Optical detection of triggered atherosclerotic plaque disruption by fluorescence emission analysis

Fluorescence emission analysis (FEA) has proven to be very sensitive for th e detection of elastin, collagen and lipids, which are recognized as the ma jor sources of autofluorescence in vascular tissues. FEA has also been repo rted to detect venous thromboemboli. In this paper we have tested the hypot hesis that FFA can reproducibly detect in vivo and in vitro triggered plaqu e disruption and thrombosis in a rabbit model. Fluorescence emission (FE) s pectra, recorded in vivo, detected Russell's viper venom (RVV)-induced tran sformation of atherosclerotic plaque. FE intensity at 410-490 nm 4 weeks af ter angioplasty was significantly lower (P < 0.0033 by analysis of variance ) in RVV-treated rabbits when compared to control animals with stable plaqu e. FE spectral profile analyses also demonstrated a significant change in c urve shape as demonstrated by polynomial regression analysis (R-2 from 0.98 0 to 0.997), We have also demonstrated an excellent correlation between cha nges in FE intensity and the structural characteristics detected at differe nt stages of "unstable atherosclerotic plaque" development using multiple r egression analysis (R-2 = 0.989), Thus, FFA applied in vivo is a sensitive and highly informative diagnostic technique for detection of triggered athe rosclerotic plaque disruption and related structural changes, associated wi th plaque transformation, in a rabbit model.