Multicenter study of patients with angiotensin-converting enzyme inhibitor-induced angioedema who present to the emergency department

Unilateral tongue swelling: an unusual presentation of angiotensin-converting enzyme inhibitor-related angioedema

Angioedema is a rare but potentially fatal complication of angiotensin-converting enzyme inhibitor (ACEi) treatment. This class of drugs is widely used in the treatment of hypertension, cardiac failure and other common conditions.This case report discusses a male patient in his 60s who presented with acute swelling of the right side of his tongue, an unusual manifestation of angioedema, which typically involves bilateral swelling of orofacial structures.Accurate and early identification of this complication affords the opportunity for early, potentially life-saving intervention during the acute episode and also cessation of the treatment, reducing the risk of recurrence in the future.This case is one of only a few reported in English language medical literature and the first from Africa, suggesting either rarity or under-reporting. The case contributes to the understanding of ACEi-induced angioedema, particularly in Africa where hypertension is prevalent and ACEi is commonly used.

Advances in the structural basis for angiotensin-1 converting enzyme (ACE) inhibitors

Human somatic angiotensin-converting enzyme (ACE) is a key zinc metallopeptidase that plays a pivotal role in the renin-angiotensin-aldosterone system (RAAS) by regulating blood pressure and electrolyte balance. Inhibition of ACE is a cornerstone in the management of hypertension, cardiovascular diseases, and renal disorders. Recent advances in structural biology techniques have provided invaluable insights into the molecular mechanisms underlying ACE inhibition, facilitating the design and development of more effective therapeutic agents. This review focuses on the latest advancements in elucidating the structural basis for ACE inhibition. High-resolution crystallographic studies of minimally glycosylated individual domains of ACE have revealed intricate molecular details of the ACE catalytic N- and C-domains, and their detailed interactions with clinically relevant and newly designed domain-specific inhibitors. In addition, the recently elucidated structure of the glycosylated form of full-length ACE by cryo-electron microscopy (cryo-EM) has shed light on the mechanism of ACE dimerization and revealed continuous conformational changes which occur prior to ligand binding. In addition to these experimental techniques, computational approaches have also played a pivotal role in elucidating the structural basis for ACE inhibition. Molecular dynamics simulations and computational docking studies have provided atomic details of inhibitor binding kinetics and energetics, facilitating the rational design of novel ACE inhibitors with improved potency and selectivity. Furthermore, computational analysis of the motions observed by cryo-EM allowed the identification of allosteric binding sites on ACE. This affords new opportunities for the development of next-generation allosteric inhibitors with enhanced pharmacological properties. Overall, the insights highlighted in this review could enable the rational design of novel ACE inhibitors with improved efficacy and safety profiles, ultimately leading to better therapeutic outcomes for patients with hypertension and cardiovascular diseases.

Tranexamic acid for angiotensin converting enzyme inhibitor induced angioedema: A retrospective multicenter study

BACKGROUND

Angiotensin converting enzyme inhibitors (ACE-Is) prevent the breakdown of bradykinin and can lead to life threatening angioedema. Tranexamic acid is an antifibrinolytic that inhibits formation of precursors involved in bradykinin synthesis and, in case reports, has been described as a potential treatment for ACE-I angioedema.

METHODS

This retrospective study included patients who presented to the emergency department (ED) from January 2018 to August 2021 with angioedema while taking an ACE-I. Patients who received tranexamic acid (treatment group) were compared with patients who did not receive tranexamic acid (control group). Primary outcome was length of stay (LOS). Secondary outcomes evaluated included ICU admissions, intubations, and safety events.

RESULTS

A total of 262 patients were included in this study (73 treatment; 189 control). Overall, the median ED LOS was longer in the treatment group than controls (20.9 h vs 4.8 h, p < 0.001). ICU admission rates were higher in the treatment group (45% vs 16%, p < 0.001). More patients were intubated in the treatment group (12% vs 3%, p = 0.018). No difference was seen between the treatment group and the controls for return within 7 days, complications related to thrombosis, and death. In patients presenting with severe angioedema symptoms who were admitted to the hospital, median LOS was not different between the two groups (58.7 h vs 55.7 h, p = 0.61).

CONCLUSIONS

Patients who received tranexamic acid had increased ED LOS, rates of ICU admission, and need for intubation. This finding may be related to the severity of presentation. Administration of tranexamic acid appears safe to use in ACE-I angioedema. Prospective randomized controlled studies should be considered to determine whether tranexamic acid is an effective treatment for ACE-I angioedema.

Angiotensin-Converting Enzyme (ACE) Inhibitor-Induced Angioedema in an African American Male With Coronavirus Disease 2019 (COVID-19)

Angioedema is a condition characterized by non-pitting swelling of the subcutaneous or submucosal tissues in particular the face, lips, and oral cavity. Angiotensin-converting enzyme (ACE) inhibitors are known to contribute to the development of angioedema by increasing the levels of bradykinin and its active metabolites. Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is hypothesized to contribute to the development of angioedema by modifying ACE II levels and further increasing the level of bradykinin in patients taking ACE inhibitors. African Americans may be at particular risk of developing angioedema with concomitant SARS-CoV-2 infection and ACE inhibitor use. This case involves a 31-year-old African American male diagnosed with coronavirus disease 2019 (COVID-19) who developed angioedema while taking an ACE inhibitor.

Meta-analysis of ACE inhibitor-induced angioedema identifies novel risk locus

BACKGROUND

Angioedema is a rare but potentially life-threatening adverse drug reaction in patients receiving angiotensin-converting enzyme inhibitors (ACEis). Research suggests that susceptibility to ACEi-induced angioedema (ACEi-AE) involves both genetic and nongenetic risk factors. Genome- and exome-wide studies of ACEi-AE have identified the first genetic risk loci. However, understanding of the underlying pathophysiology remains limited.

OBJECTIVE

We sought to identify further genetic factors of ACEi-AE to eventually gain a deeper understanding of its pathophysiology.

METHODS

By combining data from 8 cohorts, a genome-wide association study meta-analysis was performed in more than 1000 European patients with ACEi-AE. Secondary bioinformatic analyses were conducted to fine-map associated loci, identify relevant genes and pathways, and assess the genetic overlap between ACEi-AE and other traits. Finally, an exploratory cross-ancestry analysis was performed to assess shared genetic factors in European and African-American patients with ACEi-AE.

RESULTS

Three genome-wide significant risk loci were identified. One of these, located on chromosome 20q11.22, has not been implicated previously in ACEi-AE. Integrative secondary analyses highlighted previously reported genes (BDKRB2 [bradykinin receptor B2] and F5 [coagulation factor 5]) as well as biologically plausible novel candidate genes (PROCR [protein C receptor] and EDEM2 [endoplasmic reticulum degradation enhancing alpha-mannosidase like protein 2]). Lead variants at the risk loci were found with similar effect sizes and directions in an African-American cohort.

CONCLUSIONS

The present results contributed to a deeper understanding of the pathophysiology of ACEi-AE by (1) providing further evidence for the involvement of bradykinin signaling and coagulation pathways and (2) suggesting, for the first time, the involvement of the fibrinolysis pathway in this adverse drug reaction. An exploratory cross-ancestry comparison implicated the relevance of the associated risk loci across diverse ancestries.

The bradykinin-forming cascade in anaphylaxis and ACE-inhibitor induced angioedema/airway obstruction

Anaphylaxis is a potentially life-threatening multi-system allergic reaction to a biological trigger resulting in the release of potent inflammatory mediators from mast cells and basophils and causing symptoms in at least two organ systems that generally include skin, lungs, heart, or gastrointestinal tract in any combination. One exception is profound hypotension as an isolated symptom. There are two types of triggers of anaphylaxis: immunologic and non-Immunologic. Immunologic anaphylaxis is initiated when a foreign antigen directly binds to IgE expressed on mast cells or basophils and induces the release of histamine and other inflammatory substances resulting in vasodilation, vascular leakage, decreased peripheral vascular resistance, and heart muscle depression. If left untreated, death by shock (profound hypotension) or asphyxiation (airway obstruction) can occur. The non-immunologic pathway, on the other hand, can be initiated in many ways. A foreign substance can directly bind to receptors of mast cells and basophils leading to degranulation. There can be immune complex activation of the classical complement cascade with the release of anaphylatoxins C3a and C5a with subsequent recruitment of mast cells and basophils. Finally, hyperosmolar contrast agents can cause blood cell lysis, enzyme release, and complement activation, resulting in anaphylactoid (anaphylactic-like) symptoms. In this report we emphasize the recruitment of the bradykinin-forming cascade in mast cell dependent anaphylactic reactions as a potential mediator of severe hypotension, or airway compromise (asthma, laryngeal edema). We also consider airway obstruction due to inhibition of angiotensin converting enzyme with a diminished rate of endogenous bradykinin metabolism, leading not only to laryngeal edema, but massive tongue swelling with aspiration of secretions.

Pharmacogenetic markers of development of angioneurotic edema as a secondary side effect to enalapril in patients with essential arterial hypertension

BACKGROUND

Angioneurotic edema is the most dangerous complication in angiotensin-converting enzyme inhibitors (ACEIs) therapy. Based on the current data, the clinical and genetic predictors of angioedema development are still understudied, which demonstrates the relevance of this study.

OBJECTIVE

To reveal the pharmacogenetic predictors of the angioedema as a secondary side effect to enalapril in patients with essential arterial hypertension.

METHODS

The study enrolled 111 subjects randomized into two groups: study group, patients with the angioedema as a secondary side effect to enalapril; and control group, patients without adverse drug reaction. All patients underwent pharmacogenetic testing.

RESULTS

An association between the development of the angioneurotic edema and the genotypes AA rs2306283 of gene SLCO1B1, TT rs4459610 of gene ACE, and CC rs1799722 of gene BDKRB2 in patients was revealed.

CONCLUSION

The findings justify further investigations of the revealed genetic predictors of angioedema with larger-size patient populations.

Angiotensin-Converting Enzyme Inhibitors and Other Medications Associated With Angioedema

Angioedema is a localized swelling of the dermis, subcutaneous tissues, and/or submucosal tissues caused by fluid extravasation into these tissues. Angioedema is associated with certain vasoactive molecules and is typically mediated by histamine or bradykinin. It manifests clinically as facial edema, swelling of the extremities and urogenital area, and potential involvement of the larynx, leading to dyspnea and inspiratory stridor, which can become life-threatening. Histamine-mediated angioedema is associated with urticaria and pruritus and will show classic signs of allergic (type 1 hypersensitivity) reactions. Bradykinin-mediated angioedema is often familial (hereditary angioedema) and is more often associated with gastrointestinal symptoms (abdominal pain, nausea, vomiting, diarrhea), edema of the extremities and trunk, and a lack of urticaria and pruritus. Angiotensin-converting enzyme inhibitors (ACEIs) are a class of medications commonly prescribed for hypertension, heart failure, and diabetic nephropathy. ACEIs are associated with an increased risk of angioedema, which can range from a mild reaction to severe and life-threatening. ACEI-induced angioedema is a bradykinin-mediated reaction that can occur in individuals with a genetic predisposition. Other medications, such as angiotensin receptor blockers, nonsteroidal anti-inflammatory drugs, and certain antibiotics, most notably those in the beta-lactam class, can also cause drug-induced angioedema. The present investigation describes current knowledge of the pathophysiology, epidemiology, clinical manifestations, predisposing factors, and management of drug-induced angioedema.

Angiotensin-Converting Enzyme Inhibitor-Induced Angioedema

Angioedema is a well-recognized and potentially lethal complication of angiotensin-converting enzyme inhibitor (ACEi) therapy. In ACEi-induced angioedema, bradykinin accumulates due to a decrease in its metabolism by ACE, the enzyme that is primarily responsible for this function. The action of bradykinin at bradykinin type 2 receptors leads to increased vascular permeability and the accumulation of fluid in the subcutaneous and submucosal space. Patients with ACEi-induced angioedema are at risk for airway compromise because of the tendency for the face, lips, tongue, and airway structures to be affected. The emergency physician should focus on airway evaluation and management when treating patients with ACEi-induced angioedema.

Bradykinin Metabolism and Drug-Induced Angioedema

Bradykinin (BK) metabolism and its receptors play a central role in drug-induced angioedema (AE) without urticaria through increased vascular permeability. Many cardiovascular and diabetic drugs may cause BK-mediated AE. Angiotensin-converting enzyme inhibitors (ACEIs) and neprilysin inhibitors impair BK catabolism. Dipeptidyl peptidase-IV (DPP-IV) inhibitors reduce the breakdown of BK and substance P (SP). Moreover, angiotensin receptor blockers, thrombolytic agents, and statins may also induce BK-mediated AE. Understanding pathophysiological mechanisms is crucial for preventing and treating drug-induced AE.

Efficacy of human C1 esterase inhibitor concentrate for treatment of ACE-inhibitor induced angioedema

BACKGROUND

ACE inhibitor (ACEi) induced angioedema predominantly affects the upper aerodigestive tract. As ACEi induced angioedema is mediated by bradykinin, therapeutic response to antihistamines and glucocorticoids remains unsatisfactory. In bradykinin mediated hereditary angioedema, C1-esterase inhibitor (C1INH) is an effective and approved treatment since many years. Our aim was to evaluate the therapeutic effect of C1INH in ACEi induced angioedema.

METHODS

We performed a double-blind, parallel-group, multicentre randomised placebo-controlled trial between December 2013 and September 2018. Eligible were adults with ACEi induced angioedema with airway obstruction. Participants were randomised 1:1 to single doses of either C1INH (20 IU/kg) or placebo (0.9% NaCl) i.v in addition to standard care (i.v. 500 mg prednisolone and 2.68 mg clemastine) i.v. Composite symptom scores were assessed at baseline and up to 48 h, at discharge and 1 week after discharge. Physician assessed time to complete oedema resolution (TCER) and time to onset of relief (TOR).

RESULTS

30 patients (16 C1INH, 14 placebo) were randomised and dosed. 25 (9 C1INH, 12 placebo) completed the study. TCER was 29.63 h ± 15.56 h in the C1INH and 17.29 h ± 10.40 h in the placebo arm (p = 0.0457). TORs were 4.13 h ± 3.38 h and 2.86 h ± 1.29 h for C1INH and placebo, respectively (p = 0.4443). There were no adverse events related to study medication.

CONCLUSIONS

In the context of baseline application of steroids and antihistamines C1INH was inferior in the treatment of ACEi induced angioedema when compared to placebo with respect to time to complete resolution of symptoms. Eudra-CT Number: 2012-001670-28.

Clinical predictors of endotracheal intubation in patients presenting to the emergency department with angioedema

OBJECTIVES

The objective of this study is to identify predictors of airway compromise among patients presenting to the emergency department with angioedema in order to develop and validate a risk score to augment clinician gestalt regarding need for intubation.

METHODS

Retrospective chart review of emergency department patients with a diagnosis of angioedema. After data extraction they were randomly divided into a training and test set. The training set was used to identify factors associated with intubation and to develop a model and risk score to predict intubation. The model and risk score were then applied to the test set.

RESULTS

A total of 594 patients were included. Past medical history of hypertension, presence of shortness of breath, drooling, and anterior tongue or pharyngeal swelling were independent predictors included in our final model and risk score. The Area Under the Curve for the Receiver Operator Characteristic curve was 87.55% (83.42%-91.69%) for the training set and 86.1% (77.62%-94.60%) for the test set.

CONCLUSIONS

A simple scoring algorithm may aid in predicting angioedema patients at high and low risk for intubation. External validation of this score is necessary before wide-spread adoption of this decision aid.

Large Predominance of Off-Label Prescriptions of C1-Inhibitor Concentrates and Icatibant in a Real-Life Setting: A Retrospective Clinical Study

C1-inhibitor (C1INH) concentrates and the selective bradykinin B2 receptor antagonist icatibant are approved only for treating hereditary angioedema with C1INH deficiency. Yet, they are regularly prescribed off label in other types of bradykinin-mediated angioedema including angiotensin-converting enzyme inhibitor (ACEi)-related and undetermined angioedema. We conducted a retrospective chart review of inpatient prescriptions of C1INH concentrates and icatibant between 2016 and 2020 in the University Hospital of Angers. The first outcome was the proportion of prescriptions with explicit indication. Then, we determined the compliance of prescriptions with European Medicines Agency approvals and the French bradykinin-mediated angioedema reference center guidelines. Finally, we estimated the economic impact of inappropriate prescribing. The therapeutic indication was explicit in 90.4% of prescriptions (n = 66/73). Only 17.8% of prescriptions were for hereditary angioedema with C1INH deficiency, while 31.5% were for ACEi-related and 28.7% for undetermined angioedema. However, most off-label prescriptions were consistent with the French bradykinin-mediated angioedema reference center guidelines (73.3%). We estimated that 13% of drug expenditures were potentially excessive. The predominance of off-label prescriptions may be explained by the infrequency of hereditary angioedema and the absence of approved alternatives in other types of bradykinin-mediated angioedema. Most attacks were related to ACEis. Epinephrine was rarely prescribed as first-line therapy in attacks of unknown origin. Given the high prices of these drugs, we advocate the development of a readily available management algorithm of angioedema to reduce inappropriate prescriptions in our center. In addition, we think that the drug prescription circuit should be redesigned to ensure the traceability of prescribed vials in the dispensing areas.

Geriatric Pharmacotherapy Case Series: Recurrent Angioedema Following Discontinuation of ACE Inhibitor Therapy

Introduction Angiotensin-converting enzyme inhibitors (ACEIs) are first-line pharmaceutical agents in common chronic conditions such as hypertension and heart failure with reduced ejection fraction. When angioedema occurs, if secondary to ACEIs, discontinuation of the ACEI is necessary to mitigate the risk of recurrent angioedema. While angioedema is a well-known adverse effect of ACEIs, it is not well-known that angioedema may recur even after ACEI discontinuation. Additionally, only few reports in the literature describe this phenomenon. This case describes an older man with a history of chronic obstructive pulmonary disease, hypothyroidism, diabetes mellitus, hypertension, and heart failure who presented from an assisted living facility with recurrent angioedema 12 days after an initial episode of angioedema where his ACEI therapy (enalapril) was discontinued. Assessment Empiric methylprednisolone, diphenhydramine, intramuscular epinephrine, intravenous C1 esterase inhibitor Berinert®, and two units of fresh frozen plasma was given in the emergency department. The patient was monitored in the intensive care unit because of mild airway compromise but did not require invasive airway protection. Serum C4 level was normal, ruling out hereditary angioedema. Outcome Patient was discharged after five days in stable condition with resolution of symptoms. Conclusion ACEIs are the most common cause of drug-induced angioedema in the United States. Angioedema is self-limiting swelling that requires close airway monitoring. While health professionals recognize the risk for angioedema with active ACEI use, it is not well known that the risk of angioedema may occur for months following cessation of ACEI therapy. Increased awareness of delayed ACEI-induced angioedema following ACEI discontinuation is important for both providers and pharmacists to provide appropriate diagnosis and monitoring. Improved awareness would also allow patients with a history of ACEI-induced angioedema to be cognizant of the potential for recurrence following drug discontinuation.

Isolated Angioedema: A Review of Classification and Update on Management

OBJECTIVE

The purpose of this article is to review the various types of angioedema including diagnosis and treatment.

DATA SOURCES

PubMed search of articles in the English language various types of angioedema STUDY SELECTION: Articles on the subject matter were selected and reviewed.

RESULTS

Herein, a case based approach is presented for discussing the major types of angioedema including: hereditary angioedema (HAE) TypesI/II and normal complement, acquired angioedema, Angiotensin converting enzyme (ACE) induced angioedema, as well as histaminergic and non-histaminergic angioedema. Emerging treatments of HAE including targets of pre-kalikrein, DNA vector technology replacing C1INH protein, and CRIPSR technology targeting PKK among many others are explored. In addition, other causes as well as mimickers of angioedema are briefly reviewed. Finally, a novel algorithm is proposed to help guide the treating physician through the work up and management of patients with suspected idiopathic angioedema unresponsive to conventional therapy with antihistamines.

CONCLUSION

Over the years, many strides have been made in both understanding the pathophysiology of various types of angioedema as well as expansion of treatment options. It is important for clinicians to be aware of current and emerging treatment options. We provide a novel practical algorithm to guide clinicians in challenging cases of idiopathic angioedema refractory to antihistamines.

Pharmacovigilance study of the association between dipeptidyl peptidase-4 inhibitors and angioedema using the FDA Adverse Event Reporting System (FAERS)

Dipeptidyl peptidase-4 (DPP-4) plays a minor role in degrading vasoactive peptides that cause angioedema when angiotensin-converting enzyme (ACE) is present and fully functional. This study investigated the association between DPP-4 inhibitors (DPP-4Is) and angioedema, including cases where the concomitant use of ACE inhibitors (ACEIs) was absent. We obtained data from the US Food and Drug Administration Adverse Event Reporting System and performed a disproportionality analysis, using the reporting odds ratio (ROR) and information component (IC) for signal detection in patients aged ≥ 40 years, stratified by age group and sex. No signal was detected for DPP-4Is when the entire dataset was analyzed. However, a signal was detected for the entire female subset group, the three stratified female groups aged ≥ 60 years, and males in their 40 s. After excluding the data of concomitant ACEI users, most ROR and IC values were lower and significant only for females in their 60 s and males aged ≥ 80 years. Regarding individual DPP-4Is signals, those detected for saxagliptin and sitagliptin in some age groups disappeared after excluding the data of ACEI users. Notably, linagliptin was the only DPP-4I where signals were detected in most female groups, regardless of age and without concomitant ACEI use. Our findings suggest that some DPP-4Is were associated with a higher reporting of angioedema as per age and sex, even in the absence of concomitant ACEI use.

Ticagrelor Induced Angioedema Following Carotid Artery Stenting

Ticagrelor is a frequent component of dual antiplatelet therapy (DAPT) following carotid artery stent placement. Hemorrhagic complications remain the focus of most reports, however, other adverse events must also be known to the prescribing physician. Angioedema is a rare and potentially life-threatening complication reported following ticagrelor administration and we present 1 such case here with a review of the existing literature.

Drug-induced bowel complications and toxicities: imaging findings and pearls

The use of diverse types of drugs can result in a variety of acute and chronic complications that affect almost any organ. The bowel is one of the organs impacted by the side effects of medications. Imaging frequently plays a crucial role in the detection and characterization of complications occurring in the bowel. They include pseudomembranous colitis or antibiotic-associated colitis; angioedema induced by angiotensin-converting enzyme inhibitors; nonsteroidal anti-inflammatory drug-induced enteropathy; cocaine toxicity; clozapine-induced hypomobility; and bowel toxicity induced by chemotherapeutic agents. It is imperative that radiologists are fully aware of these complications and toxicities as well as the relevant findings. In this way, proper treatment can be implemented immediately. The treatment will involve discontinuation of a drug or a change in regimen.

Role of Submandibular Ultrasound in Airway Management of a Patient With Angioedema

Angioedema is one of several life-threatening clinical scenarios that lacks clarity on when a patient requires intubation. We present a case of angiotensin-converting enzyme-inhibitor-induced angioedema with peri-oral swelling and normal airway measurements on ultrasound, who was intubated with an abundance of caution and extubated successfully. Current tests for intubation and extubation, such as traditional bedside assessments and the cuff leak test, vary in reliability for angioedema and similar urgent situations. Submandibular ultrasound is a quick, low-cost, non-invasive method for determining quantitative criteria for and assessing when intubation and extubation is indicated, which may lead to improved quality of care and patient safety.

Initial characteristics and follow-up of patients with a diagnosis of angiotensin-converting enzyme inhibitor induced angioedema

Background: A differential diagnosis between angiotensin-converting enzyme inhibitor (ACEi) angioedema (AE) and histaminergic AE (hAE) might be challenging. Follow-up data may help discriminate these conditions but are scarcely reported. Objective: To report on the follow-up of patients with suspected ACEi-AE and to describe the baseline characteristics of AE attacks in patients with a diagnosis of ACEi-AE after follow-up. Methods: Sixty-four patients with suspected ACEi-AE (i.e., with exposure to ACEi before the first attack, no urticaria associated, and normal C1-inhibitor levels) and at least one follow-up visit were included. Data were retrospectively collected at baseline and during the follow-up. Results: After the follow-up, the diagnosis of ACEi-AE was probable in only 30 patients. The remaining patients were reclassified as having probable hAE (21 patients) or undetermined-mechanism AE (13 patients). Patients with ACEi-AE were mostly men (61%), with a median age of 64 years (interquartile range [IQR] ±17 years), with a highly variable delay from ACEi introduction (median: 23 months; interquartile range: 103 months). Attacks preferentially involved lips (50%), tongue (47%), and throat (30%). Interestingly, patients with probable ACEi-AE after a follow-up also frequently presented with a history of allergy and atopic conditions (20%), attacks with preferential evening onset (25%), and spontaneous resolution in < 24 hours (26%), which are usually considered as suggestive of hAE. ACEi-AE attacks responded to icatibant in 79% of the patients. Conclusion: Patients with probable ACEi-AE were mostly men with facial involvement. A third of the patients with an initial suspected diagnosis of ACEi-AE had a final diagnosis of probable hAE. Although a follow-up of all patients should be a standard of care, it is critical to the correct diagnosis in the case of suspected bradykinin-associated AE, which may actually be due to histamine.

The characteristics of upper airway edema in hereditary and acquired angioedema with C1-inhibitor deficiency

Background

Angioedemas localized in the upper airway are potentially life threatening, and without proper treatment, they may lead to death by suffocation. Upper airway edemas (UAE) in bradykinin‐mediated angioedemas can even be the first symptoms of the disease.

Methods

Our survey was performed with a retrospective long‐term follow‐up method from the medical history of 197 hereditary (C1‐INH‐HAE) and 20 acquired C1‐inhibitor deficiency (C1‐INH‐AAE), 3 factor XII and 3 plasminogen gene mutation (FXII‐HAE, PLG‐HAE) patients treated at our center between 1990 and 2020. The UAE group included edemas localized to the mesopharynx, hypopharynx, and larynx, as narrowing of these anatomical regions can lead to suffocation.

Results

98/197 C1‐INH‐HAE (47 families) and 13/20 C1‐INH‐AAE, 1/3 PLG‐HAE, 1/3 FXII‐HAE patients had experienced UAE at least once according to their medical history. In case of C1‐INH‐HAE patients, in 6/47 families who had undiagnosed ancestors had 13 members who died of suffocation. After the diagnosis, 1‐1 member of two families died of UAE. 44/64 C1‐INH‐HAE patients did not smoke, 20/64 did. The occurrence of UAE was significantly higher in smoker patients. We analyzed 7607 HAE attacks of 56/98 patients. Out of all attacks, the incidence of UAE in the C1‐INH‐HAE group was 4%, and 9.5% in the C1‐INH‐AAE group, respectively.

Conclusion

Early diagnosis is key in bradykinin‐mediated angioedemas cases, since the patient must be provided with adequate treatment; and also it is essential to inform patients about the importance of avoiding the trigger factors and the early symptoms of UAE, as these measures could significantly decrease the incidence of lethal UAEs.

Angioedema Without Wheals: Challenges in Laboratorial Diagnosis

Angioedema is a prevailing symptom in different diseases, frequently occurring in the presence of urticaria. Recurrent angioedema without urticaria (AE) can be hereditary (HAE) and acquired (AAE), and several subtypes can be distinguished, although clinical presentation is quite similar in some of them. They present with subcutaneous and mucosal swellings, affecting extremities, face, genitals, bowels, and upper airways. AE is commonly misdiagnosed due to restricted access and availability of appropriate laboratorial tests. HAE with C1 inhibitor defect is associated with quantitative and/or functional deficiency. Although bradykinin-mediated disease results mainly from disturbance in the kallikrein–kinin system, traditionally complement evaluation has been used for diagnosis. Diagnosis is established by nephelometry, turbidimetry, or radial immunodiffusion for quantitative measurement of C1 inhibitor, and chromogenic assay or ELISA has been used for functional C1-INH analysis. Wrong handling of the samples can lead to misdiagnosis and, consequently, mistaken inappropriate approaches. Dried blood spot (DBS) tests have been used for decades in newborn screening for certain metabolic diseases, and there has been growing interest in their use for other congenital conditions. Recently, DBS is now proposed as an efficient tool to diagnose HAE with C1 inhibitor deficiency, and its use would improve the access to outbound areas and family members. Regarding HAE with normal C1 inhibitor, complement assays’ results are normal and the genetic sequencing of target genes, such as exon 9 of F12 and PLG, is the only available method. New methods to measure cleaved high-molecular-weight kininogen and activated plasma kallikrein have emerged as potential biochemical tests to identify bradykinin-mediated angioedema. Validated biomarkers of kallikrein–kinin system activation could be helpful in differentiating mechanisms of angioedema. Our aim is to focus on the capability to differentiate histaminergic AE from bradykinin-mediated AE. In addition, we will describe the challenges developing specific tests like direct bradykinin measurements. The need for quality tests to improve the diagnosis is well represented by the variability of results in functional assays.

Angioedema associated with dipeptidyl peptidase-IV inhibitors

BACKGROUND

Dipeptidyl peptidase-IV (DPP-IV) inhibitors, also known as gliptins, are a class of oral antidiabetic agents. Postmarketing reports have documented the occurrence of angioedema in patients treated with gliptins and it was found that these drugs increased the risk of angioedema in patients concurrently treated with angiotensin-converting enzyme inhibitors (ACEIs). The aim of this manuscript is to provide an overview of the risk of angioedema associated with gliptins.

METHODS

The keywords used for the literature search in the PubMed database included "angioedema" and "dipeptidyl peptidase", "gliptins", or the name of each DPP-IV inhibitor. Articles in English published up to December 2020 were taken into consideration.

RESULTS

The available data appear to rule out a higher risk of angioedema associated with gliptin monotherapy and have revealed an increased susceptibility in patients simultaneously treated with gliptins and ACEIs. However, one single multicenter phase IV trial and case reports, even if very limited in number, have shown that angioedema can also occur during treatment with DPP-IV inhibitors without the concomitant use of ACEIs. The involvement of other drugs and drug interactions has occasionally been suggested. In a few patients, deficiency of enzymes involved in bradykinin catabolism was detected and this finding can constitute a risk factor for angioedema exacerbated by treatment with DPP-IV inhibitors.

CONCLUSIONS

This risk of angioedema associated with the use of gliptins has mostly been related to the concurrent administration of ACEIs, and has been considered rare, but it might be underestimated and underreported. The role of additional risk factors or drug interactions deserves further investigations. Caution should be taken when considering the use of DPP-IV inhibitors in patients treated with ACEIs or presenting with other known risk factors for angioedema.

Angiotensin-Converting Enzyme Inhibitor-Induced Angioedema

Angioedema is a well-recognized and potentially lethal complication of angiotensin-converting enzyme inhibitor (ACEi) therapy. In ACEi-induced angioedema, bradykinin accumulates due to a decrease in its metabolism by ACE, the enzyme that is primarily responsible for this function. The action of bradykinin at bradykinin type 2 receptors leads to increased vascular permeability and the accumulation of fluid in the subcutaneous and submucosal space. Patients with ACEi-induced angioedema are at risk for airway compromise because of the tendency for the face, lips, tongue, and airway structures to be affected. The emergency physician should focus on airway evaluation and management when treating patients with ACEi-induced angioedema.

A Case Report of Delayed Post-operative Angioedema Associated With Angiotensin-Converting Enzyme Inhibitor Use

Angiotensin-converting enzyme inhibitors are known to precipitate angioedema. Drug-induced angioedema is rare in the perioperative setting. Even fewer cases described hours following a minor procedure. In this case report, we present a 45-year-old female who developed drug-induced angioedema hours following an obstetric procedure.

Risk Factors Associated with Intubation and Readmissions in patients with Angioedema: A Single Center Experience

BACKGROUND

Given the heterogeneity of etiologies, pathophysiology and presentation of angioedema, variations in clinical outcomes, such as intubation and hospital readmissions, need further clarification.

OBJECTIVE

To determine factors associated with intubation and hospital readmissions in patients with angioedema.

METHODS

Retrospective study of patients evaluated with a diagnosis of angioedema over a 6year period. Demographic and clinical data such as medication use, family history, comorbidities, and symptoms were recorded. Multivariable logistic regression was used to analyze factors associated with intubation, while Cox regression was used to analyze readmissions.

RESULTS

From 636 patients, the most common etiology of angioedema was angiotensin converting enzyme inhibitor (ACEI) induced at 58%. The overall mortality was 0.5%. After adjusting for gender, race, comorbidities, and type of angioedema, smoking (OR=1.79, 95% CI=1.10-2.93, p=0.02), calcium channel blocker (CCB) therapy (OR=1.91, 95% CI=1.18-3.10, p=0.009), histaminergic symptoms (OR=3.21, 95% CI=1.93-5.33, p<0.001) and age (OR=1.02, 95% CI=1.00-1.04, p=0.023) were independently associated with increased odds of intubation. Involvement of either the pharynx, larynx or tongue was associated with higher odds of intubation (OR=20.96, 95% CI=10.63-41.33, p<0.001). 10% of patients had a readmission for angioedema within 90 days and 75% occurred within 30 days. After Multivariable Cox Regression analysis, only COPD/asthma (OR=2.13, 95% CI=1.12-4.07, p=0.022) and ACEI related angioedema (OR=2.93, 95% CI=1.33-6.47, p=0.008) were significantly associated with readmissions.

CONCLUSION

Smoking, CCB use, histaminergic symptoms, age, and upper airway involvement were significantly associated with intubation. Presence of COPD/asthma and ACEI related angioedema were independently associated with increased odds of readmission.

Association of Variants Near the Bradykinin Receptor B2 Gene With Angioedema in Patients Taking ACE Inhibitors

BACKGROUND

Angioedema is a rare but potentially life-threatening adverse reaction associated with angiotensin-converting enzyme (ACE) inhibitors. Identification of potential genetic factors related to this adverse event may help identify at-risk patients.

OBJECTIVES

The aim of this study was to identify genetic factors associated with ACE inhibitor-associated angioedema.

METHODS

A genomewide association study involving patients of European descent, all taking ACE inhibitors, was conducted in a discovery cohort (Copenhagen Hospital Biobank), and associations were confirmed in a replication cohort (Swedegene). Cases were defined as subjects with angioedema events and filled prescriptions for ACE inhibitors ≤180 days before the events. Control subjects were defined as those with continuous treatment with ACE inhibitors without any history of angioedema. Odds ratios (ORs) and 95% confidence intervals (CIs) were computed for angioedema risk using logistic mixed model regression analysis. Summary statistics from the discovery and replication cohorts were analyzed using a fixed-effects meta-analysis model.

RESULTS

The discovery cohort consisted of 462 cases and 53,391 ACE inhibitor-treated control subjects. The replication cohort consisted of 142 cases and 1,345 ACE inhibitor-treated control subjects. In the discovery cohort, 1 locus, residing at chromosome 14q32.2, was identified that associated with angioedema at the genomewide significance level of P <5 × 10^-8. The lead variant at this locus, rs34485356, is an intergenic variant located 60 kb upstream of BDKRB2 (OR: 1.62; 95% CI: 1.38 to 1.90; P = 4.3 × 10^-9). This variant was validated in our replication cohort with a similar direction and effect size (OR: 1.60; 95% CI: 1.13 to 2.25; P = 7.2 × 10^-3). We found that carriers of the risk allele had significantly lower systolic (-0.46 mm Hg per T allele; 95% CI: -0.83 to -0.10; P = 0.013) and diastolic (-0.26 mm Hg per T allele; 95% CI: -0.46 to -0.05; P = 0.013) blood pressure.

CONCLUSIONS

In this genomewide association study involving individuals treated with ACE inhibitors, we found that common variants located in close proximity to the bradykinin receptor B₂ gene were associated with increased risk for ACE inhibitor-related angioedema.

Underreported Risk of Lisinopril-Induced Angioedema in a Veteran Population

BACKGROUND

Lisinopril-induced angioedema (LIA) is a rare but serious adverse drug event (ADE) with a published incidence of 0.1% to 0.7%. It is well known that ADEs are widely underreported; however, LIA is one of the most reported ADEs within the Veterans Health Administration (VHA).

OBJECTIVE

To estimate the effect of underreporting on the risk of LIA within VHA.

METHODS

The reported risk of LIA was calculated from reports submitted to the Veterans Affairs (VA) Adverse Drug Event Reporting System (VA ADERS) and the number of veterans prescribed lisinopril. To estimate underreporting, local chart review identified cases of LIA that were compared to reports submitted. The underreporting rate was then applied to the national reported risk.

RESULTS

Locally, 68 reports of LIA were submitted of the 21 262 patients prescribed lisinopril, for a reported risk of 0.32%. Nationwide, 14 289 reports of LIA were submitted of the 3 109 661 patients prescribed lisinopril, for a crude reported risk of 0.46%. Of the 324 patients identified for chart review, 240 patients were diagnosed with LIA, suggesting that at least 71.7% of cases were unreported. When this underreporting rate is extrapolated to the national reported risk, a better estimate of the risk of LIA within VHA could increase to 1.6%.

CONCLUSION AND RELEVANCE

When estimating the effect of underreporting, the risk of LIA increases to approximately 1.6% or 1 in 63 patients. Because this ADE may affect more patients than previously understood, providers may wish to take LIA into consideration when prescribing lisinopril.

Overcoming Cough and Angioedema: Advocating for the Use of ARBs Over ACE Inhibitors

Angiotensin II receptor blockers (ARBs) and angiotensin-converting enzyme (ACE) inhibitors have comparable efficacy, but ARBs have a preferential safety profile with particular regard to cough and angioedema. Although guidelines have historically advocated for ACE inhibitor use before ARBs simply because of earlier market entry, data accumulation, and generic availability, updated verbiage advises an "ACE inhibitor or ARB" recommendation, as opposed to the classic "ACE inhibitor then ARB" approach. Despite these updates, clinical inertia in favor of ACE inhibitor use before ARBs overwhelmingly remains. Prescribers and educators should consider an "ARBs only" mentality, especially in high angioedema-risk groups such as black patients.

Case Report: Compromised Airway Following Anesthesia and Its Correlation With the Use of ACE Inhibitors-An Unexpected Clinical Event and Review of Literature

Angiotensin-converting enzyme inhibitors associated angioedema involving the upper aerodigestive tract is indisputably a hazardous airway condition which is clinically poorly recognized and frequently underestimated. We describe and present case of a 70-year old man on ramipril who developed massive tongue swelling post-operatively after unremarkable laryngeal mask anaesthesia which was fortuitously managed conservatively. High index of suspicion, timely recognition and knowledge of pathophysiology and the clinical course should guide airway and further supportive management in these patients.

Effectiveness of C1-INH therapy in angiotensin converting enzyme inhibitor induced angioedema

Introduction

Angiotensin Converting Enzyme Inhibitors (ACEI) are a common cause of Emergency Room presentation for angioedema. Although no treatment guidelines exist, C1 esterase inhibitor concentrate (C1-INH) is used on an off label basis for management of ACEI acquired angioedema (ACEI AAE).

Objective

To evaluate the efficacy of C1-INH in management of ACEI AAE at our local centers.

Results

Nine patients, from 3 academic sites, were identified through Allergy Service consultation data and records from Diagnostic Services Manitoba, Canada from 2010–2020. The majority of the patients (n = 8/9) required endotracheal intubation prior to the initiation of C1-INH. Overall, approximately 56% of patients (n = 5/9) had resolution of angioedema ranging between 12 and 17 h, with a median time of 13.5 h, and no recurrence after the administration of C1-INH concentrate. One patient had transient symptom resolution in 14 h, however, recurrence of angioedema required re-intubation. The remainder of patients (n = 4/9), had resolution of angioedema between 22 and 72 h, with a median time of 33.75 h.

Conclusion

Our findings demonstrate continued ambivalence of the efficacy and role of C1-INH concentrate in the treatment of ACEI AAE, secondary to multiple uncontrolled confounding factors. Further research into characterizing a subgroup of intubated patients in our study that responded to C1-INH concentrate needs to be completed.

Recurrent angioedema: Experience at a tertiary care urban medical center

OBJECTIVE

To determine the demographics, presentation, management, and outcomes of patients with recurrent angioedema. To compare the findings to patients with ACE inhibitor related angioedema.

METHODS

Retrospective case series with chart review of patients who presented to a tertiary-care hospital between January 2010 and December 2017 with two or more episodes of angioedema. Excluded were patients with anaphylactic reaction, medication induced angioedema, or angioedema secondary to an infectious etiology. A group of 88 patients who presented during the same time period with ACE inhibitor related angioedema was used as a control. Statistical analysis was conducted using a two-tailed Fisher exact test and a multivariate logistical regression model to determine significant associations.

RESULTS

Ninety-one patients were identified; 61 met the selection criteria and had 217 total episodes of angioedema episodes presenting to the emergency department. Fifty percent were Caucasian or Hispanic. The average number of episodes was 3.5 (range: 2-23). The lips and tongue were the most commonly affected sites (37% and 39%). The larynx and floor of mouth were least likely to be involved (7% and 6%). Only 1 patient was found to have C1 esterase inhibitor deficiency. Twenty-eight percent of patients had asthma, allergic rhinitis, food allergies, or atopic dermatitis. Only 11% of episodes required airway intervention. No patients required airway intervention after admission.

CONCLUSION

Recurrent angioedema was primarily idiopathic, was less severe than ACE inhibitor angioedema, and was associated with an atopic history. There was less frequent worsening of symptoms after admission, and recurrences occurred more frequently are at the same anatomic subsite.

LEVEL OF EVIDENCE

IV.

Angioedemas associated with renin-angiotensin system blocking drugs: Comparative analysis of spontaneous adverse drug reaction reports

INTRODUCTION

Angioedema is a subcutaneous swelling typically affecting the face, larynx or pharynx. It is a known adverse drug reaction (ADR) of ACE inhibitors (ACEi), angiotensin-II-receptor blockers (ARBs) and aliskiren (renin inhibitor). Several studies have reported pathophysiological mechanisms and risk factors of ACEi-associated angioedemas, whereas little is known for ARBs and aliskiren. The aim of the study was to analyze comparatively ACEi versus ARBs and aliskiren angioedema reports contained in the European ADR database EudraVigilance with regard to reported risk factors and clinical phenotypes.

METHODS

All spontaneous angioedema reports received between 01/2010-06/2017 reporting either an ACEi, ARB, or aliskiren as "suspected/interacting" drug were identified using the Standardized MedDRA Query "angioedema (narrow)". In order to perform a comparative analysis, odds ratios (ORs) were calculated for angioedema reports of ACEi (n = 3.194) versus ARBs (n = 687) and aliskiren (n = 162).

RESULTS

More patients with a history of allergy were included in angioedema reports of ARBs (6.8%) and aliskiren (13.6%) versus ACEi (4.3%). "Urticaria" as an ADR was reported more frequently in angioedema reports of ARBs (18.5%) and aliskiren (9.0%) versus ACEi (5.0%). ACEi-associated angioedemas were more often designated as "life-threatening" compared to ARBs (OR 2.2 [1.6-2.9]) and aliskiren-associated angioedemas (OR 14.2 (3.5-57.4). Concomitant therapy with mTOR inhibitors (OR 4.3 [1.0-17.9]) and fibrinolytics (OR 7.8 [1.1-57.2]) was reported more often in ACEi versus ARBs angioedema reports.

CONCLUSION

The reported clinical phenotypes differed between ACEi versus ARBs and aliskiren angioedema reports. Differences between the patient populations as observed in our study or differences with regard to underlying pathomechanisms could account for this finding. Due to the methodological limitations of spontaneous reporting systems, we cannot draw a firm conclusion in this regard. Hence, further research is necessary to confirm our observation and elucidate the underyling causes.

ACE inhibitor angioedema: characterization and treatment versus non-ACE angioedema in acute hospitalized patients

Background

ACE angioedema has not been characterized in comparison with angioedema from other causes in acute hospitalized patients.

Methods

We retrospectively compared ACE-angioedema and non-ACE angioedema patients from January 2013 to May 2017.

Results

Of 855 cases screened, 575 met the inclusion criteria of angioedema diagnosis and an electronic medical record. Of these, 297 (51.7%) had ACE angioedema and 278 had angioedema from other causes, of these 31 who were taking an ACE inhibitor that was not considered to be the cause of angioedema (ACE other cause). At least 80% of cases in all groups were African American. Epinephrine was prescribed in 21% of ACE angioedema cases. One-third of patients in all groups were admitted to the ICU, and about 25% required intubation. Previous history of ACE inhibitor-induced angioedema was found in 63 of 278 non-ACE cause angioedema patients (23%) and in 23 (8%) in the ACE cause group.

Conclusion

ACE angioedema was the cause of half of angioedema admissions over a 4.5-year period. Mortality, morbidity, and treatment did not differ between the groups. Patients on ACE inhibitors were often treated with medications known not to be effective for ACE angioedema. Over one-fourth of patients not taking an ACE inhibitor had a previous history of ACE angioedema, and 31 patients taking ACE inhibitors were diagnosed with non-ACE angioedema. Regardless of the etiology of angioedema, 25% of patients required airway protection in the form of intubation.

Acquired angioedema induced by angiotensin-converting enzyme inhibitors - experience of a hospital-based allergy center

Angiotensin-converting enzyme inhibitors (ACEIs) represent an important group of pharmacological compounds, largely prescribed for more than 30 years. They have been extensively evaluated in clinical trials, demonstrating significant reduction of morbidity and mortality of patients with cardiovascular diseases, mainly high blood pressure, myocardial infarction, heart failure and stroke. Besides their beneficial effects and a general good safety profile, it was proven that ACEIs might also induce adverse effects in some patients, most notably angioedema (AE) and chronic cough. The occurrence rate of adverse events induced by ACEIs is low, but the number of suffering patients is relatively high, since ACEIs is one of the most frequently prescribed medication worldwide. The aim of our study was to evaluate clinical pattern, risk factors and general management of ACEI-induced angioedema in a cohort of patients addressed for allergist evaluation in one university hospital in Romania, during a period of 32 months. It was found that ACEI-induced angioedema (ACEI-AE) represented more than half of the total number of patients addressed for angioedema without urticaria, with variable clinical and time-patterns. Most of the patients were referred by general practitioners (GPs) with diagnosis of urticaria or other skin allergy and continued to take ACEIs for months and years after onset of angioedema. We concluded that the awareness of acquired, non-allergic angioedema induced by ACEI therapy in medical practice is still low and there is a need for improved knowledge and interdisciplinary collaboration in this field.

Clinical features of angioedema induced by renin-angiotensin-aldosterone system inhibition: a retrospective analysis of 84 patients

Background and objectives: Bradykinin-mediated angioedema (AE) induced by antihypertensive drugs primarily affect the head and neck region and may occur even after several years of uneventful treatment. Many facts about the clinical course remain unknown. Diagnosis is not easy, as the clinical appearance resembles allergic AE. No specific diagnostic markers are known and no officially approved treatment is currently available.

Methods: All patients who presented to the ORL department between 2010 and 2016 with acute AE were included. Those with a history of renin-angiotensin-aldosterone system (RAAS) blocker intake were defined as RAE and their pathophysiological characteristics and clinical course of the disease were analyzed.

Results: A total of 84 patients (median age of 71 years) with RAE was identified. The majority (80%) was on ACE inhibition. The oral cavity was most often affected. Nearly 60% were medicated for more than 1 year before AE occurred. RAE occurred more often during the morning hours. The necessity for emergency intubation and/or tracheostomy was nine times higher in patients with acute RAE compared to patients with AE due to other reasons.

Conclusions: Event-free, long-term therapy with an RAAS blocker before the first development of edema does not exclude RAE. RAE is associated with an increased risk for emergency airway management.

Abbreviations ACE: Angiotensin Converting Enzyme; ACEi AE: ACE inhibitor-induced angioedema; AE: Angioedema; ARB: Angiotensin II receptor 1 blocker; C1 INH: C1 Inhibitor; CI: Confidence Interval; CRP: C-reactive protein; DPP IV: Dipeptidyl peptidase IV; ENT: Ear, Nose and Throat; HAE: Hereditary Angioedema; ICD 10: International Statistical Classification of Diseases and Related Health Problems, 10th Edition; OR: Odds Ratio; ORL: Otorhinolaryngology; RAAS: Renin-Angiotensin-Aldosterone System; RAE: RAAS-blocker-induced angioedema

ACE inhibitor-mediated angioedema

Angioedema (AE) occurring during ACE inhibitor therapy (ACEi-AE) is a rare complication involving between 0.1 and 0.7% of treated patients. AE can also complicate other therapeutic regimens that block the renin-angiotensin aldosterone system. Other drugs, such as immune suppressors, some type of antidiabetics or calcium antagonists, can increase the likelihood of ACEi-AE when associated to ACEi. There is a clear ethnic predisposition, since African-Americans or Hispanics show a higher prevalence of this condition compared to Caucasians. At least in African-Americans the genetic predisposition accounts for a general higher prevalence of AE, independently from the cause. People that experience ACEi-AE may have some recurrence when they are switched to an angiotensin-receptor blocker (ARB); however, epidemiological studies on large cohorts have shown that angiotensin receptor blockers (ARB) do not increase the likelihood of AE compared to other antihypertensives. Clinical manifestations consist of edema of face, lips, tongue, uvula and upper airways, requiring intubation or tracheotomy in severe cases. Attacks last for 48-72 h and require hospital admission in most cases. Intestinal involvement with sub-occlusive symptoms has also been reported. The pathogenesis of ACEi-AE depends mainly on a reduced catabolism and accumulation of bradykinin, which is normally metabolized by ACE. Genetic studies have shown that some single nucleotide polymorphisms at genes encoding relevant molecules for bradykinin metabolism and action may be involved in ACEi-AE, giving a basis for the ethnic predisposition. Treatment of ACEi-AE is still a matter of debate. Corticosteroids and antihistamines do not show efficacy. Some therapeutic attempts have shown some efficacy for fresh frozen plasma or C1 inhibitor concentrate infusion. Interventional studies with the specific bradykinin receptor antagonist icatibant have shown conflicting results; there might be a different ethnic predisposition to icatibant efficacy which has been proven in caucasian but not in black patients.

Significant predictive factors of the severity and outcomes of the first attack of acute angioedema in children

Background

The initial episode of angioedema in children can be potential life-threatening due to the lack of prompt identification and treatment. We aimed to analyze the factors predicting the severity and outcomes of the first attack of acute angioedema in children.

Methods

This was a retrospective study with 406 children (< 18 years) who presented in the emergency department (ED) with an initial episode of acute angioedema and who had subsequent follow-up visits in the out-patient department from January 2008 to December 2014. The severity of the acute angioedema was categorized as severe (requiring hospital admission), moderate (requiring a stay in the short-term pediatric observation unit [POU]), or mild (discharged directly from the ED). The associations among the disease severity, patient demographics and clinical presentation were analyzed.

Result

In total, 109 (26.8%) children had severe angioedema, and the majority of those children were male (65.1%). Most of the children were of preschool age (56.4%), and only 6.4% were adolescents. The co-occurrence of pyrexia or urticaria, etiologies of the angioedema related to medications or infections, the presence of respiratory symptoms, and a history of allergies (asthma, allergic rhinitis) were predictors of severe angioedema (all p < 0.05). Finally, the duration of angioedema was significantly shorter in children who had received short-term POU treatment (2.1 ± 1.1 days) than in those who discharged from ED directly (2.3 ± 1.4 days) and admitted to the hospital (3.5 ± 2.0 days) (p < 0.001).

Conclusion

The co-occurrence of pyrexia or urticaria, etiologies related to medications or infections, the presence of respiratory symptoms, and a history of allergies were predictors of severe angioedema. More importantly, short-term POU observation and prompt treatment might be benefit for patients who did not require hospital admission.

Bradykinin-Mediated Angioedema: An Update of the Genetic Causes and the Impact of Genomics

Recurrent episodes of bradykinin-mediated angioedema (Bk-AE) can associate with acquired or hereditary conditions, the former most commonly developing secondarily to a pharmacological treatment. Despite successful genomic advances that have led to the identification of a large number of disease genes irrespective of disease prevalence, their application to Bk-AE has barely occurred. As a consequence, the genetic causes of Bk-AE remain poorly understood, obstructing the identification of patient subtypes and the development of precision medicine strategies. This review provides an update of the genetic studies completed to date on the acquired forms, which have almost exclusively focused on Bk-AE secondarily to the angiotensin-converting enzyme inhibitor treatment, and the blooming subdivision of the hereditary forms established by the identification of novel causal genes with next-generation sequencing (NGS) technology-based exome studies in genetically undiagnosed patients. Finally, based on the diverse benefits that are offered by the technology, we present arguments favoring the use of holistic NGS approaches as first-tier genetic tests as a promise to reduce the diagnostic odyssey of patients with suspected hereditary forms of Bk-AE.

[Postoperative angioedema induced by angiotensin-converting enzyme inhibitor: case report]

BACKGROUND AND OBJECTIVES

Angioedema is a potentially fatal condition that may occur at any time in the perioperative period. It may result from histamine release, hypersensitivity reaction to drugs, or be triggered by bradykinin, in non-allergic reactions of hereditary or acquired etiology. The aim of this report is to report a case of angioedema in the early postoperative period in a patient on antihypertensive medication involving angiotensin-converting enzyme inhibitors.

CASE REPORT

A 67-year-old male, Afro-descendant, hypertensive, and taken enalapril maleate underwent orthopedic shoulder surgery under general anesthesia combined with brachial plexus block. The procedure lasted 3hours uneventfully. After discharge from the post-anesthesia care unit, the patient presented with angioedema and severe airway impairment. Tracheal intubation was attempted but it was impossible due to edema affecting the lips, tongue, and oropharyngeal region Emergency cricothyroidotomy was performed. The onset of angioedema had no causal relationship with the administration of any medication; there were no cutaneous manifestations and also not response to therapy for hypersensitivity reaction to drugs, such as antihistamines, corticoid, and adrenaline. It was considered to be mediated by bradykinin, as the patient had already had two similar episodes and was on regular medication (enalapril). The evolution was satisfactory.

CONCLUSION

Angioedema is a potentially fatal condition when it affects the airway, and should be recognized by anesthesiologists and physicians working in the emergency departments.

Clinical Features and Outcomes Associated with Angioedema in the Emergency Department

Introduction

Angioedema represents self-limited, localized swelling of submucosal or subcutaneous tissues. While the underlying etiology may be undeterminable in the emergent setting, nonhistaminergic and histaminergic angioedema respond differently to therapeutic interventions, with implications for empiric treatment. Clinical features and outcome differences among nonhistaminergic vs histaminergic angioedema patients in the emergency department (ED) are poorly characterized. We aim to describe the clinical characteristics and outcomes among ED patients with angioedema by suspected etiology.

Methods

This was a 10-year retrospective study of adult ED patients with angioedema, using data abstracted from the electronic health record. We evaluated univariable associations of select clinical features with etiology and used them to develop a multivariable logistic regression model for nonhistaminergic vs histaminergic angioedema.

Results

Among 450 adult angioedema patients, the mean +/− standard deviation age was 57 +/− 18 years, and 264 (59%) were female. Among patients, 30% had suspected nonhistaminergic angioedema, 30% had suspected histaminergic angioedema, and 40% were of unknown etiology. As compared to histaminergic angioedema, nonhistaminergic angioedema was associated with angiotensin-converting enzyme inhibitors (ACEI) or use of angiotensin II receptor blockers (ARB) (odds ratio [OR] [60.9]; 95% confidence interval [CI], 23.16–160.14) and time of onset one hour or more prior to ED arrival (OR [5.91]; 95% CI,1.87–18.70) and was inversely associated with urticaria (OR [0.05]; 95% CI, 0.02–0.15), dyspnea (OR [0.23]; 95% CI, 0.08–0.67), and periorbital or lip edema (OR [0.25]; 95% CI, 0.08–0.79 and OR [0.32]; 95% CI, 0.13–0.79, respectively).

Conclusion

As compared to histaminergic angioedema, patients with nonhistaminergic angioedema were more likely to present one hour or more after symptom onset and take ACEI or ARB medications, and were less likely to have urticaria, dyspnea, or periorbital or lip angioedema. Identification of characteristics associated with the etiology of angioedema may assist providers in more rapidly initiating targeted therapies.

Angioedema: a rare and sometimes delayed side effect of angiotensin-converting enzyme inhibitors

The effects of angiotensin converting enzyme (ACE) inhibitors result from the inhibition of the ACE (kininase II) to ultimately influence both the renin-angiotensin system and the degradation of the bradykinin (BK) metabolism. ACE inhibitors block the degradation of BK and substance P by ACE. In addition, an active metabolite of BK (Des-Arg9-BK) is catalysed by kininase I and its degradation is controlled in part by the conversion enzyme. These molecules have been associated with increased plasma extravasation associated with ACE inhibitors. ACE inhibitors are the leading cause of drug-induced Angioedema (AE). Symptoms of AE mainly occur after the first month of treatment by ACE. However, very late onset cases, sometimes after several years of stable therapy, are also described in the literature. It has been observed that patients previously stable under ACE inhibitor will most likely develop AE soon after the addition of another medication, including the combination of aspirin or non-steroid anti-inflammatory drugs with ACE inhibitor which has proved to be the most common cause, accounting for close to 50% of all AE cases related to ACE inhibitors. This side effect of ACE inhibitors, sometimes very late and rare, deserves to be recalled.