Efficacy and safety for the achievement of guideline-recommended lower low-density lipoprotein cholesterol levels: a systematic review and meta-analysis

Aim: The 2018 American Heart Association/American College of Cardiology/Multi-Society Cholesterol Guidelines recommended the addition of non-statins to statin therapy for high-risk secondary prevention patients above a low-density lipoprotein cholesterol (LDL-C) threshold of ≥70 mg/dL (1.8 mmol/L). We compared effectiveness and safety of treatment to achieve lower (<70) vs. higher (≥70 mg/dL) LDL-C among patients receiving intensive lipid-lowering therapy (statins alone or plus ezetimibe or proprotein convertase subtilisin/kexin type 9 inhibitors). Methods and results: Eleven randomized controlled trials (130 070 patients), comparing intensive vs. less-intensive lipid-lowering therapy, with follow-up ≥6 months and sample size ≥1000 patients were selected. Meta-analysis was reported as random effects risk ratios (RRs) [95% confidence intervals] and absolute risk differences (ARDs) as incident cases per 1000 person-years. The median LDL-C levels achieved in lower LDL-C vs. higher LDL-C groups were 62 and 103 mg/dL, respectively. At median follow-up of 2 years, the lower LDL-C vs. higher LDL-C group was associated with significant reduction in all-cause mortality [ARD -1.56; RR 0.94 (0.89-1.00)], cardiovascular mortality [ARD -1.49; RR 0.90 (0.81-1.00)], and reduced risk of myocardial infarction, cerebrovascular events, revascularization, and major adverse cardiovascular events (MACE). These benefits were achieved without increasing the risk of incident cancer, diabetes mellitus, or haemorrhagic stroke. All-cause mortality benefit in lower LDL-C group was limited to statin therapy and those with higher baseline LDL-C (≥100 mg/dL). However, the RR reduction in ischaemic and safety endpoints was independent of baseline LDL-C or drug therapy. Conclusion: This meta-analysis showed that treatment to achieve LDL-C levels below 70 mg/dL using intensive lipid-lowering therapy can safely reduce the risk of mortality and MACE.