There is not enough evidence to recommend the widespread use of statins in people with no previous history of heart disease, according to a new Cochrane Systematic Review. Researchers say statins should be prescribed with caution in those at low risk of cardiovascular disease (CVD).
CVD is the most common cause of death, accounting for nearly a third of all deaths worldwide. Cholesterol-lowering statins are first line treatments for heart patients and the benefits are well established. However, there is less evidence that statins are beneficial for preventing heart problems in those who have no history of CVD. Given that low cholesterol has been shown to increase the risk of death from other causes, statins may do more harm than good in some patients.
The researchers reviewed data from 14 trials involving 34,272 patients. Outcomes in patients given statins were compared to outcomes in patients given placebos or usual care. Combined data from eight trials involving 28,161 patients that provided data on deaths from all causes showed that statins reduced the risk of dying from 9 to 8 deaths for every 1000 people treated with statins each year. Statins reduced fatal and non-fatal events, including heart attack, stroke and revascularization surgery, as well as blood cholesterol levels.
However, the researchers say that the conclusions of their review are limited by unclear, selective and potentially biased reporting and that careful consideration should be given to patients' individual risk profiles before prescribing statins.
"It is not as simple as just extrapolating the effects from studies in people who have a history of heart disease," said lead researcher Fiona Taylor, from the Cochrane Heart Group at the London School of Hygiene and Tropical Medicine in London, UK. "This review highlights important shortcomings in our knowledge about the effects of statins in people who have no previous history of CVD. The decision to prescribe statins in this group should not be taken lightly."
The researchers point out that all but one of the trials they reviewed were industry-sponsored. "We know that industry-sponsored trials are more likely to report favourable results for drugs versus placebos, so we have to be cautious about interpreting these results," said Taylor. "The numbers eligible for treatment with statins are potentially great so there might be motivations, for instance, to stop trials earlier if interim results support their use."
A separate Cochrane Systematic Review, conducted by some of the same authors, considered the effects of combined approaches to reducing the risk of heart disease, including using education and counselling to encourage people to change their diets and stop smoking. The authors concluded that combined interventions had little or no impact on deaths or disease caused by CVD. In an editorial accompanying the reviews, Carl Heneghan, University of Oxford, concluded that, "Although various multiple prevention strategies exist, the most effective and cost-effective intervention for primary prevention in adults at low risk currently remains unclear."