Statins may be ineffective for primary prevention in older adults
Current guidelines justify treating most patients 75 and older with cholesterol-lowering drugs based on their estimated risk of cardiovascular disease (CVD). However, a new cohort study published in The BMJ suggests statins are ineffective at primary prevention in this elderly population.
The study did identify one subpopulation that may benefit from statins—those with type 2 diabetes younger than 85. For diabetic patients older than that, the protective effect of statins appeared to diminish substantially and disappear altogether once they reached their 90s.
“Our results show a lack of association between statin treatment and reduction in atherosclerotic CVD events or all-cause mortality in the absence of type 2 diabetes mellitus in old and very old groups, although the incidence (ie, risk) of atherosclerotic CVD in both age groups was significantly higher than the risk thresholds proposed for statin use in the guidelines for cardiovascular prevention,” wrote Rafel Ramos, with the Catalan Institute of Health in Catalonia, Spain, and colleagues.
The researchers studied 46,864 Spanish people 75 or older without clinically recognized atherosclerotic CVD (ASCVD) who hadn’t taken statins in the past 18 months. For those in the 75-85 age range who began taking statins, the reductions in ASCVD events (6 percent) and all-cause mortality (2 percent) weren’t statistically significant. ASCVD events encompassed angina, myocardial infarction, coronary revascularization and stroke.
Likewise, among new statin users older than 85, reductions in ASCVD (7 percent) and mortality (4 percent) were insignificant.
However, among diabetics aged 75-84, statin use was associated with 24 percent lower odds of ASCVD and 16 percent lower odds of all-cause death. According to the authors, statin treatment in this population would be expected to prevent seven cardiovascular events each year per 1,000 people, and three deaths per year for each 1,000 individuals treated.
Ramos and colleagues noted there is limited evidence on statins’ effectiveness in older populations, primarily because most studies have few people older than 74—and even fewer older than 84. Their results suggest new prediction models must be developed to more accurately reflect ASCVD risk among elderly populations, which may help guide treatment.
Using current models, old age alone is enough to tilt the 10-year risk to a point where statin prescriptions could be recommended.
“Shorter term (i.e., five year) prediction tools may be reasonable in older people, because life expectancy at older ages is limited,” the authors wrote. “Inclusion of information about functional capacity in the risk prediction also could make sense because Cruz et al. reported that everyday functional capacity has a greater impact on 10-year mortality risk in very old people compared with traditional cardiovascular risk factors.”
Other things to consider, according to Ramos and coauthors, include degrees of frailty, comorbidities and drug combinations.
The researchers noted their sample sizes in some of the studied subpopulations were small, limiting the statistical power of their calculations. In addition, they weren’t able to compare various intensities of statin treatment.
Based on all the available evidence, the authors of an accompanying editorial said the decision to prescribe statins to older individuals may come down to patient preference.
“If in the process of shared decision making, older patients express a preference for extending longevity, then current evidence supporting statins for primary prevention remains limited,” wrote Aidan Ryan, MD, and Paul Cook, PhD, MSc. “A patient preference for reduction in myocardial infarction or stroke, however, might help to tilt the balance in favor of statin prescription, but the absolute risk reduction and number needed to treat to prevent a CVD event in older patients remains uncertain.”
Daniel joined TriMed’s Chicago editorial team in 2017 as a Cardiovascular Business writer. He previously worked as a writer for daily newspapers in North Dakota and Indiana.