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Angioedema occurring in the head and neck region is a rare and sometimes life-threatening adverse reaction to angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs). Few studies have investigated the association of common variants with this extreme reaction, but none have explored the combined influence of rare variants yet. Adjudicated cases of ACEI-induced angioedema (ACEI-AE) or ARB-induced angioedema (ARB-AE) and controls were recruited at five different centers. Sequencing of 1,066 samples (408 ACEI-AE, ARB-AE, and 658 controls) was performed using exome-enriched sequence data. A common variant of the F5 gene that causes an increase in blood clotting (rs6025, p.Arg506Gln, also called factor V Leiden), was significantly associated with both ACEI-AE and ARB-AE (odds ratio: 2.85, 95% confidence interval (CI), 1.89–4.25). A burden test analysis of five rare missense variants in F5 was also found to be associated with ACEI-AE or ARB-AE, P = 2.09 × 10−3. A combined gene risk score of these variants, and the common variants rs6025 and rs6020, showed that individuals carrying at least one variant had 2.21 (95% CI, 1.49–3.27, P = 6.30 × 10−9) times the odds of having ACEI-AE or ARB-AE. The increased risk due to the common Leiden allele was confirmed in a genome-wide association study from the United States. A high risk of angioedema was also observed for the rs6020 variant that is the main coagulation defect-causing variant in black African and Asian populations. We found that deleterious missense variants in F5 are associated with an increased risk of ACEI-AE or ARB-AE.

Background: Studies examining the role of factor V Leiden among patients at higher risk of atherothrombotic events, such as those with established coronary heart disease (CHD), are lacking. Given that coagulation is involved in the thrombus formation stage on atherosclerotic plaque rupture, we hypothesized that factor V Leiden may be a stronger risk factor for atherothrombotic events in patients with established CHD. Methods: We performed an individual-level meta-analysis including 25 prospective studies (18 cohorts, 3 case-cohorts, 4 randomized trials) from the GENIUS-CHD (Genetics of Subsequent Coronary Heart Disease) consortium involving patients with established CHD at baseline. Participating studies genotyped factor V Leiden status and shared risk estimates for the outcomes of interest using a centrally developed statistical code with harmonized definitions across studies. Cox proportional hazards regression models were used to obtain age- and sex-adjusted estimates. The obtained estimates were pooled using fixed-effect meta-analysis. The primary outcome was composite of myocardial infarction and CHD death. Secondary outcomes included any stroke, ischemic stroke, coronary revascularization, cardiovascular mortality, and all-cause mortality. Results: The studies included 69 681 individuals of whom 3190 (4.6%) were either heterozygous or homozygous (n=47) carriers of factor V Leiden. Median follow-up per study ranged from 1.0 to 10.6 years. A total of 20 studies with 61 147 participants and 6849 events contributed to analyses of the primary outcome. Factor V Leiden was not associated with the combined outcome of myocardial infarction and CHD death (hazard ratio, 1.03 [95% CI, 0.92–1.16]; I 2 =28%; P -heterogeneity=0.12). Subgroup analysis according to baseline characteristics or strata of traditional cardiovascular risk factors did not show relevant differences. Similarly, risk estimates for the secondary outcomes including stroke, coronary revascularization, cardiovascular mortality, and all-cause mortality were also close to identity. Conclusions: Factor V Leiden was not associated with increased risk of subsequent atherothrombotic events and mortality in high-risk participants with established and treated CHD. Routine assessment of factor V Leiden status is unlikely to improve atherothrombotic events risk stratification in this population.

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.

BackgroundWe characterised the phenotypic consequence of genetic variation at the PCSK9 locus and compared findings with recent trials of pharmacological inhibitors of PCSK9.MethodsPublished and individual participant level data (300,000+ participants) were combined to construct a weighted PCSK9 gene-centric score (GS). Fourteen randomized placebo controlled PCSK9 inhibitor trials were included, providing data on 79,578 participants. Results were scaled to a one mmol/L lower LDL-C concentrationResultsThe PCSK9 GS (comprising 4 SNPs) associations with plasma lipid and apolipoprotein levels were consistent in direction with treatment effects. The GS odds ratio (OR) for myocardial infarction (MI) was 0.53 (95%CI 0.42; 0.68), compared to a PCSK9 inhibitor effect of 0.90 (95%CI 0.86; 0.93). For ischemic stroke ORs were 0.84 (95%CI 0.57; 1.22) for the GS, compared to 0.85 (95%CI 0.78; 0.93) in the drug trials. ORs with type 2 diabetes mellitus (T2DM) were 1.29 (95% CI 1.11; 1.50) for the GS, as compared to 1.00 (95%CI 0.96; 1.04) for incident T2DM in PCSK9 inhibitor trials. No genetic associations were observed for cancer, heart failure, atrial fibrillation, chronic obstructive pulmonary disease, or Alzheimer’s disease – outcomes for which large-scale trial data were unavailable.ConclusionsGenetic variation at the PCSK9 locus recapitulates the effects of therapeutic inhibition of PCSK9 on major blood lipid fractions and MI. Apparent discordance between genetic associations and trial outcome for T2DM might be explained lack by a of statistical precision, or differences in the nature and duration of genetic versus pharmacological perturbation of PCSK9.FundingThis research was funded by the British Heart Foundation (SP/13/6/30554, RG/10/12/28456, FS/18/23/33512), UCL Hospitals NIHR Biomedical Research Centre, by the Rosetrees and Stoneygate Trusts.Condensed abstractEvidence on the long-term efficacy and safety of therapeutic inhibition of PCSK9 is lacking. To explore potential long-term effects of PCSK9 inhibition, we characterised the phenotypic consequence of LDL-cholesterol lowering variants at the PCSK9 locus. A PCSK9 gene score comprising 4 SNPs recapitulated the effects of therapeutic inhibition of PCSK9 on major blood lipid fractions and risk of myocardial infarction, and was associated with an increased risk of type 2 diabetes. No associations with safety outcomes such as cancer, COPD, Alzheimer’s disease or atrial fibrillation were identified. Our findings suggest PCSK9 inhibition may be safe and effective during prolonged use.

INTRODUCTION: A large proportion of the coumarin dose variability is explained by environmental factors and by common genetic variants in the VKORC1 and CYP2C9 genes. Genotype-guided coumarin dosing has been proposed for a more accurate prediction of the coumarin dose in order to reduce the incidence of coumarin-related complications. AREAS COVERED: This review discusses the current state of coumarin pharmacogenetics, the evidence from recent randomized controlled trials and economic evaluations regarding the possible clinical implementation of genotype-guided coumarin dosing. EXPERT OPINION: When the VKORC1 and CYP2C9 genotypes are available before the start of coumarin therapy in individuals of European ancestry, a genetic-guided algorithm should be used for dose determination. Ethnicity-specific pharmacogenetic algorithms should be tested in other populations. At this moment the evidence is not sufficient to support genotyping before coumarin therapy initiation. Based on results from recent randomized controlled trials, a clinical dosing algorithm could be considered in the initial phase of coumarin treatment. Current economic studies indicate that genotype-guided dosing could be cost-effective, but the clinical implementation of genetic-guided coumarin therapy will depend on the cost of pharmacogenetic tests and the availability of novel oral anticoagulants.

Background— Studies of recurrent or subsequent disease events may be susceptible to bias caused by selection of subjects who both experience and survive the primary indexing event. Currently, the magnitude of any selection bias, particularly for subsequent time-to-event analysis in genetic association studies, is unknown. Methods and Results— We used empirically inspired simulation studies to explore the impact of selection bias on the marginal hazard ratio for risk of subsequent events among those with established coronary heart disease. The extent of selection bias was determined by the magnitudes of genetic and nongenetic effects on the indexing (first) coronary heart disease event. Unless the genetic hazard ratio was unrealistically large (>1.6 per allele) and assuming the sum of all nongenetic hazard ratios was Conclusions— In most empirical settings, selection bias is expected to have a limited impact on genetic effect estimates of subsequent event risk. Nevertheless, because of undercoverage increasing with sample size, most confidence intervals will be over precise (not wide enough). When there is no effect modification by history of coronary heart disease, the false-positive rates of association tests will be close to nominal.

Coumarin derivates are oral anticoagulants commonly prescribed for treatment and prevention of thromboembolism. Due to a small therapeutic index and large inter- and intrapatient differences in dose requirements, treatment with coumarins is challenging, particularly in its starting phase. Extensive evidence suggests that common genetic variants in CYP2C9 and VKORC1 genes together with a number of clinical factors are important determinants of the coumarin dose variability. Pharmacogenetic algorithms comprising both genetic and non-genetic factors were developed to improve the safety of coumarin therapy initiation. Recently, three randomized controlled trials (the COAG and the EU-PACT trials) on pharmacogenetic dosing of warfarin, acenocoumarol and phenprocoumon were published. In these trials different coumarin dosing strategies were compared to investigate whether or not pharmacogenetic testing could be beneficial for coumarin management. The purpose of this review was to present and discuss the design and results of these studies within the context of previously published randomized controlled trials and to address the issues surrounding the incorporation of coumarin pharmacogenetic testing into clinical practice.

Objectives: This study describes the occurrence of angioedema among patients initiating ACEI therapy and evaluates the association of this outcome with demographic factors, co-medication and chronic comorbidities. Methods: A nested case-control study was conducted in a cohort of patients newly treated with ACEIs from 2007 to 2014 in the CPRD. Cases who had angioedema only during ACEI treatment were identified using medical codes and were matched on the duration of ACEI treatment at the angioedema date (index date) with up to 20 controls who never had angioedema recorded. The use of co-medication (anti-diabetics, antihistamines, anti-asthmatics, non-steroidal anti-inflammatory drugs (NSAIDs), systemic corticosteroids, calcium channel blockers and statins), was acquired from CPRD prescription records within a three months' time window before the index date. The history of comorbidities (asthma, allergy, chronic obstructive pulmonary disease (COPD), diabetes mellitus and rheumatoid arthritis) was retrieved from medical records any time before the index date. Odds ratios (ORs) and p-values were estimated using univariate logistic regression analysis. Results: The cohort included 276,977 patients aged ≥ 45 years initiating ACEI therapy. The study population included 416 cases of angioedema during ACEI therapy matched with 4,335 controls. Age over 65 years was associated with angioedema. The proportions of asthma, allergy, COPD and rheumatoid arthritis were significantly higher in ACEI consumers who developed angioedema during ACEI therapy (ORs 1.83, 2.03, 2.08 and 2.83 respectively; p

Recent genome-wide association studies identified single nucleotide polymorphisms (SNPs) on the chromosome 9p21.3 conferring the risk for CAD (coronary artery disease) in individuals of Caucasian ancestry. We performed a genetic association study to investigate the effect of 12 candidate SNPs within 9p21.3 locus on the risk of CAD in the Saudi population of the Eastern Province of Saudi Arabia. A total of 250 Saudi CAD patients who had experienced an myocardial infarction (MI) and 252 Saudi age-matched healthy controls were genotyped using TaqMan assay. Controls with evidenced lack of CAD provided 90% of statistical power at the type I error rate of 0.05. Five percent of the results were rechecked for quality control using Sanger sequencing, the results of which concurred with the TaqMan genotyping results. Association analysis of 12 SNPs indicated a significant difference in the genotype distribution for four SNPs between cases and controls (rs564398 p = 0.0315, χ² = 4.6, odds ratio (OD) = 1.5; rs4977574 p = 0.0336, χ² = 4.5, OD = 1.4; rs2891168 p = 1.85 × 10 - 10, χ² = 40.6, OD = 2.1 and rs1333042 p = 5.14 × 10 - 9, χ² = 34.1, OD = 2.2). The study identified three protective haplotypes (TAAG p = 1.00 × 10 - 4; AGTA p = 0.022 and GGGCC p = 0.0175) and a risk haplotype (TGGA p = 2.86 × 10 - 10) for the development of CAD. This study is in line with others that indicated that the SNPs located in the intronic region of the CDKN2B-AS1 gene are associated with CAD.

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.