Abstract
INTRODUCTION: Despite the effect on blood lipid levels, the clinical benefits of intensive versus standard pharmacological lipid-lowering therapy remain unclear. Previous reviews have presented relative effects on the risk of clinical outcomes, but not the absolute risk reductions (ARRs) and the time gained to a clinical outcome, also called outcome postponement (OP). The aim of this study was to estimate the effect of intensive versus standard lipid-lowering therapy in terms of ARR and OP of major adverse cardiovascular events (MACE), myocardial infarction (MI), stroke, and all-cause mortality. METHODS: We searched PubMed, Embase, and prior reviews to identify trials comparing intensive versus standard lipid-lowering therapy for the risk of cardiovascular disease. We extracted the number of patients with MACE, MI, stroke, and all-cause mortality. Risk of bias was assessed according to the five domains of the Cochrane Risk of Bias Tool 2.0. We calculated ARRs and OPs to assess the clinical benefits of intensive versus standard therapy for each outcome. We conducted meta-analyses standardizing the results to 2 and 5 years of follow-up. RESULTS: We identified 11 double-blind, randomized, controlled trials (n = 101,357). The follow-up period ranged from 1.5 to 7.0 years, with an average follow-up duration of 3.7 years. Risk of bias was generally high. During an estimated 2 years of intensive versus standard lipid-lowering therapy, 1.1% (95% confidence interval [CI] 0.7-1.5) fewer patients had MACE and the OP of MACE was 4.1 days (95% CI 2.6-5.6). The effects were 0.7% (95% CI 0.4-0.8) and 2.5 days (95% CI 1.6-3.3) for MI, 0.2% (95% CI 0.1-0.3) and 0.9 days (95% CI 0.5-1.2) for stroke, and 0.2% (95% CI - 0.1 to 0.4) and 0.6 days (95% CI - 0.4 to 1.5) for all-cause death. During on average 5 years of intensive versus standard lipid-lowering therapy, 2.4% (95% CI 1.5-3.3) fewer patients had MACE and the time gained to MACE was 23.5 days (95% CI 14.9-32.0). The effects were 1.5% (95% CI 1.0-2.1) and 14.6 days (95% CI 9.3-20.0) for MI, 0.6% (95% CI 0.4-0.8) and 5.3 days (95% CI 3.3-7.4) for stroke, and 0.4% (95% CI -0.2 to 0.1) and 3.6 days (95% CI - 2.1 to 9.2) for all-cause death. CONCLUSION: Intensive lipid-lowering therapy during 2 or 5 years did not lead to fewer deaths or lifetime gained, and the effects on MI and stroke were negligible. The largest effect was that MACE did not occur in two of 100 patients and was postponed 3-4 weeks after 5 years of intensive treatment. Given the small effect, patients should receive this information as part of shared decision making.