The Role of Pharmacogenomics in Contemporary Cardiovascular Therapy: A position statement from the European Society of Cardiology Working Group on Cardiovascular Pharmacotherapy

Genotype-Guided Antiplatelet Therapy: JACC Review Topic of the Week

The clinical efficacy and safety of antiplatelet agents vary among patients. Consequently, some patients are at increased risk of recurrent ischemic events during treatment. This interindividual variability can be a result of genetic variants in enzymes that play a role in drug metabolism. The field of pharmacogenomics explores the influence of these genetic variants on an individual's drug response. Tailoring antiplatelet treatment based on genetic variants can potentially result in optimized dosing or a change in drug selection. Most evidence supports guiding therapy based on the CYP2C19 allelic variants in patients with an indication for dual antiplatelet therapy. In ticagrelor-treated or prasugrel-treated patients, a genotype-guided de-escalation strategy can reduce bleeding risk, whereas in patients treated with clopidogrel, an escalation strategy may prevent ischemic events. Although the clinical results are promising, few hospitals have implemented these strategies. New results, technological advancements, and growing experience may potentially overcome current barriers for implementation in the future.

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.

Precision medicine in cardiovascular therapeutics: Evaluating the role of pharmacogenetic analysis prior to drug treatment

Pharmacogenomics is the examination of how genetic variation influences drug metabolism and response, in terms of both efficacy and safety. In cardiovascular disease, patient-specific diplotypes determine phenotypes, thereby influencing the efficacy and safety of drug treatments, including statins, antiarrhythmics, anticoagulants and antiplatelets. Notably, polymorphisms in key genes, such as CYP2C9, CYP2C19, VKORC1 and SLCO1B1, significantly impact the outcomes of treatment with clopidogrel, warfarin and simvastatin. Furthermore, the CYP2C19 polymorphism influences the pharmacokinetics and safety of the novel hypertrophic cardiomyopathy inhibitor, mavacamten. In this review, we critically assess the clinical application of pharmacogenomics in cardiovascular disease and delineate present and future utilization of pharmacogenomics. This includes insights into identifying missing heritability, the integration of whole genome sequencing and the application of polygenic risk scores to enhance the precision of personalized drug therapy. Our discussion encompasses health economic analyses that underscore the cost benefits associated with pre-emptive genotyping for warfarin and clopidogrel treatments, albeit acknowledging the need for further research in this area. In summary, we contend that cardiovascular pharmacogenomic analyses are underpinned by a wealth of evidence, and implementation is already occurring for some of these gene-drug pairs, but as with any area of medicine, we need to continually gather more information to optimize the use of pharmacogenomics in clinical practice.

Association between gene polymorphisms and initial warfarin therapy in patients after heart valve surgery

BACKGROUND

Warfarin is widely used for the prevention and treatment of thrombotic events. This study aimed to examine the influence of gene polymorphisms on the early stage of warfarin therapy in patients following heart valve surgery.

METHODS

Nine single nucleotide polymorphisms were genotyped using microarray chips, categorizing patients into three groups: normal responders (Group I), sensitive responders (Group II), and highly sensitive responders (Group III). The primary clinical outcomes examined were time in therapeutic range (TTR) and international normalized ratio (INR) variability. To investigate potential influencing factors, a generalized linear regression model was employed.

RESULTS

Among 734 patients, the prevalence of CYP2C9*3-1075A > C, CYP2C19*3-636G > A, and CYP2C19*17-806C > T variants were 11.2%, 9.9%, and 1.9% of patients, respectively. VKORC1-1639G > A or the linked -1173C > T variant was observed in 99.0% of the patients. Generalized linear model analysis revealed an impact of sensitivity grouping on INR variability. Compared to Group I, Group II showed higher TTR values (p = 0.023), while INR variability was poorer in Group II (p < 0.001) and Group III (p < 0.001). Individual gene analysis identified significant associations between CYP2C9*3-1075A > C (p < 0.001), VKORC1-1639G > A or the linked -1173 C > T (p = 0.009) and GGCX-3261G > A (p = 0.019) with INR variability.

CONCLUSION

The genotypes of CYP2C9, VKORC1, and GGCX were found to have a significant impact on INR variability during the initial phase of warfarin therapy. However, no significant association was observed between TTR and gene polymorphisms. These findings suggest that focusing on INR variability is crucial in clinical practice, and preoperative detection of gene polymorphisms should be considered to assist in the initiation of warfarin therapy.

Use of Genomics to Develop Novel Therapeutics and Personalize Hypertension Therapy

Hypertension is a prevalent public health problem, contributing to >10 million deaths annually. Though multiple therapeutics exist, many patients suffer from treatment-resistant hypertension or try several medications before achieving blood pressure control. Genomic advances offer mechanistic understanding of blood pressure variability, therapeutic targets, therapeutic response, and promise a stratified approach to treatment of primary hypertension. Cyclic guanosine monophosphate augmentation, aldosterone synthase inhibitors, and angiotensinogen blockade with silencing RNA and antisense therapies are among the promising novel approaches. Pharmacogenomic studies have also been done to explore the genetic bases underpinning interindividual variability in response to existing therapeutics. A polygenic approach using risk scores is likely to be the next frontier in stratifying responses to existing therapeutics.

Genetic risk factors for drug-induced long QT syndrome: findings from a large real-world case-control study

Aim: Drug-induced long QT syndrome (diLQTS), an adverse effect of many drugs, can lead to sudden cardiac death. Candidate genetic variants in cardiac ion channels have been associated with diLQTS, but several limitations of previous studies hamper clinical utility. Materials & methods: Thus, the purpose of this study was to assess the associations of KCNE1-D85N, KCNE2-I57T and SCN5A-G615E with diLQTS in a large observational case-control study (6,083 self-reported white patients treated with 27 different high-risk QT-prolonging medications; 12.0% with diLQTS). Results: KCNE1-D85N significantly associated with diLQTS (adjusted odds ratio: 2.24 [95% CI: 1.35-3.58]; p = 0.001). Given low minor allele frequencies, the study had insufficient power to analyze KCNE2-I57T and SCN5A-G615E. Conclusion: KCNE1-D85N is a risk factor for diLQTS that should be considered in future clinical practice guidelines.

Advances and Perspectives in methods for identifying high platelet reactivity

Antiplatelet therapy is the foundational treatment for the prevention and treatment of coronary and cerebrovascular ischemic events in patients with coronary heart disease, ischemic stroke, and transient ischemic attack (TIA). However, with more and more studies reporting an increased risk of thrombosis in some patients due to poor response to therapeutic agents, the selection of appropriate P2Y12 inhibitors has become a major challenge that needs to be addressed urgently. Currently, commonly used oral P2Y12 inhibitors include clopidogrel, ticagrelor, and prasugrel. Assessing patients' risk factors before the development of treatment regimens by effectively predicting the risk of high platelet reactivity with specific P2Y12 inhibitors in advance to avert the occurrence of major adverse cardiovascular and cerebrovascular events (MACCE) is the key point to the problem. Up to now, methods available for predicting platelet reactivity include genetic testing, platelet function testing, and risk scores. This review provides a summarization of the existent available identification methods and analyzes the advantages and drawbacks of different methods in specific clinical settings, intending to guide the rational clinical application of P2Y12 receptor inhibitors.

A randomized trial of genotype-guided perindopril use

OBJECTIVE

Cough caused by angiotensin-converting enzyme inhibitors (ACEIs) limits their clinical application and cardiovascular benefits. This randomized trial investigated whether genotype-guided perindopril use could reduce drug-related cough in 20 to 79-year-old individuals with hypertension.

METHODS

After screening 120 patients and randomization, 68 were assigned to genotyping ( n  = 41) and control ( n  = 27) groups. NELL1 p.Arg382Trp (rs8176786) and intron (rs10766756) genotype information was used to subdivide the genotyping group into high-risk and low-risk subgroups with at least one or no risk alleles for ACEI-related cough, respectively. The high-risk subgroup received candesartan (8 mg/day) for 6 weeks, whereas the low-risk subgroup received perindopril (4 mg/day). The control group, which was not genotyped, received perindopril (4 mg/day). The primary outcome variables were cough and moderate/severe cough; the secondary outcome variable was any adverse event.

RESULTS

During the 6-week period, the risk of cough was lower in the genotyping group than in the control group [five (12.2%) and nine (33.3%) participants, respectively; hazard ratio: 0.25; log-rank P  = 0.017]. The moderate/severe cough risk was also lower in the genotyping group [one (2.4%) and five (18.5%) participants, respectively; hazard ratio: 0.12; log-rank P  = 0.025]. Differences in cough (hazard ratio: 0.56; log-rank P  = 0.32) and moderate/severe cough risk (hazard ratio: 0.26; log-rank P  = 0.19) between the low-risk and control groups were not significant. The risk of total adverse events was similar between any two groups.

CONCLUSION

Cough risk was lower during genotype-guided treatment than during conventional treatment. These results support the utility of NELL1 variant data in clinical decision making to personalize renin-angiotensin system blocker therapy use.

TRIAL REGISTRATION

ClinicalTrials.gov number: NCT05535595 (retrospectively registered at September 7, 2022).

SLCO1B1*5 is protective against non-senile cataracts in cohort prescribed statins: analysis in a British-South Asian cohort

BACKGROUND

Reported association between statin use and cataract risk is controversial. The SLCO1B1 gene encodes a transport protein responsible for statin clearance. The aim of this study was to investigate a possible association between the SLCO1B1*5 reduced function variant and cataract risk in statin users of South Asian ethnicity.

METHODS

The Genes & Health cohort consists of British-Bangladeshi and British-Pakistani participants from East London, Manchester and Bradford, UK. SLCO1B1*5 genotype was assessed with the Illumina GSAMD-24v3-0-EA chip. Medication data from primary care health record linkage was used to compare those who had regularly used statins compared to those who had not. Multivariable logistic regression was used to test for association between statin use and cataracts, adjusting for population characteristics and potential confounders in 36,513 participants. Multivariable logistic regression was used to test association between SLCO1B1*5 heterozygotes or homozygotes and cataracts, in subgroups having been regularly prescribed statins versus not.

RESULTS

Statins were prescribed to 35% (12,704) of participants (average age 41 years old, 45% male). Non-senile cataract was diagnosed in 5% (1686) of participants. An apparent association between statins and non-senile cataract (12% in statin users and 0.8% in non-statin users) was negated by inclusion of confounders. In those prescribed a statin, presence of the SLCO1B1*5 genotype was independently associated with a decreased risk of non-senile cataract (OR 0.7 (CI 0.5-0.9, p 0.007)).

CONCLUSIONS

Our findings suggest that there is no independent association between statin use and non-senile cataract risk after adjusting for confounders. Among statin users, the SLCO1B1*5 genotype is associated with a 30% risk reduction of non-senile cataracts. Stratification of on-drug cohorts by validated pharmacogenomic variants is a useful tool to support or repudiate adverse drug events in observational cohorts.

Racial and ethnic differences in pharmacotherapy to prevent coronary artery disease and thrombotic events

Awareness of racial/ethnic disparities represents a key challenge for healthcare systems that attempt to provide effective healthcare and to reduce existing inequalities in the use of and adherence to guideline-recommended cardiovascular drugs to improve clinical outcomes for cardiovascular disease (CVD). In this review, we describe important racial/ethnic differences between and within ethnic groups in the prevalence, risk factors, haemostatic factors, anti-inflammatory and endothelial markers, recurrence, and outcomes of CVD.

We discuss important differences in the selection, doses, and response [efficacy and adverse drug reactions (ADRs)] in ethnically diverse patients treated with antithrombotics or lipid-lowering drugs. Differences in drug response are mainly related to racial/ethnic differences in the frequency of polymorphisms in genes encoding drug-metabolizing enzymes (DMEs) and drug transporters. These polymorphisms markedly influence the pharmacokinetics, dose requirements, and safety of warfarin, clopidogrel, and statins. This review aims to support a better understanding of the genetic differences between and among populations to identify patients who may experience an ADR or a lack of drug response, thus optimizing therapy and improving outcomes. The greater the understanding of the differences in the genetic variants of DMEs and transporters that determine the differences in the exposure, efficacy, and safety of cardiovascular drugs between races/ethnicities, the greater the probability that personalized medicine will become a reality.

Pharmacogenetics of clopidogrel and warfarin in the treatment of cardiovascular diseases: an overview of reviews

Pharmacogenetics (PGx) is the relationship between an individual's genetic variations and the response to pharmacological treatment. We chose to perform an overview of reviews on PGx testing-guided treatment for cardiovascular diseases, based on clinically relevant gene-drug pairs. We conducted a search on Medline, Embase and Cochrane Library, from their inception to 18 June 2020. The most studied gene-drug pairs were clopidogrel and warfarin associated with cytochrome p450 and vitamin K epoxide reductase complex subunit 1 genes (CYP2C19, CYP2C9 and VKORC1), classified as critically low quality. There is a need for more quality primary studies and systematic reviews that assess the risk of bias, with consistent definitions of clinical outcomes to consider the benefits of PGx testing for cardiovascular diseases.

Effects of Dapagliflozin in Asian Patients With Heart Failure and Reduced Ejection Fraction in DAPA-HF

Background

Patients with heart failure with reduced ejection fraction (HFrEF) in Asia exhibit many differences from those in other parts of the world.

Objectives

This study sought to investigate the efficacy and safety of dapagliflozin, compared with placebo, in HFrEF patients in Asia, compared with those elsewhere, enrolled in the DAPA-HF (Dapagliflozin and Prevention of Adverse-outcomes in Heart Failure) trial.

Methods

Patients in New York Heart Association functional class II to IV with a left ventricular ejection fraction ≤40% and elevated N-terminal pro–B-type natriuretic peptide were eligible for the DAPA-HF trial. The primary outcome in the DAPA-HF trial was the composite of an episode of worsening HF (HF hospitalization or urgent HF visit requiring intravenous therapy) or cardiovascular death.

Results

Of the 4,744 patients in the DAPA-HF trial, 1,096 (23.1%) were enrolled in Asia; 721 (15.2% overall, 65.8% of patients in Asia) were enrolled in East Asia (237 in China, 343 in Japan, and 141 in Taiwan), 138 (2.9% overall, 12.6% in Asia) in South-East Asia (Vietnam), and 237 (5.0% overall, 21.6% in Asia) in South Asia (India). Patients from Asia had similar rates of worsening HF events and mortality compared with patients elsewhere. Compared with placebo, dapagliflozin reduced the risk of the primary endpoint to the same extent in patients from Asia (HR: 0.65; 95% CI: 0.49 to 0.87) as elsewhere (HR: 0.77; 95% CI: 0.66 to 0.89) (P for interaction = 0.32). Consistent benefits were observed for the other prespecified outcomes and among the regions of Asia. Study drug discontinuation and prespecified adverse events did not differ between regions.

Conclusions

Dapagliflozin, compared with placebo, reduced the risk of worsening HF events and cardiovascular death to the same extent in Asian patients as elsewhere. (Study to Evaluate the Effect of Dapagliflozin on the Incidence of Worsening Heart Failure or Cardiovascular Death in Patients With Chronic Heart Failure [DAPA-HF]; NCT03036124)

Pharmacogenetics to Avoid Adverse Reactions in Cardiology: Ready for Implementation?

Cardiovascular Diseases (CVs) are one of the main causes of mortality and disability around the world. Advances in drug treatment have greatly improved survival and quality of life in the past decades, but associated adverse events remain a relevant problem. Pharmacogenetics can help individualize cardiovascular treatment, reducing associated toxicities and improving outcomes. Several scientific societies and working groups periodically review available studies and provide consensus recommendations for those gene-drug pairs with a sufficient level of evidence. However, these recommendations are rarely mandatory, and the indications on how to adjust treatment can vary between different guidelines, which limits their clinical applicability. The aim of this review is to compile, compare and discuss available guidelines and recommendations by the main Pharmacogenetics Consortiums (Clinical Pharmacogenetics Implementation Consortium (CPIC); Dutch Pharmacogenetics Working Group (DPWG); the French Network of Pharmacogenetics (Réseau national de pharmacogénétique (RNPGx) and The Canadian Pharmacogenomics Network for Drug Safety (CPNDS) regarding how to apply pharmacogenetic results to optimize pharmacotherapy in cardiology. Pharmacogenetic recommendations included in European or American drug labels, as well as those included in the European Society of Cardiology (ESC) and the American College of Cardiology (ACC) and the American Heart Association (AHA) treatment guidelines are also discussed.

Pharmacogenetic testing in psychiatry and neurology: an overview of reviews

Pharmacogenetic testing is available to healthcare professionals to guide drug selection and prevent adverse events. However, its implementation in the clinical practice of psychiatry/neurology still has barriers, mainly due to a lack of evidence. We conducted a literature search on Cochrane Library, Embase and Pubmed, from their inception to 18 June 2020. We included 16 published systematic reviews. The most studied drug categories were anticonvulsants and selective serotonin reuptake inhibitors associated with human leukocyte antigen and cytochrome P450 genes (HLA-A, HLA-B, CYP2C9, CYP2D6, CYP2C19), classified as critically low quality/low quality. There is a need for more robust studies with adequate design to assess the potential benefits of adopting pharmacogenetics in health systems and services.