Lower Coated-Platelet Levels Are Associated With Increased Mortality After Spontaneous Intracerebral Hemorrhage.

BACKGROUND AND PURPOSE Coated-platelets are highly procoagulant platelets observed on dual-agonist stimulation with collagen and thrombin. Coated-platelet levels are decreased in patients with spontaneous intracerebral hemorrhage when compared with controls and inversely correlated with bleed volume. We sought to investigate whether coated-platelets are associated with increased mortality at 30 days after spontaneous intracerebral hemorrhage. METHODS Coated-platelet levels were assayed in 95 consecutive patients with spontaneous intracerebral hemorrhage. The main outcome was mortality at 30 days according to coated-platelet levels at enrollment. Subjects were grouped into tertiles of the observed coated-platelet level distribution. Groups defined by tertile of coated-platelet level were compared using either ANOVA or a Kruskal-Wallis test for small group size for continuous measures and an exact Cochrane-Armitage trend test for categorical measures. Logistic regression was used to estimate the adjusted odds of death within 30 days associated with coated-platelet levels. RESULTS Cumulative mortality at 30 days was 23% (22 subjects). Mortality at 30 days differed among the coated-platelet tertiles: 44% for the first tertile (lowest coated-platelet levels), 19% for the second tertile, and 6% for the third tertile (trend test; P=0.0004). Logistic regression examining the association between mortality and coated-platelet levels showed that the odds of death at 30 days in those with levels <27% (n=47) were 6.83× the odds for patients with levels ≥27% (95% confidence interval, 2.10-22.23). CONCLUSIONS These results support a link between impaired coated-platelet potential and outcome in intracerebral hemorrhage.