Effect of Aspiration Thrombectomy on Microvascular Dysfunction in ST-Segment Elevation Myocardial Infarction With an Elevated Neutrophil Count

Abstract

Background and ObjectivesAspiration 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.Subjects and MethodsSeventy 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/mm3, 5,300-7,600/mm3, and >7,600/mm3). 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.ResultsThere 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.ConclusionA higher neutrophil count at presentation in STEMI is associated with more severe microvascular dysfunction after primary PCI, which is not improved with AT.

Neutrophil to Lymphocyte Ratio Predicts Long-Term Clinical Outcomes in Patients with ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

“…Proposed mechanisms responsible for this association include leukocyte-mediated no-reflow, leukocyte-mediated hypercoagulable state and indirect cardiotoxicity mediated through proinflammatory cytokines 14)15). The prognostic significance of different WBC subtypes varies in patients with acute myocardial infarction 16-22). Elevated neutrophil count predicts a larger infarction size, worse angiographic outcomes and poor short-term prognosis in patients with STEMI 16)17).…”

“…The prognostic significance of different WBC subtypes varies in patients with acute myocardial infarction 16-22). Elevated neutrophil count predicts a larger infarction size, worse angiographic outcomes and poor short-term prognosis in patients with STEMI 16)17). Neutrophils produce several inflammatory mediators (such as elastase, myeloperoxidase and acid phosphatase) as well as substances that cause acute myocardial injury or further tissue damage after STEMI 18)19).…”

The relationship between neutrophil/lymphocyte ratio and infarct-related artery patency before mechanical reperfusion in patients with ST-elevation myocardial infarction

“…The prognostic significance of different WBC subtypes varies in patients with acute myocardial infarction [33][34][35][36]. In particular, neutrophils are the first leukocytes to be found in the damaged myocardial area.…”

Efficacy of Combination Treatment with Intracoronary Abciximab and Aspiration Thrombectomy on Myocardial Perfusion in Patients with ST-Segment Elevation Myocardial Infarction Undergoing Primary Coronary Stenting

“…Microvascular obstruction (MVO) or no-reflow phenomenon refers to a state of poor myocardial perfusion at the microvascular level despite successful restoration of the patency of the epicardial coronary artery 1,2,3. Ischemia itself, reperfusion injury, inflammation, or distal embolization of a thrombus and/or plaque debris can cause development of MVO during primary percutaneous coronary intervention (PCI) for STEMI 1,2,3,4,5. Poor myocardial perfusion is associated with a higher occurrence of extensive infarction, left ventricular remodeling, and increased mortality than good myocardial perfusion 6,7,8.…”