Efficacy and Safety of Lipid Lowering Therapy: A Systematic Review

Abstract

Introduction: Dyslipidemia is the most important modifiable risk factor for myocardial infarction worldwide. We conducted a systematic review and meta-analysis to highlight the evidence for the safety, efficacy of lipid-lowering therapy, and clinical effectiveness from trials comparing more intensive statin therapy with less intensive statin therapy.
Methods: A comprehensive electronic search was conducted in MEDLINE, EMBASE, and Cochrane databases to identify articles that aimed to assess the preventive effect of lipid-lowering therapy, particularly in CHD. The titles and abstracts of the resultant articles were read by two independent reviewers to identify relevant articles as a primary screening step and to exclude irrelevantly, duplicated or review articles. The full texts of these relevant articles were retrieved and the in-depth reading was conducted to exclude the irrelevant articles as a secondary screening step. The articles were assessed against inclusion criteria such as clinical trials, published in the last 10 years and written in English language. The population studied should be patients with CHD, while included intervention was lipid-lowering therapy. The outcomes assessed were the mortality indicators in rates or percentages.
Results: Seventy-five studies reporting RCTs of head-to-head comparisons on statins were included. Most studies had similar baseline characteristics, except the rosuvastatin-related studies. A daily dose of atorvastatin 10 mg, fluvastatin 80 mg, lovastatin 40–80 mg, and simvastatin 20 mg could decrease LDL-C by 30–40%, and fluvastatin 40 mg, lovastatin 10–20 mg, pravastatin 20–40 mg, and simvastatin 10 mg could decrease LDL-C by 20–30%. The only two statins that could reduce LDL-C more than 40% were rosuvastatin and atorvastatin at a daily dose of 20 mg or higher. Meta-analysis indicated a statistically significant but clinically minor difference (<7%) between statins in cholesterol-lowering effect. Comparisons of coronary heart disease prevention and safety could not be made because of insufficient data.
Conclusions: The HDL-elevating and triglyceride-lowering effects are similar among different statins at equivalent doses. The current data are not sufficient to determine the relative safety of the different statins or their relative effectiveness in CHD prevention.