ORIGINAL ARTICLES
Platelet activation in acute pulmonary embolism

https://doi.org/10.1111/j.1538-7836.2007.02461.xGet rights and content
Under an Elsevier user license
open archive

Summary

Background: Platelet activation is implicated in thrombotic disorders, but has not been described in acute clinical pulmonary embolism (PE). Objectives: To investigate the natural history of platelet activation in PE and associated markers of inflammation, thrombosis and cardiac dysfunction. Methods: Thirty‐five consecutive patients (age 62 ±17 years) with acute PE were prospectively enrolled and followed for 6 months. Platelet activation was assessed by flow cytometry [measuring expression of platelet P‐selectin, conformational activation of glycoprotein IIb/IIIa complex (PAC‐1) and formation of platelet–leukocyte complexes] and by plasma soluble P‐selectin. Platelet activation, right ventricular (RV) function (assessed as RV ejection area by transthoracic echocardiography), D‐dimer and high‐sensitivity C‐reactive protein (hs‐CRP) were measured at presentation and repeated over 6 months follow‐up. Results: Soluble P‐selectin (56 ±19 ng mL−1, anovaP < 0.0001) and PAC‐1 (1.5 ± 1.8%, anovaP = 0.005) were mildly but significantly increased in patients with acute PE relative to healthy young men (soluble P‐selectin 33 ± 13 ng mL−1, P < 0.001; PAC‐1 binding 0.5 ± 0.6%, P < 0.01) and age‐matched controls (soluble P‐selectin 31 ± 9 ng mL−1, P < 0.001; PAC‐1 binding 0.4 ±0.4%, P < 0.05). Platelet P‐selectin expression and platelet–leukocyte complexes were not increased during acute PE. Echocardiographic RV ejection area correlated inversely with soluble P‐selectin (r= −0.47, P = 0.007) and positively with platelet P‐selectin (r = 0.49, P = 0.0007), suggesting P‐selectin is shed from activated platelets in proportion to the severity of RV dysfunction. Elevated soluble P‐selectin, D‐dimer and hs‐CRP demonstrated a time‐dependent return to normal during 6 months follow‐up. Conclusion: Platelet activation is evident after acute PE. Platelet activation correlates with the severity of RV dysfunction, and can persist for several months after acute PE.

Keywords

platelet activation
pulmonary embolism
right ventricular dysfunction
soluble P‐selectin
venous thrombosis

Cited by (0)