Statin Therapy Reduces 5-Year CVD Risk in Adults Aged 75 and Older

Starting statin therapy can reduce the 5-year risk of cardiovascular disease (CVD) for patients aged 75 and older without increasing risks for severe adverse effects, according to new findings just published in Annals of Internal Medicine.¹

The study looked at 2 main age groups: 75 to 84 years (n = 42,680) and 85 years and older (n = 5390). With an average follow-up of 5.3 years, 9676 and 1600 adults in each age group, respectively, developed a form of CVD. All patients met indications for statin initiation, with comorbidities such as diabetes, hypertension, peripheral vascular disease, and obesity. Data were collected from public electronic medical records in Hong Kong.

The study also included 2 analyses: the intention-to-treat (ITT) analysis, simulating that everyone who was supposed to take the statin did, and the per protocol (PP) analysis, which only considered those who followed the statin regimen as prescribed.

For adults aged 75 to 84 years, the ITT analysis revealed that over a 5-year period, those who started taking statins had a 1.2% (95% CI, 0.57%-1.82%) reduced risk of developing CVD by. The risk reduction jumped to 5% (95% CI, 1.11%-8.89%) after taking statin as prescribed for 5 years in the PP analysis.

Meanwhile, if everyone aged 85 and older started taking statins, their risk of developing CVD over 5 years would drop by 4.44% (95% CI, 1.40%-7.48%). For those who strictly follow the statin treatment, the study showed that their risk reduction is even greater at 12.50% (95% CI, 4.33%-20.66%). The authors did not report any significantly increased risks for myopathies or liver dysfunction in either age group.

When looking at 5-year all-cause mortality risk, ITT analysis showed a 1.44% reduction in risk for adults aged 75 to 84 years and a 4.18% reduction for those aged 85 and older. After PP analysis, these translated to a 1.38% reduction in the younger of the 2 age groups, and a 6.85% reduction in the older age group.

“There may be unmeasured confounding factors that could be associated with both statin use and the risk for CVD or death,” the authors said when noting the study’s limitations.² “If present, such factors could cause bias in the observed association. In addition, a significant portion of the study population was excluded due to missing data, potentially affecting the generalizability of the findings.”

Interestingly, statin use did not lead to any significantly increased risks of an adverse event, which is an argument often used to keep older patients off statin therapy.¹ Statins not only lower lipid levels—which reduces the buildup in atherosclerotic plaques—but also have anti-inflammatory and antioxidative properties that help prevent the plaques from worsening. Vascular aging is characterized by increased oxidative stress and endothelial dysfunction, and is further aggravated by a decreased ability to withstand cellular and molecular stressors. According to the study authors, these factors worsen vascular inflammation and accelerate the cycle of atherosclerosis and CVD in older patients, making the anti-inflammatory effects of statins potentially more significant for them than for younger individuals.

As mentioned in the study, one systematic review and meta-analysis found that statins were well tolerated and relatively safe for older adults regarding muscle issues. In other studies, mild to moderately increased liver enzyme levels due to statins did not lead to severe liver disease and were generally safe, except in patients with preexisting liver or biliary disease. In the current study, population-based data and target trial emulation confirmed the overall safety of statin therapy in older adults.

“Considering the increasing burden related to CVD in the aging population, our study results support the prescription of statin therapy for primary prevention of CVD in old and very old adults,” the authors concluded.

References

1. Xu W, Lee AL, Lam CLK, Danaei G, Wan EYF. Benefits and risks associated with statin therapy for primary prevention in old and very old adults: real-world evidence from a target trial emulation study. Ann Intern Med. Published online May 27, 2024. doi:10.7326/M24-0004
2. Xu W, Lee AL, Lam CLK, Danaei G, Wan EYF. Summary for patients: benefits and risks associated with statin therapy for primary prevention in old and very old adults. Ann Intern Med. Published online May 27, 2024. doi:10.7326/P24-0001