Analysis Of Slow Flow/No-reflow Phenomenon After Emergency PCI In Patients With Acute Anterior Myocardial Infarction Combined With New Complete Right Bundle Branch Block

Objective:We retrospectively analyzed the general hospitalization data and intraoperative imaging data of patients with acute anterior myocardial infarction to explore the clinical characteristics of patients with acute anterior infarction combined with new complete right bundle branch block and the occurrence of slow flow/no-reflow phenomenon after emergency PCI to provide new ideas and references for clinical diagnosis and treatment.Methods:A total of 261 patients with acute anterior myocardial infarction who attended the Department of Cardiology of the First Affiliated Hospital of Dali University and underwent emergency PCI from December 2019 to December 2022 were retrospectively included,including 40 patients with combined new complete right bundle branch block(CRBBB group)and 221 patients without combined complete right bundle branch block(no-CRBBB group).General information and hospitalization data were collected from all study subjects,and the clinical characteristics and prognosis of patients with acute anterior myocardial infarction combined with new complete right bundle branch block were compared and analyzed.The relationship between acute anterior myocardial infarction combined with new complete right bundle branch block and slow flow/no-reflow phenomenon after emergency PCI was further investigated in four aspects: TIMI flow classification,index of microcirculatory resistance(ca IMR),corrected TIMI flow frame count(CTFC)and ST segment regression in ECG(STR)of the infarct-related artery.Results:1.A total of 350 patients with acute anterior myocardial infarction were collected in the preliminary phase of this study,of which 46 patients with definite combined new complete right bundle branch block,with an incidence of approximately13%.2.There were significant differences in age,Killip grade at admission,GLUC,TG,HDL,BUN,GFR,AST,ALT,WBC,TNI,IRA and intraoperative use of dopamine between CRBBB group and no-CRBBB group(P < 0.05).The CRBBB group had lower admission blood pressure,faster heart rate,and longer median FMC2 W and ischemia time than the no-CRBBB group,but the differences were not statistically significant(P > 0.05).There was no significant difference in gender,past medical history,family history,smoking history,alcohol history,PCI modality,TC,LDL,LP(a),UA,Scr,RBC,HB,PLT,BNP,MYO,CK-MB,D-D,preoperative TIMI grade of IRA,thrombus,number of diseased vessels,stent diameter,stent length and intraoperative use of IABP,atropine,norepinephrine,tirofiban,nitroglycerin,sodium nitroprusside,adenosine and nicodil(P > 0.05).3.The differences in in-hospital major adverse cardiovascular events,LVEF,post-PCI vasoactive drug use and duration of use between the CRBBB and no-CRBBB groups were statistically significant(P < 0.05),and the differences in LVEDD were not statistically significant(P > 0.05).4.In the CRBBB group,the proportion of patients with TIMI blood flow ≤ grade 2 after PCI was higher(25% vs 8.6%),the proportion of patients with STR< 50% was higher(65% vs 18.1%),and the median ca IMR was higher(40.25 vs 29.5),all of the differences were statistically significant(P < 0.05).The postoperative median CTFC of IRA in the CRBBB group was larger than that in the no-CRBBB group(24.71 vs 21.18)frames,but there was no statistical significance(P > 0.05).After adjusting for confounding factors,patients with acute anterior myocardial infarction with combined new complete right bundle branch block were independently associated with TIMI flow≤ grade 2(OR=6.833,95% CI: 1.009～46.287,P=0.049),STR ≥ 50%(OR=0.176,95%CI: 0.051～0.606,P=0.006),CTFC(OR=1.079,95%CI: 1.009～1.155,P=0.027),and ca IMR(OR=1.120,95%CI: 1.059～1.185,P<0.001)after emergency PCI.Conclusion:1.Approximately 13% of patients with acute anterior wall myocardial infarction have a combination of complete right bundle branch block.2.In patients with acute anterior myocardial infarction,patients with new complete right bundle branch block are older,have worse cardiac function and prognosis than those without complete right bundle branch block,and are often unstable in hemodynamics,which should be paid attention to in clinical diagnosis and treatment.3.Among acute anterior myocardial infarction patients admitted to hospital for emergency PCI,patients with new complete right bundle branch block are more likely to have slow flow/no-reflow phenomenon after surgery,which should be treated as soon as possible to prevent its occurrence in advance.