Patent foramen ovale and long-term risk of ischaemic stroke after surgery

Abstract

Aims: Pre-operatively diagnosed patent foramen ovale (PFO) is associated with an increased risk of ischaemic stroke within 30 days after surgery. This study aimed to assess the PFO-attributable ischaemic stroke risk beyond the perioperative period.

Methods and results: This observational study of adult patients without history of stroke undergoing non-cardiac surgery with general anaesthesia examined the association of PFO with ischaemic stroke 1 and 2 years after surgery using multivariable logistic regression. Of the 144 563 patients included, a total of 1642 (1.1%) and 2376 (1.6%) ischaemic strokes occurred within 1 and 2 years after surgery, 54 (4.7%) and 76 (6.6%) among patients with PFO, and 1588 (1.1%) and 2300 (1.6%) among patients without PFO, respectively. The odds of ischaemic stroke within 1 and 2 years after surgery were increased in patients with PFO: adjusted odds ratio (aOR) 2.01, 95% confidence interval (CI) 1.51-2.69; P < 0.001 and aOR 2.10, 95% CI 1.64-2.68; P < 0.001, respectively. Among patients who underwent contrast transoesophageal echocardiography, the frequency of PFO was 27%, and the increased stroke risk in patients with PFO was robust (aOR 3.80, 95% CI 1.76-8.23; P = 0.001 for year 1). The PFO-attributable risk was mitigated by post-operative prescription of combination antithrombotic therapy (odds ratio 0.41, 95% CI 0.22-0.75; P for interaction = 0.004).

Conclusion: Patients with PFO are vulnerable to ischaemic stroke for an extended period of time after surgery. Physicians should consider implementing PFO screening protocols in patients scheduled for major non-cardiac surgery.

Keywords: Antithrombotic agents; Paradoxical embolism; Patent foramen ovale; Stroke; Surgery.