Abstract 13072: Association Between Baseline Lipoprotein(a) and Five-Year Outcomes in Patients Underwent Coronary Artery Bypass Grafting: A Post-Hoc Analysis of DACAB Trial

Abstract

Introduction: Serum lipoprotein(a) [Lp(a)] is genetically determined and has been proposed to be associated with coronary artery lesion severity and clinical outcomes in coronary artery disease (CAD). But some researches suggested heterogeneous effects and marked variations of Lp(a) level between ethnic groups. The aim of this study was to investigate the impact of baseline Lp(a) on five-year clinical outcomes in Chinese population who underwent coronary artery bypass grafting (CABG). Methods: We performed a post-hoc analysis of the DACAB trial (NCT02201771), in which patients aged 18 to 80 years, male or female, underwent primary, isolated and elective CABG, were randomly assigned to receive different antiplatelet treatments. Serum Lp(a) was obtained and analyzed in 270/272 patients of one single center. The primary outcome was major adverse cardiovascular events (MACE). MACE-5 included all-cause death, myocardial infarction, stroke, repeated revascularization and rehospitalization for unstable angina, and MACE-3 included cardiovascular death, myocardial infarction, and stroke. The mean follow-up reached 59.4±9.4 months. Results: The baseline characteristics were generally comparable. High Lp(a) level was identified in 71 (26.3%) (cut-off ≥30mg/dL) and 33 (12.2%) (cut-off ≥50mg/dL) patients, respectively. During 5-year follow-up, MACE-5 reported in high and low Lp(a) group were 34.2% vs 28.8% when the cut-off value was 30mg/dL (hazard ratio [HR], 1.11; 95% CI, 0.69-1.78, p=0.66). While the cut-off value was 50mg/dL, MACE-5 reported in high and low Lp(a) group were 39.4% vs 28.9% (HR, 1.32; 95% CI, 0.73-2.38, p=0.36). Similar results were observed in MACE-3 (Cut-off value 30mg/dL: 24.2% vs 21.9%, HR 1.08, p=0.78; Cut-off value 50mg/dL: 27.3% vs 21.8%, HR 1.24, p=0.56). No statistical significant difference was achieved between the two groups. Conclusions: In this single center post-hoc analysis, baseline Lp(a) level ≥30mg/dL or ≥50mg/dL had no statistical significant association with 5-year MACE in post-CABG Chinese population. But higher baseline Lp(a) levels seem to be associated with more MACE in longer follow-up. Larger sample size from multicenter are needed to confirm our findings.