Residual inflammatory risk after contemporary lipid lowering therapy

Abstract

Background: Recently, there has been an increasing interest in targeting inflammation to reduce major adverse cardiovascular events (MACE) in patients with cardiovascular risk. Statins, PCSK9 inhibitors, and ezetimibe have been shown to reduce MACE owing to reduction in low-density lipoproteins cholesterol (LDL-c). Herein, we investigate whether the intensity of these agents is associated with (i) discernible reduction in inflammation measured by the levels of high-sensitivity C-reactive protein (hsCRP); (ii) reduction in MACE; (iii) if there is an association between the baseline hsCRP and MACE.

Methods and results: Electronic databases were searched for randomized controlled trials (RCTs) that compared statins, ezetimibe, PCSK9 inhibitors with placebos/active controls and reported MACEs and hsCRP (mg/L). Studies were stratified based on baseline hsCRP (<2, 2-3, >3) with subgroup analysis conducted across each stratum. Fourteen RCTs including 133 109 patients randomized into more intensive therapy (MIT) and less intensive therapy were selected. Meta-analysis did not demonstrate any significant differences between use of MIT and hsCRP levels (mean difference, -0.02; CI, -0.06, 0.02; P = 0.31). The MIT significantly reduced the risk of MACE (RR, 0.82; CI, 0.75, 0.91; P < 0.001). The relative risk and absolute risk remained consistent across the strata. However, there was a 0.5% statistically significant absolute risk reduction in all-cause mortality in patients with higher hsCRP (RD, -0.005; CI, -0.009, -0.001; P = 0.01).

Conclusion: Overall, LDL-c lowering therapies reduce relative risk of MACEs particularly in patients with higher baseline hsCRP. However, there appears to be a residual inflammatory risk despite the use of contemporary lipid lowering agents.

Keywords: Inflammation; Myocardial infarction; Randomized control trials; Stroke.