Table 1 Human coronary morphological plaque vulnerability index (MPVI) definition and AHA classifications

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 (> 150 μm); little or no inflammation at plaque shoulders

Type 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 (65 – 150 μm); moderate intraplaque hemorrhage; moderate inflammation.

Type Va, IV/V with 30-40% NC by area

V = 4

Highly unstable

Large lipid core(>40%); thin fibrous cap (< 65 μm); large intraplaque hemorrhage; extensive inflammation; evidence of previous plaque rupture

Type VI; IV/V with > 40% NC by area