Efficacy of more intensive lipid-lowering therapy on cardiovascular diseases: a systematic review and meta-analysis

Background

Cardiovascular disease is the leading cause of morbidity and mortality with incidence rates of 5–10 per 1000 person-years, according to primary prevention studies. To control hyperlipidemia—a major risk factor of cardiovascular disease—initiation of lipid-lowering therapy with therapeutic lifestyle modification or lipid-lowering agent is recommended. Few systematic reviews and meta-analyses are available on lipid-lowering therapy for the primary prevention of cardiovascular diseases. In addition, the operational definitions of intensive lipid-lowering therapies are heterogeneous. The aim of our study was to investigate whether intensive lipid-lowering therapies reduce greater cardiovascular disease risks in primary prevention settings.

Methods

MEDLINE, EMBASE, and Cochrane Library databases were searched from inception to March 2019 for randomized controlled trials. We used random effects model for overall pooled risk ratio (RR) estimation with cardiovascular events of interest and all-cause mortality rate for the intensive lipid-lowering group using the standard lipid-lowering group as the reference. The Cochrane Risk of Bias Tool was used for quality assessment.

Results

A total of 18 randomized controlled trials were included. The risk reductions in cardiovascular outcomes and all-cause mortality associated with more intensive vs. standard lipid-lowering therapy across all trials were 24 and 10%, respectively (RR 0.76, 95% confidence interval 0.68–0.85; RR 0.90, 95% confidence interval 0.83–0.97); however, the risk reduction varied by baseline LDL-C level in the trial. A greater risk reduction was noted with higher LDL-C level. Intensive lipid-lowering for coronary heart disease protection was more pronounced in the non-diabetic populations than in the diabetic populations.

Conclusions

More intensive LDL-C lowering was associated with a greater reduction in risk of total and cardiovascular mortality in trials of patients with higher baseline LDL-C levels than less intensive LDL-C lowering. Intensive lipid-lowering was associated with a significant risk reduction of coronary heart disease and must be considered even in the non-diabetic populations.

Intensive lipid-lowering therapy, time to think beyond low-density lipoprotein cholesterol

Statins have been shown to be effective in reducing cardiovascular events. Their magnitude of benefits has been proportionate to the reduction in low-density lipoprotein cholesterol (LDL-c). Intensive lipid-lowering therapies using ezetimibe and more recently proprotein convertase subtilisin kexin 9 inhibitors have further improved clinical outcomes. Unselective application of these treatments is undesirable and unaffordable and, therefore, has been guided by LDL-c level. Nonetheless, the residual risk in the post-statin era is markedly heterogeneous, including thrombosis and inflammation risks. Moreover, the lipo-protein related risk is increasingly recognised to be related to other non-LDL-c markers such as Lp(a). Emerging data show that intensive lipid-lowering therapy produce larger absolute risk reduction in patients with polyvascular disease, post coronary artery bypass graft and diabetes. Notably, these clinical entities share similar phenotype of large burden of atherosclerotic plaques. Novel plaque imaging may aid decision making by identifying patients with propensity to develop lipid rich plagues at multi-vascular sites. Those patients may be suitable candidates for intensive lipid lowering treatment.

Benefits of intensive lipid-lowering therapies in patients with acute coronary syndrome: a systematic review and meta-analysis

BACKGROUND

Previous meta-analyses have investigated the efficacy of lipid-lowering therapies for atherosclerotic cardiovascular disease; however, few have focused on patients with acute coronary syndrome (ACS). This meta-analysis aimed to compare the benefits of intensive lipid-lowering therapy with those of background statin therapy in patients with ACS.

METHODS

Searches were performed on PubMed, Embase, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov databases for articles published until April 13, 2023. Randomized controlled trials that compared intensive lipid-lowering therapies and background statin therapies in patients with prior ACS and recorded the outcome of three-point major cardiovascular events (MACE) were included. The risk ratio (RR) with 95% confidence interval (CI) was used as a measure of primary and secondary outcomes.

RESULTS

Nine trials involving 38,640 patients with ACS were identified. Pooled results suggested that intensive lipid-lowering therapies are associated with a reduction in the risk of three-point MACE (RR, 0.88; 95% CI, 0.83-0.94; p < 0.001), recurrent ACS (RR, 0.82; 95% CI, 0.71-0.96; p = 0.013), nonfatal myocardial infarction (MI) (RR, 0.87; 95% CI, 0.81-0.93; p < 0.001), stroke (RR, 0.83; 95% CI, 0.73-0.94; p = 0.003), and unstable angina-related hospitalization (RR, 0.57; 95% CI, 0.33-0.99; p = 0.046), but not all-cause mortality (RR, 0.94; 95% CI, 0.82-1.07; p = 0.329), cardiovascular disease-related mortality (RR, 0.96; 95% CI, 0.88-1.06; p = 0.457) or coronary revascularization (RR, 0.89; 95% CI, 0.79-1.00; p = 0.057).

CONCLUSIONS

Intensive lipid-lowering therapies may reduce the risk of three-point MACE, recurrent ACS, nonfatal MI, stroke, and hospitalization for unstable angina in patients with ACS undergoing background statin therapy. These results may assist in clinical decision-making for the secondary prevention of cardiovascular events to initiate intensive lipid-lowering therapies immediately after ACS.