Subjects: R and D
Soon after treatment onset, high-dose Lipitor cuts inflammation in carotid plaques and reduces the incidence potentially dangerous cerebral microemboli, say scientists from Cambridge University.
Their study also provides early validation of a new method for detecting inflammation in such plaques. This could prove to be a boon for those who study atherosclerosis of the carotid arteries, a risk factor for stroke.
Jonathan Gillard and colleagues test-drove ultrasmall superparamagnetic iron oxide particles as the contrast agent in their MRI-based study.
The particles are ingested by macrophages, a major constituent of inflamed plaques which often cause strokes.
Heretofore, the only noninvasive means to detect vessel inflammation had been fluorodeoxyglucose positron emission tomography, but radiation exposure associated with repeated PET scanning limits its use in studies requiring repeat scans to assess disease progress.
In the study, Gillard’s team randomized 47 high-risk plaque-afflicted patients to receive either 10- or 80-mg of Lipitor once per day for 12 weeks.
MRIs performed at 6 weeks revealed a marked reduction in macrophage activity, but only in the group randomized to receive 80 mg of Lipitor. MRIs at 12 weeks showed continued improvement, but again only in the high-dose group.
In these patients, cerebral microemboli counts, as measured by transcranial Doppler, fell 91% compared with baseline.
The write-up appears in the Journal of the American College of Cardiology.
“Our study may support the hypothesis that dampening of plaque inflammation rather than morphological regression (may be responsible for the) the early beneficial effects of statins seen in clinical practice,” wrote the scientists.
Still, it’s too early to pop the corks, at least for the new imaging technique. The contrast agent may promote oxidation of LDL cholesterol in the plaque which might cause it to destabilize and rupture.