Cost-effectiveness of CYP2C19-guided antiplatelet therapy in patients with acute coronary syndrome and percutaneous coronary intervention informed by real-world data

Cost-effectiveness of implementing a genotype-guided de-escalation strategy in patients with acute coronary syndrome

AIMS

A genotype-guided P2Y12-inhibitor de-escalation strategy, switching acute coronary syndrome (ACS) patients without a CYP2C19 loss-of-function allele from ticagrelor or prasugrel to clopidogrel, has shown to reduce bleeding risk without affecting the effectivity of therapy by increasing ischaemic risk. We estimated the cost-effectiveness of this personalized approach compared to standard dual antiplatelet therapy (DAPT; aspirin plus ticagrelor/prasugrel) in the Netherlands.

METHODS AND RESULTS

We developed a 1-year decision tree based on results of the FORCE-ACS registry, comparing a cohort of ACS patients who underwent genotyping with a cohort of ACS patients treated with standard DAPT. This was followed by a lifelong Markov model to compare lifetime costs and quality-adjusted life years (QALYs) for a fictional cohort of 1000 patients. The cost-effectiveness analysis was performed from the perspective of the Dutch healthcare system. A genotype-guided de-escalation strategy led to an increase of 57.73 QALYs and saved €808788 compared to standard DAPT based on a lifetime horizon. Probabilistic sensitivity analysis showed that the genotype-guided strategy was cost-saving in 96% and increased QALYs in 87% of simulations. The intervention remained cost-effective in the scenario where prices for all P2Y12 inhibitors were equalized. The genotype-guided strategy remained dominant in various other scenarios and sensitivity analyses.

CONCLUSION

A genotype-guided de-escalation strategy in patients with ACS was both cost-saving and yielded higher QALYs compared to standard DAPT, highlighting its potential for implementation in clinical practice. Trial registration: ClinicalTrials.gov identifier: NCT03823547.

Demographic diversity in platelet function and response to antiplatelet therapy

Recent studies have highlighted the complexity of platelet biology, revealing their diverse roles beyond hemostasis. Pathological platelet activation is now recognized as a key contributor to thrombosis and inflammation that are both central to cardiovascular disease (CVD). Emerging research emphasizes the significant impact of demographic factors - such as age, sex, race, and ethnicity - on CVD risk and responses to antiplatelet therapies. These population-based differences, shaped by genetic and non-genetic factors, highlight the need for reevaluation of antiplatelet strategies. We address current knowledge and emphasize the pressing need for further research into platelet biology and cardiovascular outcomes across diverse populations. In this review we advocate for tailored therapeutic approaches in CVD based on the recent demographic-focused findings.

International Consensus Statement on Platelet Function and Genetic Testing in Percutaneous Coronary Intervention: 2024 Update

Current evidence indicates that dual antiplatelet therapy with aspirin plus a P2Y12 inhibitor is essential for the prevention of thrombotic events after percutaneous coronary interventions. However, dual antiplatelet therapy is associated with increased bleeding which may outweigh the benefits. This has set the foundations for customizing antiplatelet treatments to the individual patient. However, bleeding and ischemic risks are often present in the same patient, making it difficult to achieve this balance. The fact that oral P2Y12 inhibitors (clopidogrel, prasugrel, and ticagrelor) have diverse pharmacodynamic profiles that affect clinical outcomes supports the rationale for using platelet function and genetic testing to individualize antiplatelet treatment regimens. Indeed, up to one-third of patients treated with clopidogrel, but a minority of those treated with prasugrel or ticagrelor, exhibit high residual platelet reactivity resulting in an increased thrombotic risk. On the other hand, prasugrel and ticagrelor are frequently associated with low platelet reactivity and increased bleeding risk compared with clopidogrel without providing any additional reduction in ischemic events compared with patients who adequately respond to clopidogrel. The use of platelet function and genetic testing may allow for a guided selection of oral P2Y12 inhibitors. However, the nonuniform results of randomized controlled trials have led guidelines to provide limited recommendations on the implementation of these tests in patients undergoing percutaneous coronary intervention. In light of recent advancements in the field, this consensus document by a panel of international experts fills in the guideline gap by providing updates on the latest evidence in the field as well as recommendations for clinical practice.

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.

Cost-effectiveness of platelet function testing in dual antiplatelet therapy decision-making after intracranial aneurysm treatment with flow diversion

Dual antiplatelet therapy (DAPT) use is the standard of practice after flow diversion (FD) for intracranial aneurysms (IAs). Yet, no consensus exists in the literature regarding the optimal regimen. Certain institutions utilize various platelet function testing (PFT) to assess patient responsiveness to DAPT. Clopidogrel is the most commonly prescribed drug during DAPT; however, up to 52% of patients can be non-responders, justifying PFT use. Additionally, prices vary significantly among antiplatelet drugs, often further complicated by insurance restrictions. We aimed to determine the most cost-effective strategy for deciding DAPT regimens for patients after IA treatment. A decision tree with Monte Carlo simulations was performed to simulate patients undergoing various three-month postoperative DAPT regimens. Patients were either universally administered aspirin alongside clopidogrel, ticagrelor, or prasugrel without PFT, or administered one of the former thienopyridine medications based on platelet reactivity unit (PRU) results after clopidogrel. Input data for the model were extracted from the current literature, and the willingness-to-pay threshold (WTP) was defined as $100,000 per QALY as per standard practice in the US. The baseline comparison was with universal clopidogrel DAPT without any PFT. Probabilistic and deterministic sensitivity analyses were performed to evaluate the robustness of the model. Utilizing PFT and switching clopidogrel to prasugrel if resistance is documented was the most cost-effective regimen compared to universal clopidogrel, with a base-case incremental cost-effectiveness ratio (ICER) of $-35,255 (cost $2,336.67, effectiveness 0.85). Performing PFT and switching clopidogrel to ticagrelor (ICER $-4,671; cost $2,995.06, effectiveness 0.84), universal prasugrel (ICER $5,553; cost $3,097.30, effectiveness 0.84), or universal ticagrelor (ICER $75,969; cost $3,801.36, effectiveness 0.84) were all more cost-effective than treating patients with universal clopidogrel (cost $3,041.77, effectiveness 0.83). These conclusions remain robust in probabilistic and deterministic sensitivity analyses. The most cost-effective strategy guiding DAPT after FD for IAs is to perform PFTs and switch clopidogrel to prasugrel if resistance is documented, alongside aspirin. The cost of PFT is strongly justified and recommended when deciding patient-specific DAPT regimens.

CYP2C19 Genetic Testing for Oral P2Y12 Inhibitor Therapy: A Scientific Statement From the American Heart Association

There is significant variability in the efficacy and safety of oral P2Y12 inhibitors, which are used to prevent ischemic outcomes in common diseases such as coronary and peripheral arterial disease and stroke. Clopidogrel, a prodrug, is the most used oral P2Y12 inhibitor and is activated primarily after being metabolized by a highly polymorphic hepatic cytochrome CYP2C219 enzyme. Loss-of-function genetic variants in CYP2C219 are common, can result in decreased active metabolite levels and increased on-treatment platelet aggregation, and are associated with increased ischemic events on clopidogrel therapy. Such patients can be identified by CYP2C19 genetic testing and can be treated with alternative therapy. Conversely, universal use of potent oral P2Y12 inhibitors such as ticagrelor or prasugrel, which are not dependent on CYP2C19 for activation, has been recommended but can result in increased bleeding. Recent clinical trials and meta-analyses have demonstrated that a precision medicine approach in which loss-of-function carriers are prescribed ticagrelor or prasugrel and noncarriers are prescribed clopidogrel results in reducing ischemic events without increasing bleeding risk. The evidence to date supports CYP2C19 genetic testing before oral P2Y12 inhibitors are prescribed in patients with acute coronary syndromes or percutaneous coronary intervention. Clinical implementation of such genetic testing will depend on among multiple factors: rapid availability of results or adoption of the concept of performing preemptive genetic testing, provision of easy-to-understand results with therapeutic recommendations, and seamless integration in the electronic health record.

Clinical impact of preemptive pharmacogenomic testing on antiplatelet therapy in a real-world setting

CYP2C19 genotyping to guide antiplatelet therapy after patients develop acute coronary syndromes (ACS) or require percutaneous coronary interventions (PCIs) reduces the likelihood of major adverse cardiovascular events (MACE). Evidence about the impact of preemptive testing, where genotyping occurs while patients are healthy, is lacking. In patients initiating antiplatelet therapy for ACS or PCI, we compared medical records data from 67 patients who received CYP2C19 genotyping preemptively (results >7 days before need), against medical records data from 67 propensity score-matched patients who received early genotyping (results within 7 days of need). We also examined data from 140 patients who received late genotyping (results >7 days after need). We compared the impact of genotyping approaches on medication selections, specialty visits, MACE and bleeding events over 1 year. Patients with CYP2C19 loss-of-function alleles were less likely to be initiated on clopidogrel if they received preemptive rather than early or late genotyping (18.2%, 66.7%, and 73.2% respectively, p = 0.001). No differences were observed by genotyping approach in the number of specialty visits or likelihood of MACE or bleeding events (all p > 0.21). Preemptive genotyping had a strong impact on initial antiplatelet selection and a comparable impact on patient outcomes and healthcare utilization, compared to genotyping ordered after a need for antiplatelet therapy had been identified.

Real-World Implementation of a Genotype-Guided P2Y12 Inhibitor De-Escalation Strategy in Acute Coronary Syndrome Patients

BACKGROUND

CYP2C19 genotype-guided de-escalation from ticagrelor or prasugrel to clopidogrel may optimize the balance between ischemic and bleeding risk in patients with acute coronary syndrome (ACS).

OBJECTIVES

This study sought to compare bleeding and ischemic event rates in genotyped patients vs standard care.

METHODS

Since 2015, ACS patients in the multicenter FORCE-ACS (Future Optimal Research and Care Evaluation in Patients with Acute Coronary Syndrome) registry received standard dual antiplatelet therapy (DAPT). Since 2021, genotype-guided P2Y12 inhibitor de-escalation was recommended at a single center, switching noncarriers of the loss-of-function allele CYP2C19∗3 or CYP2C19∗2 from ticagrelor or prasugrel to clopidogrel, whereas loss-of-function carriers remained on ticagrelor or prasugrel. The primary ischemic endpoint, a composite of cardiovascular mortality, myocardial infarction, or stroke, and the primary bleeding endpoint, Bleeding Academic Research Consortium 2, 3, or 5 bleeding, were compared between a genotyped cohort and a cohort treated with standard DAPT after 1 year.

RESULTS

Among 5,321 enrolled ACS patients, 406 underwent genotyping compared with 4,915 nongenotyped ACS patients on standard DAPT. In the genotyped cohort, 65.3% (n = 265) were noncarriers, 88.7% (n = 235) of whom were switched to clopidogrel. The primary ischemic endpoint occurred in 5.2% (n = 21) of patients in the genotyped cohort compared to 6.9% (n = 337) in the standard care cohort (adjusted HR: 0.82; 95% CI: 0.53-1.28). The primary bleeding rate was significantly lower in the genotyped cohort compared to the standard care cohort (4.7% vs 9.8%; adjusted HR: 0.47; 95% CI: 0.30-0.76).

CONCLUSIONS

The implementation of a CYP2C19 genotype-guided P2Y12 inhibitor de-escalation strategy in a real-world ACS population resulted in lower bleeding rates without an increase in ischemic events compared to a standard DAPT regimen.

Variability patterns in dual antiplatelet therapy following endovascular repair of intracranial aneurysms: Insight into regimen heterogeneity and the need for a consensus

This comprehensive review delves into the evolving field of neurointervention for intracranial aneurysms, exploring the critical adjunct of Dual Antiplatelet Therapy (DAPT) to endovascular coiling, stent-assisted coiling (SAC), flow-diversion stents, and flow-disruption (intrasaccular) devices. Despite growing evidence supporting the success of DAPT in reducing thromboembolic events, the lack of consensus on optimal regimens, doses, and duration is evident. Factors contributing to this variability include genetic polymorphisms affecting treatment response and ongoing debates regarding the clinical significance of hemorrhagic complications associated with DAPT. This review analyzes pre- and post-procedural antiplatelet usage across various interventions. The imperative lies in ongoing research to define optimal DAPT durations, ensuring a nuanced approach to the delicate balance between thrombosis and hemorrhage in intracranial aneurysm management.

Safety and Efficacy of CYP2C19 Genotype-Guided Escalation of P2Y12 Inhibitor Therapy After Percutaneous Coronary Intervention in Chronic Kidney Disease: a Post Hoc Analysis of the TAILOR-PCI Study

PURPOSE

Chronic kidney disease (CKD) is a risk factor for ischemic and bleeding events with dual antiplatelet therapy after percutaneous coronary intervention (PCI). Whether the presence of CYP2C19 loss of function (LOF) alleles modifies this risk, and whether a genotype-guided (GG) escalation of P2Y12 inhibitor therapy post PCI is safe in this population is unclear.

METHODS

This was a post hoc analysis of randomized patients in TAILOR PCI. Patients were divided into two groups based on estimated glomerular filtration rate (eGFR) threshold of < 60 ml/min/1.73 m2 for CKD (n = 539) and non-CKD (n = 4276). The aggregate of cardiovascular death, stroke, myocardial infarction, stent thrombosis, and severe recurrent coronary ischemia at 12-months post-PCI was assessed as the primary endpoint. Secondary endpoint was major or minor bleeding.

RESULTS

Mean (standard deviation) eGFR among patients with CKD was 49.5 (8.4) ml/min/1.72 m2. Among all patients, there was no significant interaction between randomized strategy and CKD status for any endpoint. Among LOF carriers, the interaction between randomized strategy and CKD status on composite ischemic outcome was not significant (p = 0.2). GG strategy was not associated with an increased risk of bleeding in either CKD group.

CONCLUSIONS

In this exploratory analysis, escalation of P2Y12 inhibitor therapy following a GG strategy did not reduce the primary outcome in CKD. However, P2Y12 inhibitor escalation following a GG strategy was not associated with increased bleeding risk in CKD. Larger studies in CKD are needed.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT01742117?term=TAILOR-PCI&draw=2&rank=1 . NCT01742117.

Consideration of the Medical Economics of Cardiac Genetics, Focusing on the Cost-Effectiveness of P2Y12 Inhibitor Selection Based on the CYP2C19 Loss-of-Function Allele: A Semi-Systematic Review

Medical economics is essential in cardiac genetics for the clinical application and development of research results. However, related economic evaluations are unclear, and limited systematic reviews are available on the cost-effectiveness of drug selection based on the CYP2C19 LOF allele. This review analyzed research in the MEDLINE database from January 2012 to June 2023 using more evidence than a well-designed cohort study, owing to the lack of relevant research in the database. For example, cost-effectiveness analyses are often reported as simulation assays, and were included in this analysis. No conditions related to patient background or antiplatelet drug therapy were selected. This review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement (2020). Twenty-one cardiac genetic studies were selected, of which nineteen involved antiplatelet therapy after PCI. A universal group consisting of clopidogrel and other drugs was used as the baseline and compared with the drug selection groups based on the CYP2C19 LOF allele. The incremental cost–effectiveness ratio was generally below 50,000 (US$/Qaly), and drug selection based on the CYP2C19 LOF allele was the most cost-effective, followed by universal clopidogrel. Although cardiac genetic and economic data are rudimentary, this review indicates that antiplatelet therapy (drug selection based on the CYP2C19 LOF allele) after PCI is generally cost-effective.

Genetic-Guided Pharmacotherapy for Coronary Artery Disease: A Systematic and Critical Review of Economic Evaluations

BACKGROUND

Genetic-guided pharmacotherapy (PGx) is not recommended in clinical guidelines for coronary artery disease (CAD). We aimed to examine the extent and quality of evidence from economic evaluations of PGx in CAD and to identify variables influential in changing conclusions on cost-effectiveness.

METHODS AND RESULTS

From systematic searches across 6 databases, 2 independent reviewers screened, included, and rated the methodological quality of economic evaluations of PGx testing to guide pharmacotherapy for patients with CAD. Of 35 economic evaluations included, most were model-based cost-utility analyses alone, or alongside cost-effectiveness analyses of PGx testing to stratify patients into antiplatelets (25/35), statins (2/35), pain killers (1/35), or angiotensin-converting enzyme inhibitors (1/35) to predict CAD risk (8/35) or to determine the coumadin doses (1/35). To stratify patients into antiplatelets (96/151 comparisons with complete findings of PGx versus non-PGx), PGx was more effective and more costly than non-PGx clopidogrel (28/43) but less costly than non-PGx prasugrel (10/15) and less costly and less effective than non-PGx ticagrelor (22/25). To predict CAD risk (51/151 comparisons), PGx using genetic risk scores was more effective and less costly than clinical risk score (13/17) but more costly than no risk score (16/19) or no treatment (9/9). The remaining comparisons were too few to observe any trend. Mortality risk was the most common variable (47/294) changing conclusions.

CONCLUSIONS

Economic evaluations to date found PGx to stratify patients with CAD into antiplatelets or to predict CAD risk to be cost-effective, but findings varied based on the non-PGx comparators, underscoring the importance of considering local practice in deciding whether to adopt PGx.

Assessing the utility of measurement methods applied in economic evaluations of pharmacogenomics applications

An increasing number of economic evaluations are published annually investigating the economic effectiveness of pharmacogenomic (PGx) testing. This work was designed to provide a comprehensive summary of the available utility methods used in cost-effectiveness/cost-utility analysis studies of PGx interventions. A comprehensive review was conducted to identify economic analysis studies using a utility valuation method for PGx testing. A total of 82 studies met the inclusion criteria. A majority of studies were from the USA and used the EuroQol-5D questionnaire, as the utility valuation method. Cardiovascular disorders was the most studied therapeutic area while discrete-choice studies mainly focused on patients' willingness to undergo PGx testing. Future research in applying other methodologies in PGx economic evaluation studies would improve the current research environment and provide better results.

Elevations in Norclobazam Concentrations and Altered Mental Status in CYP2C19 Poor Metabolizer Phenotype: A Case Report

Clobazam is a 1,5-benzodiazepine frequently used as an adjunctive agent for refractory seizures and status epilepticus. Clobazam undergoes metabolism to an active metabolite norclobazam which is subsequently hydroxylated by CYP2C19, a cytochrome with several pharmacogenetic variants. Patients with poor metabolizer phenotypes may have elevated norclobazam levels and subsequent adverse effects. We present a case of an Asian American male receiving clobazam at a standard therapeutic dose for seizure disorder who became comatose secondary to significantly elevated norclobazam concentrations. Genetic testing revealed the patient was a poor CYP2C19 metabolizer, accounting for the impaired clearance. Clinicians should be aware of the patient populations at risk for these genetic polymorphisms and adjust initial doses based on package labeling or consider therapeutic drug monitoring to avoid adverse effects.

CYP2C19 Genotype Prevalence and Association With Recurrent Myocardial Infarction in British-South Asians Treated With Clopidogrel

Background

Cytochrome P450 family 2 subfamily C member 19 (CYP2C19) is a hepatic enzyme involved in the metabolism of clopidogrel from a prodrug to its active metabolite. Prior studies of genetic polymorphisms in CYP2C19 and their relationship with clinical efficacy have not included South Asian populations.

Objectives

The objective of this study was to assess prevalence of common CYP2C19 genotype polymorphisms in a British-South Asian population and correlate these with recurrent myocardial infarction risk in participants prescribed clopidogrel.

Methods

The Genes & Health cohort of British Bangladeshi and Pakistani ancestry participants were studied. CYP2C19 diplotypes were assessed using array data. Multivariable logistic regression was used to test for association between genetically inferred CYP2C19 metabolizer status and recurrent myocardial infarction, controlling for known cardiovascular disease risk factors, percutaneous coronary intervention, age, sex, and population stratification.

Results

Genes & Health cohort participants (N = 44,396) have a high prevalence (57%) of intermediate or poor CYP2C19 metabolizers, with at least 1 loss-of-function CYP2C19 allele. The prevalence of poor metabolizers carrying 2 CYP2C19 loss-of-function alleles is 13%, which is higher than that in previously studied European (2.4%) and Central/South Asian populations (8.2%). Sixty-nine percent of the cohort who were diagnosed with an acute myocardial infarction were prescribed clopidogrel. Poor metabolizers were significantly more likely to have a recurrent myocardial infarction (OR: 3.1; P = 0.019).

Conclusions

A pharmacogenomic-driven approach to clopidogrel prescribing has the potential to impact significantly on clinical management and outcomes in individuals of Bangladeshi and Pakistani ancestry.

Cost-effectiveness of Arg16Gly in ADRB2 pharmacogenomic-guided treatment for pediatric asthma

OBJECTIVES

To assess the cost-effectiveness of Arg16Gly ADRB2 pharmacogenomic testing compared with no Arg16Gly ADRB2 testing to guide the use of long-acting β2 receptor agonist (LABA) in asthma patients aged 1 to 5 years in China.

METHODS

This economic evaluation developed a Markov model with four health states (no exacerbation, mild exacerbation, moderate-to-severe exacerbation, and death). Transition probabilities were estimated from the rate of exacerbations, the case-fatality rate of patients hospitalized for exacerbations, and natural mortality. Costs included drug costs and exacerbation management costs. Cost inputs and utilities for each health state were gained from public databases and the literatures. Costs and quality-adjusted life years (QALYs) were estimated for ten years. Deterministic and probabilistic sensitivity analyses were performed.

RESULTS

In the base case analysis, in contrast to the group without the genotype test, the incremental total cost was -¥334.7, and the incremental QALY was 0.001 in the Arg16Gly ADRB2 genotyping group. Therefore, the Arg16Gly ADRB2 test group was the dominant strategy for children with asthma in China. The sensitivity analyses showed that the model was relatively stable.

CONCLUSION

Arg16Gly ADRB2 testing before using LABA is a cost-effective approach compared with no gene testing for pediatric asthma.

Economic evaluation of pharmacogenomic-guided antiplatelet treatment in Spanish patients suffering from acute coronary syndrome participating in the U-PGx PREPARE study

BACKGROUND

Cardiovascular diseases and especially Acute Coronary Syndrome (ACS) constitute a major health issue impacting millions of patients worldwide. Being a leading cause of death and hospital admissions in many European countries including Spain, it accounts for enormous amounts of healthcare expenditures for its management. Clopidogrel is one of the oldest antiplatelet medications used as standard of care in ACS.

METHODS

In this study, we performed an economic evaluation study to estimate whether a genome-guided clopidogrel treatment is cost-effective compared to conventional one in a large cohort of 243 individuals of Spanish origin suffering from ACS and treated with clopidogrel. Data were derived from the U-PGx PREPARE clinical trial. Effectiveness was measured as survival of individuals while study data on safety and efficacy, as well as on resource utilization associated with each adverse drug reaction were used to measure costs to treat these adverse drug reactions. A generalized linear regression model was used to estimate cost differences for both study groups.

RESULTS

Based on our findings, PGx-guided treatment group is cost-effective. PGx-guided treatment demonstrated to have 50% less hospital admissions, reduced emergency visits and almost 13% less ADRs compared to the non-PGx approach with mean QALY 1.07 (95% CI, 1.04-1.10) versus 1.06 (95% CI, 1.03-1.09) for the control group, while life years for both groups were 1.24 (95% CI, 1.20-1.26) and 1.23 (95% CI, 1.19-1.26), respectively. The mean total cost of PGx-guided treatment was 50% less expensive than conventional therapy with clopidogrel [€883 (95% UI, €316-€1582), compared to €1,755 (95% UI, €765-€2949)].

CONCLUSION

These findings suggest that PGx-guided clopidogrel treatment represents a cost-effective option for patients suffering from ACS in the Spanish healthcare setting.

Evaluation of Potential Racial Disparities in CYP2C19-Guided P2Y12 Inhibitor Prescribing After Percutaneous Coronary Intervention

Black patients suffer worse outcomes after percutaneous coronary intervention (PCI) than White patients. Inequities in antiplatelet prescribing may contribute to this health disparity. We compared P2Y12 inhibitor prescribing by race following CYP2C19 genotyping to guide antiplatelet therapy selection after PCI. Patients from 9 sites that performed clinical CYP2C19 genotyping after PCI were included. Alternative therapy (e.g., prasugrel or ticagrelor) was recommended for CYP2C19 no-function allele carriers, in whom clopidogrel is predicted to be less effective. The primary outcome was choice of P2Y12 inhibitor (clopidogrel vs. alternative therapy) based on genotype. Of 3,342 patients included, 2,448 (73%) were White, and 659 (20%) were Black. More Black than White patients had a no-function allele (34.3% vs. 29.7%, P = 0.024). At hospital discharge following PCI, 44.2% of Black and 44.0% of White no-function allele carriers were prescribed alternative therapy. At the time of the last follow-up within 12 months, numerically fewer Black (51.8%) than White (56.7%) no-function allele carriers were prescribed alternative therapy (P = 0.190). However, the difference was not significant after accounting for other factors associated with P2Y12 inhibitor selection (odds ratio 0.79, 95% confidence interval 0.58-1.08). Alternative therapy use did not differ between Black (14.3%) and White (16.7%) patients without a no-function allele (P = 0.232). Among real-world patients who received CYP2C19 testing after PCI, P2Y12 inhibitor prescribing rates did not differ between Black and White patients. Our data suggest an absence of racial disparity in genotype-guided antiplatelet prescribing among patients receiving CYP2C19 testing.

Pharmacogenetics of P2Y12 receptor inhibitors

Oral P2Y12 inhibitors are commonly prescribed for cardiovascular disease and include clopidogrel, prasugrel, and ticagrelor. Each of these drugs has its strengths and weaknesses. Prasugrel and ticagrelor are more potent inhibitors of platelet aggregation and were shown to be superior to clopidogrel in preventing major adverse cardiovascular events after an acute coronary syndrome and percutaneous coronary intervention (PCI) in the absence of genotyping. However, both are associated with an increased risk for non-coronary artery bypass-related bleeding. Clopidogrel is a prodrug requiring bioactivation, primarily via the CYP2C19 enzyme. Approximately 30% of individuals have a CYP2C19 no function allele and decreased or no CYP2C19 enzyme activity. Clopidogrel-treated carriers of a CYP2C19 no function allele have decreased exposure to the clopidogrel active metabolite and lesser inhibition of platelet aggregation, which likely contributed to reduced clopidogrel efficacy in clinical trials. The pharmacogenetic data for clopidogrel are most robust in the setting of PCI, but evidence is accumulating for other indications. Guidance is available from expert consensus groups and regulatory agencies to assist with integrating genetic information into P2Y12 inhibitor prescribing decisions, and CYP2C19 genotype-guided antiplatelet therapy after PCI is one of the most common examples of clinical pharmacogenetic implementation. Herein, we review the evidence for pharmacogenetic associations with clopidogrel response and outcomes with genotype-guided P2Y12 inhibitor selection and describe guidance to assist with pharmacogenetic implementation. We also describe processes for applying genotype data for P2Y12 inhibitor therapy selection and remaining gaps in the field. Ultimately, consideration of both clinical and genetic factors may guide selection of P2Y12 inhibitor therapy that optimally balances the atherothrombotic and bleeding risks.

The Clinical Implementation of CYP2C19 Genotyping in Patients with an Acute Coronary Syndrome: Insights From the FORCE-ACS Registry

BACKGROUND

Guidelines recommend prasugrel or ticagrelor for acute coronary syndrome (ACS) patients. However, these P2Y12 inhibitors increase bleeding risk compared to clopidogrel. Although genotype-guided P2Y12-inhibitor selection has been shown to reduce bleeding risk, data on its clinical implementation is lacking.

METHODS

The study included ACS patients receiving genotype-guided antiplatelet therapy, utilising either a point-of-care (POC) device or laboratory-based testing. We aimed to collect qualitative and quantitative data on genotyping, eligibility for de-escalation, physician adherence to genotype results, time to de-escalation and cost reduction.

RESULTS

Of the 1,530 patients included in the ACS registry from 2021 to 2023, 738 ACS patients treated with ticagrelor received a CYP2C19 genotype test. The median turnover time of genotyping was 6.3 hours (interquartile range [IQR], 3.2-16.7), with 82.3% of the genotyping results known within 24 hours after admission. POC genotyping exhibited significantly shorter turnaround times compared to laboratory-based testing (with respective medians of 5.7 vs 47.8 hours; P < .001). Of the genotyped patients, 81.7% were eligible for de-escalation which was carried out within 24 hours in 70.9% and within 48 h in 93.0%. The time to de-escalation was significantly shorter using POC (25.4 hours) compared to laboratory-based testing (58.9 hours; P < .001). Implementing this strategy led to a reduction of €211,150.50 in medication costs.

CONCLUSIONS

CYP2C19 genotype-guided-de-escalation in an all-comers ACS population is feasible. POC genotyping leads to shorter turnaround times and quicker de-escalation. Time to de-escalation from ticagrelor to clopidogrel in noncarriers was short, with high physician adherence to genotype results.

Cost Effectiveness of Pharmacogenetic Testing for Drugs with Clinical Pharmacogenetics Implementation Consortium (CPIC) Guidelines: A Systematic Review

The objective of this study was to evaluate the evidence on cost-effectiveness of pharmacogenetic (PGx)-guided treatment for drugs with Clinical Pharmacogenetics Implementation Consortium (CPIC) guidelines. A systematic review was conducted using multiple biomedical literature databases from inception to June 2021. Full articles comparing PGx-guided with nonguided treatment were included for data extraction. Quality of Health Economic Studies (QHES) was used to assess robustness of each study (0-100). Data are reported using descriptive statistics. Of 108 studies evaluating 39 drugs, 77 (71%) showed PGx testing was cost-effective (CE) (N = 48) or cost-saving (CS) (N = 29); 21 (20%) were not CE; 10 (9%) were uncertain. Clopidogrel had the most articles (N = 23), of which 22 demonstrated CE or CS, followed by warfarin (N = 16), of which 7 demonstrated CE or CS. Of 26 studies evaluating human leukocyte antigen (HLA) testing for abacavir (N = 8), allopurinol (N = 10), or carbamazepine/phenytoin (N = 8), 15 demonstrated CE or CS. Nine of 11 antidepressant articles demonstrated CE or CS. The median QHES score reflected high-quality studies (91; range 48-100). Most studies evaluating cost-effectiveness favored PGx testing. Limited data exist on cost-effectiveness of preemptive and multigene testing across disease states.

Cost Effectiveness of a CYP2C19 Genotype-Guided Strategy in Patients with Acute Myocardial Infarction: Results from the POPular Genetics Trial

INTRODUCTION

The POPular Genetics trial demonstrated that a CYP2C19 genotype-guided P2Y₁₂ inhibitor strategy reduced bleeding rates compared with standard treatment with ticagrelor or prasugrel without increasing thrombotic event rates after primary percutaneous coronary intervention (PCI).

OBJECTIVE

In this analysis, we aimed to evaluate the cost effectiveness of a genotype-guided strategy compared with standard treatment with ticagrelor or prasugrel.

METHODS

A 1-year decision tree based on the POPular Genetics trial in combination with a lifelong Markov model was developed to compare costs and quality-adjusted life-years (QALYs) between a genotype-guided and a standard P2Y₁₂ inhibitor strategy in patients with myocardial infarction undergoing primary PCI. The cost-effectiveness analysis was conducted from a Dutch healthcare system perspective. Within-trial survival and utility data were combined with lifetime projections to evaluate lifetime cost effectiveness for a cohort of 1000 patients. Costs and utilities were discounted at 4 and 1.5%, respectively, according to Dutch guidelines for health economic studies. Besides deterministic and probabilistic sensitivity analyses, several scenario analyses were also conducted (different time horizons, different discount rates, equal prices for P2Y₁₂ inhibitors, and equal distribution of thrombotic events between the two strategies).

RESULTS

Base-case analysis with a hypothetical cohort of 1000 subjects demonstrated 8.98 QALYs gained and €725,550.69 in cost savings for the genotype-guided strategy (dominant). The deterministic and probabilistic sensitivity analysis confirmed the robustness of the model and the cost-effectiveness results. In scenario analyses, the genotype-guided strategy remained dominant.

CONCLUSION

In patients undergoing primary PCI, a CYP2C19 genotype-guided strategy compared with standard treatment with ticagrelor or prasugrel resulted in QALYs gained and cost savings.

TRIAL REGISTRATION

Clinicaltrials.gov number: NCT01761786, Netherlands trial register number: NL2872.

CYP2C19 Genotype-Guided Antiplatelet Therapy After Percutaneous Coronary Intervention in Diverse Clinical Settings

Background Studies have demonstrated increased risk of major atherothrombotic events in CYP2C19 loss-of-function (LOF) variant carriers versus non-carriers treated with clopidogrel after percutaneous coronary intervention (PCI). We sought to evaluate real-world outcomes with the clinical implementation of CYP2C19-guided antiplatelet therapy after PCI. Methods and Results Data from 9 medical centers where genotyping was performed in the setting of PCI were included. Alternative therapy with prasugrel or ticagrelor was recommended for patients with a CYP2C19 LOF variant. The primary outcome was the composite of major atherothrombotic events (all-cause death, myocardial infarction, ischemic stroke, stent thrombosis, or hospitalization for unstable angina) within 12 months following PCI. Moderate or severe/life-threatening bleeding within 12 months was a secondary outcome. Among 3342 patients, 1032 (31%) were LOF carriers, of whom 571/1032 (55%) were treated with alternative therapy. In LOF carriers, the rate of major atherothrombotic events was lower in patients treated with alternative therapy versus clopidogrel (adjusted HR, 0.56; 95% CI 0.39-0.82). In those without a LOF allele, no difference was observed (adjusted HR, 1.07; 95% CI 0.71-1.60). There was no difference in bleeding with alternative therapy versus clopidogrel in either LOF carriers or those without a LOF allele. Conclusions Real-world data demonstrate lower atherothrombotic risk in CYP2C19 LOF carriers treated with alternative therapy versus clopidogrel and similar risk in those without a LOF allele treated with clopidogrel or alternative therapy. These data suggest that PCI patients treated with clopidogrel should undergo genotyping so that CYP2C19 LOF carriers can be identified and treated with alternative therapy.

Translational Pharmacogenomics: Discovery, Evidence Synthesis and Delivery of Race-Conscious Medicine

Response to medications, the principal treatment modality for acute and chronic diseases, is highly variable, with 40-70% of patients exhibiting lack of efficacy or adverse drug reactions. With ~ 15-30% of this variability explained by genetic variants, pharmacogenomics has become a valuable tool in our armamentarium for optimizing treatments and is poised to play an increasing role in clinical care. This review presents the progress made toward elucidating genetic underpinnings of drug response including discovery of race/ancestry-specific pharmacogenetic variants and discusses the current evidence and evidence framework for actionability. The review is framed in the context of changing demographics and evolving views related to race and ancestry. Finally, it highlights the vital role played by cohort studies in elucidating genetic differences in drug response across race and ancestry and the informal collaborations that have enabled the field to bridge the "bench to bedside" translational gap.

Evaluation of population-level pharmacogenetic actionability in Alabama

The evolution of evidence and availability of Clinical Pharmacogenetic Implementation Consortium (CPIC) guidelines have enabled assessment of pharmacogenetic (PGx) actionability and clinical implementation. However, population‐level actionability is not well‐characterized. We leveraged the Alabama Genomic Health Initiative (AGHI) to evaluate population‐level PGx actionability. Participants (>18 years), representing all 67 Alabama counties, were genotyped using the Illumina Global Screening array. Using CPIC guidelines, actionability was evaluated using (1) genotype data and genetic ancestry, (2) prescribing data, and (3) combined genotype and medication data. Of 6,331 participants, 4230 had genotype data and 3386 had genotype and prescription data (76% women; 76% White/18% Black [self‐reported]). Genetic ancestry was concordant with self‐reported race. For CPIC level A genes, 98.6% had an actionable genotype (99.4% Blacks/African; 98.5% White/European). With the exception of DPYD and CYP2C19, the prevalence of actionable genotypes by gene differed significantly by race. Based on prescribing, actionability was highest for CYP2D6 (70.9%), G6PD (54.1%), CYP2C19 (53.5%), and CYP2C9 (47.5%). Among participants prescribed atenolol, carvedilol, or metoprolol, ~ 50% had an actionable ADRB1 genotype, associated with decreased therapeutic response, with higher actionability among Blacks compared to Whites (62.5% vs. 47.4%; p < 0.0001). Based on both genotype and prescribing frequencies, no significant differences in actionability were observed between men and women. This statewide effort highlights PGx population‐level impact to help optimize pharmacotherapy. Almost all Alabamians harbor an actionable genotype, and a significant proportion are prescribed affected medications. Statewide efforts, such as AGHI, lay the foundation for translational research and evaluate “real‐world” outcomes of PGx.

Cost-effectiveness of CYP2C19-guided antiplatelet therapy for acute coronary syndromes in Singapore

We evaluated the cost-effectiveness of a genotype-guided strategy among patients with acute coronary syndromes using a decision-tree model based on the Singapore healthcare payer's perspective over a 1-year time horizon. Three dual antiplatelet strategies were considered: universal clopidogrel, genotype-guided, and universal ticagrelor. The prevalence of loss-of-function alleles was assumed to be 61.7% and model inputs were identified from the literature. Our primary outcome of interest was incremental cost-effectiveness ratio (ICER) compared to universal clopidogrel. Both genotype-guided (72,158 SGD/QALY) and universal ticagrelor (82,269 SGD/QALY) were considered cost-effective based on a willingness-to-pay (WTP) threshold of SGD 88,991. In our secondary analysis, the ICER for universal ticagrelor was 114,998 SGD/QALY when genotype-guided was taken as a reference. Probabilistic sensitivity analysis revealed that genotype-guided was the most cost-effective strategy when the WTP threshold was between SGD 70,000 to 100,000. Until more data are available, our study suggests that funding for a once-off CYP2C19 testing merits a consideration over 1 year of universal ticagrelor.

Short- and long-term cost-effectiveness analysis of CYP2C19 genotype-guided therapy, universal clopidogrel, versus universal ticagrelor in post-percutaneous coronary intervention patients in Qatar

BACKGROUND

Patients having CYP2C19 loss-of-function alleles and receiving clopidogrel are at higher risk of adverse cardiovascular outcomes. Ticagrelor is an effective antiplatelet that is unaffected by the CYP2C19 polymorphism. The main aim of the current research is to evaluate the cost-effectiveness among CYP2C19 genotype-guided therapy, universal ticagrelor, and universal clopidogrel after a percutaneous coronary intervention (PCI).

METHODS

A two-part decision-analytic model, including a one-year model and a 20-year follow-up Markov model, was created to follow the use of (i) universal clopidogrel, (ii) universal ticagrelor, and (iii) genotype-guided antiplatelet therapy. Outcome measures were the incremental cost-effectiveness ratio (ICER, cost/success) and incremental cost-utility ratio (ICUR, cost/quality-adjusted life years [QALY]). Therapy success was defined as survival without myocardial infarction, stroke, cardiovascular death, stent thrombosis, and no therapy discontinuation because of adverse events, i.e. major bleeding and dyspnea. The model was based on a multivariate analysis, and a sensitivity analysis confirmed the robustness of the model outcomes, including against variations in drug acquisition costs.

RESULTS

Against universal clopidogrel, genotype-guided therapy was cost-effective over the one-year duration (ICER, USD 6102 /success), and dominant over the long-term. Genotype-guided therapy was dominant against universal ticagrelor over the one-year duration, and cost-effective over the long term (ICUR, USD 1383 /QALY). Universal clopidogrel was dominant over ticagrelor for the short term, and cost-effective over the long-term (ICUR, USD 10,616 /QALY).

CONCLUSION

CYP2C19 genotype-guided therapy appears to be the preferred antiplatelet strategy, followed by universal clopidogrel, and then universal ticagrelor for post-PCI patients in Qatar.

The effect of de-escalation of P2Y12 receptor inhibitor therapy after acute myocardial infarction in patients undergoing percutaneous coronary intervention: A nationwide cohort study

To examine the effect of de-escalation of P2Y₁₂ inhibitor in dual antiplatelet therapy (DAPT) on major adverse cardiovascular events (MACE) and bleeding complications after acute myocardial infarction (AMI) in Taiwanese patients undergoing percutaneous coronary intervention (PCI). Patients who had received PCI during hospitalization for AMI (between 2013 and 2016) and were initially treated with aspirin and ticagrelor and without adverse events after 3 months of treatment were retrospectively evaluated. In total, 1,901 and 8,199 patients were identified as “de-escalated DAPT” (switched to aspirin and clopidogrel) and “unchanged DAPT” (continued on aspirin and ticagrelor) cohorts, respectively. With a mean follow-up of 8 months, the incidence rates (per 100 person-year) of death, AMI readmission and MACE were 2.89, 3.68, and 4.91 in the de-escalated cohort and 2.42, 3.28, and 4.72 in the unchanged cohort, respectively, based on an inverse probability of treatment weighted approach that adjusting for baseline characteristics of the patients. Multivariate Cox regression analyses showed the two groups had no significant differences in the hazard risk of death, AMI admission, and MACE. Additionally, there was no observed difference in the risk of bleeding, including major or clinically relevant non-major bleeding. The real-world data revealed that de-escalation of P2Y₁₂ inhibitor in DAPT was not associated with a higher risk of death or AMI readmission in Taiwanese patients with AMI undergoing successful PCI.

A model-based cost-effectiveness analysis of pharmacogenomic panel testing in cardiovascular disease management: preemptive, reactive, or none?

Purpose

Pharmacogenomics (PGx) studies how inherited genetic variations in individuals affect drug absorption, distribution, and metabolism. PGx panel testing can potentially help improve efficiency and accuracy in individualizing therapy. This study compared the cost-effectiveness between preemptive PGx panel testing, reactive PGx panel testing and usual care (no testing) in cardiovascular disease management.

Methods

We developed a decision analytic model from the US payer’s perspective for a hypothetical cohort of 10,000 patients ≥45 years old, using a short-term decision tree and long-term Markov model. The testing panel included the following gene–drug pairs: CYP2C19–clopidogrel, CYP2C9/VKORC1–warfarin, and SLCO1B1–statins with 30 test-return days. Costs were reported in 2019 US dollars and effectiveness was measured in quality-adjusted life years (QALYs). The primary outcome was incremental cost-effectiveness ratio (ICER = ΔCost/ΔQALY), assuming 3% discount rate for costs and QALYs. Scenario and probabilistic sensitivity analyses were performed to assess the impact of demographics, risk level, and follow-up timeframe.

Results

Preemptive testing was found to be cost-effective compared with usual care (ICER $86,227/QALY) at the willingness-to-pay threshold of $100,000/QALY while reactive testing was not (ICER $148,726/QALY). Sensitivity analyses suggested that our cost-effectiveness results were sensitive to longer follow-up, and the age group 45–64 years.

Conclusion

Compared with usual care, preemptive PGx panel testing was cost-effective in cardiovascular disease management.

Evaluating the extent of reusability of CYP2C19 genotype data among patients genotyped for antiplatelet therapy selection

PURPOSE

Genotype-guided antiplatelet therapy is increasingly being incorporated into clinical care. The purpose of this study is to determine the extent to which patients initially genotyped for CYP2C19 to guide antiplatelet therapy were prescribed additional medications affected by CYP2C19.

METHODS

We assembled a cohort of patients from eight sites performingCYP2C19 genotyping to inform antiplatelet therapy. Medication orders were evaluated from time of genotyping through one year. The primary endpoint was the proportion of patients prescribed two or more CYP2C19 substrates. Secondary endpoints were the proportion of patients with a drug-genotype interaction and time to receiving a CYP2C19 substrate.

RESULTS

Nine thousand one hundred ninety-one genotyped patients (17% nonwhite) with a mean age of 68 ± 3 years were evaluated; 4701 (51%) of patients received two or more CYP2C19 substrates and 3835 (42%) of patients had a drug-genotype interaction. The average time between genotyping and CYP2C19 substrate other than antiplatelet therapy was 25 ± 10 days.

CONCLUSIONS

More than half of patients genotyped in the setting of CYP2C19-guided antiplatelet therapy received another medication impacted by CYP2C19 in the following year. Given that genotype is stable for a patient's lifetime, this finding has implications for cost effectiveness, patient care, and treatment outcomes beyond the indication for which it was originally performed.