IDEAL study

• the Incremental Decrease in End Points Through Aggressive Lipid Lowering (IDEAL) study compared the effectiveness of high-dose atorvastatin (80mg daily) with simvastatin (20mg or 40mg daily) in the secondary prevention of cardiovascular (CV) disease
• IDEAL
  • an open-label study in 8,888 patients (mean age 62, 81% male) with a history of myocardial infarction (MI). It included a blinded endpoint evaluation, and had a median follow-up of 4.8 years
  • patients were randomised to initially receive atorvastatin 80mg daily or simvastatin 20mg daily
    • at 24 weeks, the atorvastatin dose could be reduced to 40mg if there were adverse events, and the simvastatin dose could be increased to 40mg if total cholesterol levels were >5mmol/l
    • mean low-density lipoprotein cholesterol (LDL-C) level throughout the study was lower in the atorvastatin group than in the simvastatin group (2.1 vs. 2.7mmol/l)
    • there was no significant difference between treatments in its primary composite endpoint — coronary death, hospitalisation for non-fatal acute MI, or cardiac arrest with resuscitation (atorvastatin 9.3% vs. simvastatin 10.4%; HR 0.89, 95% CI 0.78 to 1.01, P=0.07)
    • examination of the individual composite or secondary endpoints in IDEAL suggested no mortality benefit (CV, non-CV, or all-cause) for atorvastatin
    • were indications of a difference in favour of atorvastatin for some CV events, e.g. for coronary revascularisation (13.0% vs. 16.7%, P<0.001) and non-fatal acute MI (6.0% vs. 7.2%, P=0.02) - note though that, as the study was not powered to detect differences in these endpoints, caution is necessary when interpreting the significance of these results (the power of a study is based on the primary endpoint being investigated)
• a MeReC review states that the IDEAL study provides no compelling evidence that high-dose atorvastatin (80mg daily) should be used routinely ahead of simvastatin (20mg or 40mg daily) as part of a general management strategy for secondary prevention of CV events

Reference:

1. MeReC Extra (March 2006); 21:1.
2. Pederson TR et al. High-dose atorvastatin vs usual-dose simvastatin for secondary prevention after myocardial infarction: the IDEAL study: a randomized controlled trial. JAMA. 2005 Nov 16;294(19):2437-45