Correlation Between Serum Markers of Unstable Plaque and Virtual Histology of Unstable Plaque Visualized by IVUS

Serum markers of unstable plaque Myeloperoxidase is a lysosomal enzyme, requiring heme as a cofactor, released from neutrophilic granules, monocytes, and some subtypes of tissue macrophages.

Myeloperoxidase is also linked to oxidation of lipids in low-density lipoproteins (LDL), dysfunctional high density lipoproteins (HDL), and consumption of nitric oxide thereby rendering the normally anti-thrombotic endothelial surface thrombogenic via the expression of various pro-thrombotic and anti-fibrinolytic factor (19).

Myeloperoxidase plays a role in the degradation of the fibrous cap, making it both a marker of inflammation and one of plaque instability.

Interest in MPO intensified after a report by Brennan and colleagues (20) indicated that a single initial measurement of plasma myeloperoxidase independently predicts the early risk of myocardial infraction, as well as the risk of major adverse cardiac events in the ensuring 30-day and 6-month periods.

Two markers of recent interest relating to plaque vulnerability pregnancy-associated protein A(PAPP-A) and placenta growth factor (P1GF).