Introduction: Non-high-density-lipoprotein cholesterol (non-HDL-C) is a secondary therapeutic target in cardiovascular diseases and is used for residual risk assessment in patients with coronary artery syndrome (ACS). This study was designed to determine the association between non-HDL-C in patients with prior coronary artery bypass graft (CABG) with ACS and clinical outcomes.
Methods: We retrospectively analyzed 468 patients with prior CABG with ACS and categorized them into two groups based on the median non-HDL-C level. The primary endpoints were major adverse cardiovascular events (MACEs), including cardiovascular death and recurrent myocardial infarction. Kaplan–Meier curves, Cox proportional-hazard regressions, and restricted cubic splines were used to determine the association between non-HDL-C and MACEs. The discrimination and reclassification of the nomogram based on non-HDL-C were assessed using time-dependent receiver operating characteristic (ROC) curves and net reclassification improvement (NRI).
Results: During the average follow-up time of 744.5 days, non-HDL-C was independently associated with the occurrence of MACEs (hazard ratio [HR] = 5.01, 95% confidence interval [CI] = 1.65– 15.24; p = 0.005) after adjusting for other lipid parameters. The spline curves indicated a linear relationship between non-HDL-C and MACEs (p-nonlinear: 0.863). The time-dependent areas under the ROC curves of prior-CABG-ACS nomograms containing non-HDL regarding MACEs in two consecutive years were 91.7 (95% CI: 85.5– 97.9) and 91.5 (95% CI: 87.3– 95.7), respectively. The NRI analysis indicated that the prior-CABG-ACS model improved the reclassification ability for 1- and 2-year MACEs (22.4% and 7%, p < 0.05, respectively).
Discussion: Non-HDL is independently associated with the risk of MACEs in patients with prior CABG with ACS. The prior-CABG-ACS nomogram based on non-HDL-C and five convenient variables generates valid and stable predictions of MACE occurrence.
Keywords: non-HDL cholesterol, major adverse cardiovascular events, prior coronary artery bypass grafting, GRACE score