Hemodynamic Consequences of Continuing Angiotensin Inhibitors in a NonCardiac Surgical Population

Abstract

BACKGROUND: Despite widespread use of angiotensin converting enzyme inhibitors and angiotensin II receptor antagonists (ACEI/ARBs), controversy exists on the optimal perioperative management of these agents due to their association with post-induction hypotension during non-cardiac surgery. Additionally, it is unknown if elderly patients taking ACEI/ARBs are at increased risk of this adverse event compared to younger surgical patients. OBJECTIVES: To determine if ACEI/ARBs should be continued or held on the morning of non-cardiac surgery. Primary outcome was post-induction hypotension rates within 30 minutes taken at 5 minute intervals. Secondary outcomes were vasopressor use at 0-15 or 16-30 minutes and death by any cause, cardiac events, or stroke occurring during surgery or until time of hospital discharge. Outcomes for patients less than 65 years were compared to patients 65 years of age or older. METHODS: A retrospective chart review was performed at Trillium Health Partners – Credit Valley Hospital from October 2014 to June 2015. Adult patients taking chronic ACEI/ARBs therapy and undergoing elective surgery with post-surgical admission to an inpatient ward were included. RESULTS: A total of 395 patients were included. Hypotension rates in patients who received ACEI/ARBs prior to surgery were 34.8% compared to 26.7%, in patients who had their ACEI/ARB held prior to surgery (P=0.068). Continuation of ACEI/ARBs on the morning of surgery was not associated with increased vasopressor use (P= 0.151), cardiac events, stroke, or death (P=0.268). There were no differences in primary or secondary outcomes based on patient age. Previously published hypotension rates were higher than collected rates suggesting the study was underpowered to detect statistically significant differences in outcomes. Vasopressor use increased when systolic blood pressure was less than 90 mmHg. CONCLUSION: In patients who continued ACEI/ARBs on the morning of surgery, there was a non- significant trend towards an increased risk of post-induction hypotension. With continued data collection, this study has the potential to optimize perioperative management of ACEI/ARBs and prevent adverse outcomes.