Effect of Statin Therapy on Clinical Outcomes in Patients With Cardiovascular Risks: A Systematic Review and Meta-Analysis.

Statin therapy effectively reduces low-density lipoprotein (LDL) cholesterol, thereby lowering the risk of atherosclerosis and cardiovascular (CV) events. This systematic review and meta-analysis assessed its impact on all-cause mortality, CV mortality, major adverse cardiovascular events (MACE), such as heart attack, stroke, coronary revascularization, and CV hospitalization in adults with CV risk factors or established cardiovascular disease (CVD). A systematic search of PubMed, Google Scholar, and Cochrane Central (2013-2024) included randomized controlled trials, prospective cohorts, and retrospective studies. Primary outcomes were all-cause mortality, CV mortality, MACE, and CV hospitalization. A random-effects model was employed, with heterogeneity assessed using the I² statistic. Seven studies, comprising 506,813 patients (118,491 statin users and 388,322 non-users), with a mean follow-up of 3.7 years, were included. Statin therapy significantly reduced all-cause mortality (relative risk (RR) 0.60, 95% confidence interval (CI): 0.43-0.83, p<0.00001, I²=91%), and MACE (RR 0.75, 95% CI: 0.70-0.82, p<0.00001, I²=0%). The high heterogeneity observed in mortality outcomes likely reflects differences in study populations, statin types, and baseline risk profiles. A non-significant trend was observed toward CV mortality (RR 0.74, 95% CI: 0.53-1.02, p<0.00001, I²=90%). Additionally, no significant reduction in CV hospitalizations was observed (RR 0.97, 95% CI: 0.83-1.13, p=0.58, I²=0%). Statin therapy significantly lowers all-cause mortality and MACE, reinforcing its role in CV risk management. However, its effect on CV mortality and CV hospitalization remains uncertain, warranting further investigation into complementary strategies for reducing hospital admissions.