title: Predictors of intraoperative hypotension and bradycardia.
abstract: BACKGROUND
  Perioperative hypotension and bradycardia in the surgical patient are associated with adverse outcomes, including stroke. We developed and evaluated a new preoperative risk model in predicting intraoperative hypotension or bradycardia in patients undergoing elective noncardiac surgery.
  
  
  METHODS
  Prospective data were collected in 193 patients undergoing elective, noncardiac surgery. Intraoperative hypotension was defined as systolic blood pressure <90 mm Hg for >5 minutes or a 35% decrease in the mean arterial blood pressure. Intraoperative bradycardia was defined as a heart rate of <60 beats/min for >5 minutes. A logistic regression model was developed for predicting intraoperative hypotension or bradycardia with bootstrap validation. Model performance was assessed using area under the receiver operating curves and Hosmer-Lemeshow tests.
  
  
  RESULTS
  A total of 127 patients developed hypotension or bradycardia. The average age of participants was 67.6 ± 11.3 years, and 59.1% underwent major surgery. A final 5-item score was developed, including preoperative Heart rate (<60 beats/min), preoperative hypotension (<110/60 mm Hg), Elderly age (>65 years), preoperative renin-Angiotensin blockade (angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, or beta-blockers), Revised cardiac risk index (≥3 points), and Type of surgery (major surgery), entitled the "HEART" score. The HEART score was moderately predictive of intraoperative bradycardia or hypotension (odds ratio, 2.51; 95% confidence interval, 1.79-3.53; C-statistic, 0.75). Maximum points on the HEART score were associated with an increased likelihood ratio for intraoperative bradycardia or hypotension (likelihood ratio, +3.64).
  
  
  CONCLUSIONS
  The 5-point HEART score was predictive of intraoperative hypotension or bradycardia. These findings suggest a role for using the HEART score to better risk-stratify patients preoperatively and may help guide decisions on perioperative management of blood pressure and heart rate-lowering medications and anesthetic agents.
authors.affiliation: Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Cheung
authors.affiliation: Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Alan
authors.initials: A
authors.lastname: Martyn
authors.affiliation: Department of Medicine and Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Norman
authors.initials: N
authors.lastname: Campbell
authors.affiliation: Department of Medicine, University of Minnesota and HealthPartners, Minneapolis.
authors.forename: Shaun
authors.initials: S
authors.lastname: Frost
authors.affiliation: Department of Medicine, Western University, London, Ontario, Canada.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Gilbert
authors.affiliation: Department of Hospital Medicine, Medicine Institute, Cleveland Clinic, Cleveland, Ohio.
authors.forename: Franklin
authors.initials: F
authors.lastname: Michota
authors.affiliation: Department of Anesthesia, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Douglas
authors.initials: D
authors.lastname: Seal
authors.affiliation: Department of Medicine and Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada; Department of Community Health Sciences, University of Calgary, Calgary, Alberta, Canada.
authors.forename: William
authors.initials: W
authors.lastname: Ghali
authors.affiliation: Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada. Electronic address: nakhanubc@gmail.com.
authors.forename: Nadia A
authors.initials: NA
authors.lastname: Khan
mesh_terms: D000368:Aged; D001919:Bradycardia / Q000453:epidemiology*; D003661:Decision Support Techniques; D017558:Elective Surgical Procedures; D005260:Female; D006801:Humans; D007022:Hypotension / Q000453:epidemiology*; D007431:Intraoperative Complications / Q000453:epidemiology*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012372:ROC Curve; D018570:Risk Assessment
keywords: Bradycardia; Hypotension; Risk stratification