A new meta-analysis published in The Lancet has shown evidence that statins significantly reduce risk of major heart issues, irrespective of age
In a meta-analysis of nearly 187,000 people who had taken part in 28 large clinical trials, researchers from the University of Sydney’s Clinical Trials Centre have found statin treatment reduced the risk of a major vascular event across all ages – including those over 75 years.
Investigators analysed individual participant data from 27 randomised controlled trials (n=174,149) and detailed summary data from one trial (n=12,705).
Of the total 186,854 participants, 14,483 (8%) were older than 75 years at randomisation, and the median follow-up duration was 4·9 years.
Participants were divided into six different age groups ranging from under 55 years to over 75 years to assess the effects of statins on heart attacks, strokes, coronary revascularisations, cancer incidence and deaths.
Overall statin therapy or a more intensive statin regimen led to a 21% (RR 0·79, 95% CI 0·77–0·81) proportional reduction in major vascular events per 1·0 mmol/L reduction in LDL cholesterol, according to the study published in The Lancet this week.
Statin or more intensive therapy yielded a 24% (RR 0·76, 95% CI 0·73–0·79) proportional reduction in major coronary events per 1·0 mmol/L reduction in LDL cholesterol.
With increasing age there was a trend towards smaller proportional risk reductions in major coronary events (ptrend=0·009).
Proportional reductions in major vascular events also diminished slightly with age, but this trend was not statistically significant (ptrend=0·06).
Researchers observed a 25% (RR 0·75, 95% CI 0·73–0·78) proportional reduction in the risk of coronary revascularisation procedures with statin therapy or a more intensive statin regimen per 1·0 mmol/L lower LDL cholesterol, which did not differ significantly across age groups.
The evidence was less definitive among people aged over 75 without pre-existing vascular disease—those who were prescribed statin therapy for the primary prevention of heart attacks and strokes.
Proportional reduction in major vascular events was similar – irrespective of age – among patients with pre-existing vascular disease, but appeared smaller among older than among younger individuals not known to have vascular disease.
Researchers found a 12% (RR 0·88, 95% CI 0·85–0·91) proportional reduction in vascular mortality per 1·0 mmol/L reduction in LDL cholesterol, with a trend towards smaller proportional reductions with older age, although this trend did not persist after exclusion of four trials which enrolled only patients with heart failure or undergoing renal dialysis.
Statin therapy was found to have no effect at any age on non-vascular mortality, cancer death, or cancer incidence.
“Statin therapy has been shown to prevent cardiovascular disease in a wide range of people, but there has been uncertainty about its efficacy and safety among older people over 75 years,” said lead investigator, Professor Anthony Keech, Deputy Director of the NHMRC Clinical Trials Centre at the University of Sydney.
“Our study summarised all the available evidence from major trials to help clarify this issue, and found that there were significant reductions in major vascular events in each of the six age groups considered, including in patients aged over 75 years at the start of treatment.”
Co-investigator, Dr Jordan Fulcher from the University of Sydney, added: “We now have definitive evidence that statins benefit older people who have suffered a heart attack or stroke.
“This study will provide reassurance and guidance for doctors and patients alike that people are not automatically ‘too old’ for treatments like statins to be effective,” said Dr Fulcher.
Professor Garry Jennings AO, Executive Director of Sydney Health partners, Chief Medical Advisor of the Heart Foundation and Senior Director from the Baker Heart and Diabetes Institute, said while the evidence base for statins is “huge”, the medicine remains the subject of recurring controversies.
“Some of these controversies are misguided, bordering on mischievous but others such as whether the benefits diminish in older people are real,” he said.
“[This] analysis provided strong support for the use of statins in people aged over 75 who have a history of heart or vascular disease, probable benefit for people aged over 75 without a history of heart or vascular disease and no support for their routine use in older people with heart failure or on dialysis treatment.
“Fifteen thousand is a large number, but given the diversity of studies included in the meta-analysis, it is not enough to provide a definitive answer to the question of who benefits from statins at an older age,” said Professor Jennings.
“Nevertheless, this is important new information and provides support for current common practice in prescribing statins to older people, especially those with a history of heart or vascular disease.”
He also said the study adds to the large amount of evidence that statins do not cause cancer in older people.
Professor Jennings said the forthcoming STAREE study, a global randomised controlled trial of 18,000 people aged 70 years or more run by Monash University investigators “will fill in all the gaps that remain after this meta-analysis”.
Read the full study here (open access)