Early prognostic factors in ischemic stroke. The role of protein C and protein S.

Abstract

Protein C and protein S have been found reduced in some patients with ischemic cerebrovascular diseases, but the relevance of this finding for prognosis is unsettled. In 43 consecutive patients admitted over 6 months for acute ischemic stroke, protein C and free protein S were evaluated on admission, and at 2 and 6 months after stroke. Excluded were all patients with known causes liable to reduce the levels of protein C, free protein S, or both. In 14% of patients, abnormally low levels of protein C were found at entry. In comparison to the remaining sample, this group had a significantly lower initial score on the Barthel and Canadian neurological scales, a higher prevalence of emboligenic cardiac diseases, and had a higher mortality at 6 months. No statistical difference was found for the other vascular risk factors. Eight patients (18.4%) had abnormally low levels of free protein S at entry. In comparison to the remaining sample, there was no statistical difference in the severity scores, prevalence of emboligenic cardiac diseases, mortality, or vascular risk factors. These findings suggest that low levels of protein C in the acute stroke reflect the massive activation of coagulation factors and are predictive of adverse outcome, whereas the significance of low levels of free protein S remains to be clarified.