Cardiovascular disease (CVD) is a leading healthcare burden and cause of mortality globally.^1,2 The elderly are particularly at risk but are underrepresented in randomized controlled trials (RCTs) evaluating lipid-lowering drugs such as statins.^1,3 As such, despite the recommendation for statin use to prevent CVD events and all-cause mortality in adults aged 40-75 years, there is insufficient evidence to support statin use in adults >75 years of age.^1,2 A recent study led by researchers from the University of Hong Kong LKS Faculty of Medicine (HKUMed) and the Harvard TH Chan School of Public Health examined the benefits and safety of statin therapy in adults aged ≥75 years using real-world evidence from electronic medical records in Hong Kong.¹ The findings from this study support the prescription of statin therapy for primary cardiovascular disease (CVD) prevention in the elderly.¹

Major international guidelines for the use of statins for primary CVD prevention do not provide specific recommendations for adults ≥75 years as there has been insufficient evidence to determine the balance of benefits and risks of statin use in this population.^1,2 However, the elderly population faces the greatest risk and burden of CVD morbidity and mortality, as the cardiovascular consequences tend to be more severe in older patients.³ To address this knowledge gap, a local study used real-world electronic health records (EHRs) to evaluate the benefits and risks of statin use for primary prevention of CVD in old (75-84 years) and very old (≥85 years) adults.¹

Using EHRs from the clinical management system of the Hong Kong Health Authority, all adult patients >60 years of age who did not have pre-existing diagnosed CVDs and met indications for statin treatment between 2008 and 2015 were identified.¹ The major indications for statin therapy were individuals with 0 or 1 CVD risk factor (e.g. hypertension, obesity, smoking, impaired fasting glycemia) and low-density lipoprotein cholesterol (LDL-C) ≥4.1mmol/L, individuals with ≥2 CVD risk factors and LDL-C ≥3.4mmol/l, and those with coronary heart disease (CHD) risk equivalents and LDL-C ≥2.6mmol/L.¹ Statin therapy was defined as treatment with simvastatin, atorvastatin, fluvastatin, rosuvastatin, lovastatin, pitavastatin, and/or pravastatin at any dose.¹ Patients who had used statins or other lipid-lowering drugs before baseline were excluded from the analysis.¹

The study utilized propensity score matching to emulate the randomization of the eligible participants at baseline.¹ The process matched statin initiators and non-initiators 1:1 within each age group (60-74,75-84, ≥85 years).¹ The matching factors included demographic characteristics, clinical variables, comorbidities, drug history within 1 year before baseline, and lifestyle behaviors.¹ The analysis included 14,684 matched participants aged 60-74 years, 42,680 matched participants aged 75-84 years, and 5,390 matched participants aged ≥85 years.¹ The researchers then evaluated the incidence and hazard ratios [HRs] for a composite cardiovascular outcome (including myocardial infarction, heart failure and stroke), all-cause mortality, and major adverse events (such as myopathies and liver dysfunction) across the different age groups.¹

The study found that statin use was associated with reduced CVD risk across all age groups.¹ In the 60-74 years age group, the intention-to-treat (ITT) analysis showed an HR of 0.89, while the per-protocol (PP) analysis had an HR of 0.77, indicating a lower risk of overall CVD incidence.¹ Similar risk reductions were observed in the older age groups as well, with the 75-84 years group having an ITT HR of 0.94 and a PP HR of 0.79, and the ≥85 years group having an ITT HR of 0.85 and a PP HR of 0.65.¹

The estimated 5-year absolute risk reduction for overall CVD incidence was 1.20% in the ITT analysis and 5.00% in the PP analysis for adults aged 75-84 years.¹ For those aged ≥85 years, the absolute risk reduction was even greater, with a 4.44% reduction in the ITT analysis and a 12.50% reduction in the PP analysis.¹ Based on these findings, the number needed to treat (NNT) to prevent 1 CVD event in 5 years was 20 for those aged 76-84 years, and 8 for those aged ≥85 years.¹ Importantly, no significant increased risks for myopathies and liver dysfunction were observed in any of the age groups.¹

In summary, this study evaluated the long-term benefits and safety of statin initiation among older adults ≥75 years in real-world settings, demonstrating a reduction in risks for CVD and all-cause mortality without increasing risks for severe adverse effects.¹ Additionally, these benefits remain substantial even among the population ≥85 years.¹ Given the increased burden related to CVD in aging populations, these results support the use of statin for primary prevention of CVD in older adults.¹