Background:Ticagrelor reduced the rate of myocardial infarction and death compared with clopidogrel in patients with acute coronary syndrome. However, little is understood about chronic treatment of ticagrelor on microvascular dysfunction. The objective of this study was to assess the impact of ticagrelor maintenance treatment on microvascular system and coronary flow in comparison with clopidogrel.Methods:This study was a nonblinded, open-label, parallel-group, prospective, randomized controlled trial that enrolled 120 patients with acute coronary syndrome requiring stent implantation. Patients were randomized into the ticagrelor (180 mg loading dose, 90 mg twice daily thereafter) or clopidogrel (300 to 600 mg loading dose, 75 mg daily thereafter) group. The primary end point was coronary microvascular dysfunction as measured by an index of microcirculatory resistance (IMR) at 6 months after treatment.Results:The baseline clinical characteristics and physiological parameters, such as fractional flow reserve, coronary flow reserve, and IMR, did not differ between the ticagrelor and clopidogrel groups. Six-month follow-up physiological data showed that the IMR value was significantly lower in the ticagrelor group than the clopidogrel group (15.57±5.65 versus 21.15±8.39, P<0.01), and coronary flow reserve was higher in the ticagrelor group than in the clopidogrel group (3.85±0.72 versus 3.37±0.76, P<0.01). However, there was no difference in fractional flow reserve (0.87±0.08 versus 0.87±0.09, P=0.94) between the 2 groups. The improvement in IMR after 6 months of treatment was higher in the ticagrelor group (P<0.01). Analyses of 223 nonculprit vessels of registered patients based on physiological results showed no differences in baseline fractional flow reserve (0.93±0.13 versus 0.92±0.09, P=0.58), coronary flow reserve (3.62±1.27 versus 3.51±1.24, P=0.16), or IMR (21.37±12.37 versus 24.19±21.08, P=0.22) or in follow-up fractional flow reserve (0.91±0.09 versus 0.91±0.08, P=0.67), coronary flow reserve (3.91±1.22 versus 3.75±1.16, P=0.36), or IMR (19.43±10.32 versus 21.52±18.90, P=0.34) between the 2 groups.Conclusions:Compared with clopidogrel, 6 months of ticagrelor therapy significantly improved microvascular dysfunction in acute coronary syndrome patients with stent implantation.Clinical Trial Registration:URL: https://www.clinicaltrials.gov. Unique identifier: NCT02618733.

中文翻译：

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使用侵入性生理指标比较替卡格雷洛和氯吡格雷对急性冠脉综合征患者微血管功能障碍的影响。

背景：与氯吡格雷相比，替加格雷洛降低了急性冠脉综合征患者的心肌梗塞和死亡率。然而，关于替卡格雷的微血管功能障碍的慢性治疗知之甚少。这项研究的目的是评估氯吡格雷与氯吡格雷相比对替格瑞洛维持治疗对微血管系统和冠状动脉血流的影响。方法：本研究是一项无盲，开放标签，平行分组，前瞻性，随机对照试验，招募了120名患者急性冠脉综合征需要支架植入。患者被随机分为替卡格雷（180 mg负荷剂量，此后每天90 mg，每日两次）或氯吡格雷（300至600 mg负荷剂量，此后每天75 mg）组。主要终点是治疗后6个月时通过微循环阻力指数（IMR）测得的冠状动脉微血管功能障碍。结果：基线临床特征和生理参数（例如分流储备，冠状动脉血流储备和IMR）没有替卡格雷和氯吡格雷组之间存在差异。六个月的随访生理数据显示，替卡格雷组的IMR值明显低于氯吡格雷组（15.57±5.65对21.15±8.39，P <0.01），替卡格雷组的冠状动脉血流储备高于氯吡格雷组（3.85±0.72 vs 3.37±0.76，P <0.01）。但是，两组之间的分流储备没有差异（0.87±0.08对0.87±0.09，P = 0.94）。替卡格雷组治疗6个月后IMR的改善更高（P <0.01）。根据生理结果对注册患者的223例非罪犯血管进行的分析显示，基线分数血流储备（0.93±0.13对0.92±0.09，P = 0.58），冠状动脉血流储备（3.62±1.27对3.51±1.24，P = 0.16）没有差异或IMR（21.37±12.37与24.19±21.08，P= 0.22）或随访分数血流储备（0.91±0.09对0.91±0.08，P = 0.67），冠状动脉血流储备（3.91±1.22对3.75±1.16，P = 0.36）或IMR（19.43±10.32对21.52）两组之间的差异为±18.90，P = 0.34）结论：与氯吡格雷相比，替卡格雷治疗6个月可显着改善急性冠脉综合征综合征置入支架患者的微血管功能障碍。临床试验注册：URL：https：//www.clinicaltrials。政府 唯一标识符：NCT02618733。