Meta-analysis Of The Effect Of High-intensity Statin Or Ticagrelor On Coronary Microvascular Dysfunction

Part 1:Effect of high-intensity statin pretreatment on coronary microvascular dysfunction in patients with coronary heart disease undergoing PCI:A meta-analysis of randomized controlled trialsAims:The purpose of this meta-analysis is to evaluate the role of high-intensity statin pretreatment on coronary microvascular dysfunction in patients with coronary heart disease undergoing percutaneous coronary intervention(PCI).Methods:Pub Med,Cochrane and Embase were searched.This meta-analysis selection included randomized controlled trials(RCTs),involving high-intensity statin pretreatment as active treatment,and measurement of thrombolysis in myocardial infarction(TIMI),myocardial blush grade(MBG)or index of microvascular resistance(IMR)in coronary heart disease patients undergoing PCI.I~2test was used to evaluate heterogeneity.Pooled effects of continuous variables were reported as Standard mean difference(SMD)and 95%confidence intervals(CI).Pooled effects of discontinuous variables were reported as risk ratios(RR)and 95%confidence intervals(CI).Random-effect or fix-effect meta-analyses were performed.Benefit was further examined based on clinical characteristics including diagnosis and statin type by using subgroup analyses.Publication bias was examined by quantitative Egger’s test and funnel plot.We performed sensitivity analyses to examine the robustness of pooled effects.Results:Twenty RCTs were enrolled.The data on TIMI<3 was reported in 18 studies.Comparing with non-high-intensity statin,high-intensity statin pretreatment significantly improved TIMI after PCI(RR=0.62,95%CI:0.50 to 0.78,P<0.0001).The data on MBG<2 was reported in 3 studies.The rate of MBG<2 was not different between groups(RR=1.29,95%CI:0.87 to 1.93,P=0.21).The data on IMR was reported in 2 studies.High-dose statin pretreatment significantly improved IMR after PCI comparing with non-high-dose statin(SMD=-0.94,95%CI:-1.47 to-0.42,P=0.0004).There were no significant between-subgroup differences in subgroups based on statin type and diagnosis.Publication bias was not indicated by using quantitative Egger’s test(P=0.97)and funnel plot.Sensitivity analyses confirmed the robustness of these findings.Conclusions:Comparing with non-high-intensity statin,high-intensity statin pretreatment significantly improved TIMI and IMR after PCI.In the future,RCTs with high quality and large sample are needed to test these endpoints.Part 2: Effect of ticagrelor treatment on coronary microvascular dysfunction in acute coronary syndrome patients undergoing PCI: A meta-analysis of randomized controlled trialsAims: The purpose of this meta-analysis is to evaluate whether ticagrelor can effectively improve coronary microvascular dysfunction in acute coronary syndrome(ACS)patients undergoing PCI comparing with clopidogrel.Methods: Pub Med,Cochrane,Embase,CNKI and Wanfang were searched.This meta-analysis selection included randomized controlled trials(RCTs),involving ticagrelor treatment as active treatment,and measurement of index of microvascular resistance(IMR)in ACS patients undergoing PCI.I2 test was used to evaluate heterogeneity.Pooled effects of continuous variables were reported as standard mean difference(SMD)and 95% confidence intervals(CI).Random-effect or fix-effect meta-analyses were performed.Sensitivity analyses were conducted to test the robustness of pooled effects.Results: Four RCTs were enrolled.The data on IMR immediately after PCI was reported in 4 studies.Ticagrelor significantly reduced IMR immediately after PCI in patients with ACS comparing with clopidogrel(SMD=-0.51,95% CI:-0.88 to-0.15,P=0.005).The data on IMR after 6 months of treatment was reported in 2 studies.Ticagrelor significantly reduced IMR after 6 months of treatment in patients with ACS comparing with clopidogrel(SMD=-0.76,95% CI:-1.07 to-0.45,P < 0.00001).In the sensitivity analysis,after excluding Park(2016),the pooled results of IMR immediately after PCI still showed a decreasing trend,but the difference was not significant.However,the results of IMR after 6months of treatment were unchanged.Conclusion: Comparing with clopidogrel,ticagrelor significantly reduced the IMR immediately after PCI and IMR after 6 months of treatment.However,RCTs with high quality and large sample are needed to test these endpoints.