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Impact of Ticagrelor Versus Clopidogrel on Coronary Microvascular Function After Non-ST-Segment-Elevation Acute
James Xu1,2, Sidney Lo1,2, Christian J Mussap1,2
1Department of Cardiology, Liverpool Hospital, Sydney, Australia (J.X., S.L., C.J.M., J.K.P., R.P.).
Insights
Ticagrelor improved coronary microvascular function in non-ST-segment-elevation acute coronary syndrome patients compared to clopidogrel. This study evaluated the acute effects of ticagrelor versus clopidogrel pretreatment on coronary microvascular function.
Area of Science:
- Cardiology
- Vascular Biology
- Pharmacology
Background:
- Coronary microvascular dysfunction impacts prognosis after acute coronary syndrome.
- Limited data exists on P2Y12-inhibitors' effects on microvascular function in non-ST-segment-elevation acute coronary syndrome (NSTE-ACS).
Purpose of the Study:
- To compare the acute effects of ticagrelor versus clopidogrel pretreatment on coronary microvascular function in NSTE-ACS patients.
Main Methods:
- Randomized trial comparing ticagrelor and clopidogrel in NSTE-ACS patients.
- Intracoronary pressure-temperature sensor-tipped wire used to measure index of microcirculatory resistance, coronary flow reserve, and resistive reserve ratio.
Main Results:
- Ticagrelor group showed lower baseline and post-PCI index of microcirculatory resistance and higher resistive reserve ratio compared to clopidogrel.
- No significant difference in coronary flow reserve between groups.
- No differences observed in the non-infarct-related artery.
Conclusions:
- Ticagrelor significantly improved coronary microvascular function in NSTE-ACS patients before and after percutaneous coronary intervention (PCI) compared to clopidogrel.
Background:
Coronary microvascular dysfunction after acute coronary syndrome is an important predictor of long-term prognosis. Data is lacking on the effects of oral P2Y12-inhibitors on coronary microvascular function in non-ST-segment-elevation acute coronary syndrome. The aim of this study was to compare the acute effects of ticagrelor versus clopidogrel pretreatment on coronary microvascular function in non-ST-segment-elevation acute coronary syndrome patients.
Methods:
Hospitalized non-ST-segment-elevation acute coronary syndrome patients were randomized (1:1) to ticagrelor or clopidogrel. The index of microcirculatory resistance, coronary flow reserve, and resistive reserve ratio were obtained using an intracoronary pressure-temperature sensor-tipped wire.
Results:
In total, 128 patients were randomized between March 2018 and July 2020. Mean age 59.2±11.8 years, 84% were male, mean Global Registry of Acute Coronary Events score was 93.7±24.5. Intracoronary physiological measurements were obtained in 118 patients (60 ticagrelor, 58 clopidogrel). In the infarct-related artery, the ticagrelor group had lower baseline index of microcirculatory resistance (22.0 [13.0-34.9] versus 27.7 [19.3-29.8]; P=0.02) and higher baseline resistive reserve ratio (3.0 [2.3-4.4] versus 2.4 [1.7-3.4]; P=0.01) compared with the clopidogrel group. A total of 88 patients underwent percutaneous coronary intervention (PCI; 45 ticagrelor, 43 clopidogrel). The ticagrelor group had lower post-PCI index of microcirculatory resistance (22.0 [15.0-29.0] versus 27.0 [18.5-47.5]; P=0.02) and higher post-PCI resistive reserve ratio (3.0 [1.8-3.8] versus 1.8 [1.5-3.4]; P=0.006) compared with the clopidogrel group. The coronary flow reserve was not significantly different between the 2 groups at baseline or post-PCI. No between-group differences were seen in any of the indices in the non-infarct-related artery.
Conclusions:
In non-ST-segment-elevation acute coronary syndrome patients, ticagrelor significantly improved coronary microvascular function before and after PCI compared with clopidogrel.
Registration:
URL: https://www.anzctr.org.au; Unique identifier: ACTRN12618001610224.
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