title: Effect of Aspiration Thrombectomy on Microvascular Dysfunction in ST-Segment Elevation Myocardial Infarction With an Elevated Neutrophil Count.
abstract: OBJECTIVE
  Aspiration thrombectomy (AT) during primary percutaneous coronary intervention (PCI) is an effective adjunctive therapy for ST-segment elevation myocardial infarction (STEMI). An elevated neutrophil count in STEMI is associated with microvascular dysfunction and adverse outcomes. We evaluated whether AT can improve microvascular dysfunction in patients with STEMI and an elevated neutrophil count.
  
  
  METHODS
  Seventy patients with STEMI undergoing primary PCI from August 2007 to February 2009 in our institution were classified by tertiles of neutrophil count on admission (<5,300/mm(3), 5,300-7,600/mm(3), and >7,600/mm(3)). The angiographic outcome was post-procedural thrombolysis in myocardial infarction (TIMI) flow grade. Microvascular dysfunction was assessed by TIMI myocardial perfusion (TMP) grade and ST-segment resolution on electrocardiography 90 minutes after PCI. The clinical outcome was major adverse cardiac event (MACE), defined as cardiac death, re-infarction, and target lesion revascularization at 9 months.
  
  
  RESULTS
  There were no significant differences in the clinical characteristics and pre- and post-procedural TIMI flow grades between the neutrophil tertiles. As the neutrophil count increased, a lower tendency toward TMP grade 3 (83% vs. 52% vs. 54%, p=0.06) and more persistent residual ST-segment elevation (>4 mm: 13% vs. 26% vs. 58%, p=0.005) was observed. The 9-month MACE rate was similar between the groups. On subgroup analysis of AT patients (n=52) classified by neutrophil tertiles, the same tendency toward less frequent TMP grade 3 (77% vs. 56% vs. 47%, p=0.06) and persistent residual ST-segment elevation (>4 mm: 12% vs. 28% vs. 53%, p=0.05) was observed as neutrophil count increased.
  
  
  CONCLUSIONS
  A higher neutrophil count at presentation in STEMI is associated with more severe microvascular dysfunction after primary PCI, which is not improved with AT.
authors: Division of Cardiology, Department of Internal Medicine, Sanggye Paik Hospital, Inje University College of Medicine, Seoul, Korea.
authors: Hye Young
authors: HY
authors: Lee
authors: Jeong Hoon
authors: JH
authors: Kim
authors: Byung Ok
authors: BO
authors: Kim
authors: Yoon Jung
authors: YJ
authors: Kang
authors: Hyo Seung
authors: HS
authors: Ahn
authors: Mee Won
authors: MW
authors: Hwang
authors: Kyoung Min
authors: KM
authors: Park
authors: Young Sup
authors: YS
authors: Byun
authors: Choong Won
authors: CW
authors: Goh
authors: Kun Joo
authors: KJ
authors: Rhee