Background/Aim
The efficacy of lipid-lowering therapies (LLT) among different ethnicities and regions remains unclear. We aimed to assess cardiovascular event reductions associated with LLT according to ethnicity and region in previously published randomized clinical trials (RCTs).
Methods
Medline, EMBASE and Cochrane CENTRAL were searched for RCTs of statins, ezetimibe or proprotein convertase subtilisin/kexin type 9 inhibitors comparing intensive versus less intensive low-density lipoprotein cholesterol (LDL-C) lowering. The primary endpoint was major adverse cardiovascular events (MACE) defined as the composite of cardiovascular mortality, myocardial infarction, stroke and revascularisation. Random effects meta-analysis was used to pool risk ratios (RR) with 95% confidence intervals (CI) adjusted per mmol/L reduction in LDL-C.
Results
Fifty-three trials with 329,897 participants were included. Among participants, 39.5% were from Europe, 16.0% from North America, 9.0% from Japan, 2.8% from Australasia, 1.8% from South America, 1.1% from Asia, 0.6% from South Africa and 29.2% were unspecified. Among trials reporting ethnicities, there were 60.3% White, 20.2% Japanese, 9.4% Asian, 5.5% Black and 4.7% Latin American. There was reduction in MACE with LLT in regions including Australasia (RR 0.75, 95% CI 0.67-0.85), North America (RR 0.75, 95% CI 0.69-0.83), Europe (RR 0.78, 95% CI 0.71-0.86) and Japan (RR 0.73, 95% CI 0.63-0.85), and in Black ethnicity (RR 0.55, 95% CI 0.37-0.82). Head-to-head comparisons between regions and ethnicities revealed no significant differences in MACE reduction.
Conclusions
Despite underrepresentation in clinical trials, regional and ethnic minority groups such as Australasia and Blacks appear to derive at least as much cardiovascular benefit from LLT.