title: Smoking Paradox in Patients Hospitalized With Coronary Artery Disease or Acute Ischemic Stroke: Findings From Get With The Guidelines.
abstract: BACKGROUND
  Smoking is a potent risk factor for coronary artery disease (CAD) and acute ischemic stroke (AIS), but there are numerous reports of lower in-hospital mortality among smokers versus nonsmokers hospitalized for these events.
  
  
  RESULTS
  We analyzed all consecutive patients hospitalized with a first index CAD (n=158 054) or AIS (n=899 295) event in Get With The Guidelines from 2002 to 2012; 20.4% of AIS and 30.4% of patients with CAD were past-year smokers. Multivariable models and age-stratified analyses were used to estimate the adjusted odds ratio of in-hospital mortality in smokers versus nonsmokers. Smokers were younger, more often male, with fewer vascular risk factors, and were more likely to be admitted to hospitals that were large, academic, or in the South. In-hospital mortality was significantly lower among smokers in both CAD (2.7% versus 5.2%; P<0.0001) and AIS (3.5% versus 5.8%; P<0.0001). The difference between unadjusted and adjusted odds ratios for smoking (0.57 versus 0.86 in CAD; 0.56 versus 0.86 in AIS) indicates the presence of substantial confounding by age and other covariates, but a significant association of past-year smoking remained.
  
  
  CONCLUSIONS
  Among patients hospitalized with CAD and AIS, smoking is a risk factor for early age of onset, even among those with few vascular risk factors. The persistent association with lower in-hospital mortality after adjusted and stratified analyses probably represents residual unmeasured confounding, although a biological effect of smoking cannot be excluded. Further clinical and prospective population-based studies are needed to explore variables that contribute to outcomes in these patients.
authors.affiliation: From the Department of Neurology, Massachusetts General Hospital/Harvard Medical School, Boston (S.F.A., L.H.S.); Department of Clinical Neurosciences and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada (E.E.S.); Department of Epidemiology and Biostatistics, Michigan State University, East Lansing (M.J.R.); Duke Clinical Research Institute, Durham, NC (X.Z., Y.X., A.F.H.); Division of Cardiology, Brigham and Women's Hospital Heart and Vascular Institute, Boston, MA (D.L.B.); Harvard Medical School, Boston, MA (D.L.B.); and Division of Cardiology, Ronald Reagan-UCLA Medical Center (G.C.F.).
authors.forename: Syed F
authors.initials: SF
authors.lastname: Ali
authors.affiliation: From the Department of Neurology, Massachusetts General Hospital/Harvard Medical School, Boston (S.F.A., L.H.S.); Department of Clinical Neurosciences and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada (E.E.S.); Department of Epidemiology and Biostatistics, Michigan State University, East Lansing (M.J.R.); Duke Clinical Research Institute, Durham, NC (X.Z., Y.X., A.F.H.); Division of Cardiology, Brigham and Women's Hospital Heart and Vascular Institute, Boston, MA (D.L.B.); Harvard Medical School, Boston, MA (D.L.B.); and Division of Cardiology, Ronald Reagan-UCLA Medical Center (G.C.F.).
authors.forename: Eric E
authors.initials: EE
authors.lastname: Smith
authors.affiliation: From the Department of Neurology, Massachusetts General Hospital/Harvard Medical School, Boston (S.F.A., L.H.S.); Department of Clinical Neurosciences and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada (E.E.S.); Department of Epidemiology and Biostatistics, Michigan State University, East Lansing (M.J.R.); Duke Clinical Research Institute, Durham, NC (X.Z., Y.X., A.F.H.); Division of Cardiology, Brigham and Women's Hospital Heart and Vascular Institute, Boston, MA (D.L.B.); Harvard Medical School, Boston, MA (D.L.B.); and Division of Cardiology, Ronald Reagan-UCLA Medical Center (G.C.F.).
authors.forename: Mathew J
authors.initials: MJ
authors.lastname: Reeves
authors.affiliation: From the Department of Neurology, Massachusetts General Hospital/Harvard Medical School, Boston (S.F.A., L.H.S.); Department of Clinical Neurosciences and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada (E.E.S.); Department of Epidemiology and Biostatistics, Michigan State University, East Lansing (M.J.R.); Duke Clinical Research Institute, Durham, NC (X.Z., Y.X., A.F.H.); Division of Cardiology, Brigham and Women's Hospital Heart and Vascular Institute, Boston, MA (D.L.B.); Harvard Medical School, Boston, MA (D.L.B.); and Division of Cardiology, Ronald Reagan-UCLA Medical Center (G.C.F.).
authors.forename: Xin
authors.initials: X
authors.lastname: Zhao
authors.affiliation: From the Department of Neurology, Massachusetts General Hospital/Harvard Medical School, Boston (S.F.A., L.H.S.); Department of Clinical Neurosciences and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada (E.E.S.); Department of Epidemiology and Biostatistics, Michigan State University, East Lansing (M.J.R.); Duke Clinical Research Institute, Durham, NC (X.Z., Y.X., A.F.H.); Division of Cardiology, Brigham and Women's Hospital Heart and Vascular Institute, Boston, MA (D.L.B.); Harvard Medical School, Boston, MA (D.L.B.); and Division of Cardiology, Ronald Reagan-UCLA Medical Center (G.C.F.).
authors.forename: Ying
authors.initials: Y
authors.lastname: Xian
authors.affiliation: From the Department of Neurology, Massachusetts General Hospital/Harvard Medical School, Boston (S.F.A., L.H.S.); Department of Clinical Neurosciences and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada (E.E.S.); Department of Epidemiology and Biostatistics, Michigan State University, East Lansing (M.J.R.); Duke Clinical Research Institute, Durham, NC (X.Z., Y.X., A.F.H.); Division of Cardiology, Brigham and Women's Hospital Heart and Vascular Institute, Boston, MA (D.L.B.); Harvard Medical School, Boston, MA (D.L.B.); and Division of Cardiology, Ronald Reagan-UCLA Medical Center (G.C.F.).
authors.forename: Adrian F
authors.initials: AF
authors.lastname: Hernandez
authors.affiliation: From the Department of Neurology, Massachusetts General Hospital/Harvard Medical School, Boston (S.F.A., L.H.S.); Department of Clinical Neurosciences and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada (E.E.S.); Department of Epidemiology and Biostatistics, Michigan State University, East Lansing (M.J.R.); Duke Clinical Research Institute, Durham, NC (X.Z., Y.X., A.F.H.); Division of Cardiology, Brigham and Women's Hospital Heart and Vascular Institute, Boston, MA (D.L.B.); Harvard Medical School, Boston, MA (D.L.B.); and Division of Cardiology, Ronald Reagan-UCLA Medical Center (G.C.F.).
authors.forename: Deepak L
authors.initials: DL
authors.lastname: Bhatt
authors.affiliation: From the Department of Neurology, Massachusetts General Hospital/Harvard Medical School, Boston (S.F.A., L.H.S.); Department of Clinical Neurosciences and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada (E.E.S.); Department of Epidemiology and Biostatistics, Michigan State University, East Lansing (M.J.R.); Duke Clinical Research Institute, Durham, NC (X.Z., Y.X., A.F.H.); Division of Cardiology, Brigham and Women's Hospital Heart and Vascular Institute, Boston, MA (D.L.B.); Harvard Medical School, Boston, MA (D.L.B.); and Division of Cardiology, Ronald Reagan-UCLA Medical Center (G.C.F.).
authors.forename: Gregg C
authors.initials: GC
authors.lastname: Fonarow
authors.affiliation: From the Department of Neurology, Massachusetts General Hospital/Harvard Medical School, Boston (S.F.A., L.H.S.); Department of Clinical Neurosciences and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada (E.E.S.); Department of Epidemiology and Biostatistics, Michigan State University, East Lansing (M.J.R.); Duke Clinical Research Institute, Durham, NC (X.Z., Y.X., A.F.H.); Division of Cardiology, Brigham and Women's Hospital Heart and Vascular Institute, Boston, MA (D.L.B.); Harvard Medical School, Boston, MA (D.L.B.); and Division of Cardiology, Ronald Reagan-UCLA Medical Center (G.C.F.). lschwamm@partners.org.
authors.forename: Lee H
authors.initials: LH
authors.lastname: Schwamm
mesh_terms: D000208:Acute Disease; D017668:Age of Onset; D000368:Aged; D015331:Cohort Studies; D015986:Confounding Factors, Epidemiologic; D003324:Coronary Artery Disease / Q000453:epidemiology* / Q000401:mortality; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007511:Ischemia / Q000453:epidemiology* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012907:Smoking / Q000453:epidemiology* / Q000401:mortality; D020521:Stroke / Q000453:epidemiology* / Q000401:mortality
keywords: coronary artery disease; mortality; risk factor; smoking; stroke