Background: Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a specific biomarker specific for vascular inflammation. Inflammation has a significant association with plaque progression. The fibrous-cap thickness (FCT) is one of the major determinants of plaque vulnerability in atherosclerotic plaques. However, data on the relationship between Lp-PLA2 activity and FCT in lipid plaque are limited. This study aimed to evaluate the in-vivo association between changes in Lp-PLA2 activity and FCT and plaque volume in patients with acute coronary syndrome (ACS).
Patients and methods: Twenty-four consecutive patients with ACS were enrolled between May 2010 and May 2012. The plaque volume and FCT of nonculprit lipid-rich plaques were assessed by intravascular ultrasound and optical coherence tomography, respectively, at baseline and after 12 months. Lp-PLA2 activity was determined using the colorimetric assay kit.
Results: During the 12 months of observation, FCT increased significantly from baseline to follow-up, with a mean percent change of 74.4±46.8%. A significant correlation was observed between changes in Lp-PLA2 activity and changes in FCT (r=-0.56, P=0.006). Changes in plaque volume were also correlated significantly with changes in Lp-PLA2 activity during the study period (r=0.52, P=0.01).
Conclusion: Significant associations between serial changes in Lp-PLA2 activity and changes in FCT and plaque volume were observed in patients with ACS.