Prognostic impact of lipoprotein(a) in patients undergoing percutaneous coronary intervention modified by low density lipoprotein cholesterol

Background: It is well established that lipoprotein(a)[Lp(a)] and low-density lipoprotein cholesterol (LDL-C) play a vital role in atherosclerosis. We investigated the prevalence and prognostic implications of increased Lp(a) in patients undergoing percutaneous coronary intervention (PCI) according to different LDL-C concentrations.Methods: A total of 9,190 patients with CAD after PCI were consecutively enrolled in the study and subsequently divided into three groups according to baseline LDL-C at cut-off of 70 and 100 mg/dl. Increased Lp(a) was defined as > 30 mg/dl. The primary endpoint was all-cause death. Second endpoint was cardiac death. Cox regression, Kaplan-Meier and Sensitivity analysis were performed.Results: During an average of 5.0 y of follow-up, 354 (3.9 %) patients experienced all-cause death with 213(2.3 %) of whom from cardiac death. Increased Lp(a) was present in 25.7 %, 34.2 %, and 40.6 % across the LDL-C < 70, 70-100 and >= 100 mg/dl groups, respectively. After multivariate adjustment, Lp(a) elevation remained significantly associated with 5-y all-cause death (adjusted HR, 1.243; 95 % CI 1.001-1.544; p = 0.048) in the total cohort and only in those with LDL-C >= 100 mg/dl (adjusted HR, 1.642; 95 % CI 1.139-2.367; p = 0.008) when analyzed within each LDL-C category. Consistently with the results of associations between Lp(a) and cardiac death (adjusted HR, 1.534; 95 % CI 1.164-2.021; p = 0.002 for total cohort and adjusted HR, 2.404; 95 % CI 1.439-3.872; p < 0.001 for LDL-C >= 100 mg/dl). And this relationship holds after adjusting for LDL-Ccorr additionally. These findings are confirmed again in sensitivity analyses that excluded patients with Lp(a) con-centrations in the top or the bottom 5 %.Conclusions: We confirmed that increased Lp(a) was associated with increased risk of long-term outcomes, and such an association was modified by the baseline LDL-C concentrations. Screening of high Lp(a) in individuals with elevations of LDL-C may enables risk stratification for poor prognosis.