Thursday, March 16, 2006


Asteroid stands for "A Study To Evaluate the effect of Rosuvastatin On Intravascular Ultrasound-Derived coronary atheroma burden". This is a study of the effect of 40mg rosuvastatin on atheroma plaque volume, pre and post treatment. 1183 patients were screened and 507 patients had the pre-treatment angiography, 349 patients had a followup angiogram at 2 years. All the patients were CAD patients who needed an angiogram and intervention.

The setup is almost like that of "REVERSAL" study, by Pfizer, that compared high dose atorvastatin (agressive cholesterol lowering) against pravastatin 40 mg (moderate cholesterol lowering). The P.I. is the same, namely Dr Steve Nissen (an intravascular ultrasound expert from Cleveland clinic and president-elect of the American College of Cardiology).

This study did show that rosuvastatin at 40 mg effective lower LDL-cholesterol, by some 57% with a 14.7% increase of HDL-cholesterol. As a result of this, the atheroma plaque burden, reduce by 6.8-9.1%. This is probably the highest reduction in plaque volume that you can get with medical angioplasty (medical statin for plaque reduction).

However, this study raises a few question, for example, there is no control group. It is a one-treatment arm study, over time. Some subgroup analysis showed regression in the patient groups with LDL-cholesterol of 100mg% abd HDL-cholesterol of <35mg%. Without a control group, it is difficult to exclude some other explanation for the regression. Also the population under study is also a rather safe group with low female and diabetic numbers in the cohort. It appears that the patients had severe disease which was angioplastied and the minimal stenosis in one artery receiving the ultrasound that form the study population. What is obviously missing is the clinical end-point of major adverse cardiac events. Obviously, this study is not powered for this. We do not know if this nice ultrasound findings will translate to better patient morbidity and mortality.

I suppose we are supposed to infer from other statins study that a 51% reduction of LDL-cholesterol and a 14% increase in HDL-cholesterol must translate to lower MACE, but remember, there is no control group. What is comforting is that the side-effects were few. The adverse events were mainly musculoskeletal (3.7%) with no rhabdomyolysis. This is comforting remembering that earlier experience with high dose rosuvastatin was associated with renal side-effects and rhabdomyolysis.

Also for us Asians, we must remember that we are more sensitve to rosuvastatin, so what is 40mg for American may translate to 20mg for Asians. Another study to show that statins can regress plaque.

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