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  • 1
    Online Resource
    Online Resource
    Abstract WP439: Mean Platelet Volume and Platelet Count are not Associated With Coated-Platelet Levels Among Patients With Asymptomatic Carotid Stenosis
    Ovid Technologies (Wolters Kluwer Health) ; 2017
    In:  Stroke Vol. 48, No. suppl_1 ( 2017-02)
    Details
    In: Stroke, Ovid Technologies (Wolters Kluwer Health), Vol. 48, No. suppl_1 ( 2017-02)
    Abstract: Background: Coated-platelets, a subset of activated platelets observed with dual-agonist stimulation with collagen and thrombin, represent 30% of the platelet population in normal controls. In recently published work, we have shown that elevated coated-platelet levels ( 〉 45%) are predictive of stroke in asymptomatic carotid stenosis. We now investigate if platelet count and mean platelet volume (MPV) are related to coated-platelet levels. Methods: Coated-platelet levels were measured in a cohort of asymptomatic outpatients referred for carotid ultrasound studies. Platelet count and mean platelet volume for each subject were recorded from the VA electronic medical record at the closest possible time period (within ≤6 months) to the date of coated-platelet sample. Correlations between each parameter and coated-platelet levels were determined and those reaching significance at p≤0.1 were included in a multiple regression model with LDL and systolic blood pressure (SBP), variables previously known to correlate with coated-platelet levels. Results: Platelet count and mean platelet volume data were available within the specified period for 289 patients (96% male, mean age 66 years). On univariate analysis, coated-platelet levels correlated with platelet count (r = 0.15, p=0.01), but not with MPV (r=-0.04, p=0.53). When platelet count was included in a multiple regression analysis with LDL and SBP, platelet count was no longer significantly associated with coated-platelet levels. In the final model, higher coated-platelet levels were associated with LDL (p=0.008) and SBP (p=0.007) after controlling for all potentially confounding variables, including medications and comorbidities. Conclusions: Among asymptomatic patients with carotid atherosclerosis, neither MPV, which has been previously shown to correlate with platelet aggregation, nor platelet count are significantly associated with coated-platelet levels after accounting for all potential confounding variables. These findings support the notion of coated-platelets as a unique measure of platelet procoagulant potential.
    Type of Medium: Online Resource
    ISSN: 0039-2499 , 1524-4628
    URL: Article
    DOI: 10.1161/str.48.suppl_1.wp439
    RVK:
    XA 10000
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2017
    detail.hit.zdb_id: 1467823-8
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  • 2
    Online Resource
    Online Resource
    Abstract TP113: Elevated Coated-Platelets and SSRI Use Are Associated with Silent Brain Infarction in Asymptomatic Carotid Artery Stenosis
    Ovid Technologies (Wolters Kluwer Health) ; 2018
    In:  Stroke Vol. 49, No. Suppl_1 ( 2018-01-22)
    Details
    In: Stroke, Ovid Technologies (Wolters Kluwer Health), Vol. 49, No. Suppl_1 ( 2018-01-22)
    Abstract: Background: Silent brain infarction (SBI) is a marker of stroke risk in asymptomatic carotid stenosis. Increased SBI burden downstream of stenosis has not been consistently shown, emphasizing that mechanisms of SBI formation in carotid stenosis remain unclear. Coated-platelets are a subset of procoagulant platelets observed upon dual agonist stimulation with collagen and thrombin, and elevated levels are associated with TIA/stroke in asymptomatic carotid stenosis. We now examine if coated-platelet levels are associated with SBI in asymptomatic carotid stenosis. Methods: Consecutive asymptomatic ≥50% carotid stenosis patients were enrolled and coated-platelets assayed. Brain MRI or CT scans within 12 months of enrollment were reviewed by a blinded neurologist for SBI, defined as a focal, ≥ 3mm, cavitary lesion with T1 hypointensity and T2 hyperintensity features on MRI or hypodense on CT. Demographics, medications and comorbidities were recorded. The optimal coated-platelet cutoff was determined by ROC analysis. Logistic regression analysis included variables having significant (p 〈 .05) bivariate correlations with SBI as potential predictors. Variables with p 〈 0.05 were retained in the final model. Results: Brain imaging was available for 64 subjects. The optimal coated-platelet cutoff for predicting SBI was 52.7% (p=0.0002) by ROC analysis. Both elevated coated-platelets (OR=10.4, p=0.043) and SSRI use (OR=3.8, p=0.027) were associated with increased odds of SBI (p=0.005). Stenosis ≥70% was associated with presence (p=0.0005) and number (p 〈 0.0001) of downstream SBI on bivariate analysis, but was no longer significant in the multivariate model (p=0.14). Conclusions: Elevated coated-platelets and SSRI use were associated with SBI in this asymptomatic carotid stenosis cohort. Interestingly, presence of ≥70% stenosis was no longer significantly associated with SBI after accounting for coated-platelet levels and SSRI use by multivariate analysis. SSRI use has been linked to recurrent stroke previously, although results have varied. Our findings are the first showing a strong association between platelet procoagulant potential and SBI and warrant further study to confirm our results and explore mechanisms involved.
    Type of Medium: Online Resource
    ISSN: 0039-2499 , 1524-4628
    URL: Article
    DOI: 10.1161/str.49.suppl_1.TP113
    RVK:
    XA 10000
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2018
    detail.hit.zdb_id: 1467823-8
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  • 3
    Online Resource
    Online Resource
    Abstract TP120: IL-17a Correlates With Coated-Platelet Levels Among Patients With Carotid Atherosclerosis
    Ovid Technologies (Wolters Kluwer Health) ; 2016
    In:  Stroke Vol. 47, No. suppl_1 ( 2016-02)
    Details
    In: Stroke, Ovid Technologies (Wolters Kluwer Health), Vol. 47, No. suppl_1 ( 2016-02)
    Abstract: Introduction: Coated-platelets are a subset of platelets with high procoagulant potential observed on dual agonist stimulation with collagen and thrombin. Elevated coated-platelets identify asymptomatic carotid stenosis patients at high risk for stroke or TIA and are associated with stenosis progression. Hypothesis: Specific inflammatory markers correlate with coated-platelet levels among patients with carotid atherosclerosis. Methods: Patients referred for carotid Doppler evaluation with at least one additional follow-up scan were analyzed. Coated-platelet levels were determined at baseline and reported as percent of cells converted to coated-platelets. Serum was obtained simultaneously for measurement of inflammatory markers using the Bio-Plex Pro Human Cytokine 27-plex Assay kit (Bio-Rad Laboratories). Rank order correlation between inflammatory marker concentrations and coated-platelet levels was determined using the Spearman correlation coefficient. Results: Among 28 subjects followed for a mean of 28.6 ± 5.7 months, 9 developed progression of carotid stenosis severity. IL-17a concentration significantly correlated with coated-platelet levels (r = 0.68, p = 0.005). There was a trend toward a significant correlation between IL-17a and progression of carotid stenosis severity (r = 0.46, p = 0.08), which was no longer apparent after controlling for baseline coated-platelet level (r = 0.26, p = 0.37). Conclusions: Coated-platelet levels correlate with IL-17a concentration among patients with carotid atherosclerosis. Produced by a subclass of T helper cells, IL-17a has been associated with plaque instability in previous human studies demonstrating increased expression of IL-17a mRNA in patients with symptomatic carotid plaques. These results, in combination with previous findings showing an association between coated-platelets and carotid stenosis progression, support a role for inflammation and coated-platelets in modulation of atherosclerotic plaque.
    Type of Medium: Online Resource
    ISSN: 0039-2499 , 1524-4628
    URL: Article
    DOI: 10.1161/str.47.suppl_1.tp120
    RVK:
    XA 10000
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2016
    detail.hit.zdb_id: 1467823-8
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  • 4
    Online Resource
    Online Resource
    Abstract WMP113: Coated-Platelet Levels are Elevated in Subarachnoid Hemorrhage and Inversely Associated with Mortality at 30 Days
    Ovid Technologies (Wolters Kluwer Health) ; 2013
    In:  Stroke Vol. 44, No. suppl_1 ( 2013-02)
    Details
    In: Stroke, Ovid Technologies (Wolters Kluwer Health), Vol. 44, No. suppl_1 ( 2013-02)
    Abstract: Background: Coated-platelets are a subset of platelets with high procoagulant potential 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 patients with spontaneous intracerebral hemorrhage (ICH) and inversely correlated with bleed size. We now report the first investigation of coated-platelet production in patients with subarachnoid hemorrhage (SAH). Methods: Coated-platelet levels were determined in 38 consecutive patients with non-traumatic SAH within 48 hours from symptom onset and in 40 controls frequency-matched for gender, race and age. Results are reported as percent of cells converted to coated-platelets. Mortality at 1 month was obtained through chart reviews or telephone interviews. Baseline characteristics were compared either with a t-test for continuous measures or a Chi-square test for categorical measures. Results: Coated-platelet levels (mean±SD) were significantly higher in patients with SAH compared to controls (41.0±10.7% vs. 30.0±12.1%, p 〈 0.0001). No differences were detected between patients and controls for demographics, medication use or pertinent comorbidities (p values 〉 0.17). Among all patients, mortality at 1 month was 21% (8 deaths). Patients were then analyzed according to tertiles of coated-platelet levels (split at ≤36.6%, 36.6-45.5%, 〉 45.6%). The 1-month mortality differed significantly between the coated-platelet tertiles (p=0.019, Fisher’s exact test), with 50% mortality (6/12) among patients in the lowest tertile (lowest levels) compared to 7.7% (1/13) among those in the middle and highest tertiles. Conclusions: Coated-platelet levels are elevated in SAH compared to controls for reasons not currently clear. However, the association between lower coated-platelet levels and mortality in SAH patients is compatible with prior observations made in ICH. These data also provide further evidence of the role played by these prothrombotic platelets in events leading to thrombosis or hemorrhage. Supported by Award 1I01CX000340 from the Clinical Science R & D Service of the VA ORD (Prodan)
    Type of Medium: Online Resource
    ISSN: 0039-2499 , 1524-4628
    URL: Article
    DOI: 10.1161/str.44.suppl_1.AWMP113
    RVK:
    XA 10000
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2013
    detail.hit.zdb_id: 1467823-8
    Location Call Number Limitation Availability
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