This invention provides methods, devices and kits for treating coronary artery disease, particularly "soft" or vulnerable plaque. The invention is based on the local delivery of crosslinking means to crosslink the collagen covering the plaque and other proteins that may be present at the site to stabilize the plaque and prevent leakage of thrombogenic material into the lumen of the coronary artery. In certain embodiments, catheters are employed to achieve local delivery of a crosslinking agent or ultraviolet light.