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

Micklesfield, Ramsay M, Sarah P, Peter J. A GWAS of ACE Inhibitor-Induced Angioedema in a South African Population

Background

Angiotensin-converting enzyme inhibitor-induced angioedema (AE-ACEI) is a life-threatening adverse event and, globally, the commonest cause of emergency presentations with angioedema. Several large genome-wide association studies (GWAS) have found genomic associations with AE-ACEI. However, despite African Americans having a 5-fold increased risk of AE-ACEI, there are no published GWAS from Africa. The aim of this study was to conduct a case-control GWAS of AE-ACEI in a South African population and perform a meta-analysis with an African American and European American population.

Methods

The GWAS included 202 South African adults with a history of AE-ACEI and 513 controls without angioedema following angiotensin-converting enzyme inhibitor (ACEI) treatment for at least 2 years. A meta-analysis was conducted with GWAS summary statistics from an African American and European American cohort (from Vanderbilt/Marshfield with 174 cases and 489 controls).

Results

No SNPs attained genome-wide significance. However, 26 SNPs in the post-imputation standard GWAS of the South African cohort and 37 SNPs in the meta-analysis were associated to AE-ACEI with suggestive threshold(p-value<5.0×10-06). Some of these SNPs were found to be located close to the genes PRKCQ and RIMS1, previously linked with drug-induced angioedema, and also close to the CSMD1 gene linked to ACEI cough, providing replication at the gene level, but with novel lead SNPs.

Conclusions

Our results highlight the importance of African populations to detect novel variants in replication studies. Further increased sampling across the continent and matched functional work are needed to confirm the importance of genetic variation in understanding the biology of AE-ACEI.

A pharmacovigilance study assessing risk of angioedema with angiotensin receptor blockers using the US FDA Adverse Event Reporting System

BACKGROUND

Angiotensin receptor blockers (ARBs) are widely used for treating hypertension and heart failure. Angioedema has been reported as a controversial adverse effect of ARBs and the evidence on individual ARB risks is limited. This study aimed to assess signals of angioedema with different ARBs using the US FDA Adverse Event Reporting System (AERS) database.

RESEARCH DESIGN AND METHODS

Reports of angioedema from 2004 to 2024 in AERS with an ARB as the primary suspect were extracted using Medical Dictionary for Regulatory Activities queries. Disproportionality analyses including reporting odds ratio, proportional reporting ratio, Bayesian confidence propagation neural network and multi-item gamma Poisson shrinker were conducted to identify safety signals for individual ARBs.

RESULTS

A total of 3,683 unique reports met the selection criteria. Irbesartan and losartan generated signals in all statistical measures, followed by telmisartan and candesartan in some measures. Valsartan had the highest report count. Most reports reported hospitalization, prolonged hospitalization or life-threatening outcomes consequent to angioedema.

CONCLUSION

This pharmacovigilance study using AERS highlights potential higher risks of angioedema with losartan and irbesartan compared to other ARBs, warranting validation through prospective epidemiological studies to characterize individual ARB safety profiles.

Cardiovascular Pharmacogenetics: From Discovery of Genetic Association to Clinical Adoption of Derived Test

Recent breakthroughs in human genetics and in information technologies have markedly expanded our understanding at the molecular level of the response to drugs, i.e., pharmacogenetics (PGx), across therapy areas. This review is restricted to PGx for cardiovascular (CV) drugs. First, we examined the PGx information in the labels approved by regulatory agencies in Europe, Japan, and North America and related recommendations from expert panels. Out of 221 marketed CV drugs, 36 had PGx information in their labels approved by one or more agencies. The level of annotations and recommendations varied markedly between agencies and expert panels. Clopidogrel is the only CV drug with consistent PGx recommendation (i.e., "actionable"). This situation prompted us to dissect the steps from discovery of a PGx association to clinical translation. We found 101 genome-wide association studies that investigated the response to CV drugs or drug classes. These studies reported significant associations for 48 PGx traits mapping to 306 genes. Six of these 306 genes are mentioned in the corresponding PGx labels or recommendations for CV drugs. Genomic analyses also highlighted the wide between-population differences in risk allele frequencies and the individual load of actionable PGx variants. Given the high attrition rate and the long road to clinical translation, additional work is warranted to identify and validate PGx variants for more CV drugs across diverse populations and to demonstrate the utility of PGx testing. To that end, pre-emptive PGx combining genomic profiling with electronic medical records opens unprecedented opportunities to improve healthcare, for CV diseases and beyond. SIGNIFICANCE STATEMENT: Despite spectacular breakthroughs in human molecular genetics and information technologies, consistent evidence supporting PGx testing in the cardiovascular area is limited to a few drugs. Additional work is warranted to discover and validate new PGx markers and demonstrate their utility. Pre-emptive PGx combining genomic profiling with electronic medical records opens unprecedented opportunities to improve healthcare, for CV diseases and beyond.

Bradykinin attenuates endothelial-mesenchymal transition following cardiac ischemia-reperfusion injury

AIMS

Endothelial-mesenchymal transition (EndMT) is a crucial pathological process contributing to cardiac fibrosis. Bradykinin has been found to protect the heart against fibrosis. Whether bradykinin regulates EndMT has not been determined.

MATERIALS AND METHODS

Rats were subjected to ligation of the left anterior descending coronary artery for 1 h and subsequent reperfusion to induce cardiac ischemia-reperfusion (IR) injury. Bradykinin (0.5 μg/h) was infused by an osmotic pump implanted subcutaneously at the onset of reperfusion. Fourteen days later, the functional, histological, and molecular analyses were performed to investigate the changes in cardiac fibrosis and EndMT. Human coronary artery endothelial cells were utilized to determine the molecular mechanisms in vitro.

RESULTS

Bradykinin treatment improved cardiac function and decreased fibrosis following cardiac IR injury, accompanied by ameliorated EndMT and increased nitric oxide (NO) production. In vitro experiments found that bradykinin mitigated transforming growth factor β1 (TGFβ1)-induced EndMT. Significantly, the bradykinin B2 receptor antagonist or endothelial nitric oxide synthase inhibitor abolished the effects of bradykinin on EndMT inhibition, indicating that the bradykinin B2 receptor and NO might mediate the effects of bradykinin on EndMT inhibition.

CONCLUSION

Bradykinin plays an essential role in the process of cardiac fibrosis. Bradykinin preserves the cellular signature of endothelial cells, preventing them from EndMT following cardiac IR injury, possibly mediated by bradykinin B2 receptor activation and NO production.

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.

Pharmacogenomic knowledge and awareness among diverse patients treated with angiotensin converting enzyme inhibitors

We developed novel electronic phenotyping algorithms for the BioMe biobank data, which accurately identified angiotensin converting enzyme inhibitor (ACEi)-induced angioedema cases and controls. A survey was mailed to all 1075 patients and 91 were returned. Over a third reported that prescribing physicians had not discussed with them the concepts of interindividual drug response variability or adverse event risk, and 73% of patients were previously unaware of pharmacogenomics; however, most patients were interested in having pharmacogenomic testing. Moreover, 67% of patients indicated that pharmacogenomic testing would positively influence their medication compliance. In addition to identifying an innovative approach to define biobank cohorts for pharmacogenomic studies, these results indicate that patients are interested in pharmacogenomic testing, which could translate to improved adherence.

GWAS of Chronic Spontaneous Urticaria Reveals Genetic Overlap with Autoimmune Diseases, Not Atopic Diseases

Although chronic spontaneous urticaria (CSU) is a common disease, GWASs of CSU are lacking. We aimed to identify susceptibility SNPs by performing a GWAS in Chinese Han adults with CSU. The discovery cohort included 430 CSU cases and 482 healthy controls. The GWAS findings were validated in 800 CSU cases and 900 healthy controls. Genetic, functional enrichment, and bioinformatic analyses of genome-wide significant SNPs were performed to assess the association between CSU and autoimmunity or atopy. Five genome-wide significant SNPs were identified: rs434124/LILRA3, rs61986182/IGHG1/2, rs73075571/TDGF1, rs9378141/HLA-G, and rs3789612/PTPN22. The first four SNPs were in linkage disequilibrium with autoimmune-related diseases‒associated SNPs and were cis-expression quantitative trait loci in immune cells. The five SNPs-annotated genes were significantly enriched in immune processes. Higher polygenic risk scores and allele frequencies of rs3789612∗T, rs9378141∗C, and rs73075571∗G were significantly associated with autoimmune-related CSU phenotypes, including positive antithyroglobulin IgG, positive anti-FcεRIα IgG, total IgE <40 IU/ml, and positive antithyroid peroxidase IgG but not with atopic or allergic sensitized CSU phenotypes. This GWAS of CSU identifies five risk loci and reveals that CSU shares genetic overlap with autoimmune diseases and that genetic factors predisposing to CSU mainly manifest through associations with autoimmune traits.

Polygenic risk score for ACE-inhibitor-associated cough based on the discovery of new genetic loci

AIMS

To search for sequence variants associated with ACEi discontinuation and to test their association with ACEi-associated adverse drug reactions (ADRs).

METHODS AND RESULTS

A genome-wide association study (GWAS) on ACEi discontinuation was conducted, including 33 959 ACEi-discontinuers and 44 041 controls. Cases were defined as persons who switched from an ACEi treatment to an angiotensin receptor blocker. Controls were defined as persons who continued ACEi treatment for at least 1 year. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were computed for ACEi discontinuation risk by mixed model regression analysis. Summary statistics from the individual cohorts were meta-analyzed with a fixed-effects model. To test for association with specific ACEi-associated ADRs, any genome-wide significant (P < 5 × 10-8) ACEi discontinuation variants was tested for association with ACEi-associated cough and angioedema. A polygenetic risk score (PRS) based on ACEi discontinuation GWAS data was constructed and tested for association with ACEi-associated cough and angioedema in two population-based samples. In total, seven genetic genome-wide loci were identified, of which six were previously unreported. The strongest association with ACEi discontinuation was at 20q13.3 (NTSR1; OR: 1.21; 95% CI: 1.17-1.24; P = 2.1 × 10-34). Five of seven lead variants were associated with ACEi-associated cough, whereas none were associated with ACEi-associated angioedema. The ACEi discontinuation PRS was associated with ACEi-associated cough in a dose-response manner but not with ACEi-associated angioedema. ACEi discontinuation was genetically correlated with important causes for cough, including gastro-esophageal reflux disease, allergic rhinitis, hay fever, and asthma, which indicates partly shared genetic underpinning between these traits.

CONCLUSION

This study showed the advantage of using prescription patterns to discover genetic links with ADRs. In total, seven genetic loci that associated with ACEi discontinuation were identified. There was evidence of a strong association between our ADR phenotype and ACEi-associated cough. Taken together, these findings increase insight into the pathophysiological processes that underlie ACEi-associated ADRs.

Molecular Genetic Screening in Patients With ACE Inhibitor/Angiotensin Receptor Blocker-Induced Angioedema to Explore the Role of Hereditary Angioedema Genes

Angioedema is a relatively rare but potentially life-threatening adverse reaction to angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARBs). As with hereditary forms of angioedema (HAE), this adverse reaction is mediated by bradykinin. Research suggests that ACEi/ARB-induced angioedema has a multifactorial etiology. In addition, recent case reports suggest that some ACEi/ARB-induced angioedema patients may carry pathogenic HAE variants. The aim of the present study was to investigate the possible association between ACEi/ARB-induced angioedema and HAE genes via systematic molecular genetic screening in a large cohort of ACEi/ARB-induced angioedema cases. Targeted re-sequencing of five HAE-associated genes (SERPING1, F12, PLG, ANGPT1, and KNG1) was performed in 212 ACEi/ARB-induced angioedema patients recruited in Germany/Austria, Sweden, and Denmark, and in 352 controls from a German cohort. Among patients, none of the identified variants represented a known pathogenic variant for HAE. Moreover, no significant association with ACEi/ARB-induced angioedema was found for any of the identified common [minor allele frequency (MAF) >5%] or rare (MAF < 5%) variants. However, several non-significant trends suggestive of possible protective effects were observed. The lowest p-value for an individual variant was found in PLG (rs4252129, p.R523W, p = 0.057, p.adjust > 0.999, Fisher’s exact test). Variant p.R523W was found exclusively in controls and has previously been associated with decreased levels of plasminogen, a precursor of plasmin which is part of a pathway directly involved in bradykinin production. In addition, rare, potentially functional variants (MAF < 5%, Phred-scaled combined annotation dependent depletion score >10) showed a nominally significant enrichment in controls both: 1) across all five genes; and 2) in the F12 gene alone. However, these results did not withstand correction for multiple testing. In conclusion, our results suggest that HAE-associated mutations are, at best, a rare cause of ACEi/ARB-induced angioedema. Furthermore, we were unable to identify a significant association between ACEi/ARB-induced angioedema and other variants in the investigated genes. Further studies with larger sample sizes are warranted to draw more definite conclusions concerning variants with limited effect sizes, including protective variants.

Editor-in-Chief's Top Picks From 2021

Each week, I record audio summaries for every paper in JACC, as well as an issue summary. This process has become a true labor of love due to the time they require, but I am motivated by the sheer number of listeners (16M+), and it has allowed me to familiarize myself with every paper that we publish. Thus, I have selected the top 100 papers (both Original Investigations and Review Articles) from distinct specialties each year. In addition to my personal choices, I have included papers that have been the most accessed or downloaded on our websites, as well as those selected by the JACC Editorial Board members. In order to present the full breadth of this important research in a consumable fashion, we will present these abstracts in this issue of JACC, as well as their Central Illustrations and podcasts. The highlights comprise the following sections: Artificial Intelligence & Machine Learning (NEW section), Basic & Translational Research, Biomarkers (NEW section), Cardiac Failure & Myocarditis, Cardiomyopathies & Genetics, Cardio-Oncology, Cardiovascular Disease in Women, Coronary Disease & Interventions, Congenital Heart Disease, Coronavirus, Hypertension, Imaging, Metabolic & Lipid Disorders, Neurovascular Disease & Dementia, Promoting Health & Prevention, Rhythm Disorders & Thromboembolism, Vascular Medicine, and Valvular Heart Disease.^1-100.

Cohort profile: Copenhagen Hospital Biobank - Cardiovascular Disease Cohort (CHB-CVDC): Construction of a large-scale genetic cohort to facilitate a better understanding of heart diseases

PURPOSE

The aim of Copenhagen Hospital Biobank-Cardiovascular Disease Cohort (CHB-CVDC) is to establish a cohort that can accelerate our understanding of CVD initiation and progression by jointly studying genetics, diagnoses, treatments and risk factors.

PARTICIPANTS

The CHB-CVDC is a large genomic cohort of patients with CVD. CHB-CVDC currently includes 96 308 patients. The cohort is part of CHB initiated in 2009 in the Capital Region of Denmark. CHB is continuously growing with ~40 000 samples/year. Patients in CHB were included in CHB-CVDC if they were above 18 years of age and assigned at least one cardiovascular diagnosis. Additionally, up-to 110 000 blood donors can be analysed jointly with CHB-CVDC. Linkage with the Danish National Health Registries, Electronic Patient Records, and Clinical Quality Databases allow up-to 41 years of medical history. All individuals are genotyped using the Infinium Global Screening Array from Illumina and imputed using a reference panel consisting of whole-genome sequence data from 8429 Danes along with 7146 samples from North-Western Europe. Currently, 39 539 of the patients are deceased.

FINDINGS TO DATE

Here, we demonstrate the utility of the cohort by showing concordant effects between known variants and selected CVDs, that is, >93% concordance for coronary artery disease, atrial fibrillation, heart failure and cholesterol measurements and 85% concordance for hypertension. Furthermore, we evaluated multiple study designs and the validity of using Danish blood donors as part of CHB-CVDC. Lastly, CHB-CVDC has already made major contributions to studies of sick sinus syndrome and the role of phytosterols in development of atherosclerosis.

FUTURE PLANS

In addition to genetics, electronic patient records, national socioeconomic and health registries extensively characterise each patient in CHB-CVDC and provides a promising framework for improved understanding of risk and protective variants. We aim to include other measurable biomarkers for example, proteins in CHB-CVDC making it a platform for multiomics cardiovascular studies.