The Effect Of Duration Of Dual Antiplatelet Therapy On Prognosis Of Patients With Non-obstructive Myocardial Infarction

Objective:By observing the clinical situation and prognosis of patients with Myocardial Infarction with Non-obstructive Coronary Arteries（MINOCA）,this paper summarizes and analyzes the clinical characteristics and prognostic risk factors of MINOCA patients,and compares the effects of different durations of dual anti-platelet therapy on their prognosis,so as to improve the understanding of this disease and guide the future treatment direction.Methods:Enrolled total of 266 patients who were diagnosed with MINOCA at the First Affiliated Hospital of Dalian Medical University from January 1^st2010 to December31^st2019.Collect the general clinical information,complication,auxiliary examination results and medication situation,analyze the general clinical characteristics of the patients.The time of diagnosis of MINOCA was taken as the starting time of follow-up,and telephone follow-up was conducted until November 2020.Patients were asked about the type of medication taken after discharge,the duration of medication taken,and the incidence of compound end points（all-cause death,chest pain readmission,recurrent myocardial infarction,heart failure,and malignant arrhythmias）during follow-up.According to the patients with oral dual antiplatelet drug duration for grouping patients,respectively,marked as group A（double anti treatment time 1 month or less）and group B（double anti treatment time>and<1 months to 12 months）,group C（double resistance treatment time is 12 months or more）,comparative composite end point events differences between groups,analysis the influence factors of the composite end point events in MINOCA patients.Results:1.This study included 10327 patients with AMI,and 282 patients were diagnosed with MINOCA,with a prevalence rate of 2.7%,A total of 266 subjects were finally included in the study,including 173 males（65%）and 93 females（35%）,with an average age of 57.83±10.70 years,The acute non-ST-segment elevation myocardial infarction（NSTEMI）was in 182 patients（68.4%）,and the acute ST-segment elevation myocardial infarction（STEMI）was in 84 patients（31.6%）,The predisposing factors includes hypertension 45.9%（122 cases）,smoking history 36.1%（96 cases）,hyperlipidemia21.0%（56 cases）,hyperuricemia 16.9%（45 cases）and diabetes 12%（32 cases）.2.All patients were grouped according to the time of dual antiplatelet treatment after discharge,respectively marked as group A（dual antiplatelet treatment time≤1month,94 cases,35.4%）,group B（dual antiplatelet treatment time>1 month and<12months,114 cases,42.8%）,group C（dual antiplatelet treatment time≥12 months,58cases,21.8%）,three groups of patients with general information,complications,auxiliary examination results,and the discharge medication was no significant statistical difference（P>0.05）.3.The occurrence of compound endpoint events in 266 subjects was followed up by telephone.A total of 50 people composite end point events（18.8%）,Among them,26 cases（52%）had chest pain readmission,12 cases（24%）had recurrent myocardial infarction,6 cases（12%）died,2 cases（4%）had heart failure,and 4 cases（8%）had malignant arrhythmia.The incidence of chest pain readmission in group B and C was lower than that in group A,and the difference was statistically significant（P<0.05）.There was no significant difference in the incidence of chest pain readmission between group B and C（P>0.05）.There was no statistical difference among the three groups of recurrent myocardial infarction,death,heart failure and malignant arrhythmia（P>0.05）,three groups of composite end point event rates were 26.0%in group A（24 cases）and20.1%in group B（23 cases）,5.1%（3 cases）in group C,Comparison between groups showed no significant difference in the incidence of compound endpoint events between group A and group B（P>0.05）,and the incidence of compound endpoint events in groups A and B was higher than that in group C,with statistical significance（P<0.05）.4.Log-rank was used to analyze the difference of the duration of dual antiplatelet therapy on the prognosis of patients with MINOCA,and Kaplan-Meier was used to draw the survival curve.Comparison between groups showed that the survival rate of patients in group A and group B was lower than that in group C,with statistically significant differences（P<0.05 each）,while there was no statistically significant difference in survival rate between group A and group B（P>0.05）.5.Cox regression multivariate survival analysis hints that the risk of composite endpoints can be increased by smocking,elderly,left ventricular ejection fraction and hypercholesterolemia,but the risk of composite endpoints occurrence can be reduced by extending dual anti-platelet’s therapy time.Conclusion:1.MINOCA patients among AMI patients have a lower morbidity rate,NSTEMI is more commonly seen than STEMI,The predisposing factors are hypertension,smoking,hyperlipidemia,hyperuricemia and diabetes.2.Smocking,elderly,low left ventricular ejection fraction and hypercholesterolemia are the independent risky factors for the incidence of composite endpoints to MINOCA patients,and extending dual anti-platelet’s therapy time is the protective factor for the composite endpoints to MINOCA patients.3.The MINOCA patients prognosis can be effectively improved by reinforcing anti-platelet therapy and extending dual anti-platelet’s therapy time.