Should We Rethink the Use of Statins in Patients at Low Risk for CVD?

New research indicates that there is not enough evidence to recommend the widespread use of statins in people with no previous history of heart disease.

According to a news release from Wiley titled “Statins: Benefits Questionable in Low-Risk Patients," the authors of a recent Cochrane Systematic Review say that their analysis of available data have led them to conclude that “statins should be prescribed with caution in those at low risk of cardiovascular disease.” Although the benefits of using statins as first-line treatment for patients who have been diagnosed with cardiovascular disease (CVD) are well supported by many clinical studies, there is less evidence that statins are beneficial for preventing heart problems in patients with no history of CVD. Now, “given that low cholesterol has been shown to increase the risk of death from other causes,” researchers are claiming that “statins may do more harm than good in some patients.”

The news release reports that researchers reviewed data from 14 trials involving 34,272 patients and compared outcomes in patients treated with statins 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.” Researchers also found that statins “reduced fatal and non-fatal events, including heart attack, stroke and revascularization surgery, as well as blood cholesterol levels.”

However, the reviewers cautioned that their results were “limited by unclear, selective and potentially biased reporting and that careful consideration should be given to patients’ individual risk profiles before prescribing statins.” Fiona Taylor, from the Cochrane Heart Group at the London School of Hygiene and Tropical Medicine in London, UK, said that the review “highlights important shortcomings in our knowledge about the effects of statins in people who have no previous history of CVD.”

The actual Cochrane Review, titled “Statins for the Primary Prevention of Cardiovascular Disease,” is published in The Cochrane Database of Systematic Reviews 2011 Issue 1. In their conclusion, the authors wrote that “Although reductions in all-cause mortality, composite endpoints and revascularisations were found with no excess of adverse events, there was evidence of selective reporting of outcomes, failure to report adverse events and inclusion of people with cardiovascular disease. 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 editorial on the Cochrane Reviews site titled “Considerable Uncertainty Remains in the Evidence for Primary Prevention of Cardiovascular Disease,” Carl Heneghan, Director Centre for Evidence-Based Medicine & Clinical Reader, Dept of Primary Health Care, University of Oxford, cautioned that “there are a number of concerning points with this review that arise due to limitations in the published data,” including:

• In the majority of trials in the review power calculations were based on composite outcomes
• Outcomes were reported selectively in more than one-third of the trials
• Adverse events were not reported for eight of the trials
• Two large trials were prematurely stopped because “significant reductions in primary composite outcomes had been observed”

Because of these and other concerns, Heneghan concluded that “the most effective and cost-effective intervention for primary prevention in adults at low risk currently remains unclear,” and that it is therefore “unwise to use such studies to determine the overall benefits and harms to the population at risk and drive policy.”