RHI As A Predictor For MACEs In Patients With Acute Cornoary Syndrome Treated By Percutaneous Coronary Intervention

BackgroudAcute coronary syndrome(ACS)is one of the cardiovascular critical illnesses in cardiology with extremely high morbidity and mortality events.Although rapid development has been made in percutaneous coronary intervention(PCI),which significantly reduces patients' mortality and improves patients' outcomes.The incidence of major adverse cardiovascular events(MACEs)in patients with ACS after PCI is still high,and even the late stent thrombosis of drug-eluting stents(DES)somewhat offsets the benefits of preventing in-stent restenosis.Endothelial dysfunction has been demonstrated to be an essential step in occurrence and progression of atherosclerosis which participates in the occurrence,development and clinical complications of arteriosclerosis.It also has been considered to play an important role in ACS.Numerous studies have indicated that the practical applications of reactive hyperemia index(RHI)measured by RH-PAT can independently predict the risk of future cardiovascular events in comparison with traditional risk factors.The decrease in RHI is closely related to MACEs in patients with coronary heart disease.Although several studies have indicated the practical applications of RH-PAT,the role of RHI in MACEs among ACS patients treated with PCI has not been confirmed.Thus,we postulate that RHI may be a predictor of MACEs in ACS patients who are treated with PCI.ObjectiveIdentify the predictive role of endothelial function assessed by the RH-PAT index(RHI)for future MACEs in ACS patients treated with PCI.MethodsFrom December 1,2015 to September 8,2016,312 consecutive patients with ACS who underwent PCI were enrolled in our department.All subjects were tested for RHI using Endo-PAT2000.Patients were divided into normal endothelial function(NEF,RHI?1.67)group and endothelial dysfunction(DEF,RHI<1.67)group according to RHI.There was monthly follow-up with patients until September 30,2017 or until an endpoint event occurred.Moreover,the first MACEs for a subject was considered in the analysis if he/she suffered from more than 2 types of MACEs.The subjects were prospective followed up for a mean of 16 months [interquartile range(IQR): 14 to 20 months],with MACEs [cardiac death,acute myocardial infarction(AMI),target vessel reconstruction(TVR),non-fatal ischemic stroke,and cardiac hospitalization] were the endpoints and the differences in the incidence of MACEs between the two groups were compared.Results1)A total of 312 ACS patients who were treated with PCI underwent the endothelial function assessment by Endo-PAT2000.According to RHI,we divided the patients into the DEF group(n=191)and NEF group(n=121).Finally,follow-up was completed in 308 patients,whereas 4 patients were lost to follow-up during the follow-up period,which including 189 patients in DEF group and 119 patients in NEF group,respectively.2)A total of 67 patients(21.75%)with ACS had a MACEs in follow-up period.The overall incidence of MACEs was 25.39% in the DEF group and 15.96% in the NEF group,respectively(p<0.05).Kaplan-Meier analysis also demonstrated a significantly higher probability of cumulative MACEs was 30.52% vs.18.80% between NEF and DEF groups(p<0.05).3)The incidence of non-fatal ischemic stroke in the NEF and DEF groups was 3.70% vs.0.00%(p=0.046),respectively.The incidence of AMI was 5.04% vs.4.76% in the two groups(p=0.389)while the incidence of cardiac death was 0.84% vs.3.70%(p=0.157).Furthermore the rate of cardiac hospitalization was 10.92% vs.11.64%(p=0.501)and the rate of TVR was 0.84% vs.1.59% in the NEF and DEF groups(p=0.285).4)Multivariate Cox hazard analysis showed that both RHI and SYNTAX scores were independent risk predictors for future MACEs after PCI treatment in patients with ACS.In Cox analysis,systolic and diastolic blood pressure as continuous variables in model 2:RHI(HR=0.425,95%CI: 0.198-0.914,p=0.029),SYNTAX scores(HR=1.043,95%CI: 1.019-1.067,p < 0.001);while it was adjusted by hypertension history as a two-category variable instead of systolic and diastolic blood pressure in model 1: RHI(HR=0.415,95% CI: 0.195-0.884,p=0.023),SYNTAX scores(HR=1.043,95% CI: 1.019-1.067,p<0.001).ConclusionsRHI was associated with MACEs after PCI in patients with ACS.Furthermore,RHI and SYNTAX scores both are independent predictors of MACEs which suggesting that RHI may be useful as a candidate biomarker in the risk stratification and management of patients with ACS after PCI treatment.