Remnant Cholesterol as a Predictor of Cardiovascular Outcomes in Acute Coronary Syndrome Patients with Low-Density Lipoprotein Cholesterol Levels Below 1.8 mmol/L: Insights from the MPCS-ACS Study

Aims : This study aimed to investigate the influence of remnant cholesterol (RC) on the risk of cardiovascular events in patients with acute coronary syndrome (ACS) who have tightly controlled low-density lipoprotein cholesterol (LDL-C) levels. Methods : Analyzing data from the MPCS-ACS study, this investigation targeted individuals aged 18 to 79 diagnosed with ACS, who were admitted to three Chinese medical centers between June 2016 and May 2021, and who maintained LDL-C levels below 1.8 mmol/L. Results: Out of 17,500 screened patients, 4,329 were analyzed. RC levels were calculated, with patients then categorized into quartiles. The primary focus was on all-cause and cardiovascular mortality. Secondary objectives involved assessing the incidence of major adverse cardiovascular and cerebrovascular events (MACCE) as well as major adverse cardiovascular events (MACE). Through analysis of outcome events across different groups, coupled with multivariable adjustments and the use of restricted cubic splines, findings revealed that RC is a significant, independent risk factor for adverse outcomes in ACS patients when LDL-C levels are strictly controlled below 1.8 mmol/L, and this association remains significant even when LDL-C levels are further controlled below 1.4 mmol/L. Restricted cubic splines analysis illustrated a U-shaped, non-linear relationship between RC levels and endpoint events (all-cause and cardiovascular mortality, MACE, and MACCE), with the lowest risk observed at RC levels ranging from 0.29 to 0.45 mmol/L. Conclusions : The study identifies RC as an independent risk factor for cardiovascular complications and highlights its U-shaped correlation with adverse outcomes.