Abstract P268: Serum Lipids, Apolipoproteins, and Mortality among Coronary Artery Disease Patients
Authors: Ding Ding , Li Xinrui , Qiu Jian , Li Rui , Zhang Yuan , Su Dongfang , Li Zhongxia , Wang Min , Lv Xiaofei , Wang Dongliang , Yang Yan , Xia Min , Hu Gang , Ling Wenhua 
Published: July 2021

Background:
The proatherogenic effect of LDL cholesterol and antiatherogenic effect of HDL cholesterol have been confirmed in general population. But controversy arises on the protective role of HDL cholesterol and predictive superiority of apolipoprotein (apo)B among CAD patients.

Objectives:
This study was to identify the association of different lipid measurements with CAD prognosis and compare their prognostic significance.

Methods:
The study cohort included 1916 CAD patients who were 40-85 years of age. Cox proportional hazards regression models were used to estimate the association of baseline 6 lipid factors (HDL cholesterol, LDL cholesterol, total cholesterol, non-HDL cholesterol, apoA-I, and apoB) and 3 ratios with all-cause and CVD mortality.

Results:
During a median follow-up of 3.1 years, 147 deaths were recorded, 113 of which were due to CVD. When lipid factors were categorized, HDL cholesterol showed a U-shape association with all-cause and CVD mortality after adjustment for major CVD risk factors. The multivariable-adjusted hazard ratios in HDL cholesterol<40 mg/dL and ≥70 mg/dL groups were 2.09 (95% CI 1.37-3.20) and 3.06 (95% CI 1.08-8.70) for all-cause mortality, and 2.59 (95% CI 1.53-4.38) and 4.83 (95% CI 1.47-15.8) for CVD mortality, compared with HDL cholesterol between 40 and 49 mg/dL group. ApoA-I level was inversely associated with the risk of all-cause and CVD mortality. The multivariable-adjusted hazard ratios across quartiles of apoA-I were 1.00, 0.59 (95% CI 0.38-0.92), 0.43 (95% CI 0.26-0.70), and 0.56 (95% CI 0.35-0.88) for all-cause mortality (P for trend =0.004), and 1.00, 0.55 (95% CI 0.33-0.91), 0.39 (95% CI 0.22-0.70), and 0.57 (95% CI 0.34-0.95) for CVD mortality (P=0.007). Serum LDL cholesterol, apoB, LDL/HDL ratio, and apoB/apoA-I ratio were positively associated with the risk of CVD mortality. Patients with LDL cholesterol ≥190 mg/dL had a 4.35-fold risk of CVD mortality (95% CI 1.34-14.2) compared with patients with LDL cholesterol<70 mg/dL. Patients with apoB ≥110 mg/dL had a 2.06-fold risk of CVD mortality (95% CI 1.10-3.85) compared with patients with apoB<90 mg/dL. The multivariable-adjusted hazard ratios in highest quartiles of LDL/HDL ratio and apoB/apoA-I ratio were 1.61 (95% CI 1.01-2.56) and 2.00 (95% CI 1.21-3.31) for all-cause mortality, and 1.74 (95% CI 1.02-2.96) and 2.33 (95% CI 1.32-4.14) for CVD mortality compared with the lowest quartiles. After further pair-wise comparison, LDL/HDL ratio and LDL cholesterol had stronger associations with all-cause and CVD mortality than other proatherogenic measurements.

Conclusions:
There was a U-shape association between HDL cholesterol and CVD mortality among CAD patients. High levels of LDL cholesterol and apoB, high LDL/HDL ratio and apoB/apoA-I ratio, and low level of apoA-I were independently associated with an increased risk of CVD mortality among Chinese CAD patients.