title: Combining clinical and angiographic variables for estimating risk of target lesion revascularization after drug eluting stent placement.
abstract: BACKGROUND
  Drug-eluting stents (DES) reduce restenosis but require prolonged antiplatelet therapy, when compared with bare metal stents. Ideally, the patient should be involved in this risk:benefit assessment prior to selecting DES, to maximize the benefits and cost-effectiveness of care, and to improve medication adherence. However, accurate estimation of restenosis risk may require angiographic factors identified at cardiac catheterization.
  
  
  METHODS
  In a large PCI registry, we used logistic regression to identify clinical and angiographic predictors of clinically-driven target lesion revascularization (TLR) over the first year after stent placement. Discrimination c-statistic and integrated discrimination improvement (IDI) were used to calculate the incremental utility of angiographic variables when added to clinical predictors.
  
  
  RESULTS
  Of 8501 PCI patients, TLR occurred in 4.5%. After adjusting for DES use, clinical TLR predictors were younger age, female sex, diabetes, prior PCI, and prior bypass surgery (model c-statistic 0.630). Angiographic predictors were vein graft PCI, in-stent restenosis lesion, longer stent length, and smaller stent diameter (c-statistic 0.650). After adding angiographic factors to the clinical model, c-statistic improved to 0.680 and the average separation in TLR risk among patients with and without TLR improved by 1% (IDI=0.010, 95% CI 0.009-0.014), primarily driven by those experiencing TLR (from 5.9% to 6.9% absolute risk).
  
  
  CONCLUSIONS
  Among unselected PCI patients, the incidence of clinically-indicated TLR is <5% at 1-year, and standard clinical variables only moderately discriminate who will and will not experience TLR. Angiographic variables significantly improve TLR risk assessment, suggesting that stent selection may be best performed after coronary anatomy has been delineated.
  Although several recent studies have challenged traditional expectations regarding the duration of dual antiplatelet therapy, current guidelines recommend at least 6 to 12months of treatment after implantation of a drug eluting stent, with a shorter course for bare metal stents. Stent selection ideally should involve input from the patient receiving these stents, but multiple studies have suggested that angiographic factors - obtained after the patient has received sedation during the diagnostic catheterization - are important predictors of repeat revascularization. In this analysis from a large registry of patients receiving coronary stents, angiographic characteristics were found to significantly improve risk assessment for target lesion revascularization, when added to clinical variables alone.
authors.affiliation: Mercy Heart and Vascular, Washington, MO, United States; Saint Louis University, St. Louis, MO, United States. Electronic address: jstolker@yahoo.com.
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Stolker
authors.affiliation: Saint Luke's Mid America Heart Institute, Kansas City, MO, United States; University of Missouri-Kansas City, Kansas City, MO, United States. Electronic address: dcohen@saint-lukes.org.
authors.forename: David J
authors.initials: DJ
authors.lastname: Cohen
authors.affiliation: Saint Luke's Mid America Heart Institute, Kansas City, MO, United States. Electronic address: kfkennedy@saint-lukes.org.
authors.forename: Kevin F
authors.initials: KF
authors.lastname: Kennedy
authors.affiliation: Duke Clinical Research Institute, Duke University, Durham, NC, United States. Electronic address: michael.pencina@duke.edu.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Pencina
authors.affiliation: Saint Luke's Mid America Heart Institute, Kansas City, MO, United States. Electronic address: suz.v.arnold@gmail.com.
authors.forename: Suzanne V
authors.initials: SV
authors.lastname: Arnold
authors.affiliation: Methodist DeBakey Heart and Vascular Center, Houston, TX, United States. Electronic address: NKleiman@houstonmethodist.org.
authors.forename: Neal S
authors.initials: NS
authors.lastname: Kleiman
authors.affiliation: Saint Luke's Mid America Heart Institute, Kansas City, MO, United States; University of Missouri-Kansas City, Kansas City, MO, United States. Electronic address: spertusj@umkc.edu.
authors.forename: John A
authors.initials: JA
authors.lastname: Spertus
mesh_terms: D000368:Aged; D016009:Chi-Square Distribution; D017023:Coronary Angiography; D023903:Coronary Restenosis / Q000209:etiology; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D054855:Drug-Eluting Stents; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects / Q000295:instrumentation*; D011237:Predictive Value of Tests; D011474:Prosthesis Design; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States
keywords: Drug-eluting stent; Percutaneous coronary intervention; Restenosis; Risk assessment