasive Imaging, Prevention, Congenital Heart Disease, CHD and Pediatrics and Arrhythmias, CHD and Pediatrics and Imaging, CHD and Pediatrics and Quality Improvement, Echocardiography/Ultrasound

Keywords: Airway Extubation, Anesthesia, General, Echocardiography, Foramen Ovale, Patent, Heart Defects, Congenital, Outcome Assessment (Health Care), Perioperative Period, Prevalence, Primary Prevention, Risk, Stroke, Surgical Procedures, Operative


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