title: Cardiothoracic ratio within the "normal" range independently predicts mortality in patients undergoing coronary angiography.
abstract: OBJECTIVE
  To determine whether cardiothoracic ratio (CTR), within the range conventionally considered normal, predicted prognosis in patients undergoing coronary angiography.
  
  
  METHODS
  Cohort study with a median of 7-years follow-up.
  
  
  METHODS
  Consecutive patients undergoing coronary angiography at Barts and The London National Health Service (NHS) Trust.
  
  
  METHODS
  1005 patients with CTRs measured by chest radiography, and who subsequently underwent coronary angiography. Of these patients, 7.3% had a CTR > or =0.5 and were excluded from the analyses.
  
  
  RESULTS
  All-cause mortality and coronary event (non-fatal myocardial infarction or coronary death). Adjustments were made for age, left ventricular dysfunction, ACE inhibitor treatment, body mass index, number of diseased coronary vessels and past coronary artery bypass graft.
  
  
  RESULTS
  The risk of death was increased among patients with a CTR in the upper part of the normal range. In total, 94 (18.9%) of those with a CTR below the median of 0.42 died compared with 120 (27.8%) of those with a CTR between 0.42 and 0.49 (log rank test p<0.001). After adjusting for potential confounders, this increased risk remained (adjusted HR 1.45, 95% CI 1.03 to 2.05). CTR, at values below 0.5, was linearly related to the risk of coronary event (test for trend p = 0.024).
  
  
  CONCLUSIONS
  In patients undergoing coronary angiography, CTR between 0.42 and 0.49 was associated with higher mortality than in patients with smaller hearts. There was evidence of a continuous increase in risk with higher CTR. These findings, along with those in healthy populations, question the conventional textbook cut-off point of > or =0.5 being an abnormal CTR.
authors.affiliation: Department of Epidemiology and Public Health, University College London, London, UK. j.zaman@ucl.ac.uk
authors.forename: M Justin S
authors.initials: MJ
authors.lastname: Zaman
authors.forename: Julie
authors.initials: J
authors.lastname: Sanders
authors.forename: Angela M
authors.initials: AM
authors.lastname: Crook
authors.forename: Gene
authors.initials: G
authors.lastname: Feder
authors.forename: Martin
authors.initials: M
authors.lastname: Shipley
authors.forename: Adam
authors.initials: A
authors.lastname: Timmis
authors.forename: Harry
authors.initials: H
authors.lastname: Hemingway
mesh_terms: D000886:Anthropometry / Q000379:methods*; D015331:Cohort Studies; D017023:Coronary Angiography / Q000401:mortality*; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000401:mortality* / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006321:Heart / Q000033:anatomy & histology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012016:Reference Values; D018570:Risk Assessment / Q000379:methods / Q000592:standards; D012307:Risk Factors; D016019:Survival Analysis; D013909:Thorax / Q000033:anatomy & histology*