Higher levels of coated-platelets are observed in patients with subarachnoid hemorrhage but lower levels are associated with increased mortality at 30 days

• Published in: Journal of the neurological sciences Vol. 334; no. 1; pp. 126 - 129
• Main Authors: Prodan, Calin I, Vincent, Andrea S, Kirkpatrick, Angelia C, Hoover, Steven L, Dale, George L
• Format: Journal Article
• Language: English
• Published: Netherlands 15.11.2013
• Subjects: Case-Control Studies; Female; Humans; Male; Middle Aged; Neurology; Platelet Count; Risk Factors; Subarachnoid Hemorrhage - blood; Subarachnoid Hemorrhage - mortality; Time Factors; Stroke; Ischemia; Platelets; Subarachnoid hemorrhage; Hemostasis; Thrombosis
• ISSN: 0022-510X; 1878-5883
• DOI: 10.1016/j.jns.2013.08.008

Abstract Background Coated-platelets are procoagulant platelets observed upon dual agonist stimulation with collagen and thrombin. Coated-platelet levels are elevated in non-lacunar ischemic stroke compared to either lacunar stroke or controls. In contrast, coated-platelet levels are decreased in spontaneous intracerebral hemorrhage (ICH) and inversely correlated with bleed size. We now report the first investigation of coated-platelets in patients with subarachnoid hemorrhage (SAH). Methods Coated-platelet levels were determined in 40 consecutive patients with spontaneous SAH and in 40 controls. Results are reported as percent of cells converted to coated-platelets. Mortality at one month was recorded for all patients. Results Coated-platelet levels (mean ± SD) were significantly higher in SAH patients compared to controls (41.8 ± 11.4% vs. 30.7 ± 12.2%, p < 0.0001). Among all patients, mortality at 1 month was 20% (8 deaths). Patients were analyzed according to tertiles of coated-platelet levels (split at < 36.7%, 36.7–46.2%, > 46.2%). The 1-month mortality differed significantly between the coated-platelet tertiles (p = 0.01) with 46% mortality (6/13) among patients in the lowest tertile (lowest levels) compared to 14.3% (2/14) among those in the middle tertile and 0% in the highest tertile. Conclusions Coated-platelet levels are higher in SAH patients compared to controls. However, lower coated-platelet levels are associated with increased 1-month mortality in SAH patients, a finding compatible with prior observations of an inverse relationship between coated-platelet levels and bleed volume in ICH. The current data support the role played by these prothrombotic platelets in thrombosis or hemorrhage and suggest a potential place for coated-platelet levels in predicting prognosis after SAH.