Efficacy and safety of lowering LDL cholesterol in older patients: a systematic review and meta-analysis of randomised controlled trials

The clinical benefit of LDL cholesterol lowering treatment in older patients remains debated. We aimed to summarise the evidence of LDL cholesterol lowering therapies in older patients. In this systematic review and meta-analysis, we searched MEDLINE and Embase for articles published between March 1, 2015, and Aug 14, 2020, without any language restrictions. We included randomised controlled trials of cardiovascular outcomes of an LDL cholesterol-lowering drug recommended by the 2018 American College of Cardiology and American Heart Association guidelines, with a median follow-up of at least 2 years and data on older patients (aged ≥75 years). We excluded trials that exclusively enrolled participants with heart failure or on dialysis because guidelines do not recommend lipid-lowering therapy in such patients who do not have another indication. We extracted data for older patients using a standardised data form for aggregated study-level data. We meta-analysed the risk ratio (RR) for major vascular events (a composite of cardiovascular death, myocardial infarction or other acute coronary syndrome, stroke, or coronary revascularisation) per 1 mmol/L reduction in LDL cholesterol. Data from six articles were included in the systematic review and meta-analysis, which included 24 trials from the Cholesterol Treatment Trialists' Collaboration meta-analysis plus five individual trials. Among 244 090 patients from 29 trials, 21 492 (8·8%) were aged at least 75 years, of whom 11 750 (54·7%) were from statin trials, 6209 (28·9%) from ezetimibe trials, and 3533 (16·4%) from PCSK9 inhibitor trials. Median follow-up ranged from 2·2 years to 6·0 years. LDL cholesterol lowering significantly reduced the risk of major vascular events (n=3519) in older patients by 26% per 1 mmol/L reduction in LDL cholesterol (RR 0·74 [95% CI 0·61–0·89]; p=0·0019), with no statistically significant difference with the risk reduction in patients younger than 75 years (0·85 [0·78–0·92]; pinteraction=0·37). Among older patients, RRs were not statistically different for statin (0·82 [0·73–0·91]) and non-statin treatment (0·67 [0·47–0·95]; pinteraction=0·64). The benefit of LDL cholesterol lowering in older patients was observed for each component of the composite, including cardiovascular death (0·85 [0·74–0·98]), myocardial infarction (0·80 [0·71–0·90]), stroke (0·73 [0·61–0·87]), and coronary revascularisation (0·80 [0·66–0·96]). In patients aged 75 years and older, lipid lowering was as effe