Platelet-monocyte binding and surface P-selectin expression are sensitive markers of platelet activation. Endothelium-derived factors are known to inhibit platelet activation and may confer important anti-atherothrombotic effects. We assessed the relationship between platelet activation and endothelium-dependent vasomotion in patients with coronary heart disease (CHD). Twenty male patients with stable CHD were compared with 20 healthy men. Platelet-monocyte binding and platelet surface expression of P-selectin were assessed using two-colour flow cytometry on whole blood. Forearm blood flow was assessed in patients using venous occlusion plethysmography during intra-arterial infusions of substance P, acetylcholine and sodium nitroprusside. Platelet activation was higher in patients than healthy men (platelet-monocyte binding, 27 ± 3 vs. 20 ± 1%; P < 0.05). In patients with CHD, there was an inverse correlation between maximal substance P induced vasodilatation and both platelet-monocyte binding (P = 0.003) and P-selectin expression (P = 0.02). A similar correlation was observed between platelet-monocyte binding and the vasomotor response to acetylcholine (P = 0.08) but not with sodium nitroprusside. In patients with stable coronary heart disease, there is a strong inverse relationship between markers of platelet activation and endothelium-dependent vasomotor function. This may explain the pathophysiological mechanism linking endothelial vasomotor dysfunction and the risk of acute atherothrombotic events
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.