By: Thomas Pickering, MD, DPhil, FRCP, Director of Integrative and Behavioral Cardiology Program
of the Cardiovascular Institute at Mount Sinai School of Medicine, New York.

Several studies have shown that lowering cholesterol can prevent heart attacks and other manifestations of coronary heart disease, but these have all been done in people at high risk, either because they have already had a first heart attack, or because they have very high cholesterol levels. Now a study has shown that prevention can also be achieved in apparently healthy men and women with average levels of cholesterol. The study was called AFCAPS/TexCAPS (Air Force/Texas Coronary Atherosclerosis Prevention Study) because it was carried out at an air force base and a University campus, both in Texas. The participants were 5,608 men and 997 women aged between 45 and 73 who, at the start of the study, had total cholesterol levels between 180 and 264 mg/dl (or 4.65 to 6.82 mmol/L), LDL cholesterols between 130 and 190 mg/dl ( 3.36 to 4.91 mmol/L), HDL cholesterols below 45mg/dl (1.16 mmol/L) for men and 47 mg/dl (1.22 mmol/L) for women, and triglycerides below 400mg/dl (4.52 mmol/L). Participants were randomly allocated to take either lovastatin (in a dose of 20 or 40 milligrams a day) or placebo (inert pills).

At the end of five years, the study found that there were 37% fewer cardiovascular events (such as heart attacks, unstable angina and coronary angioplasty) in the people who had been taking lovastatin. Lovastatin reduced LDL cholesterol by 25%, total cholesterol by 18% and raised HDL cholesterol by 6%. There were no major side effects associated with taking lovastatin. The benefits of lovastatin were the same in men and women and in people with high or normal blood pressure. The study was funded by Merck and Co.

Doctor's comments

What makes this study different from the earlier ones showing protection from coronary heart disease as a result of taking a statin drug is that the participants were not sick in the usual sense of the word. Their cholesterol levels were average, although they were higher than the ideal levels recommended by the National Cholesterol Education Program (NCEP), and the HDL cholesterol levels were low. Thus the actual values in the placebo group were a total cholesterol of 228 mg/dl(5.90 mmol/L), LDL cholesterol 156 mg/dl (4.04 mmol/L), and HDL cholesterol 38 mg/dl (0.97 mmol/L). The authors of the study estimate that six million Americans would have similar levels, which raises the question: should all these people start taking lovastatin?

The answer to this involves a review of the costs and benefits. The annual cost of such treatment is around $1,000 per person. Another potential 'cost' is that we do not know much about the long-term side effects of these drugs. The figures in the study show that the benefit would be that five years of lovastatin treatment in 1,000 people would prevent 12 heart attacks, seven cases of unstable angina and 17 angioplasties or bypass operations - a total of 36 events. From the point of view of the individual patient, this means that if you take lovastatin for five years, there is a 3.6% chance that you will derive benefit from it and a 96.4% chance that you will not. These are long odds.

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