The West of Scotland Study was a landmark in preventive medicine.  It was published in the early 1990s and was the first study to definitively show that statins (a family of cholesterol-lowering medicines) could prevent a first heart attack in people with high cholesterol.  It randomized over 6,000 middle-aged men with high cholesterol who had never had a heart attack to either pravastatin (Pravachol) or placebo.  In about 5 years of follow up, pravastatin clearly prevented heart attacks and sav...