Department of Cardiology, Institute of Cellular Medicine, Newcastle University and Cardiothoracic Centre, Freeman Hospital, Newcastle Upon Tyne Hospitals National Health Service Foundation Trust, Newcastle Upon Tyne, United Kingdom.
JACC Cardiovasc Interv. 2013 Jul;6(7):671-83. doi: 10.1016/j.jcin.2013.03.014.
The PLATO (Platelet Inhibition and Patient Outcomes) angiographic substudy sought to compare the efficacy of ticagrelor versus clopidogrel with respect to angiographic outcomes before and after PCI in the setting of acute coronary syndrome.
Greater platelet inhibition has been associated with improved angiographic outcomes before and after percutaneous coronary intervention (PCI). Therefore, it was hypothesized that treatment with ticagrelor, which achieves more rapid, higher, and more consistent platelet inhibition, would be associated with improved angiographic outcomes when compared with those of clopidogrel treatment.
The angiographic cohort consists of 2,616 patients drawn from the 18,624-patient PLATO trial. Clopidogrel naïve or pre-treated patients were randomized to 180 mg of ticagrelor or 300 mg of clopidogrel (75 mg for clopidogrel pre-treated patients). PCI patients were administered, as per treatment group: 1) an additional 90 mg of ticagrelor if >24 h following the initial loading dose; or 2) an optional further 300 mg of clopidogrel or placebo (total 600 mg) prior to PCI. The substudy primary endpoint was the incidence of post-PCI TIMI (Thrombolysis In Myocardial Infarction) myocardial perfusion grade 3 (TMPG 3) among patients who received a study drug prior to PCI.
In total, 21.3% of patients were pretreated with clopidogrel prior to randomization. There was a short time interval between randomization and PCI (median: 0.68 [interquartile range (IQR): 0.30 to 2.21] h) among all patients. Post-PCI TMPG 3 was similar between the ticagrelor and clopidogrel groups (47.1% vs. 46.9%; p = 0.96). Likewise, the following pre-PCI outcomes were similar in the ticagrelor and clopidogrel groups, respectively: TMPG 3 (30.5% vs. 31.2%), TIMI flow grade 3 (37.1% vs. 39.3%), corrected TIMI frame count (median: 100 vs. 71 frames), TIMI thrombus grade 0 (24.1% vs. 27.6%), minimum lumen diameter (median: 0.3 [IQR: 0.0 to 0.6] vs. 0.3 [IQR: 0.0 to 0.6] mm) and percentage of diameter stenosis (median: 89 [IQR: 78 to 100] vs. 89 [IQR: 77 to 100]).
Neither coronary flow nor myocardial perfusion, evaluated on coronary angiograms performed before or following PCI procedures within a few hours after the start of oral antiplatelet treatment in the setting of acute coronary syndromes, demonstrated a difference with ticagrelor versus clopidogrel. (A Comparison of Ticagrelor [AZD6140] and Clopidogrel in Patients With Acute Coronary Syndrome [PLATO]; NCT00391872).
PLATO（血小板抑制和患者结局）血管造影子研究旨在比较在急性冠状动脉综合征患者经皮冠状动脉介入治疗（PCI）前后，替格瑞洛与氯吡格雷在血管造影结局方面的疗效。
更高的血小板抑制与经皮冠状动脉介入治疗（PCI）前后的血管造影结局改善相关。因此，假设与氯吡格雷治疗相比，替格瑞洛可实现更快、更高、更一致的血小板抑制，将与改善的血管造影结局相关。
血管造影队列包括来自 18624 例患者的 PLATO 试验中的 2616 例患者。氯吡格雷初治或预处理的患者被随机分配接受 180mg 替格瑞洛或 300mg 氯吡格雷（氯吡格雷预处理患者给予 75mg）。PCI 患者按治疗组给予以下药物：1）替格瑞洛初始负荷剂量后>24 小时给予额外的 90mg；或 2）在 PCI 前给予可选的进一步 300mg 氯吡格雷或安慰剂（总计 600mg）。子研究的主要终点是在 PCI 前接受研究药物的患者中，PCI 后 TIMI（血栓溶解心肌梗死）心肌灌注分级 3（TMPG 3）的发生率。
总共，21.3%的患者在随机分组前接受了氯吡格雷预处理。所有患者的随机分组和 PCI 之间的时间间隔很短（中位数：0.68 [四分位距（IQR）：0.30 至 2.21]小时）。替格瑞洛组和氯吡格雷组的 PCI 后 TMPG 3 相似（47.1%对 46.9%；p=0.96）。同样，替格瑞洛组和氯吡格雷组分别具有相似的以下 PCI 前结局：TMPG 3（30.5%对 31.2%），TIMI 血流分级 3（37.1%对 39.3%），校正 TIMI 帧数（中位数：100 对 71 帧），TIMI 血栓分级 0（24.1%对 27.6%），最小管腔直径（中位数：0.3 [IQR：0.0 至 0.6]对 0.3 [IQR：0.0 至 0.6]mm）和直径狭窄率（中位数：89 [IQR：78 至 100]对 89 [IQR：77 至 100]）。
在急性冠状动脉综合征患者口服抗血小板治疗开始后数小时内进行的 PCI 前后的冠状动脉造影中，既未观察到替格瑞洛与氯吡格雷之间的冠状动脉血流或心肌灌注存在差异。（替格瑞洛[AZD6140]与氯吡格雷在急性冠状动脉综合征患者中的比较[PLATO]；NCT00391872）。
