P2334
Association between cholesterol efflux capacity and coronary plaque lipid composition on near infrared spectroscopy

Extract

Background: High-density lipoprotein (HDL) has several atheroprotective properties. The capacity of HDL to promote cell cholesterol efflux associates with future cardiovascular events. Near Infrared Spectroscopy (NIRS) quantitates lipid content within plaque. However, little is known about the impact of HDL functionality on coronary plaques.

Purpose: We examined the association of HDL-mediated cholesterol efflux capacity (CEC) with the characteristics of NIRS.

Methods: 74 patients who underwent NIRS-intravascular ultrasound (IVUS) imaging for acute coronary syndrome or stable angina pectoris were examined. In the current NIRS-IVUS analysis, coronary plaque lipid burden [lipid core burden index (LCBI) and LCBI at the 4mm maximal segment (LCBI4mm max)] and atheroma volume were assessed. We measured ATP-binding cassette A1 (ABCA1)-, and ATP-binding cassette G1 (ABCG1)-mediated CEC of serum in cellular systems.

Results: The mean age was 60 years and 27% were female. Over 75% of plaques with above the median of LCBI4mm max were located within left anterior descending artery. Patients with LCBI4mm max >median demonstrated greater levels of triglyceride (142 vs. 124 mg/dL P=0.04) and percent atheroma volume (35.8±8.8% vs. 30.0±9.9%, P=0.01). In the whole cohort, LCBI4mm max did not correlate with CEC via ABCA1 (r=0.06, P=0.60) or ABCG1 (r=0.05, P=0.66). Similarly, mean LCBI throughout the pullback did not correlate with CEC via ABCA1 (r=0.02, P=0.84) or ABCG1 (r=0.09, P=0.42). However, ABCA1 mediated CEC inversely correlated with LCBI4mm max in patients with baseline LCBI4mm max ≤median (r=-0.34, P=0.04), but not in those with greater LCBI4mm max levels (r=0.05, P=0.78). In contrast, HDL-C did not correlate with LCBI4mm max at any level.