Evidence from clinical trials has shown that statin therapy reduces cardiovascular risk among a wide range of people, but it’s not been clear if they might also be safe and effective in older people.
They drew on the evidence from 28 randomised controlled trials, involving 186,854 patients, 14,483 of whom were over the age of 75.
Irrespective of age, statins cut the risks of major vascular events by about a fifth for every 1 mmol/l reduction in LDL cholesterol, the findings show.
For major coronary events the overall reduction was about a quarter per 1 mmol/l reduction overall, but ranged from about 30% in those younger than 55 to around 20% in the over 75s.
The relative risk reductions in stroke and coronary stenting or bypass surgery were similar in all age groups.
“Statins are a useful and affordable drug that reduce heart attacks and strokes in older patients. Until now there has been an evidence gap and we wanted to look at their efficacy and safety in older people,” explains Dr Jordan Fulcher of the Cholesterol Treatment Trialists’ (CTT) Collaboration, who is based at the University of Sydney NHMRC Clinical Trials Centre, Australia.
“Despite previous concerns we found no adverse effect on cancer or non-vascular mortality in any age group.”
Clinical trials that looked at the effect of statin therapy reported significant cardiovascular risk reductions in the 65-70 age group, but questions have remained about their benefits in older patients, particularly those over 75.
Statin therapy is often discontinued in older patients in part because of this unresolved issue around the pros and cons of treatment.
The Collaboration included 23 trials that compared statins with other treatment and a further five that compared intensive with standard statin therapy. They divided patients into six age groups, and assessed the impact on major coronary events, strokes and coronary revascularisations; new cases of cancer; and deaths from specific causes.
The analysis showed that the reduction in major vascular events – 21% for every 1 mmol/l fall in LDL cholesterol, overall – is similar and significant in all age groups, including among the over 75s.
For major coronary events the overall reduction is 24% per 1 mmol/l fall in LDL, but drops slightly with age.
There was no heightened risk of death from other causes or cancer in any age group.
Four trials included only patients who had heart failure or were on renal dialysis. Statins are not recommended for these patients.
When they were excluded, similar reductions in risk were seen across all age groups, including for major vascular events and cardiovascular deaths. A slightly smaller reduction in the risk of major coronary events with increasing age persisted.
The research also looked at the effects of statins on major vascular events in people with a history of vascular disease (secondary prevention) and in people without known vascular disease (primary prevention).
In the secondary prevention group, the researchers found similar proportional risk reductions regardless of age, which would equate to a larger absolute benefit in older people. For primary prevention, the results were similar, but as there were fewer such older participants in the trials, the conclusions were less clear-cut.
Writing in a linked comment**, Bernard Cheung of the Queen Mary Hospital at the University of Hong Kong says: “Even if risk reduction in people older than 75 years is less than expected, statin therapy may still be justified by a high baseline cardiovascular risk, which is usually present in older people.
“The present meta-analysis makes a case to reduce LDL cholesterol in people at risk of cardiovascular events regardless of age, provided that the benefits outweigh the risks and the patient accepts long-term treatment.”
“In older people who do not have existing disease, further trials are needed to determine if the overall benefits are sufficient to make firm recommendations so this remains a grey area, as does when to consider stopping statins in the very elderly,” comments Naveed Sattar, professor of metabolic medicine, University of Glasgow.
“But for all other groups, statins do what they say on the tin – they lower LDL-cholesterol and so lower risks for heart attacks and strokes.”