Covert perioperative strokes in older patients having non-cardiac surgery (PRECISION): a prospective cohort analysis

Background: Perioperative strokes may promote postoperative neurocognitive dysfunction. We thus evaluated the incidence of postoperative strokes and the association between strokes and postoperative neurocognitive outcomes in older patients recovering from non-cardiac surgery. Methods: PRECISION was a two-center prospective cohort study. We evaluated patients aged ≥60 years who had elective, non-cardiac inpatient surgery at two Chinese academic centers. Postoperative strokes were evaluated by scheduled magnetic resonance brain imaging within 7 days. Our primary outcome was the cumulative incidence of postoperative stroke. Secondary outcomes included postoperative delirium within the first 5 days after surgery, neurocognitive decline at 12 months and the association between stroke and neurocognitive dysfunction. Results: Among 934 patients (mean age, 67 years; 45% male) included in the analyses, two-thirds had neurosurgical craniotomies. There were 111 (11.9%, 95% CI 9.8% to 14.0%) covert strokes within 7 days after surgery, and no overt strokes. Postoperative delirium was observed in 117 patients (12.5%, 95% CI 10.4% to 14.7%) within 5 days and neurocognitive decline observed in 147 patients (18.8%, 95%CI 16.0% to 21.5%) at 1 year after surgery. Postoperative covert strokes were significantly associated with delirium (adjusted odds ratio 2.18, 95% CI 1.31 to 3.62; P=0.003), and 1-year neurocognitive decline (adjusted OR 2.33, 95% CI 1.31 to 4.13, P=0.004) in overall participants. Conclusions: One in 9 patients aged 60 years and older who had major non-cardiac surgery, mainly intracranial, experienced a perioperative covert stroke. Covert strokes more than doubled the risk of postoperative delirium and long-term neurocognitive decline. Covert perioperative strokes are common and clinically meaningful.