Post-stroke cognitive impairment as an independent predictor of ischemic stroke recurrence: PICASSO sub-study

Introduction: To devise appropriate preventive strategies after stroke, knowledge of the association between post-stroke cognitive impairment (PSCI) and prognosis of stroke patients is important. We investigated the association between PSCI and the vascular outcomes in patients with ischemic stroke with best medical care considering their risk factors and adherence to medications. Methods: Of the 1534 ischemic stroke patients who randomly assigned to aspirin or cilostazol treatment with best medical therapy by the PICASSO (PreventIon of CArdiovascular events in iSchemic Stroke patients with high risk of cerebral hemOrrhage) trial, 1240 with baseline mini-mental state examination (MMSE) scores were analysed retrospectively. The patients were classified into three groups based on MMSE scores. Recurrence of ischemic stroke, stroke of any type and composite of major vascular events were compared among them. Results: Of the 1240 patients, 376 had MMSE scores of 28–30 (highest tertile), 419 had scores of 24–27 (middle tertile) and 445 had scores of 0–23 (lowest tertile). The average time from stroke onset to MMSE examination was 31.8 days. By trend analysis, lower tertile of MMSE score was significantly associated with recurrent ischemic stroke (p = 0.0017), stroke of any type (p = 0.0053) and composite vascular outcome (p = 0.0122). After adjustment for covariates, PSCI was independently associated with risk of recurrent ischemic stroke (HR 2.40, 95% confidence interval 1.12–5.14). Conclusions: Cognitive impairment was associated with recurrence of ischemic stroke in high risk patients during adequate medical therapy including antiplatelet therapy. However, the other vascular events were not.