Statins are not associated with a reduction in cardiovascular disease (conditions affecting the heart and blood vessels) or death in healthy people aged over 75, finds a study published by The BMJ today.
However, in those with type 2 diabetes, statins were related to a reduction in cardiovascular disease and death from any cause up to the age of 85 years.
The results of the study, led by the University Institute for Primary Care Research Jordi Gol (IDIAPJGol) and Girona Biomedical Research Institute (IDIBGI), do not support the widespread use of statins in old and very old people, but they do support treatment in selected people, such as those aged 75-84 years with type 2 diabetes, say the researchers.
Cardiovascular disease is the leading cause of death globally, especially for those aged 75 and over. Statin prescriptions to elderly patients have increased in recent decades, and trial evidence supports statin treatment for people aged 75 years or older with existing heart disease(known as secondary prevention).
But evidence on the effects of statins for older people without heart disease (known as primary prevention) is lacking, particularly in those aged 85 years or older and those with diabetes.
So researchers based in Spain set out to assess whether statin treatment is associated with a reduction in cardiovascular disease and death in old (75-84 years) and very old (85 years and over) adults with and without type 2 diabetes.
Using data from the Catalan primary care system database (SIDIAP), they identified 46,864 people aged 75 years or more with no history ofcardiovascular disease between 2006 and 2015.
Participants were grouped into those with and without type 2 diabetes and as statin non-users or new users (anyone starting statins for the first time during the study enrollment period).
Primary care and hospital records were then used to track cases of CVD (including coronary heart disease, angina, heart attack and stroke) and death from any cause (all cause mortality) over an average of 5.6 years.
In participants without diabetes, statin treatment was not associated with a reduction in CVD or all cause mortality in both old and very old age groups, even though the risk of CVD in both groups was higher than the risk thresholds proposed for statin use in guidelines.
In participants with diabetes, however, statins were associated with significantly reduced levels of CVD (24%) and all cause mortality (16%) in those aged 75-84 years. But this protective effect declined after age 85 and disappeared by age 90.
This was an observational study, so no firm conclusions can be drawn about cause and effect, and the authors cannot not rule out the possibility that some of their results may be due to unmeasured (confounding) factors.
But they point out that this was a high quality study with a large sample size, reflecting real life clinical conditions.
A such, they conclude that their results do not support the widespread use of statins in old and very old populations, but they do support treatment in those with type 2 diabetes younger than 85 years.
In a linked editorial, Aidan Ryan at University Hospital Southampton and colleagues, say the biggest challenge for clinicians is how to stratify risk among those aged more than 75 to inform shared decision making.
These observational findings should be tested further in randomised trials, they write. In the meantime, they say "patient preference remains the guiding principle while we wait for better evidence."
Externally peer-reviewed? Yes (research), No (linked editorial)
Type of evidence: Observational