title: Safety and efficacy of 2.5-mm sirolimus-eluting stent implantation at lower deployment pressures in very small vessels (<2.5 mm).
abstract: OBJECTIVE
  Percutaneous coronary interventions for very small vessels are common in clinical practice despite an unavailability of the 2.25-mm sirolimus-eluting stent (SES) in some countries. We sought to evaluate the clinical and angiographic outcomes of 2.5-mm SES implantation at lower deployment pressures in very small coronary arteries.
  
  
  METHODS
  Between June 2004 and March 2007, a total of 244 patients underwent percutaneous coronary interventions in vessels with reference diameters less than 2.5 mm at our centers: outcomes in 126 consecutive patients undergoing 2.5-mm SES implantation at lower deployment pressures (< or =10 atmospheres) with predilatation and postdilatation were compared with those in 118 patients who received bare-metal stents (BMS).
  
  
  RESULTS
  In the SES group, rates of predilatation and postdilatation were 73.8 and 81% respectively, and mean deployment pressure was 8.3+/-1.2 atmospheres. At follow-up, in-segment late loss was markedly lower in SES versus BMS (0.21+/-0.41 vs. 0.48+/-0.63 mm, P=0.001), resulting in significantly lower rates of restenosis (14.7 vs. 37.5%, P<0.001). At 1 year, SES versus BMS use was associated with similar rates of stent thrombosis (0.8 vs. 0.8%, P>0.999), but significantly lower rates of major adverse cardiac events (MACE) (11.9 vs. 27.1%, P=0.003), mainly driven by a significantly lower need for target-lesion revascularization (9.5 vs. 26.3%, P=0.001). Multivariable analysis identified the SES use as independently associated with a reduced 1-year MACE risk (hazard ratio: 0.32; 95% confidence interval: 0.15-0.66; P=0.002).
  
  
  CONCLUSIONS
  Implantation of 2.5-mm SES in vessels with reference diameters less than 2.5 mm using lower deployment pressures and predilatation and postdilatation may lead to reduced risks of restenosis and MACE without an increased risk of stent thrombosis up to 1 year.
authors.affiliation: Division of , Toyota Memorial Hospital, Toyota, Japan. humedamd@ybb.ne.jp
authors.forename: Hisashi
authors.initials: H
authors.lastname: Umeda
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Iwase
authors.forename: Tomoko
authors.initials: T
authors.lastname: Gochi
authors.forename: Hideo
authors.initials: H
authors.lastname: Izawa
authors.forename: Ryoji
authors.initials: R
authors.lastname: Ishiki
authors.forename: Haruo
authors.initials: H
authors.lastname: Inagaki
authors.forename: Takeshi
authors.initials: T
authors.lastname: Shimizu
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Yokota
authors.forename: Toyoaki
authors.initials: T
authors.lastname: Murohara
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000295:instrumentation*; D002317:Cardiovascular Agents / Q000008:administration & dosage*; D002318:Cardiovascular Diseases / Q000000981:diagnostic imaging / Q000209:etiology / Q000517:prevention & control*; D017023:Coronary Angiography; D023903:Coronary Restenosis / Q000209:etiology; D003331:Coronary Vessels / Q000473:pathology*; D054855:Drug-Eluting Stents; D005260:Female; D006801:Humans; D007564:Japan; D053208:Kaplan-Meier Estimate; D008297:Male; D008670:Metals; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D011312:Pressure; D016016:Proportional Hazards Models; D011474:Prosthesis Design; D018570:Risk Assessment; D020123:Sirolimus / Q000008:administration & dosage*; D015607:Stents; D013927:Thrombosis / Q000209:etiology; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D002317:Cardiovascular Agents; D008670:Metals; D010975:Platelet Aggregation Inhibitors; D020123:Sirolimus