The Effect Of Delayed PCI On The Clinical Prognosis Of Acute Myocardial Infarction

Background: Primary percutaneous coronary intervention(PPCI)plays a pivotal role in the treatment of ST-segment elevation myocardial infarction(STEMI).However,it remains a controversial whether delayed PCI is applicable to STEMI beyond a recommended time window of 12 h after onset of symptoms.Objective: The AMI registration study in Xinjiang,China,is a real-world clinical trial(retrospective cohort study)based on hospitalized patients.The purpose of this study was to compare the outcomes between delayed PCI and medication therapy in the STEMI patients beyond a recommended time window of 12 h after onset of symptoms.Methods :A total of 1072 STEMI patients beyond 12 h after onset of symptoms received delayed PCI or standard medication therapy(MT)from May 2012 to December 2015.The primary endpoint was all-cause death in long-term follow-up.Secondary endpoints were the major adverse cardiac events.The main adverse cardiovascular events were defined as cardiogenic death,readmission,target remodeling and stroke.We also calculated the bleeding event.Survival analysis and log rank test using the Kaplan-Meier method were used to compare the overall and non-MACE survival of patients with different therapies.Cox multivariate regression models were used for multivariate analysis of endpoint(including death,MACE occurrence)and treatment as one of the factors.Results:The median follow-up of26 months(0-55 months),The number of all-cause deaths was 55(9.3%)and 138(28.9%),respectively,indicating significant difference(P<0.001).Cox multivariate analysis,delayed PCI was superior to medication in all-cause mortality(HR = 0.262,95% CI:0.164-0.417,P <0.001).Delayed PCI group,the total incidence of MACE drug treatment group were 141(34.1%),222(38.2%)(P = 0.019).Cardiac deaths were 47(7.9%)and 120(25.1%),respectively(P <0.001).Cox multivariate analysis showed that the effect of delayed PCI(12h <t <28d)on MACE and cardiac death were superior to those of themedication group(HR = 0.723,95% CI: 0.563-0.929,P = 0.011;HR = 0.286,95% CI:0.173-0.474,P <0.001).Treatment is an independent factor affecting the prognosis of STEMI patients.Propensity Matching Analysis(PSM)performed a rigorous adjustment of the patient’s baseline clinical characteristics.A total of 333 patients with acute myocardial infarction undergoing delayed PCI(12 h <t <28 d)and 333 patients with acute myocardial infarction were enrolled in the study after 1: 1 screening and pairing.The median follow-up was 26 months(range 0-55 months).The number of all-cause deaths was 31(9.3%)in the deferred PCI group and 86(25.8%)in the drug-treated group(p <0.001).Cox multivariate analysis showed that the effect of delayed PCI(12h <t <28d)on all-cause mortality were superior to those of the medication group(HR= 0.193,95% CI:0.112-0.334,P <0.001).Treatment,Killip classification is an independent factor affecting the prognosis of STEMI patients.Delayed PCI group,the total incidence of MACE medication group was 101(30.3%),129(38.7%)(P <0.001).Cardiac deaths were 29(8.7%)and 72(21.6%),respectively(p <0.001).Cox multivariate analysis showed that the effect of delayed PCI(12h <t <28d)on MACE and cardiac death was better than that of the medication group(HR = 0.766,95% CI: 0.566-1.018,P = 0.066;HR = 0.221,95% CI:0.123-0.397,P <0.001).Conclusion: Delayed PCI for STEMI beyond 12 h after onset of symptoms can reduce mortality and incidence of MACEs compared to medication therapy.