Abstract : ASTEROID is a prospective, open-label blinded end-points trial aiming to assess whether very intensive statin therapy with rosuvastatin 40 mg/day could regress coronary atherosclerosis as determined by intravascular ultrasound (IVUS). This multinational study included 507 patients, among whom 349 had evaluable serial IVUS examinations at 24 months. Rosuvastatin decreased LDL cholesterol level from 130 mg/dl to 61 mg/dl (- 53.2 %) and increased HDL cholesterol from 43 to 49 mg/dl (+ 14.7 %). The three prespecified IVUS efficacy parameters were positively altered by rosuvastatin, demonstrating regression of coronary atherosclerosis : the mean change in percent atheroma volume (- 0.98 %), the change in atheroma volume in the most diseased 10-mm subsegment me (- 6.1 mm3) and the change in total atheroma volume (- 6.8 %) were all significant (p < 0,001). Adverse events were infrequent and similar to other statin trials. The present study demonstrates that a 2-year treatment with a high dose of rosuvastatin 40 mg/day is able to induce significant regression of coronary atherosclerosis as determined by IVU imaging. Further ongoing studies in the GALAXY clinical investigation programme should now demonstrate that rosuvastatin, the most potent statin to reduce LDL and increase HDL cholesterol, is also able to diminish the incidence of clinical outcomes, cardiovascular events in general and major coronary events in particular.