Abstract

• The risk of having a cardiovascular event increases with age, blood pressure and serum cholesterol levels. There is an increased risk in men and in case of smoking, diabetes, a family history of premature cardiovascular events, and physical inactivity.
   
• Smoking cessation, regular physical activity, weight loss for obese patients, a Mediterranean diet, and some antihypertensive or antidiabetic treatments reduce the risk of cardiovascular events.
   
• In patients with no history of cardiovascular disease, there is no proof that statin therapy reduces the risk of cardiovascular events in patients younger than 40 years or older than 75 years.
   
• In some patients aged 40 to 70 years, daily statin therapy for about 5 years reduces the risk of fatal and non-fatal cardiovascular events. Assuming that the percentage reduction in cardiovascular risk obtained through statin therapy remains constant across all levels of baseline cardiovascular risk, which remains unproven, daily use of statin therapy for 5 years by 1000 persons with no clinically evident cardiovascular disease would prevent about: 2 to 10 deaths for those whose 5-year risk of cardiovascular death was 2%; 5 to 25 deaths for those whose 5-year risk of cardiovascular death was 5%; and 10 to 50 deaths for those whose 5-year risk of cardiovascular death was 10%.
   
• But the risk of adverse effects would be the same in all of these individuals.
   
• Whatever their baseline cardiovascular risk, most patients will gain nothing in terms of cardiovascular events, some will avoid a cardiovascular event without gaining any additional days of life, and a few will gain a few extra days of life. A tiny minority may gain a few months or years of life. The data available are insufficient to identify who would derive the most benefit from statin therapy. 
   
• No trials have evaluated the potential benefits of taking statins for 10 years or more.
   
• Daily statin therapy can provoke potentially debilitating muscle pain, the incidence of which is difficult to quantify. It causes about 4 new cases of diabetes per 1000 patients taking a statin for 4 years, and probably more among those who already have other risk factors for developing type 2 diabetes.
   
• It causes about 1 additional haemorrhagic stroke per 1000 to 2000 patients receiving statin therapy for 5 years.
   
• The harms of taking a statin every day for more than 10 years are unknown. In the long term, the risks of diabetes and of haemorrhagic stroke have not been quantified.
   
• Given these uncertainties and the cost of this preventive therapy, it is usually preferable not to use statins for primary prevention.
   
• When statin prevention is nevertheless chosen after discussing these issues with the patient, it is reasonable to choose pravastatin at a daily dose of 40 mg. It is the statin with the most favourable harm-benefit balance in secondary cardiovascular prevention. It provokes fewer drug interactions than other statins.

©Prescrire 1 July 2018

"Statins in primary cardiovascular prevention. Little benefit, documented harms and many uncertainties regarding long-term use" Prescrire Int 2018; 27 (195): 183-190. (Pdf, subscribers only)

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