Plasma viscosity and mean platelet volume in patients undergoing coronary angiography

Background: Markers of platelet activation and haemorrheological indices have been demonstrated to play a role in the pathophysiology of atherosclerosis and cardiovascular events. In this study, we aimed at investigate the association between plasma viscosity and platelet indices in patients undergoing coronary angiography. Materials and methods: Three hundred and eighty four consecutive patients scheduled to undergo coronary angiography were included in the study. Prior to coronary angiography, blood samples were withdrawn to determine routine biochemical markers, blood cell analyses and viscosity measurements. According to the results of coronary angiography, patients were classified either in a subgroup with coronary artery disease (CAD; 1 or more stenoses > 50%) or normal coronary arteries (NCA; no stenoses or <50%). Results: There was a statistically significant correlation between plasma viscosity and mean platelet volume levels in all patients undergoing coronary angiography (r = 0.199, p <0.001). Additionally, when correlation analysis was performed within each group, plasma viscosity significantly correlated with MPV both in patients with CAD (r = 0.18, p = 0.004) and in patients with NCAs (r = 0.272, p = 0.002). Linear regression analysis revealed that plasma viscosity was positively associated with MPV while platelet number was inversely but significantly associated with MPV. Conclusion: We have shown for the first time that MPV correlates with plasma viscosity in patients undergoing coronary angiography, suggesting a relation with plasma proteins and activation of circulating platelets or peripheral consumption of platelets. To evaluate this relation further controlled studies also in patients with acute coronary syndromes are warranted.