In the IDEAL trial, almost 9,000 patients with coronary heart disease were treated, after randomisation, with atorvastatin, 80 mg daily, or simvastatin, 20 or 40 mg daily, for 4.8 years. The LDL cholesterol level was 0.6 mmol/l lower in the atorvastatin group, a smaller difference than expected, and the 11% reduction in the primary end point (myocardial infarction, cardiac arrest, coronary death) in this group was not statistically significant (p = 0.07). In contrast, several secondary end points, one of which was the primary end point plus stroke, occurred statistically significantly less often in the atorvastatin group.