title: The impact of acute preoperative beta- blockade on perioperative cardiac morbidity and all-cause mortality in hypertensive South African vascular surgery patients.
abstract: BACKGROUND
  Acute β-blockade has been associated with poor perioperative outcomes in non-cardiac surgery patients, probably as a result of P-blocker-induced haemodynamic instability during the perioperative period, which has been shown to be more severe in hypertensive patients.
  
  
  OBJECTIVE
  To determine the impact of acute preoperative β-blockade on the incidence of perioperative cardiovascular morbidity and all-cause mortality in hypertensive South African (SA) patients who underwent vascular surgery at a tertiary hospital.
  
  
  METHODS
  We conducted two separate case-control analyses to determine the impact of acute preoperative β-blockade on the incidence of major adverse cardiovascular events (MACEs, a composite outcome of a perioperative troponin-I leak or all-cause mortality) and perioperative troponin-I leak alone. Case and control groups were compared using χ2, Fisher's exact, McNemar's or Student's t-tests, where applicable. Binary logistic regression was used to determine whether acute preoperative -blocker use was an independent predictor of perioperative MACEs/troponin-I leak in hypertensive SA vascular surgery patients.
  
  
  RESULTS
  We found acute preoperative β-blockade to be an independent predictor of perioperative MACEs (odds ratio (OR) 3.496; 95% confidence interval (CI) 1.948 - 6.273; p<0.001) and troponin-I leak (OR 5.962; 95% CI 3.085 - 11.52; p<0.001) in hypertensive SA vascular surgery patients.
  
  
  CONCLUSIONS
  Our findings suggest that acute preoperative β-blockade is associated with an increased risk of perioperative cardiac morbidity and all-cause mortality in hypertensive SA vascular surgery patients.
authors.forename: Y
authors.initials: Y
authors.lastname: Moodley
authors.forename: B M
authors.initials: BM
authors.lastname: Biccard