A recent meta-analysis, published in The Lancet, suggests that primary prevention with statins could be an effective intervention even in low-risk groups.

The researchers analysed data from 22 trials of statin therapy versus controls, covering 134,537 patients and five trials comparing ‘more’ versus ‘less’ statin treatment, including 39,612 patients. Major vascular events were classified as major coronary events (non-fatal myocardial infarction or coronary death); strokes; or coronary revascularisation.

Patients on control therapy (no statin or low-intensity statin) were divided into five categories of baseline five-year major vascular event risk: < 5%, 5–9%, 10–19%, 20–29% and ≥ 30%.

Lowering low density lipoprotein cholesterol (LDL-C) with statin therapy reduced the risk of major vascular events.

The rate ratio (RR) was 0.79 (95% CI: 0.77–0.81) per 1.0 mmol/L reduction in LDL-C. This finding was irrespective of age, sex, baseline LDL-C or previous vascular disease, and of vascular and all-cause mortality. The proportional reduction in major vascular events was at least as big in the two lowest risk categories as in the higher risk categories.

There was no evidence that reduction of LDL-C with a statin increased incidence of cancer, deaths from cancer or any other non-vascular mortality.

Primary care clinicians are comfortable with the notion that statins reduce LDL-C and are effective in the secondary prevention of vascular disease. However, the situation is more contentious when it comes to primary prevention and there is uncertainty surrounding the net effect in patients at low risk of vascular events.

The authors conclude that in patients with a five-year risk of major vascular events lower than 10%, each 1 mmol/L reduction in LDL-C produced an absolute reduction in major vascular events of about 11 per 1,000 over five years.

There was an increase in haemorrhagic strokes per 1.0 mmol/L LDL-C reduction of about 0.5 per 1,000 people treated over five years and an absolute excess of diabetes associated with statin treatment of about 0.1% per year. The authors felt that these adverse outcomes were outweighed by the absolute benefit observed with statin therapy in low-risk patients.

Under present guidelines such low-risk patients would not be considered suitable for statin therapy. The authors suggest that, in the light of their findings, these guidelines might need to be reconsidered.

This really leads us to the ‘statins for all patients over 50’ argument and whether medicalising the masses is the most effective or appropriate public health strategy. An argument for another day perhaps.

Dr Peter Savill

• Cholesterol Treatment Trialists (CTT) Collaborators. The effects of lowering LDL cholesterol with statin therapy in people at low risk of vascular disease: meta-analysis of individual data from 27 randomised trials. Lancet, Early Online Publication, 17 May 2012 doi:10.1016/S0140-6736(12)60367-5