The murky waters of statin prescribing may be starting to clear as study shows efficacy without increased risk.
Statins reduce the risk of cardiovascular diseases and all-cause mortality in over-75s without significantly increasing risk of adverse events, a large observational study has concluded.
This risk reduction is even more substantial in the over-85s.
The researchers used electronic health records from the clinical management system of the Hong Kong Health Authority to find all adult patients with pre-existing cardiovascular disease who met indications for statin use between 2008 and 2015.
They compared almost 147,000 individuals aged 60-74, 42,700 aged 75-84 and 5400 aged 85 or older, using equal numbers of patients who did and did not start statins in each age bracket.
The study assessed incidence of myocardial infarction, heart failure, stroke, all-cause mortality, and major adverse events such as myopathies and liver disease. The average follow up was almost six years.
The absolute risk reduction for those who adhered to their prescribed statin therapy was 5% for those aged 75-84 and 12.5% for those aged 85+. People in the treatment group who deviated from their treatment plan still showed a modest reduction in absolute risk: 1.2% for the 75-84 group and 4.4% in the 85s and older.
Indications for statin therapy included having one cardiovascular disease risk such as hypertension or obesity plus a low-density lipoprotein cholesterol level of 4.1mmol/L or greater. Those with two or more CVD risk factors with LDL-C of 3.4mmol/L or greater were also included, as well as individuals with coronary heart disease risk equivalents (hypertensive retinopathy, peripheral vascular disease etc) and a minimum LDL-C level of 2.6mmol/L.
The ongoing debate about statin use for these age groups has centred on the uncertainty of risks and whether these outweigh the benefits of the medication. Researchers say the elderly have been underrepresented in randomised control trials, causing ambiguity around clinical guidelines.
Related
A key argument for not initiating statins in over-75s is the adverse events associated with statin therapy, researchers say. However, this study did not identify substantial risks for adverse events associated with the initiation of statin use in the older adults.
The study suggested that the lipid-lowering effect of statins may not be the only reason treatment is effective in these older age brackets. The potential anti-inflammatory and antioxidative effects of statins may slow the progression of atherosclerotic plaques.
“Vascular aging often manifests as increased oxidative stress and endothelial dysfunction, worsened by decreased resistance to cellular and molecular stressors,” the authors wrote. “These factors aggravate vascular inflammation, the vicious cycle of atherosclerosis and development of CVD in older patients. Therefore, the anti-inflammatory effects of statins may be larger in older patients compared with younger ones.”
“Our study confirmed the safety of statin therapy in old and very old adults.”
Annals of Internal Medicine, online May 28.
