RT Journal Article SR Electronic T1 Evidence for local platelet activation in pulmonary vessels in patients with pulmonary hypertension secondary to chronic obstructive pulmonary disease JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 147 OP 151 DO 10.1183/09031936.93.04020147 VO 4 IS 2 A1 C Rostagno A1 D Prisco A1 M Boddi A1 L Poggesi YR 1991 UL http://erj.ersjournals.com/content/4/2/147.abstract AB To investigate the relationships between local platelet activation in pulmonary vessels and pulmonary artery pressure circulating platelet aggregates and plasma beta-thromboglobulin (beta-TG) levels were evaluated in peripheral venous blood and blood from different sites of pulmonary circulation (right ventricle, pulmonary artery and arteriolo-capillary bed) in 29 patients with COPD. Fifteen had pulmonary hypertension and 14 normal pulmonary artery pressure. In normotensive COPD no significant differences could be found in platelet aggregation and beta-TG levels among different sampling sites. On the contrary in patients with pulmonary hypertension a significant increase of platelet aggregates and beta-TG levels was found in blood withdrawn from the arteriolo-capillary bed. A significant correlation was demonstrated between platelet aggregation and both mean pulmonary artery pressure and pulmonary vascular resistance. These results indicate that in patients with pulmonary hypertension secondary to COPD a local platelet activation in pulmonary vessels does occur and may contribute to the maintainance of elevated pulmonary vascular resistance.