title: A validated simple model to predict coexistent coronary disease in patients undergoing mitral valve surgery.
abstract: OBJECTIVE
  The primary limitation of the American Heart Association/American College of Cardiology guidelines is specificity. To improve the selection process, we proposed a simple additive model including age (1 point for every 5 years above 50), male sex (2 points), hypercholesterolemia (2 points), angina (3 points), and electrocardiographic evidence of ischemia (3 points). We recommend screening angiography at 3 or more points. This model was previously derived from 359 patients at Papworth Hospital.
  
  
  METHODS
  The validation cohort was a consecutive series of patients who underwent mitral valve surgery at the Royal Brompton Hospital. Preoperative coronary angiography reports were obtained, and coronary disease was defined as luminal narrowing of 50% in 2 or more views. Sensitivities and specificities were calculated for the American Heart Association/American College of Cardiology criteria, the simple additive model, and a logistic regression model. Receiver operating characteristic curves were used to validate accuracy and compare discrimination with logistic regression.
  
  
  RESULTS
  From 1998 through 2003, angiographic details were available for 342 (86%) of 396 patients who underwent mitral valve surgery. The sensitivity and specificity of the American Heart Association/American College of Cardiology guidelines were 100% and 5%, respectively; those of the simple additive model were 91% and 44%, respectively; and those of logistic regression were 93% and 41%, respectively. The receiver operating characteristic areas for the simple additive and logistic regression model were 0.78 (95% confidence interval, 0.73-0.84) and 0.80 (95% confidence interval, 0.74-0.85), respectively.
  
  
  CONCLUSIONS
  This is the third independent cohort to highlight the poor specificity of the American Heart Association/American College of Cardiology guidelines. Although high sensitivity is achieved, the cost is the majority of patients requiring screening angiography. Our validated simple model improved the specificity and selection; however, this was achieved at the expense of decreased sensitivity.
authors.affiliation: Department of Cardiothoracic Surgery, Royal Brompton Hospital, London, United Kingdom. eric.lim@cvsnet.org
authors.forename: Eric
authors.initials: E
authors.lastname: Lim
authors.forename: Ayyaz
authors.initials: A
authors.lastname: Ali
authors.forename: Zain
authors.initials: Z
authors.lastname: Khalpey
authors.forename: Hutan
authors.initials: H
authors.lastname: Ashrafian
authors.forename: Christopher
authors.initials: C
authors.lastname: Jackson
authors.forename: Ziad
authors.initials: Z
authors.lastname: Ali
authors.forename: Themis
authors.initials: T
authors.lastname: Chamageorgakis
authors.forename: Francis
authors.initials: F
authors.lastname: Wells
authors.forename: John
authors.initials: J
authors.lastname: Pepper
authors.forename: Anthony
authors.initials: A
authors.lastname: Desouza
authors.forename: Neil
authors.initials: N
authors.lastname: Moat
mesh_terms: D000368:Aged; D003327:Coronary Disease / Q000150:complications* / Q000175:diagnosis*; D005260:Female; D006349:Heart Valve Diseases / Q000150:complications* / Q000601:surgery*; D006801:Humans; D008297:Male; D008943:Mitral Valve; D015233:Models, Statistical; D012680:Sensitivity and Specificity