Angiotensin-converting enzyme inhibitor (ACEi)-induced angioedema is a serious emergency that can cause life-threatening symptoms and death if not treated promptly. Potential treatment options for ACEi-induced angioedema include medications with limited evidence for use in this patient population. The purpose of this study was to evaluate the use, clinical efficacy, and angioedema-related medication costs of C1 esterase inhibitor (C1EI) for ACEi-induced angioedema.

This was a retrospective, propensity-matched cohort study comparing patients who received C1EI to those who did not receive C1EI for ACEi-induced angioedema. The primary outcome of interest was comparing the proportion of patients who required intubation secondary to ACEi-induced angioedema. Secondary endpoints of interest were also included.

After propensity score matching, 22 patients were stratified into both the non-C1EI group and C1EI group, respectively. There was no difference between the groups with respect to the proportion of intubation (13.6% in the C1EI group vs. 9.1% in the non-C1EI group, p > 0.999). Mean cost of angioedema-related medication therapy was higher in the C1EI group compared to the non-C1EI group [$8758.95 (± $2959.30) vs. $15.91 (± $7.32), p < 0.001].

In this retrospective cohort study, the use of C1EI for ACEi-induced angioedema did not demonstrate improved outcomes with respect to intubation and resulted in increased costs. Larger, multicenter, prospective studies are needed to further validate the results of this study and to provide more clarity on the role of C1EI therapy in ACEi-induced angioedema.