The long-term clinical impact of high-intensity statin therapy in older patients with acute myocardial infarction

Abstract Introduction Despite substantial clinical evidence supporting the benefits of high-intensity statins for acute myocardial infarction, the clinical implications of their use in elderly populations have yet to be fully elucidated. Purpose This study aims to clarify the importance of high-intensity statin therapy at discharge for patients aged over 65 with acute myocardial infarction (AMI). Methods In this retrospective cohort analysis conducted with data from the Korean Acute Myocardial Infarction Registry (KAMIR), we evaluated 4,147 patients aged 65 and above who experienced acute myocardial infarction (AMI), underwent coronary interventions utilizing second-generation drug-eluting stents, and were prescribed statins at the time of discharge. The primary outcome was major adverse cardiovascular events (MACE) at 3 years, defined as the composite of all-cause deaths, any myocardial infarction, and any coronary revascularization. The secondary outcome was target-lesion failure (TLF), defined as the composite endpoint of all cardiac deaths, target vessel myocardial infarction, and ischemia-driven target lesion revascularization at 3 years. Results In this study, 1,268 patients (30.5%) were treated with high-intensity statins at discharge. The patients were stratified into two groups using an age threshold of 78 years. In the propensity-matched cohort aged 65 to 78, the use of high-intensity statins was associated with a significant reduction in MACE (19.1% versus 14.5%, p=0.011). In the propensity score-matched cohort aged over 78, however, treatment with high-intensity statins did not lead to a reduction in MACE (24.8% versus 24.5%, p>0.99). Additionally, multivariate analysis revealed that high-intensity statin therapy was associated with a reduced risk of MACE (HR 0.69, 95% CI [0.57-0.85], p<0.001) in patients aged 65 to 78. However, the effects of high-intensity statins on TLF were not significant in matched patients aged 65 to 78 (7.9% versus 6.5%, p=0.269) and in those aged over 78 (13.7% versus 12.1%, p=0.638). Conclusion This extensive, nationwide cohort study suggests that treatment with high-intensity statins upon discharge may not offer clinical benefits in reducing MACE and TLF in patients with AMI aged over 78, compared to those aged 65 to 78.