Covert Perioperative Strokes in Older Patients Having Noncardiac Surgery (PRECISION): A Prospective Cohort Analysis

BACKGROUND: Perioperative strokes may promote postoperative neurocognitive dysfunction. This study thus evaluated the incidence of postoperative strokes and the association between strokes and postoperative neurocognitive outcomes in older patients recovering from noncardiac surgery. METHODS: The Postoperative Covert Stroke and Cognitive Dysfunction among Elderly Patients Undergoing Noncardiac Surgery study (PRECISION) was a two-center prospective cohort study evaluating patients aged 60 yr or older who had elective, noncardiac inpatient surgery at two Chinese academic centers. Postoperative strokes were evaluated by scheduled magnetic resonance brain imaging within 7 days. The 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 yr; 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 was observed in 147 patients (18.8%; 95% CI, 16.0 to 21.5%) at 1 yr 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-yr neurocognitive decline (adjusted odds ratio, 2.33; 95% CI, 1.31 to 4.13; P = 0.004) in overall participants. CONCLUSIONS: Among patients aged 60 yr and older who had major noncardiac surgery, mainly intracranial, one in nine patients 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.