title: Microvascular coronary flow comparison in acute myocardial infarction angioplasty treated with a mesh covered stent (MGUARD stent) versus bare metal stent: MICAMI-MGUARD.
abstract: BACKGROUND
  Distal embolization of thrombus/platelet aggregates decreases myocardial reperfusion during primary percutaneous coronary intervention (PCI), and is associated with worse immediate and long-term prognosis of patients with ST-elevation myocardial infarction (STEMI).
  
  
  OBJECTIVE
  Assess the efficacy of a mesh covered stent (MGuard™ stent, MGS) in preventing distal embolization and microvascular reperfusion impairment during primary PCI, compared with a bare metal stent (BMS).
  
  
  METHODS
  Forty patients with STEMI referred for primary PCI were randomized for stenting the culprit lesion with the MGS (n = 20) or a BMS (n = 20). Blinded experts performed off-line measurements of angiographic epicardial and microvascular reperfusion criteria: TIMI flow grade, myocardial blush, corrected TIMI frame count (cTFC).
  
  
  RESULTS
  At baseline clinical, angiographic and procedural variables were not different between groups. Post PCI TIMI flow grade was similar in both groups. We observed better myocardial Blush grade in group MGS compared to BMS (median value 3.0 vs 2.5, 2p = 0.006) and cTFC (mean cTFC: MGS 19.65 ± 4.07 vs BMS 27.35 ± 7.15, 2p < 0.001, cTFC mean difference MGS-BMS: 7.7, CI 95%: 3.94 to 11.46). MGS stent group had a higher percentage of successful angioplasty (cTFC ≤ 23: MGS 85% vs BMS 30%, 2p < 0.001). We had two cases of acute stent thrombosis (one for each group) at 30days follow up, but no clinical events at 6 months follow up.
  
  
  CONCLUSIONS
  In this exploratory study, MGS significantly improved microvascular reperfusion criteria compared with a BMS in primary PCI. However its safety and impact on clinical outcomes should be verified in larger randomized clinical trials.
authors: Hospital Clínico, Pontificia Universidad Católica de Chile, Chile. dslindef@puc.cl
authors: Dante S
authors: DS
authors: Lindefjeld
authors: Eduardo
authors: E
authors: Guarda
authors: Manuel
authors: M
authors: Méndez
authors: Alejandro
authors: A
authors: Martínez
authors: Osvaldo
authors: O
authors: Pérez
authors: Alejandro
authors: A
authors: Fajuri
authors: Eugenio
authors: E
authors: Marchant
authors: Mauricio
authors: M
authors: Aninat
authors: Humberto
authors: H
authors: Torres
authors: Gastón
authors: G
authors: Dussaillant
mesh_terms: D000328:Adult; D000368:Aged; D016009:Chi-Square Distribution; D002677:Chile; D017023:Coronary Angiography; D003326:Coronary Circulation; D004617:Embolism / Q000209:etiology / Q000517:prevention & control; D005260:Female; D006801:Humans; D008297:Male; D008670:Metals; D008833:Microcirculation; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects / Q000295:instrumentation*; D011474:Prosthesis Design; D015607:Stents; D013526:Surgical Mesh; D013927:Thrombosis / Q000209:etiology / Q000517:prevention & control; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D008670:Metals