Initial decrease in the lipoprotein(a) level is a novel prognostic biomarker in patients with acute coronary syndrome

Abstract

BACKGROUND Lipoprotein(a) [Lp(a)] is a causal risk factor for atherosclerotic cardiovascular diseases; however, its role in acute coronary syndrome (ACS) remains unclear. AIM To investigate the hypothesis that the Lp(a) levels are altered by various conditions during the acute phase of ACS, resulting in subsequent cardiovascular events. METHODS From September 2009 to May 2016, 377 patients with ACS who underwent emergent coronary angiography, and 249 who completed ≥ 1000 d of follow-up were enrolled. Lp(a) levels were measured using an isoform-independent assay at each time point from before percutaneous coronary intervention (PCI) to 48 h after PCI. The primary endpoint was the occurrence of major adverse cardiac events (MACE; cardiac death, other vascular death, ACS, and non-cardiac vascular events). RESULTS The mean circulating Lp(a) level decreased significantly from pre-PCI (0 h) to 12 h after (19.0 mg/dL to 17.8 mg/dL, P < 0.001), and then increased significantly up to 48 h after (19.3 mg/dL, P < 0.001). The changes from 0 to 12 h [Lp(a)Δ0-12] significantly correlated with the basal levels of creatinine [Spearman’s rank correlation coefficient (SRCC): -0.181, P < 0.01] and Lp(a) (SRCC: -0.306, P < 0.05). Among the tertiles classified according to Lp(a)Δ0-12, MACE was significantly more frequent in the lowest Lp(a)Δ0-12 group than in the remaining two tertile groups (66.2% vs 53.6%, P = 0.034). A multivariate analysis revealed that Lp(a)Δ0-12 [hazard ratio (HR): 0.96, 95% confidence interval (95%CI): 0.92-0.99] and basal creatinine (HR: 1.13, 95%CI: 1.05-1.22) were independent determinants of subsequent MACE. CONCLUSION Circulating Lp(a) levels in patients with ACS decreased significantly after emergent PCI, and a greater decrease was independently associated with a worse prognosis.