Impact of low-density lipoprotein cholesterol and lipoprotein(a) on mid-term clinical outcomes following coronary artery bypass grafting: A secondary analysis of the DACAB trial

Abstract

PurposeThe objective was to evaluate the influence of low-density lipoprotein cholesterol (LDL-C) and lipoprotein(a) [Lp(a)] on clinical outcomes in patients undergoing coronary artery bypass grafting (CABG).MethodsThis is a secondary analysis of a 5-year follow-up of the DACAB trial (NCT02201771), in which 500 patients who underwent primary isolated CABG were randomized to three-antiplatelet therapy for 1 year after surgery. Of them, 459 patients were recruited in this secondary analysis. Baseline LDL-C and Lp(a) levels were collected, and repeated measurement of LDL-C levels during the follow-up were recorded. Cut-off values for LDL-C were set at 1.8 and 2.6 mmol/L; thus, the patients were stratified into LDL-C <1.8, 1.8–<2.6, and ≥2.6 mmol/L subgroups. Cut-off value for Lp(a) was 30 mg/dL; thus, the patients were divided into Lp(a) <30 and ≥30 mg/dL subgroups. The primary outcome was 4-point major adverse cardiovascular events (MACE-4), a composite of all-cause death, myocardial infarction, stroke, and repeated revascularization. Median follow-up time was 5.2 (interquartile range, 4.2–6.1) years.ResultsDuring the follow-up, 129 (28.1%) patients achieved the attainment of LDL-C <1.8 mmol/L, 186 (40.5%) achieved LDL-C 1.8–<2.6 mmol/L, and 144 (31.4%) remained LDL-C ≥2.6 mmol/L. Compared with the postoperative LDL-C <1.8 mmol/L group, the risk of MACE-4 was significantly higher in the LDL-C 1.8–<2.6 mmol/L group [adjusted hazard ratio (aHR) = 1.92, 95% CI, 1.12–3.29; P = 0.019] and LDL-C ≥2.6 mmol/L group (aHR = 3.90, 95% CI, 2.29–6.64; P < 0.001). Baseline Lp(a) ≥30 mg/dL was identified in 131 (28.5%) patients and was associated with an increased risk of MACE-4 (aHR = 1.52, 95% CI, 1.06–2.18; P = 0.022).ConclusionsFor CABG patients, exposure to increased levels of postoperative LDL-C or baseline Lp(a) was associated with worse mid-term clinical outcomes. Our findings suggested the necessity of achieving LDL-C target and potential benefit of adding Lp(a) targeted lipid-lowering therapy in CABG population.

Impact of High Lipoprotein(a) on Long‐Term Survival Following Coronary Artery Bypass Grafting

“…However, only few studies including limited numbers of patients undergoing CABG revealed inconsistent results. 12 , 13 , 14 , 15 The distribution and prognostic implication of lipoprotein(a) in patients undergoing CABG are still largely unknown. Furthermore, much less attention has been paid to evaluating the influence of lipoprotein(a) on patients undergoing CABG with different levels of LDL‐C and different graft materials, which may be possible treatment options in the absence of approved lipoprotein(a)‐lowering therapy.…”