I work hard to de-prescribe unnecessary medications in my older patients, but I have never known what to do with statins. Are they preventing cardiovascular events or just causing trouble? Published studies included limited numbers of participants aged 75 years and older, so it has been difficult to know what to recommend.
A recent meta-analysis in The Lancet divided the subjects of 28 statin randomized trials by age groups, and identified over 14,000 who were over 75 years old. The analysis found that older adults benefit from statins for prevention of recurrent cardiovascular events (secondary prevention), but did not see a benefit for primary prevention. In the 6,000 older patients without a prior cardiovascular event, those taking statins weren't any less likely to have an event within 5 years than those taking placebos.
Unfortunately, the results aren’t definitive for primary prevention in older adults. Patients had less than a 3% risk of a cardiovascular event in the 5 years, leading to fewer than 100 events in each group - numbers too small to make firm conclusions. However, the low event rate should reassure primary prevention patients who wish to stop statins that any potential benefit is small. In addition, a large retrospective cohort study found that adults 75 years or older without vascular disease or diabetes did not benefit from statins. An ongoing primary prevention trial involving 18,000 adults over 70 years old will hopefully settle this question.
Even statins for secondary prevention in adults over 75 years old are not as valuable as in younger patients. The number needed to treat (NNT) is 125 to prevent a recurrent vascular event in 5 years, higher than the NNT for any other age group.
Another issue relevant to the decision to deprescribe a statin is the legacy effect. There is evidence of a significant benefit from having taken statins in the past, even in patients who have stopped taking them. Numerous studies have shown long-term benefit from taking statins during trials lasting only a few years. Another meta-analysis suggested that the legacy effect could be stronger for primary prevention.
Outside of the cardiovascular benefit, there isn’t much other evidence of statin benefits for older adults. The Lancet meta-analysis saw no difference in cancer incidence with statins. A Cochrane review showed that statins have no benefit for decreasing incidence of dementia.
Yet the argument for stopping statins is not strong either. Trials show that statins don’t have many adverse effects. They aren’t more likely to be associated with myalgia, rhabdomyolysis, hemorrhagic stroke or liver enzyme elevations than placebo. They do seem to increase the risk of developing diabetes at higher doses.
Deprescribing decisions will still require individualized shared decision making. An older adult without vascular events can likely stop a statin with minimal effect on risk, while a patient with a prior event will still benefit from continuing the statin, provided that he or she isn't experiencing adverse effects. You can find more in-depth information about statin use in this 2017 article on hyperlipidemia and the Practice Guidelines in the May 1 issue of AFP.
Dr. Arnold is AFP's 2019-20 Jay Siwek Medical Editing Fellow. The views expressed in this article are those of the author and do not necessarily reflect the official policy or position of the Department of the Navy, Uniformed Services University of the Health Sciences, Department of Defense, nor the U.S. Government.