Lipoprotein(a), high-sensitive c reactive protein, and long-term survival after coronary artery bypass grafting

Background Lipoprotein(a)[Lp(a)] is a possible causal risk factor for atherosclerotic cardiovascular disease (ASCVD). However, whether inflammation levels modulate the association between Lp(a) and long-term prognosis in patients undergoing coronary artery bypass grafting (CABG) remains unclear. Methods Adult patients with baseline measurements of both Lp(a) and high-sensitivity C-reactive protein (hs-CRP) who underwent primary isolated CABG from January 2013 to December 2018 were included. The primary outcome was all-cause death. Kaplan-Meier curves, log-rank test, and Cox proportional hazard regression were used for statistical calculation. Results Among 14,685 CABG patients in this study, 3,507 (23.8%) had high Lp(a) (≥ 50 mg/dL) group, and 5,917 (40.2%) had high hs-CRP (≥ 2 mg/L) values. The median follow-up time was 3.2 years, during which 436 patients experienced the primary outcome. After multivariate adjustment, the risk of all-cause death after CABG was associated with both high Lp(a) (adjusted hazard ratio [aHR]: 1.245, 95% confidence interval [CI]:1.003-1.546) and high hs-CRP (aHR: 1.258, 95% CI: 1.036-1.526). Kaplan-Meier analysis indicated that elevated levels of both Lp(a) and hs-CRP increased the risk of all-cause death (log-rank test P < 0.001). In patients with hs-CRP < 2 mg/L, elevated Lp(a) levels remained significantly associated with all-cause death risk (aHR: 1.516, 95% CI: 1.126-2.040). However, no significant association was found between the high-Lp(a) group and all-cause death in patients with hs-CRP≥ 2 mg/L (aHR: 0.962, 95% CI: 0.698-1.325, P for interaction = 0.102). Conclusion Both high Lp(a) and hs-CRP are associated with poor prognosis in patients undergoing CABG. The relationship between elevated Lp(a) and poor prognosis seemed diminished in patients with hs-CRP ≥ 2 mg/L.KM curve for death, Lp(a), and hs-CRP Lp(a), death and different hs-CRP levels