title: The effect of angiotensin-converting enzyme inhibitor on hemodynamic instability in patients undergoing cardiopulmonary bypass: results of a dose-comparison study.
abstract: BACKGROUND
  Recently, hemodynamic instability including hypotension and its effect on the clinical outcome in patients treated with angiotensin-converting enzyme inhibitors (ACEIs) during coronary artery bypass graft (CABG) has been described. However, no analysis has examined the dose of ACEIs and its risk of hypotension. In this study, we tested the hypothesis that a higher dose of ACEIs could lead to increased episodes of hypotension.
  
  
  METHODS
  A total of 300 patients scheduled for CABG were studied prospectively. They were divided into 3 groups according to their preoperative use of different doses of ACEIs. The demographic and medical characteristics were compared between these 3 groups. During CABG and throughout the intensive care unit (ICU), vasoconstrictors were infused in patients undergoing hypotension (mean arterial pressure [MAP] < 65 mm Hg or >30% below baseline). The predictive factors responsible for hypotension were investigated separately using univariate and multivariate logistic regression models.
  
  
  RESULTS
  The 3 groups were similar with regard to the patients' demographic and medical characteristics. The patients treated with ACEIs were more likely to develop hypotension (73% of high dose and 47% of low dose) in the operating room than those without ACEIs (30%). However, in the ICU, there was no significant association between hemodynamic changes and ACEIstreated patients. Other independent risk factors identified for hypotension were ejection fraction, history of myocardial infarction, coronary grafting count, and pump time during surgery and/or ICU admission.
  
  
  CONCLUSIONS
  Hemodynamic changes during CABG were observed to be directly proportional to the dosage of ACEIs prescribed preoperatively.
authors.affiliation: Cardiovascular Surgery Department, Shaheed Modarress Hospital, Shaheed Beheshti Medical University, Tehran, Iran.
authors.forename: Mehran
authors.initials: M
authors.lastname: Shahzamani
authors.forename: Zohreh
authors.initials: Z
authors.lastname: Yousefi
authors.forename: Azam Noori
authors.initials: AN
authors.lastname: Frootaghe
authors.forename: Elnaz
authors.initials: E
authors.lastname: Jafarimehr
authors.forename: Mahnoosh
authors.initials: M
authors.lastname: Froughi
authors.forename: Farhood
authors.initials: F
authors.lastname: Tofighi
authors.forename: Ali N
authors.initials: AN
authors.lastname: Azadani
authors.forename: Mohamad Amin
authors.initials: MA
authors.lastname: Pourhoseingholi
authors.forename: Peyman Nejatbakhsh
authors.initials: PN
authors.lastname: Azadani
mesh_terms: D000368:Aged; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage* / Q000009:adverse effects; D001794:Blood Pressure / Q000187:drug effects*; D002216:Captopril / Q000008:administration & dosage* / Q000009:adverse effects; D002315:Cardiopulmonary Bypass / Q000009:adverse effects; D001026:Coronary Artery Bypass / Q000009:adverse effects; D003422:Critical Care; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007022:Hypotension / Q000139:chemically induced* / Q000188:drug therapy / Q000503:physiopathology; D007432:Intraoperative Period; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D016896:Treatment Outcome; D014662:Vasoconstrictor Agents / Q000008:administration & dosage
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D014662:Vasoconstrictor Agents; D002216:Captopril