【Abstract】
Objective: It remains unclear whether aggressive low-density lipoprotein cholesterol (LDL-C) management (<1.8 mmol/L) can slow the process of vein graft stenosis. This study aimed to explore the impact of baseline LDL-C levels on vein graft patency in patients on ticagrelor with or without aspirin 1 year after coronary artery bypass grafting (CABG).
Methods: This was a post hoc analysis of the DACAB trial (NCT02201771), a randomized controlled trial (ticagrelor+aspirin or ticagrelor vs. aspirin) of patients undergoing CABG in China. The study subjects were stratified as LDL-low (baseline LDL-C <1.8 mmol/L, 148 patients with 430 vein grafts) vs. LDL-high (baseline LDL-C ≥1.8 mmol/L, 352 patients with 1030 vein grafts). The primary outcome was the 1-year vein graft patency (Fitzgibbon grade A) assessed by coronary computed tomographic angiography or coronary angiography.
Results: Baseline/1-year LDL-C were 1.4/1.6 and 2.6/2.4 mmol/L in the LDL-low and LDL-high subgroups, respectively. Regardless of antiplatelet regimen, no significant inter-subgroup difference was observed for 1-year graft patency (LDL-low: 83.8% [359/430 grafts]; LDL-high: 82.3% [848/1030 grafts]; adjusted OR for non-patency (ORadj)=0.96, 95%CI: 0.62-1.50, P=0.857). For both subgroups, the 1-year graft patency rates were higher with ticagrelor+aspirin vs. aspirin (LDL-low: ORadj=0.41, 95%CI: 0.17-0.97; LDL-high: ORadj=0.38, 95%CI: 0.20-0.71; inter P=0.679).
Conclusions: In general, baseline LDL-C is not associated with 1-year vein graft patency after CABG. Regardless of the baseline LDL-C levels, ticagrelor + aspirin was superior to aspirin alone in maintaining vein graft patency. The primary factor causing early vein graft disease might not be atherosclerosis but thrombosis.
【中文摘要】
目的：目前，強化降脂治療（低密度脂蛋白膽固醇，LDL-C<1.8 mmol/L）對延緩靜脈橋血管狹窄的作用尚不明確。本研究旨在探索基線LDL-C水平對冠狀動脈旁路移植術（CABG）後不同抗血小板治療下1年靜脈橋血管通暢率的影響。
方法： DACAB研究（NCT 02201771）是針對中國CABG術後患者的一項前瞻性、隨機、對照的臨床試驗（替格瑞洛聯用阿司匹林或替格瑞洛單藥對比阿司匹林單藥），本研究為該臨床試驗的一項事後亞組分析。根據基線LDL-C水平，患者被分至LDL-low亞組（基線LDL-C <1.8 mmol/L， 148名患者，430 支靜脈橋血管）和LDL-high亞組（基線LDL-C ≥1.8 mmol/L，352名患者，1030 支靜脈橋血管）。主要終點為1年靜脈橋通暢率（Fitzgibbon A級，冠狀動脈CT血管成像或冠狀動脈造影評估）。
結果：LDL-low亞組和LDL-high亞組在基線/1年時的LDL-C水平分別為1.4/1.6和2.6/2.4mmol/L。無論抗血小板治療方案如何，兩亞組間均未觀察到1年橋血管通暢率的差異（LDL-low：83.8% [359/430 grafts]；LDL-high：82.3% [848/1030 grafts]；橋血管非通暢的校正後OR（ORadj）=0.96，95%CI：0.62-1.50，P=0.857）。在兩個亞組中，替格瑞洛聯用阿司匹林組的1年橋血管通暢率均高於阿司匹林單藥組（LDL-low：ORadj=0.41，95%CI：0.17-0.97；LDL-high：ORadj=0.38，95%CI：0.20-0.71；交互P=0.679）。
結論：LDL基線水平高低對術後1年隨訪時的靜脈橋血管通暢率的影響尚未產生統計學差異。無論基線LDL-C水平高低，替格瑞洛聯用阿司匹林相比阿司匹林單藥均可以提高CABG術後靜脈橋血管的1年通暢率。對靜脈橋血管的病變，早期的核心問題是血栓形成，晚期動脈粥樣硬化因素可能更為重要。