title: Prognostic Significance of Polymer Coatings in Zotarolimus-Eluting Stents.
abstract: Polymer coatings on drug-eluting stents (DES) serve as a vehicle for delivery of antirestenotic drugs. Whether they influence outcomes for contemporary DES is unknown. The evolution of polymer coatings for zotarolimus-eluting stents (ZES) provides a natural experiment that facilitates such analysis. The Resolute ZES (R-ZES) uses the same antirestenotic drug as the Endeavor ZES (E-ZES) but has a more biocompatible polymer with enhanced drug release kinetics. However, there are limited data on the real-world comparative efficacy of R-ZES and the preceding E-ZES. Thus, we analyzed 17,643 patients who received either E-ZES or R-ZES from 2008 to 2014 from the British Columbia Cardiac Registry. A total of 9,869 patients (56%) received E-ZES and 7,774 patients (44%) received R-ZES. Compared with E-ZES, R-ZES was associated with lower 2-year mortality (4.1% vs 6.4%, p <0.001) and 2-year target vessel revascularization (TVR; 6.8% vs 10.7%, p <0.001). R-ZES use was an independent predictor of lower mortality rate and TVR. This was confirmed in propensity-matched analyses for 2-year mortality (hazard ratio [HR] 0.59, 95% CI 0.49 to 0.71, p <0.001) and 2-year TVR (HR 0.86, 95% CI 0.75 to 0.98, p = 0.032). Instrumental variable analyses demonstrated R-ZES to be associated with lower 2-year mortality (Δ = -2.2%, 95% CI -4.3% to -0.2%, p = 0.032) and 2-year TVR (Δ = -3.3% to 95% CI -6.1% to -0.7%, p = 0.015). Acknowledging the limitations of observational analyses, this study has shown that R-ZES was associated with lower long-term TVR and mortality. These data are reassuring for the newer R-ZES and demonstrate how polymer coatings may influence the clinical performance of DES with wider implications for future DES development and design.
authors.affiliation: Department of Cardiology, Victoria Heart Institute Foundation, Victoria, British Columbia, Canada; Department of Cardiology, Royal Jubilee Hospital, Victoria, British Columbia, Canada. Electronic address: biqbal@excite.com.
authors.forename: M Bilal
authors.initials: MB
authors.lastname: Iqbal
authors.affiliation: Department of Cardiology, Victoria Heart Institute Foundation, Victoria, British Columbia, Canada; Department of Cardiology, Royal Jubilee Hospital, Victoria, British Columbia, Canada.
authors.forename: Imad J
authors.initials: IJ
authors.lastname: Nadra
authors.affiliation: Department of Cardiology, Victoria Heart Institute Foundation, Victoria, British Columbia, Canada; Department of Cardiology, Royal Jubilee Hospital, Victoria, British Columbia, Canada.
authors.forename: Jehangir N
authors.initials: JN
authors.lastname: Din
authors.affiliation: Department of Cardiology, Victoria Heart Institute Foundation, Victoria, British Columbia, Canada; Department of Cardiology, Royal Jubilee Hospital, Victoria, British Columbia, Canada.
authors.forename: Cara
authors.initials: C
authors.lastname: Hendry
authors.affiliation: Cardiac Services BC, Provincial Health Services Authority, Vancouver, British Columbia, Canada.
authors.forename: Lillian
authors.initials: L
authors.lastname: Ding
authors.affiliation: Department of Cardiology, Vancouver General Hospital, Vancouver, British Columbia, Canada.
authors.forename: Anthony
authors.initials: A
authors.lastname: Fung
authors.affiliation: Department of Cardiology, St. Paul's Hospital, Vancouver, British Columbia, Canada.
authors.forename: Eve
authors.initials: E
authors.lastname: Aymong
authors.affiliation: Department of Cardiology, Royal Columbian Hospital, Vancouver, British Columbia, Canada.
authors.forename: Albert W
authors.initials: AW
authors.lastname: Chan
authors.affiliation: Department of Cardiology, Kelowna General Hospital, Kelowna, British Columbia, Canada.
authors.forename: Steven
authors.initials: S
authors.lastname: Hodge
authors.affiliation: Department of Cardiology, Victoria Heart Institute Foundation, Victoria, British Columbia, Canada; Department of Cardiology, Royal Jubilee Hospital, Victoria, British Columbia, Canada.
authors.forename: Simon D
authors.initials: SD
authors.lastname: Robinson
authors.affiliation: Department of Cardiology, Victoria Heart Institute Foundation, Victoria, British Columbia, Canada; Department of Cardiology, Royal Jubilee Hospital, Victoria, British Columbia, Canada.
authors.forename: Anthony
authors.initials: A
authors.lastname: Della Siega
mesh_terms: D001955:British Columbia / Q000453:epidemiology; D020099:Coated Materials, Biocompatible; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D054855:Drug-Eluting Stents; D005500:Follow-Up Studies; D006801:Humans; D062645:Percutaneous Coronary Intervention / Q000379:methods*; D011108:Polymers; D011379:Prognosis; D011474:Prosthesis Design; D012189:Retrospective Studies; D020123:Sirolimus / Q000031:analogs & derivatives* / Q000494:pharmacology; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D020099:Coated Materials, Biocompatible; D011108:Polymers; C489443:zotarolimus; D020123:Sirolimus