Armitage J, et al. - Researchers estimated less direct data regarding the advantages of using statin therapy in the older population (more than 75 years). But they found a significant reduction in major vascular events irrespective of age.

Methods

• They recruited at least 1000 cases with a scheduled treatment duration of at least 2 years for randomized trials of statin therapy in this meta-analysis.
• They estimated the each candidate's data from 22 trials (n=134,537) and detailed summary data from one trial (n=12,705) of statin therapy vs control.
• They also assessed individual participant data from 5 trials of more intensive vs less intensive statin therapy (n=39,612).
• The candidates were subdivided into 6 age groups ie, 55 years or younger, 56–60 years, 61–65 years, 66–70 years, 71–75 years, and older than 75 years.
• Effects on major vascular events (major coronary events, strokes, and coronary revascularisations), cause-specific mortality, and cancer incidence as the rate ratio (RR) per 1·0 mmol/L reduction in LDL cholesterol were also calculated.
• Proportional risk reductions in different age subgroups were compared by using standard χ² tests for heterogeneity when there were 2 groups, or trend when there were more than 2 groups.

Results

• They recorded 14,483 of 186,854 subjects in 28 trials were older than 75 years at randomization, and the median follow-up duration was 4·9 years.
• They observed a 21% (RR 0·79, 95% CI 0·77–0·81) proportional decline in major vascular events per 1·0 mmol/L reduction in LDL cholesterol while using statin therapy or a more intensive statin regimen.
• A significant reduction in major vascular events in all age groups was also observed.
• This trend was not statistically significant (p_trend=0·06) although proportional decline in major vascular events diminished slightly with age.
• They recorded 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 statin or more intensive therapy.
• They also found a trend towards smaller proportional risk reductions in major coronary events (p_trend=0·009) with increasing age.
• They recorded a 25% (RR 0·75, 95% CI 0·73–0·78) proportional reduction in the risk of coronary revascularisation procedures with statin therapy/a more intensive statin regimen per 1·0 mmol/L lower LDL cholesterol, which did not variate significantly across age groups (p_trend=0·6).
• They did not found any variation across age groups (p_trend=0·7) with the proportional reductions in stroke of any type (RR 0·84, 95% CI 0·80–0·89).
• The trend to smaller proportional risk reductions with increasing age persisted for major coronary events (p_trend=0·01), and remained non-significant for major vascular events (p_trend=0·3) after exclusion of 4 trials which enrolled only cases with heart failure or undergoing renal dialysis (among whom statin therapy has not been shown to be effective).
• They noticed similar proportional reduction in major vascular events, irrespective of age, among candidates with pre-existing vascular disease (p_trend=0·2), but appeared smaller among older than among younger subjects (not known to have vascular disease) (p_trend=0·05).
• They noted 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 (p_trend=0·004), but they did not found this persistence after exclusion of the heart failure or dialysis trials (p_trend=0·2).
• They noticed no impact of statin therapy at any age on non-vascular mortality, cancer death, or cancer incidence.