Prospective, randomized, double-blind trial investigating the effect of doxycycline on matrix metalloproteinase expression within atherosclerotic carotid plaques.

Background And Purpose: Elevated levels of matrix metalloproteinases (MMPs), particularly MMP-1 and MMP-9, have been implicated in plaque rupture. It has been suggested that inhibition of MMPs may stabilize vulnerable atherosclerotic plaques and improve clinical outcome. The aim of the study was to investigate the ability of doxycycline, a nonspecific MMP inhibitor, to reduce MMP concentration in carotid atheroma.