(1503) Evaluation of Angiotensin II for Vasoplegic Shock After Cardiac Surgery

Introduction: Vasoplegic syndrome is a complication that occurs in up to 50% of patients that undergo cardiothoracic surgery and is associated with increased morbidity and mortality. Data supporting the use of angiotensin II (ATII) for vasoplegia is limited to a post-hoc analysis and case reports.

Methods: This IRB-approved retrospective chart review included adult patients who had cardiac surgery within 48 hours of suspected vasoplegic shock and treated with ATII for ≥3 hrs between September 2020 and August 2022. The primary objective was to assess resolution of hypotension (responders), defined as patients who achieved the mean arterial pressure (MAP) goal or had an increase in MAP of greater than or equal to 10 mmHg at treatment hour 3, without an increase in background vasopressors. Secondary analysis included time to hypotension resolution, dosing of ATII and adverse events such as arrhythmias or thrombosis. Descriptive statistics were used to characterize the data. Mann-Whitney U test was used to compare continuous variables and Chi-squared was used to compare categorical variables.

Results: Nineteen patients were reviewed and a total of 16 patients were included in the analysis. At three hrs after ATII initiation, 10 (62.5%) of patients were responders and 6 (37.5%) were not with a median time to hypotension resolution of 2 hours. The overall initial median (interquartile range [IQR]) starting dose of ATII was 12.5 ng/kg/min (10-20.5) with a maximum dose of 37.5 ng/kg/min (22-55). The median starting dose in the responder group was 10 ng/kg/min vs 20 ng/kg/min in the non-responder group. Three patients experienced adverse reactions. More patients received methylene blue prior to ATII in the responder group than in the non-responder group [8 (80%) vs. 2 (33%); X2= 4.21, p = 0.04]. Non-responders had a longer median cardiopulmonary bypass time compared to responders [193 min (175-205) vs. 146 min (76-180), p < 0.001].

Conclusions: The majority of patients were considered responders to ATII, however this group received more methylene blue and had a significantly shorter cardiopulmonary bypass time compared to non-responders.