The clinical effectiveness and safety of low/moderate-intensity statins & ezetimibe combination therapy vs. high-intensity statin monotherapy: a systematic review and meta-analysis.

Background: Despite widespread use of high-intensity statin monotherapy, achieving target LDL-C levels and reducing cardiovascular events in patients with or at high risk of developing ASCVD remains challenging. Our study measured the effects of low/moderate-intensity statins and ezetimibe combination therapy compared to high-dose statin monotherapy on major adverse cardiovascular events (MACEs) and coronary atherosclerotic plaque reduction.

Methods: We searched PubMed, Scopus, Web of Science, and Cochrane CENTRAL register of trials for studies comparing the combination therapy to high-intensity statin monotherapy in terms of MACEs and coronary atherosclerotic plaque reduction. The primary outcome was a composite of cardiovascular death or major cardiovascular events (MI, HF, Revascularization, or non-fatal stroke). Other outcomes included other MACEs, lipid-lowering efficacy, and safety outcomes. A protocol was registered to PROSPERO under registration number [CRD42024545807].

Results: 15 studies encompassing 251,450 participants were included in our meta-analysis. In our pooled analysis of observational studies, combination therapy was associated with lower rates of the primary composite outcome (HR = 0.76, CI 95% [0.73, 0.80]), cardiovascular death (HR = 0.80, CI 95% [0.74, 0.88]), all-cause death (HR = 0.84, CI 95% [0.78, 0.91]), and non-fatal stroke (HR = 0.81, CI 95% [0.75, 0.87]). However, the pooled analysis of RCTs did not demonstrate a statistically significant difference between both arms concerning clinical endpoints. Combination therapy had a higher number of patients with LDL-C < 70 mg/dL (RR = 1.27, CI 95% [1.21, 1.34]), significantly lowered LDL-C (MD = -7.95, CI 95% [-10.02, -5.89]) and TC (MD = -26.77, CI 95% [-27.64, -25.89]) in the pooled analysis of RCTs. In terms of safety, the combination therapy lowered muscle-related adverse events (RR = 0.52, CI 95% [0.32, 0.85]) and number of patients with liver enzyme elevation (RR = 0.51, CI 95% [0.29, 0.89]) in the pooled analysis of RCTs and was associated with lower rates of new-onset diabetes (HR = 0.80, CI 95% [0.74, 0.87]) in the pooled analysis of observational studies.

Conclusion: Evidence from RCTs indicates that low/moderate statin therapy in combination with ezetimibe has a superior lipid-lowering effect and reduces side effects compared to high-dose statins. Observational studies suggest improved clinical outcomes but need to be corroborated by large, outcomes-powered RCTs over longer follow-up periods.