Unstable coronary plaques with surface erosion and plaque rupture lead
to acute coronary thrombosis, unstable angina pectoris and myocardial
infarction. The in-vivo detection of plaque instability by angiograph
y, intravascular ultrasound or angioscopy or by newly developed techni
ques, such as optical coherence tomography or by the observation of lo
cal temperature increases, offers the opportunity for deeper understan
ding of the mechanisms underlying plaque rupture and erosion. Pharmaco
logical and transcatheter therapy might be directed more exclusively t
o unstable plaques, once more detailed knowledge about pathophysiologi
cal mechanisms as well as direct information about the individual plaq
ue being treated is available.