Angiotensin converting enzyme inhibitor induced angio-oedema: a review of the pathophysiology and risk factors

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.

Leveraging Genetics for Hereditary Angioedema: A Road Map to Precision Medicine

Biochemical studies performed during the last decades resulted in the development of various innovative medicinal products for hereditary angioedema (HAE). These therapeutic agents target the production or the function of bradykinin-the main mediator of HAE due to C1-inhibitor (C1-INH) deficiency. However, despite these remarkable achievements, current knowledge cannot provide convincing explanations for the clinical variability of the disease. As a consequence, treatment indications apply for drugs available for C1-INH deficiency. The advent of high-throughput next-generation sequencing technologies may assist in covering the missing part of our understanding of HAE pathogenesis. During the last 3 years alone, several new entities were added to the already described genotypes. The recent discovery of four novel target genes expands our understanding of other causes which may explain recurrent angioedema in individuals and families with normal C1-INH activity. Furthermore, new genetic technologies allowed the recognition of deep intronic variants associated with the disease, and elegant functional studies characterized new variants for the C1-INH gene. Thus, evidence has been provided regarding pathogenetic aspects remaining obscure for many years, such as the defective intracellular transport of mutant C1-INH, and environmental effect on the disease expression. Therefore, it seems that the stage for Precision Medicine era in HAE management is ready. Disease endotypes are expected to be uncovered and specified targets for therapeutic intervention will be detected, promising a more effective, individualized management of the disease.

Critical angioedema induced by a renin angiotensin system blocker in the contemporary era of increasing heart failure: A case report and commentary

Bradykinin‐mediated angioedema, a nonallergic reaction most commonly caused by renin angiotensin system (RAS) blockers, has the potential to lead to a critical condition. RAS blockers are important for treating heart failure and are widely used in clinical settings. We present the case of an 85‐year‐old man who was administered enalapril after percutaneous coronary intervention for an acute myocardial infarction and developed severe angioedema requiring a tracheostomy. He had multiple risks for angioedema including advanced age, smoking history, renal dysfunction, and longstanding use of an angiotensin receptor blocker. The prompt diagnosis of drug‐induced angioedema is critical and depends on physicians' recognition of risk factors and knowledge of pathophysiology. In the present era of increasingly prevalent heart failure, it is imperative that the possibility of angioedema receives attention, especially given the continuing reliance on RAS blockers and the advent of angiotensin receptor neprilysin inhibitors, a new type of heart failure drug.

In Vitro Modeling of Bradykinin-Mediated Angioedema States

Kinins (peptides related to bradykinin, BK) are formed from circulating substrates, the kininogens, by the action of two proteases, the kallikreins. The only clinical application of a BK receptor ligand, the B₂ receptor antagonist icatibant, is the treatment of the rare hereditary angioedema (HAE) caused by the deficiency of C1-esterase inhibitor (C1-INH). Less common forms of HAE (genetic variants of factor XII, plasminogen, kininogen) are presumably mediated by increased BK formation. Acquired forms of BK-mediated angioedema, such as that associated with angiotensin-I converting enzyme (ACE) inhibition, are also known. Antibody-based analytical techniques are briefly reviewed, and support that kinins are extremely short-lived, prominently cleared by ACE. Despite evidence of continuous activation of the kallikrein–kinin system in HAE, patients are not symptomatic most of the time and their blood or plasma obtained during remission does not generate excessive immunoreactive BK (iBK), suggesting effective homeostatic mechanisms. HAE-C1-INH and HAE-FXII plasmas are both hyperresponsive to fibrinolysis activation. On another hand, we suggested a role for the alternate tissue kallikrein–kinin system in patients with a plasminogen mutation. The role of the BK B₁ receptor is still uncertain in angioedema states. iBK profiles under in vitro stimulation provide fresh insight into the physiopathology of angioedema.

Measurement of Bradykinin Formation and Degradation in Blood Plasma: Relevance for Acquired Angioedema Associated With Angiotensin Converting Enzyme Inhibition and for Hereditary Angioedema Due to Factor XII or Plasminogen Gene Variants

Bradykinin (BK)-mediated angioedema (AE) states are rare acquired or hereditary conditions involving localized edema of the subcutaneous and submucosal tissues. Citrated plasma from healthy volunteers or patients with hereditary angioedema (HAE) with normal level of C1-inhibitor (C1-INH) was used to investigate pathways of BK formation and breakdown relevant to AE physiopathology. The half-life of BK (100 nM) added to normal plasma was 34 s, a value that was increased ~12-fold when the angiotensin converting enzyme (ACE) inhibitor enalaprilat (130 nM) was added (enzyme immunoassay measurements). The BK half-life was similarly increased ~5-fold following 2 daily oral doses of enalapril maleate in healthy volunteers, finding of possible relevance for the most common form of drug-associated AE. We also addressed the kinetics of immunoreactive BK (iBK) formation and decline, spontaneous or under three standardized stimuli: tissue kallikrein (KLK-1), the particulate material Kontact-APTT™ and tissue plasminogen activator (tPA). Relative to controls, iBK production was rapid (10–20 min) and very intense in response to tPA in plasma of female heterozygotes for variants in gene F12 coding for factor XII (FXII) (p.Thr328Lys, 9 patients; p.Thr328Arg, one). An increased response to Kontact-APTT™ and an early tPA-induced cleavage of anomalous FXII (immunoblots) were also observed. Biotechnological inhibitors showed that the early response to tPA was dependent on plasmin, FXIIa and plasma kallikrein. Results from post-menopausal and pre-menopausal women with HAE-FXII were indistinguishable. The iBK production profiles in seven patients with the plasminogen p.Lys330Glu variant (HAE-PLG) did not significantly differ from those of controls, except for an unexpected, rapid and lanadelumab-resistant potentiation of KLK-1 effect. This enzyme did not cleave plasminogen or factor XII, suggesting a possible idiosyncratic interaction of the plasminogen pathogenic variant with KLK-1 activity. KLK-1 abounds in salivary glands and human saliva, hypothetically correlating with the clinical presentation of HAE-PLG that includes the swelling of the tongue, lips and contiguous throat tissues. Samples from HAE patients with normal C1-INH levels and F12 gene did not produce excessive iBK in response to stimuli. The ex vivo approach provides physiopathological insight into AE states and supports the heterogeneous physiopathology of HAE with normal C1-INH.

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.

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.

Exploring a New Natural Treating Agent for Primary Hypertension: Recent Findings and Forthcoming Perspectives

Primary hypertension describes abnormally-high systolic/diastolic blood pressure in a resting condition caused by various genetic or environmental risk factors. Remarkably, severe complications, such as ischemic cardiovascular disease, stroke, and chronic renal disease have led to primary hypertension becoming a huge burden for almost one-third of the total population. Medication is the major regimen for treating primary hypertension; however, recent medications may have adverse effects that attenuate energy levels. Hence, the search for new hypotensive agents from folk or traditional medicine may be fruitful in the discovery and development of new drugs. This review assembles recent findings for natural antihypertensive agents, extracts, or decoctions published in PubMed, and provides insights into the search for new hypotensive compounds based on blood-pressure regulating mechanisms, including the renin-angiotensin-aldosterone system and the sympathetic/adrenergic receptor/calcium channel system.

[Drug-induced angioedema : Focus on bradykinin]

On a pathophysiological level, angioedema can be differentiated into histamine- and bradykinin-mediated types. The prototype drug-associated, bradykinin-mediated form of angioedema is angiotensin-converting enzyme (ACE) inhibitor-induced angioedema. The hypothesized cause is a decrease in bradykinin degradation via ACE inhibition. In this scenario, other bradykinin-degrading enzymes assume major importance. When the effect of these enzymes is also diminished, e. g., due to genetic variants or external factors, compensation for the inhibition of ACE may be insufficient. An increased risk of angioedema has also been reported for other drugs, particularly when prescribed in combination with ACE inhibitors. Here, the suspected cause also relates to the degradation of bradykinin. When angioedema arises within the context of concomitant ACE inhibitor use, additive bradykinin degradation effects may be implicated.

Comparing Pathways of Bradykinin Formation in Whole Blood From Healthy Volunteers and Patients With Hereditary Angioedema Due to C1 Inhibitor Deficiency

Multiple pathways have been proposed to generate bradykinin (BK)-related peptides from blood. We applied various forms of activation to fresh blood obtained from 10 healthy subjects or 10 patients with hereditary angioedema (HAE-1 or −2 only) to investigate kinin formation. An enzyme immunoassay for BK was applied to extracts of citrated blood incubated at 37°C under gentle agitation for 0–2 h in the presence of activators and/or inhibitory agents. Biologically active kinins in extracts were corroborated by c-Fos accumulation in HEK 293a cells that express either recombinant human B₂ or B₁ receptors (B₂R, B₁R). Biological evidence of HAE diagnostic and blood cell activation was also obtained. The angiotensin converting enzyme inhibitor enalaprilat, without any effect per se, increased immunoreactive BK (iBK) concentration under active stimulation of blood. Tissue kallikrein (KLK-1) and Kontact-APTT, a particulate material that activates the contact system, rapidly (5 min) and intensely (>100 ng/mL) induced similar iBK generation in the blood of control or HAE subjects. Tissue plasminogen activator (tPA) slowly (≥1 h) induced iBK generation in control blood, but more rapidly and intensely so in that of HAE patients. Effects of biotechnological inhibitors indicate that tPA recruits factor XIIa (FXIIa) and plasma kallikrein to generate iBK. KLK-1, independent of the contact system, is the only stimulus leading to an inconsistent B₁R stimulation. Stimulating neutrophils or platelets did not generate iBK. In the HAE patients observed during remission, iBK formation capability coupled to B₂R stimulation appears largely intact. However, a selective hypersensitivity to tPA in the blood of HAE patients suggests a role of plasmin-activated FXIIa in the development of attacks. Proposed pathways of kinin formation dependent on blood cell activation were not corroborated.

Angiotensin-Converting Enzyme Inhibitor-Induced Gastrointestinal Angioedema: The First Danish Case Report

Angiotensin-converting enzyme inhibitors (ACEI) are widely used to treat hypertension and congestive heart failure. A rare side effect of ACEI therapy is angioedema, which in very rare cases may present as gastrointestinal angioedema (GA). A 45-year-old female presented with suddenly occurring diffuse abdominal pain. Imaging studies revealed small bowel wall edema. The patient had been on ACEI therapy for the last 6 months. The therapy was withdrawn, and the patient recovered quickly. There is no specific diagnostic test to confirm ACEI-induced GA, but symptoms usually regress completely after therapy discontinuation. An early diagnosis of ACEI-induced GA is important to avoid invasive diagnostic investigations and even laparotomy.

ACE Inhibitor-Induced Angioedema: a Review

PURPOSE OF REVIEW

This study aims to examine current knowledge on the occurrence, pathophysiology, and treatment of angioedema among patients who receive angiotensin-converting enzyme inhibitors.

RECENT FINDINGS

Angiotensin-converting enzyme inhibitors (ACE-I), a medication class used by an estimated 40 million people worldwide, are associated with angioedema that occurs with incidence ranging from 0.1 to 0.7%. The widespread use of ACE-I resulted in one third of all emergency department visits for angioedema. Angioedema occurs more frequently in African Americans, smokers, women, older individuals, and those with a history of drug rash, seasonal allergies, and use of immunosuppressive therapy. The pathophysiology of ACE-I-induced angioedema involves inhibition of bradykinin and substance P degradation by ACE (kininase II) leading to vasodilator and plasma extravasation. Treatment modalities include antihistamines, steroids, and epinephrine, as well as endotracheal intubation in cases of airway compromise. Patients with a history of ACE-I-induced angioedema should not be re-challenged with this class of agents, as there is a relatively high risk of recurrence.

CONCLUSION

ACE-I are frequently used therapeutic agents that are associated with angioedema. Their use should be avoided in high-risk individuals and early diagnosis, tracheal intubation in cases of airway compromise, and absolute avoidance of re-challenge are important.

"Nuts and Bolts" of Laboratory Evaluation of Angioedema

Angioedema, as a distinct disease entity, often becomes a clinical challenge for physicians, because it may cause a life-threatening condition, whereas prompt and accurate laboratory diagnostics may not be available. Although the bedside diagnosis needs to be established based on clinical symptoms and signs, family history, and the therapeutic response, later, laboratory tests are available. Currently, only for five out of the nine different types of angioedema can be diagnosed by laboratory testing, and these occur only in a minority of the patient population. Hereditary angioedema with C1-inhibitor (C1-INH) deficiency type I can be diagnosed by the low C1-INH function and concentration, whereas in type II, C1-INH function is low, but its concentration is normal or even elevated. C1q concentration is normal in both forms. Acquired angioedema with C1-INH deficiency type I is characterized by the low C1-INH function and concentration; however, C1q concentration is also low, and autoantibodies against C1-INH cannot be detected. Complement profile of acquired angioedema with C1-INH deficiency type II is similar to that of type I, but in this form, autoantibodies against C1-INH are present. Hereditary angioedema due to a mutation of the coagulation factor XII can be diagnosed exclusively by mutation analysis of FXII gene. Diagnostic metrics are not available for idiopathic histaminergic acquired angioedema, idiopathic non-histaminergic acquired angioedema, acquired angioedema related to angiotensin-converting enzyme inhibitor, and hereditary angioedema of unknown origin; these angioedemas can be diagnosed by medical and family history, clinical symptoms, and therapeutic response and by excluding the forms previously described. Several potential biomarkers of angioedema are used to date only in research. In the future, they could be utilized into the clinical practice to improve the differential diagnosis, therapy, as well as the prognosis of angioedema.

Adverse Drug Reactions in the Intensive Care Unit

Adverse drug reactions (ADRs) are undesirable effects of medications used in normal doses [1]. ADRs can occur during treatment in an intensive care unit (ICU) or result in ICU admissions. A meta-analysis of 4139 studies suggests the incidence of ADRs among hospitalized patients is 17% [2]. Because of underreporting and misdiagnosis, the incidence of ADRs may be much higher and has been reported to be as high as 36% [3]. Critically ill patients are at especially high risk because of medical complexity, numerous high-alert medications, complex and often challenging drug dosing and medication regimens, and opportunity for error related to the distractions of the ICU environment [4]. Table 1 summarizes the ADRs included in this chapter.

Determinants of angiotensin-converting enzyme inhibitor (ACEI) intolerance and angioedema in the UK Clinical Practice Research Datalink

AIM

The aim of the present study was to describe the occurrence and determinants of angiotensin-converting enzyme (ACE) inhibitor (ACEI) intolerance and angioedema (AE) among patients initiating ACEI therapy in a real-world primary care population.

METHODS

Two nested case-control studies were conducted in a cohort of 276 977 patients aged ≥45 years initiating ACEIs from 2007 to 2014 in the UK Clinical Practice Research Datalink (CPRD). Cases of AE occurring for the first time during ACEI therapy (n = 416) were matched with AE-free controls (n = 4335) on the duration of ACEI treatment. Documented switches to angiotensin-II receptor blockers in the prescription records were used to identify ACEI-intolerance cases (n = 24 709), and these were matched with continuous ACEI users (n = 84 238) on the duration of ACEI therapy. Conditional logistic regression was used to assess the associations of demographic factors, comorbidities and comedication with AE and ACEI intolerance.

RESULTS

AE during ACEI therapy was associated with age over 65 years [odds ratio (OR) 1.36, 95% confidence interval (CI) 1.07, 1.73], history of allergy (OR 1.53, 95% CI 1.19, 1.96), use of calcium channel blockers (OR 1.57, 95% CI 1.23; 2.01), use of antihistamines (OR 21.25, 95% CI 16.44, 27.46) and use of systemic corticosteroids (OR 4.52, 95% CI 3.26, 6.27). ACEI intolerance was significantly associated with more comorbidities and comedication compared with AE, including allergy (OR 2.02, 95% CI 1.96, 2.09), use of antiasthmatic drugs (OR 1.51, 95% CI 1.42, 1.61) and use of antihistamines (OR 1.53, 95% CI 1.43, 1.63).

CONCLUSIONS

Among ACEI users developing AE or ACEI intolerance, several comorbidities and comedication classes were significantly more prevalent compared with ACEI users not developing these adverse reactions.

Angiotensin-converting enzyme inhibitor-associated angioedema treated with c1-esterase inhibitor: A case report and review of the literature

Case Report:

A 59-year old man currently on >5 years of angiotensin-converting enzyme inhibitor (ACEI) therapy presented to the emergency department with angioedema of the tongue and difficulty swallowing. After receiving conventional therapy of antihistamine, steroids, and epinephrine, the patient's condition continued to deteriorate, with imminent intubation. The patient was treated with a C1-esterase inhibitor (C1-INH) and experienced rapid resolution of symptoms, which avoided airway complications.

Discussion:

Although no therapy has been approved for the treatment of ACEI–associated angioedema (AAE), the conventional therapy (antihistamine, steroids, and epinephrine) often proves ineffective in this bradykinin-mediated angioedema. There are drugs approved and used for hereditary angioedema that may be effective in the acute phase of ACEI-AAE that may prevent the need for further interventions, such as intubation and tracheotomy. These drugs include icatibant, ecallantide, fresh frozen plasma, and C1-INH.

Conclusion:

The literature and clinical evidence indicate C1-INH can be effectively used in the treatment of ACEI-AAE to halt the progression of the condition, prevent airway compromise and the need for intervention, and lead to rapid resolution of symptoms.

Case-control study evaluating competing risk factors for angioedema in a high-risk population

OBJECTIVES/HYPOTHESIS

Black race is a risk factor for angioedema. The primary aim was to examine the relationship between race-ethnicity and risk factors for angioedema.

STUDY DESIGN

Using a retrospective case-control study design, data was extracted with the Clinical Looking Glass utility, a data collection and management tool that captures data from electronic medical record systems within the Montefiore Healthcare System. Cases were emergency department (ED) visits with primary or secondary International Classification of Diseases, Ninth Revision, code diagnoses of angioedema in adults aged ≥ 18 years from January 2008 to December 2013 at three Montefiore centers in Bronx, New York. Controls were a random sampling of adult ED visits during the same period.

METHODS

In primary analyses, angiotensin-converting enzyme inhibitor (ACE-I) and black race were evaluated for synergy. The influence of different risk factors in the development of angioedema was evaluated using logistic regression models. Finally, race-ethnicity was further explored by evaluating for effect modification by stratification of models by race-ethnicity categories.

RESULTS

There were 1,247 cases and 6,500 controls randomly selected from a larger control pool. ACE-I use (odds ratio [OR] 3.70, 95% confidence interval [CI] 2.98, 4.60), hypertension (OR 1.88, 95% CI 1.55, 2.29), and black race (OR 2.25, 95% CI 1.86, 2.72) were the strongest risk factors. ACE-I use and black race were not synergistic (OR 1.10, 95% CI 0.80, 1.51). Race-ethnicity was an effect modifier for certain risk factors.

CONCLUSION

Race-ethnicity acts as an effect modifier for particular angioedema risk factors. The two strongest risk factors, ACE-I use and black race, were not synergistic.

LEVEL OF EVIDENCE

3b. Laryngoscope, 126:1823-1830, 2016.

[Acute non-allergic angioedema. Rare cause for intensive care unit admission]

Angiotensin-converting enzyme (ACE) inhibitor-induced angioedema usually follows an uneventful clinical course; however, if upper airway structures are involved, life-threatening complications may develop. Thus, affected patients should be carefully monitored in an intensive care unit and, if need be, the airway has to be secured early on. This case report discusses diagnostic and therapeutic approaches in a patient with suspected ACE inhibitor-induced angioedema, who had initially been admitted for neoadjuvant radiochemotherapy of rectal cancer.

Angiotensin II Receptor Blocker Neprilysin Inhibitor (ARNI): New Avenues in Cardiovascular Therapy

The burden of cardiovascular disease (CVD) is continuously and progressively raising worldwide. Essential hypertension is a major driver of cardiovascular events, including coronary artery disease, myocardial infarction, ischemic stroke and congestive heart failure. This latter may represent the final common pathway of different cardiovascular diseases, and it is often mediated by progressive uncontrolled hypertension. Despite solid advantages derived from effective and sustained blood pressure control, and the widespread availability of effective antihypertensive medications, the vast majority of the more than 1 billion hypertensive patients worldwide continue to have uncontrolled hypertension. Among various factors that may be involved, the abnormal activation of neurohormonal systems is one consistent feature throughout the continuum of cardiovascular diseases. These systems may initiate biologically meaningful "injury responses". However, their sustained chronic overactivity often may induce and maintain the progression from hypertension towards congestive heart failure. The renin-angiotensin-aldosteron system, the sympathetic nervous system and the endothelin system are major neurohormonal stressor systems that are not only able to elevate blood pressure levels by retaining water and sodium, but also to play a role in the pathophysiology of cardiovascular diseases. More recently, the angiotensin receptor neprilysin inhibitor (ARNI) represents a favourable approach to inhibit neutral endopeptidase (NEP) and suppress the RAAS via blockade of the AT1 receptors, without the increased risk of angioedema. LCZ696, the first-in-class ARNI, has already demonstrated BP lowering efficacy in patients with hypertension, in particular with respect to systolic blood pressure levels, improved cardiac biomarkers, cardiac remodelling and prognosis in patients with heart failure. This manuscript will briefly overview the main pathophysiological and therapeutic aspects of ARNI in the clinical management of hypertension and heart failure.

Angiotensin-converting enzyme inhibitors-induced angioedema treated by C1 esterase inhibitor concentrate (Berinert®): about one case and review of the therapeutic arsenal

C1 esterase inhibitor (Berinert®) is generally used to treat severe attack of hereditary angioedema. We describe here the case of a patient who presented with a severe angioedema induced by angiotensin-converting enzyme inhibitors (ACEIs) endangering her life. It could be successfully treated with that medicine.

Postanesthetic Severe Oral Angioedema in Patient's Taking Angiotensin-Converting Enzyme Inhibitor

Angiotensin-converting enzyme (ACE) inhibitors are the leading cause of a drug-induced angioedema. This occurrence is frequently underdiagnosed, but its relapse can be life-threatening. The authors' intention in reporting this clinical case is to sound a warning about reviewing attitudes and surveillance to try to improve patient perioperative safety.

Drug-induced visceral angioedema

Angioedema associated with angiotensin converting enzyme inhibitors (ACEIs) is due to the accumulation of bradykinin and its metabolites. Angiotensin receptor blockers (ARBs) produce anti-hypertensive effects by blocking the angiotensin II AT1 receptor action; hence bradykinin-related side effects are not expected. However, we notice the occurrence of ARB-induced angioedema as not a very rare side effect. Visceral drug-induced angioedema has been reported with ACEIs, not with ARBs. This underlying review will help educate readers on the pathophysiology and recent guidelines pertaining to ACEI- and ARB-induced visceral angioedema.

Neprilysin inhibition in chronic kidney disease

Despite current practice, patients with chronic kidney disease (CKD) are at increased risk of progression to end-stage renal disease and cardiovascular events. Neprilysin inhibition (NEPi) is a new therapeutic strategy with potential to improve outcomes for patients with CKD. NEPi enhances the activity of natriuretic peptide systems leading to natriuresis, diuresis and inhibition of the renin–angiotensin system (RAS), which could act as a potentially beneficial counter-regulatory system in states of RAS activation such as chronic heart failure (HF) and CKD. Early NEPi drugs were combined with angiotensin-converting enzyme inhibitors but were associated with unacceptable rates of angioedema and, therefore, withdrawn. However, one such agent (omapatrilat) showed promise of NEP/RAS inhibition in treating CKD in animal models, producing greater reductions in proteinuria, glomerulosclerosis and tubulointerstitial fibrosis compared with isolated RAS inhibition. A new class of drug called angiotensin receptor neprilysin inhibitor (ARNi) has been developed. One such drug, LCZ696, has shown substantial benefits in trials in hypertension and HF. In CKD, HF is common due to a range of mechanisms including hypertension and structural heart disease (including left ventricular hypertrophy), suggesting that ARNi could benefit patients with CKD by both retarding the progression of CKD (hence delaying the need for renal replacement therapy) and reducing the risk of cardiovascular disease. LCZ696 is now being studied in a CKD population.

Phenotype standardization of angioedema in the head and neck region caused by agents acting on the angiotensin system

Angioedema is a potentially life-threatening adverse reaction to angiotensin-converting enzyme inhibitors and angiotensin receptor blockers. To study the genetic etiology of this rare adverse event, international consortia and multicenter recruitment of patients are needed. To reduce patient heterogeneity, we have standardized the phenotype. In brief, it comprises swelling in the head and neck region that first occurs during treatment. It should not coincide with urticaria or have another likely cause such as hereditary angioedema.

ACE inhibitor-induced angioedema

Much has been written about hereditary angioedema (HAE) in recent literature; however, the prevalence of angiotensin-converting enzyme inhibitor-induced angioedema (ACEiIA) far exceeds that of HAE. Similarly, multiple therapies have been developed for HAE, yet no definitive therapy is available for ACEiIA. In this article, we discuss the mechanism, prevalence, pathophysiology, and management of ACEiIA, with focus on newer therapies recently approved for HAE and how they may be effective for ACEiIA.

IgE-Mediated Anaphylaxis to Foods, Venom, and Drugs: Influence of Serum Angiotensin Converting Enzyme Levels and Genotype

Circulating angiotensin-II protects the circulation against sudden falls in blood pressure and is generated by the enzymatic action of angiotensin converting enzyme (ACE) on angiotensin-I. The ACE genes have 2 allelic forms, “I” and “D.” The “D” genotype has both highest angiotensin-II generation and serum ACE levels compared to “I”. 120 patients with IgE-anaphylaxis, 119 healthy controls, and 49 atopics had serum ACE levels, ACE genotype, and renin levels determined. Plasma renin levels were identical for all groups. Serum ACE levels and genotypes were similar for healthy controls (HC) and atopics, but lower in anaphylaxis (P = 0.012), with ACE genotypes also showing increased “I” genes (P = 0.009). This effect was more pronounced in subjects manifesting airway angioedema and cardiovascular collapse (AACVS) than mild cutaneous and respiratory (CRA) symptoms. AACVS was significantly associated with the presence of “I” genes. For “ID” genotype OR is 5.6, 95% CI 1.8 to 17.4, and for “II” genotype OR is 44, 95% CI 5 to 1891 within the anaphylaxis group = 0.001. The results show a difference in the genotype frequency between control and anaphylaxis, suggesting a role for the renin angiotensin system in anaphylaxis manifesting with airway angioedema and cardiovascular collapse.

Neutral endopeptidase inhibition and the natriuretic peptide system: an evolving strategy in cardiovascular therapeutics

Hypertension and heart failure (HF) are common diseases that, despite advances in medical therapy, continue to be associated with high morbidity and mortality. Therefore, innovative therapeutic strategies are needed. Inhibition of the neutral endopeptidase (NEPinh) had been investigated as a potential novel therapeutic approach because of its ability to increase the plasma concentrations of the natriuretic peptides (NPs). Indeed, the NPs have potent natriuretic and vasodilator properties, inhibit the activity of the renin-angiotensin-aldosterone system, lower sympathetic drive, and have antiproliferative and antihypertrophic effects. Such potentially beneficial effects can be theoretically achieved by the use of NEPinh. However, studies have shown that NEPinh alone does not result in clinically meaningful blood pressure-lowering actions. More recently, NEPinh has been used in combination with other cardiovascular agents, such as angiotensin-converting enzyme inhibitors, and antagonists of the angiotensin receptor. Another future possible combination would be the use of NEPinh with NPs or their newly developed chimeric peptides. This review summarizes the current knowledge of the use and effects of NEPinh alone or in combination with other therapeutic agents for the treatment of human cardiovascular disease such as HF and hypertension.

Angiotensin II type 1 receptor antagonists in the treatment of hypertension in elderly patients: focus on patient outcomes

Hypertension in the elderly is one of the main risk factors of cardiovascular and cerebrovascular diseases. Knowledge regarding the mechanisms of hypertension and specific considerations in managing hypertensive elderly through pharmacological intervention(s) is fundamental to improving clinical outcomes. Recent clinical studies in the elderly have provided evidence that angiotensin II type 1 (AT(1)) receptor antagonists can improve clinical outcomes to a similar or, in certain populations, an even greater extent than other classical arterial blood pressure-lowering agents. This newer class of antihypertensive agents presents several benefits, including potential for improved adherence, excellent tolerability profile with minimal first-dose hypotension, and a low incidence of adverse effects. Thus, AT(1) receptor antagonists represent an appropriate option for many elderly patients with hypertension, type 2 diabetes, heart failure, and/or left ventricular dysfunction.

Angiotensin-converting enzyme inhibitor-induced angioedema in a community hospital emergency department

BACKGROUND

Angiotensin-converting enzyme inhibitors (ACE-Is) are associated with angioedema, a potentially life-threatening adverse reaction. Although multiple studies have been conducted in tertiary care emergency departments (EDs), scarce data are available about the presentation and management of ACE-I-induced angioedema (AIIA) in the community hospital ED.

OBJECTIVE

To describe the frequency, presentation, and management of AIIA in patients seen in a community hospital ED.

METHODS

A 5-year medical record review of all patients seen with angioedema at a community hospital ED. Data abstraction focused on demographic factors, initial clinical characteristics, and ED management and disposition of patients with AIIA.

RESULTS

We identified 166 ED visits for angioedema, including a subset of 50 visits for AIIA (30%; 95% confidence interval, 23%-38%). The AIIA was significantly more likely to be associated with an age of 65 years or older (P = .02), unilateral symptoms (P = .02), and absence of urticaria or itching (P < .001). The ED treatment choices and admission rates were similar between patients with and without AIIA. Community hospital admission rates for AIIA (14%) were significantly lower than those from a comparable tertiary care study (41%) (P = .003); ambulance transport to the ED was nearly 3-fold higher in the tertiary care center study (P = .006). Admission was most strongly related to lack of improvement (P < .001) and history of angioedema in AIIA (P = .009).

CONCLUSIONS

Angioedema frequency, presentation, and management are similar in community and tertiary care EDs (30%). Urticaria or itching may help differentiate AIIA from allergic reactions, which are otherwise similar in community ED presentation and management.