Table 2.

Morphological plaque vulnerability index (MPVI) definition and AHA classifications.

MPVI	Plaque	Description	AHA classification
V=0	Very stable	Normal or slight intimal thickening	Type I, some atherogenic lipoprotein and intimal thickening
V=1	Stable	Moderate intimal thickening, no extracellular lipid, calcification or significant inflammation	Type II (fatty streak), III (preatheroma)
V=2	Slightly unstable	Small lipid core (<30% of plaque size); calcification may be present; thick fibrous cap (> 200 μm); little or no inflammation at plaque shoulders	Types IV, Vb, and Vc with less than 30% NC by area; or VII/VIII
V=3	Moderately unstable	Moderate lipid core (30–40% of plaque size) and fibrous cap (150–200 μm); moderate intraplaque hemorrhage; moderate inflammation	Types Va, IV/V with 30–40% NC by area
V=4	Highly unstable	Large lipid core(440%); thin fibrous cap (<150 μm); large intraplaque hemorrhage; extensive inflammation; evidence of previous plaque rupture	Types VI; IV/V with > 40% NC by area