title: Late incomplete apposition after drug-eluting stent implantation: incidence and potential for adverse clinical outcomes.
abstract: OBJECTIVE
  Late-acquired incomplete stent apposition (ISA) has been documented after drug-eluting stent (DES) implantation; however, its clinical role remains controversial. We sought to investigate the incidence and long-term clinical consequences of late ISA after implantation of sirolimus- (SES) or paclitaxel-eluting stent (PES) in a non-selected population.
  
  
  RESULTS
  From our database, we analysed 195 consecutive patients who underwent DES placement (175 with SES and 20 with PES) into native artery lesions and had serial intravascular ultrasound studies (IVUS) performed at index procedure and after 6-8 months. They were clinically followed for 29 +/- 15 months (median of 24.3 months, interquartile range 18.1-31.6 months). Late ISA was defined as separation of at least one stent strut from the vessel wall in a segment without a side-branch and where the immediate post-implantation IVUS revealed complete apposition of stent struts. We identified 10 patients (5.1%) with late ISA, three patients after PES, and seven patients after SES implantation. ISA was localized almost exclusively at body of the stents (nine out of 10 cases). Mean ISA volume and length were 44.5 +/- 41.9 mm(3) and 7.4 +/- 11 mm, respectively. There was a marked increase in vessel volume from 416.0 +/- 163.9 mm(3) at baseline to 514.4 +/- 247.9 mm(3) at follow-up (P = 0.001) with no significant change in plaque volume (232.4 +/- 52.7 at baseline and 226.4 +/- 22.3 mm(3) at follow-up, P = 0.3) in patients who presented with late-acquired ISA. During the follow-up period, one patient with SES and one patient with PES who presented late-acquired ISA had late stent thrombosis and acute myocardial infarction.
  
  
  CONCLUSIONS
  Late-acquired ISA was observed in 5.1% of patients after DES implantation and is related to regional vessel positive remodelling. The relationship between late-acquired ISA and long-term adverse outcomes (e.g. stent thrombosis) requires further analysis.
authors.affiliation: Instituto Dante Pazzanese de Cardiologia, Rua Dr Dante Pazzanese 500, CEP 04012-909 São Paulo, SP, Brazil.
authors.forename: Dimytri A
authors.initials: DA
authors.lastname: Siqueira
authors.forename: Alexandre A
authors.initials: AA
authors.lastname: Abizaid
authors.forename: Jose de Ribamar
authors.initials: Jde R
authors.lastname: Costa
authors.forename: Fausto
authors.initials: F
authors.lastname: Feres
authors.forename: Luiz A
authors.initials: LA
authors.lastname: Mattos
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Staico
authors.forename: Andrea A
authors.initials: AA
authors.lastname: Abizaid
authors.forename: Luiz F
authors.initials: LF
authors.lastname: Tanajura
authors.forename: Aurea
authors.initials: A
authors.lastname: Chaves
authors.forename: Marinella
authors.initials: M
authors.lastname: Centemero
authors.forename: Amanda G M R
authors.initials: AG
authors.lastname: Sousa
authors.forename: J Eduardo M R
authors.initials: JE
authors.lastname: Sousa
mesh_terms: D001807:Blood Vessel Prosthesis; D054855:Drug-Eluting Stents; D005260:Female; D006083:Graft Occlusion, Vascular / Q000209:etiology; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000628:therapy*; D009204:Myocardial Revascularization; D017239:Paclitaxel / Q000008:administration & dosage*; D011475:Prosthesis Failure; D020123:Sirolimus / Q000008:administration & dosage*; D016896:Treatment Outcome; D014463:Ultrasonography
chemical_list: D007166:Immunosuppressive Agents; D017239:Paclitaxel; D020123:Sirolimus