Effectiveness of Tranexamic Acid for Renin-Angiotensin-Aldosterone System Inhibitor–Associated Angioedema

There are currently no direct treatments for renin-angiotensin-aldosterone system inhibitor associated angioedema (RAAS-AE). Tranexamic acid (TXA) has been proposed as a treatment option; however, there are limited studies evaluating its effectiveness in this setting. The objective of this study was to evaluate the effect of TXA on intubation rates in the emergency department for patients presenting with RAAS inhibitor associated angioedema.

This was a retrospective cohort study that evaluated patients between January 2018 and June 2025. Patients were at least 18 years of age, presented to a United States based Cleveland Clinic emergency department, and were diagnosed with RAAS-AE by ICD.10 code or clinical impression in provider documentation. Patients were excluded if they had a history of hereditary or idiopathic angioedema, chronic tracheostomy, or left the hospital against medical advice. Patients were randomized into two groups of 110 patients; those that received TXA and those that did not. The primary outcome of this study was the rate of intubation in each group. Secondary outcomes included hospital and ICU admission rates and lengths of stay, in-hospital mortality rates, and difference in blood pressure before and after TXA administration. Baseline characteristics were analyzed using descriptive statistics, categorical data were analyzed using Fisher’s exact test, and continuous data were analyzed using a paired t-test.

After exclusions, 105 patients remained in the TXA group and 108 patients in the no TXA group. Intubation occurred in 14 patients in the TXA group and 9 patients in the no TXA group (OR 1.7; 95% CI 0.7 - 4.1). Seventy-seven patients were admitted to the hospital in the TXA group vs 51 patients in the no TXA group (OR 3.1; 95% CI 2.6 - 3.6). There was no statistical difference in ICU admission rates, median ICU, or median hospital lengths of stay. No in-hospital mortality occurred in either group. Median blood pressure difference pre-/post-TXA was –7 mmHg. Final results will be available at time of presentation.

There were no significant differences in intubation rates between groups; however, there may have been provider bias based on severity of presentation where patients with more severe symptoms may have been more likely to receive TXA. TXA is safe when used for RAAS-AE; however, more studies are needed for a definitive treatment role.