People over the age of 75 do not benefit from statins as primary prevention unless they have diabetes, Spanish research finds.

In a study that questions the widespread use of statins in older people, researchers found no overall benefit of their use on the outcomes of atherosclerotic cardiovascular disease or all cause mortality.

Published in the BMJ, the retrospective study analysed GP records for 46,864 people over the age of 75 with no pre-existing cardiovascular disease, of whom, 7502 (16%) used a statin.

Over an average of almost eight years of follow up the number of atherosclerotic-related cardiovascular events was not significantly different between statin users and non-users in the 75-84 year age group (17.8 vs 18.8/1000 person years, Hazard Ratio 0.94).

Similarly, there was no difference in cardiovascular events for statin users vs non users in people over 85 (24.9 vs 30.6/1000 person years, HR 1.0).

All cause mortality rates were also no different between statin users and non-users, with Hazard Ratios of 0.98 for the 75-84 year age group and  1.0 for the over 85s.

Statin use did appear to confer some protective effect in people with diabetes, among whom the Hazard Ratio of statin use in 75-84 year olds was 0.76 for atherosclerotic cardiovascular disease and 0.84 for all cause mortality. However the protective effect waned with age, with Hazard Ratios of 0.82 and 1.05 respectively for those aged 85 and older.

The study authors noted that despite the lack of benefit, most of the patient population would be candidates for statin treatment under current guidelines, because the incidence of cardiovascular disease was well above the risk threshold of 10%.

Given that elderly people had  a higher risk of adverse events and interactions with statins, they said decisions to prescribe them as primary prevention should be individualised to each patient.

“These results do not support the widespread use of statins in old and very old populations, but they do support treatment in those with diabetes who are younger than 85 years,” they concluded.

However an Australian expert questioned whether meaningful conclusions could be drawn from a retrospective observational study with no placebo group.

Professor Garry Jennings a cardiologist and chief medical adviser to the Heart Foundation of Australia said the results could be limited by the potential for a ‘survival effect’, if older patients (> 75 years) included in the study were less likely to develop cardiovascular disease.

However he acknowledged that while statins are indicated for primary prevention for selected patients to reduce cardiovascular risk, clear evidence in people aged >75 years old is lacking.

‘These results, based on observational data, may not provide enough grounds for direct clinical recommendations, but they do show the need for randomised clinical trials to further elucidate this problem,” he said.

Professor Jennings noted that the Statins for Reducing Events in the Elderly (STAREE study) is a promising ongoing trial on primary prevention that compares atorvastatin (40 mg) with placebo in healthy people older than 70 years, but publication of the results is not expected until 2022.