LDL and Systolic Blood Pressure Are Associated with Coated-Platelet Levels in Patients with Asymptomatic Carotid Atherosclerosis (P1.235)

Objective: To examine the impact of vascular risk factors and medications on coated-platelet levels in patients with asymptomatic carotid atherosclerosis. Background: Coated-platelets, a subset of activated platelets observed with dual-agonist stimulation with collagen and thrombin, represent 30[percnt] of the entire platelet population in controls. In recently published work, we have shown that elevated coated-platelet levels (>51[percnt]) are predictive of stroke in asymptomatic carotid stenosis. We now investigate if additional clinical and laboratory parameters commonly recorded in patients with carotid atherosclerosis are related to coated-platelet measurements. Methods: Coated-platelet levels were measured in a cohort of asymptomatic outpatients referred for carotid ultrasound studies. The following parameters were recorded from the VA electronic medical records: serum creatinine, total cholesterol, LDL, HDL, and systolic blood pressure (SBP), all obtained at the closest possible timeframe (<6 months) from the coated-platelet assay. Correlations between each parameter and coated-platelet levels were determined and those that reached significance at p≤0.1 were included in a multiple regression analysis model. Results : There were 252 patients (97[percnt] male, mean age 66.5 years) in the cohort. Significant correlations were detected between coated-platelet levels and serum creatinine (p=0.03), LDL (p=0.04) and SBP (p=0.02). Through multiple regression analysis, only LDL and SBP were retained: higher coated-platelet levels were related to higher LDL (b=0.06, p=0.005) and lower SBP (b=-0.08, p=0.04), even after controlling for potentially confounding variables. Conclusions: In asymptomatic patients with carotid atherosclerosis, higher LDL and lower SBP were associated with increased coated-platelet levels. The relationship between LDL and coated-platelet levels is consistent with the recognized role of hypercholesterolemia in cardiovascular disease. The significance of the association between lower SBP and higher coated-platelet levels is less clear. These findings should be confirmed in prospective studies. Supported by grants from the American Heart Association and Clinical Science Research & Development Service (CX000340). Disclosure: Dr. Kirkpatrick has nothing to disclose. Dr. Nguyen has nothing to disclose. Dr. Vincent has nothing to disclose. Dr. Guthery has nothing to disclose. Dr. Mathews has nothing to disclose. Dr. Malatinszky has nothing to disclose. Dr. Donna-Ferreira has nothing to disclose. Dr. Dale has nothing to disclose. Dr. Prodan has received research support from the Veterans Affairs Office.