Review Raises Questions About Statins for Primary Prevention

A Cochrane Review raises troubling questions about the evidence base supporting the use of statins for primary prevention. The Cochrane reviewers analyzed 14 randomized trials including 34,272 participants and found that statins were associated with significant reductions in overall mortality, fatal and nonfatal CV endpoints, and revascularization procedures. The reviewers found no evidence of harm.

However, the authors found “evidence of selective reporting of outcomes, failure to report adverse events and inclusion of people with cardiovascular disease.” They concluded that “only limited evidence showed that primary prevention with statins may be cost effective and improve patient quality of life. Caution should be taken in prescribing statins for primary prevention among people at low cardiovascular risk.”

In an accompanying editorial, Carl Heneghan discusses the limitations of the trials under review, noting, among other limitations, that the power calculations in most of the trials were based on composite outcomes, that selective reporting of outcomes occurred in some trials, and that some trials reported no adverse outcomes at all. He concludes that “the most effective and cost-effective intervention for primary prevention in adults at low risk currently remains unclear” and argues that it is “unwise to use such studies to determine the overall benefits and harms to the population at risk and drive policy.”

This post is republished with permission from CardioExchange, a new website for cardiovascular healthcare professionals from the New England Journal of Medicine. CardioBrief readers who are healthcare professionals are invited to join the site.

Here is the press release from the Cochrane Library:

Statins: Benefits Questionable in Low-Risk Patients

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.”


Comments

  1. Actually that better than the results of a recent analysis ……”.Do statins have a role in primary prevention? An update.
    Therapeutics Letter Issue 77 / Mar – Apr 2010″ which found that … ” The claimed mortality benefit of statins for primary prevention is more likely a measure of bias than a real effect.”
    ………… The reduction in major CHD serious adverse events with statins as compared to placebo is not reflected in a reduction in total serious adverse events. “

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