Efficacy of lipid lowering therapy beyond statins to prevent cardiovascular events

Abstract Background Lipid lowering therapy is a key cornerstone in secondary prevention of patients with coronary artery disease. However, only a minority of patients with statin therapy reach LDL thresholds as suggested by the ESC. Ezetimibe, bempedoic acic, and proprotein convertase subtilisin/kexin type 9 (PCSK-9) (synthase-) inhibitors allow for the reduction in LDL-cholesterol in addition to statin therapy. Purpose We aimed to perform a meta-analysis of existing trials, evaluating how lipid lowering therapy beyond statins impacts cardiovascular outcome. In specific, we evaluated the potential influence of duration of follow-up on the association with mortality endpoints. Methods We performed a systematic search using the Pubmed, Cochrane, SCOPUS, and Web of Science databases for studies, evaluating the impact of an intensified lipid lowering therapy via ezetimibe, bempedoic acid, Bococizumab, Alirocumab, Evolocumab, Inclisiran in addition to statin therapy compared to statin therapy alone. Manuscript and congress presentations, published until 1st of August 2023, were included. We made our search specific and sensitive using Medical Subject Headings terms and free text and considered studies published in English language. Search terms used were : "Bempedoic Acid" or "Bococizumab" or "Alirocumab" or "Evolocumab" or "Ezetimibe" or "Inclisiran" and "statin" and "cardiovascular events". Results A total of 123,785 patients from 15 randomized controlled trials (IMPROVE-IT, FOURIER, ODYSSEY Outcomes, ODYSSEY LONG TERM, EWTOPIA 75, PACMAN-AMI, RACING, SIPRE I, SPIRE II, OSLER-1 and OSLER-2, CLEAR HARMONY, CLEAR OUTCOMES, CLEAR SERENITY, CLEAR WISDOM) were included. Treatment with ezetimibe or a PCSK-9 inhibitor was associated with a 19% risk reduction in cardiovascular events (OR [95%CI]: 0.81 [0.75; 0.86]). Effect sizes were similar for myocardial infarction (0.81 [0.74; 0.89]) and even more pronounced for ischemic stroke (0.77 [0.70; 0.84]). In contrast, all-cause mortality was not improved by the intensified lipid lowering therapy (0.99 [0.93; 1.04]). Stratifying by follow-up duration of < vs. ≥ 3 years, no improvement in all-cause mortality was observed in both groups (<3 years: 1.04 [0.93; 1.17]; ≥3 years: 0.97 (0.88; 1.06). No relevant heterogeneity and inconsistency between groups was present in all analyses (detailed data not shown). Conclusion Intensified LDL-lowering therapy with ezetimibe, bempedoic acic or PCSK-9 inhibitors, in addition to statins, reduces the risk of myocardial infarction and stroke, however, does not impact overall mortality. A potential survival benefit was also not observed in studies with follow-up duration of ≥ 3 years.