Although statins significantly lower cholesterol levels in patients with aortic stenosis (AS) they do not arrest or reverse disease progression, the ASTRONOMER trial has shown.

This randomised, double-blind, placebo-controlled trial assessed the impact of cholesterol lowering with rosuvastatin on the progression of aortic stenosis (AS).

A total of 269 asymptomatic patients with mild to moderate AS and no clinical indications for cholesterol lowering were studied. Patients were randomised to receive either placebo or rosuvastatin 40 mg daily.

The primary outcome was AS progression and this was assessed by annual echocardiogram, the accepted gold standard for the quantification of aortic stenosis. Median follow up was 3.5 years.

The peak AS gradient increased in patients receiving rosuvastatin from 40.8 to 57.8mmHg during the study period. The placebo group showed a similar increase from 41.6mmHg to 54.8mmHg. The investigators calculated an annualised increase in the peak AS gradient. This was 6.3+/-6.9 mm Hg in the rosuvastatin group and 6.1+/-8.2 mm Hg in the placebo group, P=0.83. Rosuvastatin lowered LDL cholesterol levels by 54.5% in the intervention group whereas levels remained unchanged in the placebo group.

Therefore rosuvastatin was not associated with a reduction in AS progression despite a significant reduction in cholesterol levels. Although this was a relatively small study an aggressive cholesterol-lowering intervention was used and failed to influence disease progression as evidenced by echo assessment.

Furthermore, these findings were in keeping with the two previous randomised controlled trials addressing this question, SEAS and SALTIRE.

Degenerative AS seems to be an increasingly common problem and this is due in part to increased life expectancy. It has also been noted that AS shares many risk factors with atherosclerosis. AS is a progressive process, although progression is slow in most cases. Early valve leaflet changes (in the absence of haemodynamic compromise) are a precursor of obstructive and potentially life-threatening valve disease.

Therefore, it would seem reasonable to propose that interventions to address risk factors such as hyperlipidaemia might arrest or even reverse valve leaflet degeneration.

I think that this illustrates rather nicely that not all good theories are borne out in practice.

Dr Peter Savill