Framingham stroke risk score and cognitive impairment for predicting first-time stroke in the oldest old.

Abstract

Predictive value of the conventional risk factors for stroke attenuates with age. Cognitive impairment has been implicated as a potential predictor for stroke in older subjects. Our aim was to compare the Framingham stroke risk score with cognitive functioning for predicting first-time stroke in a cohort of the oldest old individuals. We included 480 subjects, aged 85 years, from the Leiden 85-plus Study. At baseline, data on the Framingham stroke risk score and the Mini-Mental State Examination (MMSE) score were obtained. Risk of first-time stroke was estimated in tertiles of Framingham and MMSE scores. Receiver operating characteristic curves with corresponding areas under the curves (AUCs) and 95% confidence intervals (CIs) were constructed for both Framingham and MMSE scores. Subjects with high Framingham risk score compared with those with low Framingham risk score did not have a higher risk of stroke (hazard ratio, 0.77; 95% CI, 0.39-1.54). Conversely, subjects with high levels of cognitive impairment compared with those with low levels of cognitive impairment had a higher risk of stroke (hazard ratio, 2.85; 95% CI, 1.48-5.51). In contrast to the Framingham risk score (AUCs, 0.48; 95% CI, 0.40-0.56), MMSE score had discriminative power to predict stroke (AUCs, 0.65; 95% CI, 0.57-0.72). There was a significant difference between AUCs for Framingham risk score and MMSE score (P=0.006). In the oldest old, the Framingham stroke risk score is not predictive for first-time stroke. In contrast, cognitive impairment, as assessed by MMSE score, identifies subjects at higher risk for stroke.