title: The impact of initial and residual thrombus burden on the no-reflow phenomenon in patients with ST-segment elevation myocardial infarction.
abstract: BACKGROUND
  Limited data are available on the clinical significance of residual thrombi after thrombectomy and prestenting reduced epicardial coronary flow in ST-segment elevation myocardial infarct (STEMI) patients.
  
  
  METHODS
  The incidence of the no-reflow phenomenon, defined as a final thrombolysis in myocardial infarction (TIMI) flow grade of up to 2 or a myocardial blush grade of up to 1, was compared in 260 STEMI patients undergoing primary percutaneous coronary intervention according to thrombotic burden. Large thrombotic burden (LTB), defined as a thrombus score of at least 3, was observed in 134 patients, among whom 66 (49.3%) underwent aspiration thrombectomy. No-reflow incidence was compared on the basis of thrombectomy treatment, thrombus residue after thrombectomy, and prestenting TIMI flow grade.
  
  
  RESULTS
  The no-reflow phenomenon occurred most frequently in LTB patients without thrombectomy, followed by those who underwent thrombectomy and the small thrombus burden group (33.8 vs. 21.2 vs. 10.3%, respectively, P<0.001). Patients with a prestenting residual thrombus or a TIMI flow grade of up to 2 had higher no-reflow incidence than those with no visible prestenting thrombus and a TIMI flow grade of 3 (74 vs. 6.2%, P<0.001). Multiple logistic regression analysis identified a prestenting TIMI flow grade of up to 2 (odds ratio 36.422, 95% confidence interval 13.952-95.079) as an independent predictor of the no-reflow phenomenon.
  
  
  CONCLUSIONS
  Manual thrombus aspiration reduced no-reflow incidence in STEMI patients with LTB. However, even after thrombectomy, prestenting residual thrombi and decreased coronary flow were related to a higher occurrence of the no-reflow phenomenon.
authors.affiliation: aDivision of Cardiology, Yonsei University Wonju College of Medicine, Wonju Severance Christian Hospital, Wonju bDivision of Cardiology, Hallym University Chuncheon Sacred Heart Hospital cDepartment of Internal Medicine, Division of Cardiology, Kangwon National University College of Medicine, Kangwon National University Hospital, Chuncheon dDivision of Cardiology, University of Ulsan College of Medicine, Gangneung Asan Hospital, Gangneung, Republic of Korea.
authors.forename: Sung Gyun
authors.initials: SG
authors.lastname: Ahn
authors.forename: Hyun-Hee
authors.initials: HH
authors.lastname: Choi
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Lee
authors.forename: Jun-Won
authors.initials: JW
authors.lastname: Lee
authors.forename: Young Jin
authors.initials: YJ
authors.lastname: Youn
authors.forename: Sang-Yong
authors.initials: SY
authors.lastname: Yoo
authors.forename: Byung Ryul
authors.initials: BR
authors.lastname: Cho
authors.forename: Seung-Hwan
authors.initials: SH
authors.lastname: Lee
authors.forename: Junghan
authors.initials: J
authors.lastname: Yoon
mesh_terms: D000368:Aged; D016009:Chi-Square Distribution; D017023:Coronary Angiography; D003326:Coronary Circulation; D003328:Coronary Thrombosis / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D054855:Drug-Eluting Stents; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D054318:No-Reflow Phenomenon / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control; D016017:Odds Ratio; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects* / Q000295:instrumentation; D016032:Randomized Controlled Trials as Topic; D012189:Retrospective Studies; D012307:Risk Factors; D017131:Thrombectomy / Q000009:adverse effects / Q000379:methods; D013997:Time Factors; D016896:Treatment Outcome