Remnant cholesterol and long-term incidence of death in coronary artery disease patients

Background: Remnant cholesterol (RC), defined as non-HDL-non-LDL cholesterol, has attracted recent scientific interest as a candidate lipid factor for residual cardiovascular risk. Despite a rising amount of epidemiologic information, there are imprecisions because most available data arise from non-fasting, frozen and calculated values.

Methods: We enrolled 1474 consecutive patients with angiographically proven CAD, and measured RC in strictly fasting, non-frozen samples with a direct assay for LDL-C. Prospectively, all-cause mortality, cardiovascular mortality, and major adverse cardiovascular events (MACE) were recorded over a mean follow-up period of 11.6 ± 5.0 years, covering 17098 patient years.

Results: During follow-up, CAD patients had a rate of all-cause mortality of 52.2 % (n = 769), of cardiovascular mortality of 20.6 % (n = 303), and an incidence of major adverse cardiovascular events (MACE) of 39.1 % (n = 576). Prospectively, RC was associated with all-cause mortality (HR 1.12 [1.03-1.23], p = 0.009), cardiovascular mortality (HR 1.20 [1.06-1.36], p = 0.005), and MACE (HR 1.10 [1.01-1.21], p = 0.033) in Cox regression analyses across various levels of adjustment (age, sex, smoking, LDL-C, HDL-C, hypertension, T2DM, and BMI). Findings did not differ between women and men. Furthermore, there was no discernible influence of statin treatment.

Conclusions: From our data we conclude that RC is associated with future all-cause mortality, cardiovascular mortality and MACE in patients with established coronary artery disease. Proper pre-analytic and analytic methods provided, RC represents a reliable indicator of residual risk.