title: A dilated inferior vena cava is a marker of poor survival.
abstract: BACKGROUND
  The inferior vena cava (IVC) morphology is often used to estimate right atrial pressure; however, the association of IVC morphology and outcome is poorly described.
  
  
  METHODS
  We evaluated 4383 consecutive outpatients (98% men) undergoing echocardiography at 1 of 3 Veterans Affairs laboratories.
  
  
  RESULTS
  Of the 3729 with adequate images, 3295 (88%) had a normal IVC (< 2 cm), 358 (10%) had a dilated IVC that collapsed at least 50% with inspiration, and 76 (2%) had dilated IVC that did not collapse. Compared with patients with a normal IVC, those with a dilated IVC were older (66 +/- 13 vs 69 +/- 12 years if dilated with collapse and 70 +/- 12 years if dilated without collapse, P = .0005) and were more likely to have a history of heart failure (11% vs 18% if dilated with collapse and 38% if dilated without collapse, P < .0001). The 90-day and 1-year survival rates were 99% and 95% for those with a normal IVC, 98% and 91% for those with a dilated IVC with collapse, and 89% and 67% for those with a dilated IVC without collapse (P < .0001). After adjustment for clinical and echocardiographic characteristics including left and right ventricular function and pulmonary artery pressure, a dilated IVC without collapse remained associated with increased mortality: hazard ratio 1.43 (1.29-1.57 compared with a normal IVC, P < .0001).
  
  
  CONCLUSIONS
  A dilated IVC without collapse with inspiration is associated with worse survival in men independent of a history of heart failure, other comorbidities, ventricular function, and pulmonary artery pressure.
authors.affiliation: University of Kansas Medical Center, Kansas City, KS 66213, USA. jnath@kumc.edu
authors.forename: Jayant
authors.initials: J
authors.lastname: Nath
authors.forename: James L
authors.initials: JL
authors.lastname: Vacek
authors.forename: Paul A
authors.initials: PA
authors.lastname: Heidenreich
mesh_terms: D000368:Aged; D016280:Atrial Function, Right; D005260:Female; D006325:Heart Atria / Q000473:pathology; D006333:Heart Failure / Q000401:mortality; D006352:Heart Ventricles / Q000473:pathology; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D016019:Survival Analysis; D014463:Ultrasonography; D014682:Vena Cava, Inferior / Q000000981:diagnostic imaging / Q000473:pathology*; D016277:Ventricular Function, Left