title: Durability of antirestenotic efficacy in drug-eluting stents with and without permanent polymer.
abstract: OBJECTIVE
  We sought to assess changes in antirestenotic efficacy of drug-eluting stents (DES) by restudying subjects at 2 time points after coronary stenting (6 to 8 months and 2 years) and to compare differences in time courses of late luminal loss (LLL) between 3 different DES platforms in use at our institution.
  
  
  BACKGROUND
  DES therapy is associated with low levels of LLL at 6 to 8 months. The temporal course of neointimal formation after this time point remains unclear.
  
  
  METHODS
  This prospective, observational, systematic angiographic follow-up study was conducted at 2 centers in Munich, Germany. Patients underwent stenting with permanent-polymer rapamycin-eluting stents (RES), polymer-free RES, or permanent-polymer paclitaxel-eluting stents (PES). The primary end point was delayed LLL (the difference in in-stent LLL between 6 to 8 months and 2 years).
  
  
  RESULTS
  Of 2,588 patients undergoing stenting, 2,030 patients (78.4%) had 6- to 8-month angiographic follow-up and were enrolled in the study. Target lesion revascularization was performed in 259 patients; these patients were not considered for further angiographic analysis. Of 1,771 remaining patients, 1,331 had available 2-year reangiographic data (75.2%). Overall mean (SD) delayed LLL was 0.12 +/- 0.49 mm (0.17 +/- 0.50 mm, 0.01 +/- 0.42 mm, and 0.13 +/- 0.50 mm in permanent-polymer RES, polymer-free RES, and permanent-polymer PES groups, respectively [p < 0.001]). In multivariate analysis, only stent type (in favor of polymer-free RES) predicted delayed LLL.
  
  
  CONCLUSIONS
  Ongoing erosion of luminal caliber beyond 6 to 8 months after the index procedure is observed following DES implantation. Absence of permanent polymer from the DES platform seems to militate against this effect.
authors.affiliation: Deutsches Herzzentrum, Technische Universität, Munich, Germany. byrne@dhm.mhn.de
authors.forename: Robert A
authors.initials: RA
authors.lastname: Byrne
authors.forename: Raisuke
authors.initials: R
authors.lastname: Iijima
authors.forename: Julinda
authors.initials: J
authors.lastname: Mehilli
authors.forename: Susanne
authors.initials: S
authors.lastname: Pinieck
authors.forename: Olga
authors.initials: O
authors.lastname: Bruskina
authors.forename: Albert
authors.initials: A
authors.lastname: Schömig
authors.forename: Adnan
authors.initials: A
authors.lastname: Kastrati
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000295:instrumentation*; D002317:Cardiovascular Agents / Q000008:administration & dosage*; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000628:therapy*; D023903:Coronary Restenosis / Q000000981:diagnostic imaging / Q000209:etiology / Q000517:prevention & control*; D054855:Drug-Eluting Stents; D005260:Female; D005858:Germany; D006801:Humans; D006965:Hyperplasia; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D017239:Paclitaxel / Q000008:administration & dosage*; D011108:Polymers / Q000737:chemistry*; D011446:Prospective Studies; D011474:Prosthesis Design; D018570:Risk Assessment; D020123:Sirolimus / Q000008:administration & dosage*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D002317:Cardiovascular Agents; D011108:Polymers; D017239:Paclitaxel; D020123:Sirolimus