Statins are not associated with a reduction in cardiovascular disease (CVD) or death in healthy people aged over 75, finds a study. 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 of cardiovascular 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 enrolment 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.”
Objective: To assess whether statin treatment is associated with a reduction in atherosclerotic cardiovascular disease (CVD) and mortality in old and very old adults with and without diabetes.
Design: Retrospective cohort study.
Setting: Database of the Catalan primary care system (SIDIAP), Spain, 2006-15.
Participants: 46 864 people aged 75 years or more without clinically recognised atherosclerotic CVD. Participants were stratified by presence of type 2 diabetes mellitus and as statin non-users or new users.
Main outcome measures: Incidences of atherosclerotic CVD and all cause mortality compared using Cox proportional hazards modelling, adjusted by the propensity score of statin treatment. The relation of age with the effect of statins was assessed using both a categorical approach, stratifying the analysis by old (75-84 years) and very old (≥85 years) age groups, and a continuous analysis, using an additive Cox proportional hazard model.
Results: The cohort included 46 864 participants (mean age 77 years; 63% women; median follow-up 5.6 years). In participants without diabetes, the hazard ratios for statin use in 75-84 year olds were 0.94 (95% confidence interval 0.86 to 1.04) for atherosclerotic CVD and 0.98 (0.91 to 1.05) for all cause mortality, and in those aged 85 and older were 0.93 (0.82 to 1.06) and 0.97 (0.90 to 1.05), respectively. In participants with diabetes, the hazard ratio of statin use in 75-84 year olds was 0.76 (0.65 to 0.89) for atherosclerotic CVD and 0.84 (0.75 to 0.94) for all cause mortality, and in those aged 85 and older were 0.82 (0.53 to 1.26) and 1.05 (0.86 to 1.28), respectively. Similarly, effect analysis of age in a continuous scale, using splines, corroborated the lack of beneficial statins effect for atherosclerotic CVD and all cause mortality in participants without diabetes older than 74 years. In participants with diabetes, statins showed a protective effect against atherosclerotic CVD and all cause mortality; this effect was substantially reduced beyond the age of 85 years and disappeared in nonagenarians.
Conclusions: In participants older than 74 years without type 2 diabetes, statin treatment was not associated with a reduction in atherosclerotic CVD or in all cause mortality, even when the incidence of atherosclerotic CVD was statistically significantly higher than the risk thresholds proposed for statin use. In the presence of diabetes, statin use was statistically significantly associated with reductions in the incidence of atherosclerotic CVD and in all cause mortality. This effect decreased after age 85 years and disappeared in nonagenarians.
Rafel Ramos, Marc Comas-Cufí, Ruth Martí-Lluch, Elisabeth Balló, Anna Ponjoan, Lia Alves-Cabratosa, Jordi Blanch, Jaume Marrugat, Roberto Elosua, María Grau, Marc Elosua-Bayes, Luis García-Ortiz, Maria Garcia-Gil