Effects of Simvastatin on Individuals with High Risk of Heart Diseases
Lower concentration of LDL is associated with lower risk of coronary heart disease. No matter how low your LDL concentration is, if you can bring it down even lower, you will reduce your risk of coronary heart disease. The magnitude of risk reduction is controlled by your overall risk of cardiovascular disease. The individuals that most benefit from lowering LDL concentrations would be individuals already at high risk for coronary heart disease, for instance individuals have diabetes, or individuals have previous heart attacks.
Several clinical trials support the notion that use of statin to lower LDL will reduce coronary mortality and morbidity in high-risk individuals. On average, lowering LDL cholesterol of 1 mmol/L in at least 5 years will cut the risk of getting myocardial infarction and coronary death by 25%. Among these trials, the Heart Protection Study (HPS) can be considered to be the definitive study. The study assessed the long-term effects of simvastatin on all-cause mortality and cardiovascular-related deaths and morbidities.
The Heart Protection Study involves a total of 20 536 individuals (15 454 men and 5082 women). About 25% of the participants are aged 75 and older at study entry. 41% of them had myocardial infarction (heart attack) and 24% had some type of coronary disease. About 20% were diagnosed with diabetes and 13% had peripheral arterial disease. The average follow-up was 5 years. The patients are randomized into two arms: placebo and simvastatin. The total person-years are 51 121 in the simvastatin arm and 50 664 among in the placebo arm. The patients received 40 mg simvastatin daily or matching placebo tablets in specially prepared calendar packs.
The results of the study are very encouraging. Use of simvastatin reduces all-cause mortality by 12% and coronary death by 18%., myocardial infarction or coronary death by 25%, non-fatal or fatal stroke by 25%. The side effects of simvastatin were low and no effects on cancer rates were found.
The Heart Protection Study concluded that treatment for 5 years with simvastatin would prevent 70-100 people per 1000 from suffering heart attacks, strokes, and revascularisations. The results suggsested that simvastatin, therefore, should be recommended to treat high-risk individuals, considering its effectiveness and safety record.
Source
MRC/BHF Heart Protection Study of Cholesterol Lowering with Simvastatin in 20 536 High-Risk Individuals: A Randomized Placebo-Controlled Trial_Heart Protection Study Collaborative Group_ Lancet 2002; 360: 7–22