title: The prognostic importance of weight loss in coronary artery disease: a systematic review and meta-analysis.
abstract: OBJECTIVE
  To assess the prognostic impact of weight loss on clinical outcomes in patients with coronary artery disease (CAD).
  
  
  METHODS
  We performed a systematic review and meta-analysis of the prognostic effects of weight loss in patients with CAD on a composite outcome of all-cause mortality, cardiovascular mortality, and major adverse cardiac events considering studies published between January 1, 1964, and August 8, 2013. We considered weight loss "intentional" when it occurred in the presence of programmed therapeutic lifestyle changes and "observational" when no such intervention was specified.
  
  
  RESULTS
  We searched 1218 abstracts, of which 12 studies with 14 cohorts met the inclusion criteria. A total of 35,335 patients (mean age, 64 years; 72% male; body mass index [BMI], 30; 3.2 years of follow-up) were included. Overall, weight loss was associated with a greater risk of the composite outcome (relative risk [RR], 1.30; 95% CI, 1.00-1.69; P=.05). However, heterogeneity was high (I(2)=90%) and was substantially explained by weight loss intentionality. Presumed intentional weight loss (4 cohorts) was associated with improved outcomes (RR, 0.67; 95% CI, 0.56-0.80; P<.001), whereas observational weight loss (10 cohorts) was associated with worsened outcomes (RR, 1.62; 95% CI, 1.26-2.08; P<.001; interaction P<.001).
  
  
  CONCLUSIONS
  Whereas observational weight loss is associated with increased adverse cardiovascular events, intentional weight loss is associated with lower clinical events. These results suggest that the underlying mechanism of weight loss (ie, intentional or unintentional) affects its impact on subsequent risk in persons with known CAD.
authors.affiliation: Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic, Rochester, MN; Division of Cardiology, Department of Medicine, Baystate Medical Center, Springfield, MA.
authors.forename: Quinn R
authors.initials: QR
authors.lastname: Pack
authors.affiliation: Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic, Rochester, MN; Department of Medicine, Mount Sinai Medical Center, Miami, FL.
authors.forename: Juan Pablo
authors.initials: JP
authors.lastname: Rodriguez-Escudero
authors.affiliation: Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic, Rochester, MN.
authors.forename: Randal J
authors.initials: RJ
authors.lastname: Thomas
authors.affiliation: Division of Cardiology, University of Vermont College of Medicine, Fletcher Allen Health Care, Burlington, VT.
authors.forename: Philip A
authors.initials: PA
authors.lastname: Ades
authors.affiliation: Division of General Internal Medicine, Department of Medicine, Mayo Clinic, Rochester, MN; Division of Biomedical Statistics and Informatics, Department of Health Sciences Research, Mayo Clinic, Rochester, MN.
authors.forename: Colin P
authors.initials: CP
authors.lastname: West
authors.affiliation: Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic, Rochester, MN.
authors.forename: Virend K
authors.initials: VK
authors.lastname: Somers
authors.affiliation: Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic, Rochester, MN. Electronic address: Lopez@mayo.edu.
authors.forename: Francisco
authors.initials: F
authors.lastname: Lopez-Jimenez
mesh_terms: D015992:Body Mass Index; D003324:Coronary Artery Disease / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control; D014943:Global Health; D006801:Humans; D009017:Morbidity / Q000639:trends; D009765:Obesity / Q000150:complications / Q000453:epidemiology / Q000628:therapy; D011379:Prognosis; D015431:Weight Loss