Chronic angiotensin-converting enzyme inhibitor or angiotensin receptor blocker therapy combined with diuretic therapy is associated with increased episodes of hypotension in noncardiac surgery

Objectives: Chronic angiotensin-converting enzyme inhibitor (ACE-I) or angiotensin receptor blocker (ARB) therapy has been reported to result in intraoperative hypotension in patients undergoing general anesthesia. This study evaluated the association between ACE-I/ARB therapy and the hemodynamics of patients undergoing noncardiac surgery using a large patient dataset. Design and Setting: A prospective, observational study performed at a single tertiary care hospital. Participants: All adult patients undergoing noncardiac surgery. Interventions: None. Measurements and Main Results: Propensity score matching for the likelihood of chronic ACE-I/ARB therapy was used to create 2 patient cohorts with similar cardiovascular and pulmonary comorbidities. The number of periods of absolute and relative hypotension, vasopressor requirements, and postoperative myocardial infarction and renal failure rates were compared among patients with and without ACE-I/ARB therapy. A total of 65,043 noncardiac cases be-tween 2003 and 2006 were included. Two-digit propensity score matching resulted in a study population of 12,381 operative cases with very similar cardiovascular comorbidities between the ACE-I/ARB and control cohort. Patients with chronic ACE-I/ARB and diuretic therapy showed more periods with a mean arterial pressure <70 mmHg, periods with a 40% decrease in systolic blood pressure, periods with a 50% decrease in systolic blood pressure, and vasopressor boluses when compared with patients with diuretic therapy alone. There were no statistically significant differences in the rates of postoperative myocardial infarction or renal failure between patients with and without ACE-I/ARB therapy. Conclusions: Chronic diuretic therapy is associated with more frequent hypotension in ACE-I/ARB-treated patients undergoing noncardiac surgery. (C) 2008 Elsevier Inc. All rights reserved.