Life-threatening angioedema induced by angiotensin-converting enzyme inhibitors: Characteristics and risk factors

Background: Angioedema induced by angiotensin-converting enzyme inhibitors (ACEIs) is a well-known phenomenon and roughly accounts for one-third of angioedema cases presenting to the emergency departments. This study aimed to characterize the patients with severe reactions that required hospitalization and tried to identify the risk factors for these life-threatening events. Methods: The records of all patients hospitalized with the diagnosis of angioedema over a 10-year period were retrospectively analyzed. Patients' characteristics as well as the characteristics of the angioedema-induced hospitalizations were studied. Results: In 46 of 165 patients (28%) the angioedema was ACEI induced. The severity of the event was mild in 12 patients (26%), moderate in 25 patients (54%), and severe in 9 patients (19%). Twelve patients (26%) were admitted to the intensive care unit and six patients (13%) underwent intubation. Epinephrine was administered to 13 patients (29%), steroids were administered to 40 patients (87%), and anti-histamines were administered to 36 patients (78%). One patient died as a consequence of the event (2%). Twenty patients (45%), including the deceased patient, had recurrent events of angioedema before admission. Obese patients had significantly more recurrent events compared with nonobese patients (p = 0.03). There was also a tendency for more severe events in the obese patients (p = 0.079). Diabetes was significantly associated with moderate-to-severe events (p = 0.009) whereas treatment with beta-blockers or diuretics was significantly associated with milder events (p = 0.007 and p = 0.044, respectively). Conclusion: The high recurrence rate of ACEI-induced angioedema preceding subsequent life-threatening events suggests underdiagnosis of this potentially fatal adverse reaction. Diabetes and probably obesity are risk factors for more severe events. Physicians following patients receiving ACEI should be more aware of possible shortcomings associated with these medications.