Preoperative patent foramen ovale ups risk of ischaemic stroke following noncardiac surgery
Patent foramen ovale (PFO), diagnosed preoperatively, appears to significantly increase the risk of perioperative ischaemic stroke within 30 days after noncardiac surgery, a recent study has shown.
“[H]aving a preoperatively diagnosed PFO was significantly associated with increased risk of perioperative ischemic stroke within 30 days after surgery. Further research is needed to confirm these findings and to determine whether interventions would decrease this risk,” said researchers.
The researchers investigated the incidence of perioperative ischaemic stroke following noncardiac surgery in 150,198 adults (mean age 55±16 years; 54.6 percent female). PFO was preoperatively diagnosed in 1.0 percent of the study cohort.
Perioperative ischaemic stroke was significantly more common in patients with PFO (3.2 vs 0.5 percent; absolute risk difference [RD], 2.6 percent; 95 percent CI, 1.8–3.5). The overall incidence rate of perioperative ischaemic stroke was 0.6 percent (n=850). [JAMA 2018;319:452-462]
The risk of ischaemic stroke within 30 days after the operation was also significantly higher in those with vs without PFO (odds ratio [OR], 2.66; 1.96–3.63; p<0.001), leading to an estimated risk of 5.9 events per 1,000 patients with PFO. The resulting adjusted RD was 0.4 percent (0.2–0.6).
“The association between PFO and stroke remained consistent after adjustment for risk factors of ischemic stroke and multiple sensitivity analyses, including stratified analyses in patients who had received diagnostic tests sensitive for the detection of PFO,” said researchers.
In terms of stroke subtypes, PFO patients were also at a significantly increased risk of large-vessel territory ischaemia (relative risk ratio [RR], 3.14; 2.21–4.48; p<0.001), perioperative total anterior stroke (relative RR, 3.66; 2.20–6.08; p<0.001) and posterior circulation stroke (relative RR, 3.14; 1.75–5.63; p<0.001).
PFO also exacerbated the associated effects of stroke. The stroke-related neurologic deficits, as measured by median scores in the National Institutes of Health Stroke Scale, were more severe in stroke patients with vs without PFO (4 vs 3 points; p=0.02).
“In the current study, PFO-related strokes were more frequently large-vessel territory strokes and strokes with more severe neurological deficits. Patients with PFO also experienced an excess of perioperative complications due to systemic embolism, including acute limb ischemia and renal artery embolism,” said researchers.
“These data provide support for the view of increased vulnerability to thromboembolic complications in patients with PFO during the perioperative period,” they added.
Clinically, the current findings show that patients scheduled for noncardiac surgery and who present with a preoperative diagnosis of PFO are at a higher risk of perioperative ischaemic stroke. This represents an actionable patient subgroup for whom preventive measures, such as preoperative PFO closure and individualized risk-benefit assessment, may potentially be helpful, according to researchers.
“Future studies are required to examine if these patients would benefit from intensifying stroke-preventive measures in the perioperative period,” they said.