Inflammation drives residual risk in chronic kidney disease: a CANTOS substudy

Abstract Aims Hyperlipidaemia and inflammation jointly contribute to atherosclerotic disease. Yet, after the initiation of statin therapy, the relative contributions of these processes may differ in patient groups, such as those with and without impaired kidney function. Methods and results Among 9151 stable statin-treated post-myocardial infarction patients participating in the CANTOS trial, the contributions of residual cholesterol risk and residual inflammatory risk were evaluated as determinants of recurrent major adverse cardiovascular events (MACE) and total mortality, stratified by baseline estimated glomerular filtration rate (eGFR) above or below 60 mL/min/1.73 m2 using the race agnostic CKD-EPI 2021 formula (all participants had eGFR > 30 mL/min/1.73 m2). Analyses of residual inflammatory risk focused on high-sensitivity C-reactive protein (hsCRP) and interleukin-6 (IL-6) while analyses of residual cholesterol risk focused on LDL-cholesterol (LDL-C) and non-HDL-cholesterol (non-HDL-C). Participants were followed for a period of up to 5 years (median 3.7 years). Median baseline levels of LDL-C and hsCRP were 81 mg/dL and 4.2 mg/L. Among participants with eGFR ≥ 60 mL/min/1.73 m2, increasing quartiles of plasma hsCRP, IL-6, LDL-C, and non-HDL-C all positively associated with risks of recurrent MACE [hazard ratios (HR) comparing the top to bottom quartile for hsCRP 1.45; for IL-6 2.48; for LDL-C 1.64; and for non-HDL-C 1.68] (all P < 0.0001). By contrast, among those with eGFR < 60 mL/min/1.73 m2, increasing quartiles of hsCRP and IL-6 significantly predicted recurrent MACE [HR comparing the top to bottom quartile for hsCRP 1.50 (P = 0.021); for IL-6 1.84 (P = 0.048)], whereas increasing quartiles of LDL-C and non-HDL-C did not [HR comparing the top to bottom quartile for LDL-C 1.04 (P = 0.80); for non-HDL-C 0.98 (P = 0.88)]. The predictive utility of hsCRP and IL-6 in the setting of eGFR < 60 mL/min/1.73 m2 remained significant after adjustment for a wide range of potential confounding factors including age, sex, smoking status, blood pressure, body mass index, and diabetes. For the endpoint of total mortality, both hsCRP (HR 1.77, P = 0.0021) and IL-6 (HR 2.15, P = 0.015) were significant predictors among those with eGFR < 60 mL/min/1.73 m2, whereas LDL-C (HR 0.91, P = 0.56) and non-HDL-C (HR 0.85, P = 0.31) were not. Similar effects were observed in analyses stratified by the albumin to creatinine ratio rather than eGFR. Conclusion Among atherosclerosis patients with impaired kidney function already aggressively treated with statin therapy, residual inflammatory risk plays a substantial role in determining the risk of recurrent cardiovascular events. These data have implications for risk stratification of individuals with chronic kidney disease and for the development of novel agents that target inflammatory processes in this high-risk group of patients. Clinical Trial Registration ClinicalTrials.gov: NCT01327846