Abstract W P374: Coated-Platelet Levels Correlate With HAS-BLED Scores in Stroke Patients With Atrial Fibrillation
Background: Coated-platelets are a subset of procoagulant platelets observed upon dual agonist stimulation with collagen and thrombin. Coated-platelet levels are increased in non-lacunar ischemic stroke compared to controls; however, patients with early hemorrhagic transformation have lower coated-platelet levels than those without. In contrast to brain infarction, coated-platelet levels are decreased in intracerebral hemorrhage and inversely correlated with the size of the bleed. Because anticoagulation is a key preventive treatment in cardioembolic stroke, we investigated the existence of a relationship between coated-platelets and bleeding risk in stroke patients with atrial fibrillation.
Methods: Coated-platelet levels, reported as percent of platelets converted to coated-platelets, were determined in 45 consecutive patients with acute stroke and atrial fibrillation. Exclusion criteria consisted of dementia, stroke due to other causes than atrial fibrillation, > 96 hours between onset of symptoms and coated-platelet assay, current anticoagulation, prior thrombolytics or abnormal PT/PTT/INR. Bleeding risk was determined for each patient using the HAS-BLED score. The correlation between individual coated-platelet levels and HAS-BLED scores was determined using the Pearson correlation coefficient.
Results: Coated-platelet levels for the 45 patients were 41.0 ± 13.9% (mean ± SD, range 13.2 to 69.7%), consistent with previous data in patients with non-lacunar ischemic stroke. Mean HAS-BLED score was 3.2 ± 1.6, with a range between 1 and 7. A highly significant inverse linear correlation between coated-platelet levels and HAS-BLED scores was observed (p < 0.001, r = -0.67).
Conclusions: Lower coated-platelet levels correlate with higher HAS-BLED scores in patients with stroke due to atrial fibrillation, suggesting that decreased coated-platelet synthesis is present in patients with an increased risk for bleeding. Our results are consistent with previously published research showing lower coated-platelet levels in intracerebral hemorrhage and early hemorrhagic transformation of ischemic stroke, and support a role played by this subset of activated platelets in the balance between thrombosis and hemorrhage.
Author Disclosures: C. Prodan: Research Grant; Modest; VA Merit Award 1I01CX000340. A. Vincent: None. A. Kirkpatrick: Research Grant; Modest; VA 2011 VISN 16 Pilot Grant. G. Dale: None.
- © 2014 by American Heart Association, Inc.