Lp-PLA2 is an enzyme that operates in the arterial intima and is a marker of vascular inflammation. Higher levels of Lp-PLA2 indicate a doubling of risk for coronary heart disease and stroke. Lp-PLA2 contributes to the formation of vulnerable plaques by promoting inflammation, and its levels can help identify patients who may benefit from more aggressive treatment to lower risk of plaque rupture leading to heart attack or stroke. While methods exist to evaluate plaque composition, measuring Lp-PLA2 provides a non-invasive means to assess risk of cardiovascular events.