Frequency and clinical outcomes of CYP2C19 genotype-guided escalation and de-escalation of antiplatelet therapy in a real-world clinical setting

Effect of loss-of-function CYP2C19 variants on clinical outcomes in coronary artery disease patients treated with clopidogrel: A systematic meta-analysis approach

For many years, clopidogrel has been a commonly utilised antiplatelet drug in the management of coronary artery disease (CAD). It's thought that the CYP2C19 loss of function (LoF) polymorphism causes clopidogrel's poor metabolism, which eventually leads to resistance. Previous research produced extremely divergent and inconsistent results, making it impossible to draw definitive conclusions. Therefore, current, investigation was carried out to obtain definitive evidence from an updated meta-analysis on the connection between CYP2C19 LoF polymorphism and coronary artery event in patients treated with clopidogrel. 52,542 individuals with coronary artery disease who were receiving clopidogrel treatment were included in 87 carefully chosen trials from reliable databases that we used for our meta-analysis. According to our data, those who carry one or more CYP2C19 LoF alleles worldwide are much more likely to experience composite events and coronary artery events than people who do not carry these alleles, especially in Asian populations. Our meta-analysis observed that the global population, particularly Asians receiving clopidogrel treatment, is at risk of recurrent coronary artery events and composite events if they carry the CYP2C19 LoF alleles. Additional research is essential on alternative antiplatelet therapies for individuals who exhibit poor or intermediate metabolic activity. OBJECTIVES: 1.To systematically analyze the current evidence regarding the association of CYP2C19 variants with coronary artery disease (CAD). 2.To conduct a meta-analysis to investigate the association between loss of function (LoF) CYP2C19 modifications and CAD.

Implementing a pharmacogenomic-driven algorithm to guide antiplatelet therapy among Caribbean Hispanics: a non-randomised clinical trial

OBJECTIVES

To assess whether genotype-guided selection of oral antiplatelet drugs using a clinical decision support (CDS) algorithm reduces the rate of major adverse cardiovascular and cerebrovascular events (MACCEs) among Caribbean Hispanic patients, after 6 months.

DESIGN

An open-label, multicentre, non-randomised clinical trial.

SETTING

Eight secondary and tertiary care hospitals (public and private) in Puerto Rico.

PARTICIPANTS

300 Caribbean Hispanic patients on clopidogrel, both genders, underwent percutaneous coronary intervention (PCI) for acute coronary syndromes, stable ischaemic heart disease and documented extracardiac vascular diseases.

INTERVENTIONS

Patients were separated into standard-of-care (SoC) and genotype-guided (pharmacogenetic (PGx)-CDS) groups (150 each) and stratified by risk scores. Risk scores were calculated based on a previously developed CDS risk prediction algorithm designed to make actionable treatment recommendations for each patient. Individual platelet function, genotypes, clinical and demographic data were included. Ticagrelor was recommended for patients with a high-risk score ≥2 in the PGx-CDS group only, the rest were kept or de-escalated to clopidogrel. The intervention took place within 3-5 days after PCI. Adherence medication score was also measured.

PRIMARY AND SECONDARY OUTCOMES

The occurrence rate of MACCEs (primary) and bleeding episodes (secondary). Statistical associations between patient time free of events and predictor variables (ie, treatment groups, risk scores) were tested using Kaplan-Meier survival analyses and Cox proportional-hazards regression models.

RESULTS

The genotype-guided group had a clinically lower but not significantly different risk of MACCEs compared with the SoC group (8.7% vs 10.7%, p=0.56; HR=0.56). Among high-risk score patients, genotype-driven guidance of antiplatelet therapy showed superiority over SoC in reducing MACCE incidence 6 months postcoronary stenting (adjusted HR=0.104; p< 0.0001).

CONCLUSIONS

The potential benefit of implementing our PGx-CDS algorithm to significantly reduce the incidence rate of MACCEs in post-PCI Caribbean Hispanic patients on clopidogrel was observed exclusively among high-risk patients, with apparently no evident effect in other patient groups.

TRIAL REGISTRATION NUMBER

NCT03419325.

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.

Implementing a Pharmacogenomic-driven Algorithm to Guide Antiplatelet Therapy among Caribbean Hispanics: A non-randomized prospective cohort study

Background

After percutaneous coronary intervention (PCI), clopidogrel resistant patients are at an increased risk of major adverse cardiovascular and cerebrovascular events (MACCEs). We aimed to assess whether genotype-guided selection of oral antiplatelet drugs using a clinical decision support (CDS) algorithm reduces the occurrence of these ischemic events and improves outcomes among Caribbean Hispanic patients from Puerto Rico, who are underrepresented in clinical pharmacogenomic (PGx)-guided implementation studies.

Methods

Individual platelet function testing (PRU) measures, CYP2C19*2 and PON1 rs662 genotypes, clinical and demographic data from 8 medical facilities were included. Patients were separated into standard of care (SoC) and genotype-guided groups (150 each). Risk scores were calculated based on a previously developed CDS risk prediction algorithm designed to make actionable treatment recommendations for each patient. Alternative therapy with ticagrelor was recommended for patients with a high risk score ≥2. Statistical associations between patient time free of MACCEs and predictor variables (i.e., treatment groups, risk scores) were tested in this population using Kaplan-Meier survival analyses and Cox proportional-hazards regression models.

Results

Median age of participants is 67 years; BMI: 27.8; 48% women; 14% smokers; 59% with type-2 diabetes mellitus (T2DM). Among patients with high-risk scores who were free from MACCE events 6 months after coronary stenting, genotype-driven guidance of antiplatelet therapy showed superiority over SoC in terms of reducing the incidence rate of atherothrombotic events.

Conclusions

The clinical utility of our PGx-driven CDS algorithm to reduce the incidence rate of MACCEs among post-PCI Caribbean Hispanic patients on clopidogrel was externally demonstrated.

Clinical Trial Registration Unique Identifier

NCT03419325.

The combination of CYP2C19 polymorphism and inflammatory cell ratios in prognosis cardiac adverse events after acute coronary syndrome

Background

CYP2C19 gene polymorphism combination with inflammatory cell ratios was significant in the prognosis of coronary heart disease.

Materials and methods

A cross-sectional analysis study, with 6 months follow-up on 142 patients with acute coronary syndrome. Patients were analyzed for CYP2C19 gene polymorphisms by real-time polymerase chain reaction (PCR) and complete blood count to determine inflammatory cell ratios and recorded cardiovascular events (CEs) after following up to 6 months.

Results

For 90-day CEs, CYP2C19 gene polymorphism (Hazard Ratio (HR): 1.965, 95 % Confidence Interval (CI): 1.012-3.814), the combination of a neutrophil and lymphocyte ratio (NLR) ≥ 2.982 (HR: 13.001, 95 % CI: 1.37-97.304) or a platelet to lymphocyte ratio (PLR) ≥ 162.42 (HR: 2.878, 95 % CI: 1.212-6.835) was independent predictors of CEs. For 180-day CEs, CYP2C19 gene polymorphism combination with NLR ≥3.02 (HR: 13.946, 95 % CI: 1.833-106.121) or PLR ≥160.38 (HR: 5.349, 95 % CI: 1.379-20.745) or monocyte to lymphocyte ratio (MLR) ≥ 0.3 (HR: 4.699, 95 % CI: 1.032-31.393) were independent predictors of CEs.

Conclusion

NLR, PLR or MLR combined with CYP2C19 gene polymorphism were stronger independent predictors of cardiovascular events in patients with acute coronary syndromes compared to CYP2C19 gene polymorphism and inflammatory cell ratios separately. CYP2C19 polymorphism and high NLR was the strongest predictor of both CEs at 90 days and 180 days.

CYP2C19 gene polymorphism in Ningxia

BACKGROUND

Poor metabolizer (PM) status of CYP2C19 can be a predisposing factor for developing gastric cancer in H. pylori-infected patients. It is unclear whether PM status of CYP2C19 can also be a potential factor for H.pylori infection in healthy people.

METHODS

We used high-throughput sequencing to detect single nucleotide polymorphisms (SNPs) at just three loci, rs4244285 (CYP2C19*2), rs4986893 (CYP2C19*3) and rs12248560 (CYP2C19*17), to identify the exact CYP2C19 alleles corresponding to the mutated sites. We determined CYP2C19 genotypes of 1050 subjects from 5 cities of Ningxia from September 2019 to September 2020 and evaluated the potential correlation between H.pylori and CYP2C19 gene polymorphisms. Clinical data were analyzed using χ2 tests.

RESULTS

The frequency of CYP2C19*17 in Hui (3.7%) was higher as compared to Han (1.4%) in Ningxia (p = 0.001). The frequency of CYP2C19*1/*17 of Hui (4.7%) was higher as compared to Han (1.6%) in Ningxia (p = 0.004). The frequency of CYP2C19*3/*17 of Hui (1%) was higher as compared to Han (0%) in Ningxia (p = 0.023). The frequencies of alleles (p = 0.142) and genotypes (p = 0.928) were not found to be significantly different among the different BMI groups. The frequencies of four alleles between H. pylori positive and negative groups were not found to be statistically different (p = 0.794). The frequencies of the different genotypes between H. pylori positive and negative groups were not statistically different (p = 0.974), and no statistical difference was observed between the different metabolic phenotypes (p = 0.494).

CONCLUSION

There were regional differences observed in CYP2C19*17 distribution in Ningxia. The frequency of CYP2C19*17 in Hui was higher than in Han of Ningxia. No significant relationship was found between CYP2C19 gene polymorphism and susceptibility to H. pylori infection.

Feasibility of Community Pharmacist-Initiated and Point-of-Care CYP2C19 Genotype-Guided De-Escalation of Oral P2Y12 Inhibitors

Tailoring antiplatelet therapy based on CYP2C19 pharmacogenetic (PGx) testing can improve cardiovascular outcomes and potentially reduce healthcare costs in patients on a P2Y12-inhibitor regime with prasugrel or ticagrelor. However, ubiquitous adoption—particularly in an outpatient setting—remains limited. We conducted a proof-of-concept study to evaluate the feasibility of CYP2C19-guided de-escalation of prasugrel/ticagrelor to clopidogrel through point-of-care (POC) PGx testing in the community pharmacy. Multiple feasibility outcomes were assessed. Overall, 144 patients underwent CYP2C19 PGx testing in 27 community pharmacies. Successful test results were obtained in 142 patients (98.6%). De-escalation to clopidogrel occurred in 19 patients (20%) out of 95 (67%) eligible for therapy de-escalation, which was mainly due to PGx testing not being included in cardiology guidelines. Out of the 119 patients (84%) and 14 pharmacists (100%) surveyed, 109 patients (92%) found the community pharmacy a suitable location for PGx testing, and the majority of pharmacists (86%) thought it has added value. Net costs due to PGx testing were estimated at €43 per patient, which could be reduced by earlier testing and could turn into savings if de-escalation would double to 40%. Although the observed de-escalation rate was low, POC CYP2C19-guided de-escalation to clopidogrel appears feasible in a community pharmacy setting.

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.

Genotyping genetic variants of CYP2C19 for precision antiplatelet dosing: state of the art and future perspectives

INTRODUCTION

Clopidogrel is the only antiplatelet agent whose activity is significantly affected by CYP2C19 polymorphism.

AREAS COVERED

This review has summarized the available evidence on the clinically significant association between CYP2C19 polymorphism and clopidogrel-based therapy; reviewed the current recommendations for clinical use of CYP2C19 genotype test results in patients on clopidogrel treatment; and discussed possible pitfalls of routine application, and future perspectives of antiplatelets pharmacogenetics.

EXPERT OPINION

The available body of evidence, reflected in several meta-analyses and high-quality clinical practice guidelines, shows that the presence of CYP2C19 LOF alleles, especially CYP2C19*2, correlates with impaired activation of clopidogrel and variable platelet inhibition, followed by minimal or no antiplatelet effect, and higher risk of treatment failure. In combination with other known risk factors, CYP2C19 genetic testing could be very valuable in predicting low clopidogrel efficacy. At the same time, it could be very successful in selecting patients who will most probably benefit from the clopidogrel-based therapy, thus decreasing the pool of those who might need more expensive and otherwise riskier antiplatelet alternatives.

Efficacy and Safety of De-escalation of Antiplatelet Therapy After Percutaneous Coronary Intervention in Patients With Acute Coronary Syndrome: A Meta-Analysis of Randomized Clinical Trials

ABSTRACT

Considering that there is no definite conclusion on the efficacy and safety of switching from potent P2Y 12 inhibitors to clopidogrel, we conducted a systematic review and meta-analysis of patients with acute coronary syndromes undergoing percutaneous coronary intervention and compared the efficacy and safety of de-escalation or not of antiplatelet therapy. The relevant randomized controlled trials were included by searching several databases. Net adverse clinical events were identified as the composite end point, which was defined as a composite of cardiovascular death, myocardial infarction, revascularization, stroke, and bleeding at 12 months after acute coronary syndromes. The efficacy end points were cardiovascular death, myocardial infarction, revascularization, stroke, all-cause death, and stent thrombosis. Bleeding was designed as the safety end point. The risk ratio and 95% confidence intervals of end point events were calculated by the fixed-effects model. Six randomized controlled trials with 7627 patients met inclusion criteria. There were significant differences in the risk of net adverse clinical events (RR, 0.67, CI, 0.58-0.78, P < 0.00001) and bleeding end point (0.61, 0.52-0.71, P < 0.00001) between the 2 groups. However, there were no significant differences in the risk of all efficacy end points. In general, the strategy of de-escalation from prasugrel or ticagrelor to clopidogrel can reduce the incidence of net adverse clinical events and bleeding events in patients with ACS undergoing percutaneous coronary intervention.

Genetic Polymorphisms in CYP2C19 Cause Changes in Plasma Levels and Adverse Reactions to Anlotinib in Chinese Patients With Lung Cancer

Background: Anlotinib is a small molecular multi-targeting tyrosine kinase inhibitor. Growing evidence indicates that treatment efficacy, and toxicity varies considerably between individuals. Therefore, this study aimed to investigate the relationship between cytochrome P450 (CYP450) gene polymorphisms, drug concentrations, and their adverse reactions in anlotinib-treated patients with lung cancer.

Methods: We enrolled 139 patients with lung cancer, treated with anlotinib. Twenty loci in the following five genes of the CYP450 family were genotyped: CYP450 family 3 subfamily A member 5 (CYP3A5), 3 subfamily A member 4 (CYP3A4), 2 subfamily C member 9 (CYP2C9), 2 subfamily C member 19 (CYP2C19), and 1 subfamily A member 2 (CYP1A2). Data on adverse reactions were collected from patients, and plasma anlotinib concentrations were measured.

Results: There were significant variances in plasma trough concentration (3.95–52.88 ng/ml) and peak plasma concentration (11.53–42.8 ng/ml) following administration of 8 mg anlotinib. Additionally, there were significant differences in the plasma trough concentration (5.65–81.89 ng/ml) and peak plasma concentration (18.01–107.18 ng/ml) following administration of 12 mg anlotinib. Furthermore, for CYP2C19-rs3814637, the peak plasma concentrations of mutant allele T carriers (TT+CT) were significantly higher than those of wildtypes (CC). For CYP2C19-rs11568732, the peak plasma concentrations of the mutant allele G carriers (GT+GG) were significantly higher than those of the wild-type (TT). More importantly, the incidence rates of hypertension and hemoptysis (peripheral lung cancer) with TT+CT in rs3814637 and GT+GG in rs11568732 were significantly higher than those with CC and TT.

Conclusions: The plasma trough and peak concentrations varied significantly for both 8 and 12 mg of anlotinib. Single-nucleotide polymorphisms in CYP2C19 are significantly associated with hypertension, hemoptysis, and anlotinib peak concentrations. Polymorphisms in CYP450 may explain inter-individual differences in anlotinib-related adverse reactions.

De-escalation of Dual Antiplatelet Therapy After Percutaneous Coronary Intervention in Patients With Acute Coronary Syndrome: An Updated Meta-analysis and Trial Sequential Analysis of 21 Studies and 38,741 Patients

ABSTRACT

Dual antiplatelet therapy (DAPT) is recommended among patients with established acute coronary syndrome. In this meta-analysis, we sought to compare the clinical outcomes between de-escalation versus unchanged DAPT based on both randomized controlled trials (RCTs) and observational studies. The primary outcomes were major adverse cardiovascular events for observational studies and net clinical events for RCTs. Four RCTs and 17 observational studies with a total of 38,741 patients were included. Net clinical events were more common with unchanged DAPT than with de-escalation in RCTs [odd ratio (OR): 1.71; 95% confidence interval (CI), 1.21-2.43; I2 = 69.4%], which was mainly due to higher risks of any bleeding (OR: 1.81; 95% CI, 1.14-2.88; I2 = 75.5%) and major bleeding (OR: 1.58; 95% CI, 1.02-2.46; I2 = 0), without significant differences in ischaemic events. However, trial sequential analysis revealed that sufficient information was obtained just for net clinical events, not for respective ischaemic or bleeding events in RCTs. In the analysis based on real-world observational studies, the risks of myocardial infarction (OR: 0.77; 95% CI, 0.61-0.98; I2 = 0) and stroke (OR: 0.42; 95% CI, 0.22-0.81; I2 = 0) were lower with the unchanged DAPT group. Therefore, de-escalation of DAPT led to a marked reduction in net clinical events compared with unchanged DAPT in RCTs, which was mainly due to reduced bleeding events. However, sufficient information for ischaemic events was not obtained. In the analysis based on real-world observational studies, myocardial infarction and stroke were more common with de-escalation, which should arise our attention.

De-escalation from Prasugrel or Ticagrelor to Clopidogrel in Patients with Acute Coronary Syndrome Managed with Percutaneous Coronary Intervention: An Updated Meta-analysis of Randomized Clinical Trials

INTRODUCTION

We aimed to evaluate the clinical benefits of a de-escalation strategy from prasugrel or ticagrelor to clopidogrel versus continuation of prasugrel or ticagrelor along with aspirin in both strategies for patients presenting with acute coronary syndrome (ACS) and treated with percutaneous coronary intervention (PCI), and to analyze the effect of the recently published randomized clinical trial (RCT) by Park et al., which included the largest sample size ever and the largest switched number of patients, on current guidelines and practices.

DATA SOURCES

The PubMed, EMBASE, Scopus, Web of Science, Cochrane Central, and Google Scholar databases were searched systematically from inception to May 2021 by using the search terms ('de-escalation' OR 'switching') AND ('antiplatelet' OR 'clopidogrel' OR 'ticagrelor' OR 'prasugrel') AND ('percutaneous coronary intervention' OR 'PCI'' OR 'Acute coronary syndrome' OR 'ACS').

STUDY SELECTION AND DATA EXTRACTION

We included RCTs that reported the primary outcomes, i.e. net clinical benefits and Bleeding Academic Research Consortium (BARC) type 2 or higher bleeding. A combination of both ischemic and bleeding events was defined as a net clinical benefit.

DATA SYNTHESIS

A total of four RCTs were included, with 5952 patients. A random-effects meta-analysis revealed that a de-escalation strategy was associated with lower ischemic and bleeding events (net clinical benefits; risk ratio [RR] 0.63, 95% confidence interval [CI] 0.47-0.85; p = 0.003), and lower BARC type 2 or higher bleeding (RR 0.51, 95% CI 0.29-0.91; p = 0.02) when compared with a continuation strategy.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

The current guidelines recommend potent P2Y12 prasugrel or ticagrelor for 12 months despite their association with a high risk of bleeding. Our meta-analysis updates cardiologists, providing them with the best available evidence in managing patients with ACS who underwent PCI.

CONCLUSION

Among patients with ACS treated with PCI, a de-escalation strategy (prasugrel or ticagrelor to clopidogrel) is associated with lower ischemic and bleeding events (net clinical benefits) and lower BARC type 2 or higher bleeding; however, due to the limited number of included studies, further high-quality studies are needed to establish the clinical efficacy of the de-escalation strategy.

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.

Dosage optimization of clopidogrel via a precision medicine approach: the way forward

Clopidogrel is a prodrug chiefly metabolized by the hepatic isoenzyme CYP2C19 to its active metabolite that inhibits the platelet aggregation. It has been proven in many populations that the genetic polymorphism of CYP2C19 has influence on the pharmacokinetic and or pharmacodynamics of this drug and resulting in high inter-individual variability in the treatment outcomes. As CYP2C19 genetic polymorphism is highly prevalent among the Asian population, the influence of the same on the pharmacokinetics and; thereby, the pharmacodynamics of clopidogrel needs more attention. Using the pharmacogenetic information for drug therapy could help overcome these issues and to optimize the dosage regimen of clopidogrel, this review advocates the precision medicine approach for reducing the clopidogrel resistance and adverse cardiovascular events.

Effects of CYP2C19 LoF allele on major adverse cardiovascular events associated with clopidogrel in acute coronary syndrome patients undergoing percutaneous coronary intervention: meta-analysis

The aggregated risk of major adverse cardiovascular events (MACE) in acute coronary syndrome (ACS) patients inheriting CYP2C19 loss-of function (LoF) alleles who underwent percutaneous coronary intervention (PCI) and were treated with clopidogrel is controversial. In the current study, we searched the literature in different databases for eligible studies. The risk ratio (RR) was measured where p<0.05 was statistically significant. The ACS patients with either one or two CYP2C19 LoF alleles who underwent PCI, treated with clopidogrel were correlated with a significantly escalated risk of MACE compared with noncarriers (RR: 1.53, 95% CI: 1.39-1.69, p<0.00001), driven by CV death (RR: 1.88, 95% CI: 1.18-3.01, p=0.008), MI (RR: 1.67, 95% CI: 1.21-2.31, p=0.002) and ST (RR: 1.90, 95% CI: 1.27-2.84, p=0.002). Patients with two CYP2C19 LoF alleles were correlated with significantly greater risk of MACE compared with noncarriers (RR: 3.91, 95% CI: 2.78-5.50, p<0.00001). Further analysis revealed that the risk of MACE was markedly significant in Asian patients (RR: 2.02, 95% CI: 1.67-2.44, p<0.00001) and was comparatively low significance in western patients (RR: 1.35, 95% CI: 1.20-1.52, p<0.00001). There was no significantly different bleeding events in patients with CYP2C19 LoF alleles compared with noncarriers (RR: 0.99, 95% CI: 0.85-1.15, p=0.87). The ACS patients inheriting CYP2C19 LoF alleles, who underwent PCI and were treated with clopidogrel were correlated with significantly increased risk of MACE compared with noncarriers.

Identification of Potential Biological Factors Affecting the Treatment of Ticagrelor After Percutaneous Coronary Intervention in the Chinese Population

Background

Generally, many individual factors can affect the clinical application of drugs, of which genetic factors contribute more than 20%. Ticagrelor is a new class of receptor inhibitors receptor antagonist of P2Y12 and is used as an antiplatelet agents. But it is not affected by the influence of CYP2C19 polymorphism. With lack of predicted biomarkers, especially the research data of Chinese, it has the important significance in studying individual differences of ticagrelor in the antiplatelet efficacy and safety, through pharmacogenomics research.

Methods

Whole-exome sequencing (WES) was performed in 100 patients after PCI with ticagrelor treatment. Clinical characteristics and WES of patients were used to performed genome-wide association analysis (GWAS), region-based tests of rare DNA variant to find the influencing factors of antiplatelet effect to ticagrelor and bleeding events. Co-expression, protein–protein interaction (PPI) network and pathway enrichment analysis were then used to find possible genetic mechanisms. Atlas of GWAS (https://atlas.ctglab.nl/) were used for external data validation.

Results

DNAH17, PGS1 and ABCA1 as the potential variant genes are associated with the expected antiplatelet effect to ticagrelor. The affected pathways may include the synthesis and metabolism of lipoprotein cholesterol and the catabolic process of pyrimidine-containing compound (GO:0072529). Age, sex and PLT were found may be potential factors for ticagrelor bleeding events.

Conclusion

We systematically identified new genetic variants and some risk factors for reduced efficacy of ticagrelor and highlighted related genes that may be involved in antiplatelet effects and bleeding event of ticagrelor. Our results enhance the understanding of the absorption and metabolic mechanisms that influence antiplatelet response to ticagrelor treatment.

Trial Registration

ClinicalTrials.gov Identifier: NCT03161002. First Posted: May 19, 2017. https://clinicaltrials.gov/ct2/show/study/NCT03161002.

Antiplatelet Therapy and Bleeding Outcomes With CYP2C19 Genotyping

PURPOSE

The impact of antiplatelet therapy with availability of CYP2C19 genotyping on bleeding in a real-world setting has not been extensively studied.

METHODS

Prospective, single-center, cohort study conducted between December 2015 and October 2019 with 1-year follow-up. Patients underwent percutaneous coronary intervention (PCI), CYP2C19 genotyping, and received P2Y12 inhibitor therapy. The primary outcome was time to first bleed of any severity using Bleeding Academic Research Consortium criteria. Secondary outcomes included time to first major bleed and rates of antiplatelet switching.

RESULTS

The primary outcome occurred in 697 of 2091 (33%) participants at a median of 15 days. Major bleeding occurred in 176 (8%) of patients. Compared to clopidogrel, treatment with ticagrelor or prasugrel was associated with increased risk of any bleeding (adjusted HR [aHR] 2.04, 95% CI 1.69-2.46). For patients without CYP2C19 no function alleles, treatment with prasugrel or ticagrelor was associated with increased risk of any bleeding (aHR 2.31, 95% CI 1.83-2.90). Similar associations were observed for major bleeding. No difference in ischemic events was observed. Among patients discharged on ticagrelor or prasugrel, 199 (36%) were de-escalated to clopidogrel within 1 year. De-escalation was more likely after a bleed if patients did not have a no function allele (35.9% vs 19.1%; P = .02).

CONCLUSION

Bleeding is common in post-PCI patients on antiplatelet therapy. Patients on high potency agents had higher bleeding risk in the population at-large and in non-carriers of CYP2C19 no function alleles. Genotype-guided antiplatelet de-escalation should be further explored in prospective studies.

The Landscape of Clinical Implementation of Pharmacogenetic Testing in Central China: A Single-Center Study

Purpose

Pharmacogenetic testing is recognized as the major method for the individualized pharmacotherapy in clinical pharmacy practice, but information about the clinical implementation of pharmacogenetic testing in China is limited. The present study aimed to determine the situation of clinical implementation for pharmacogenetic testing in central China.

Methods

The study is conducted in the department of clinical pharmacy in The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China. We collected and analyzed pharmacogenetic testing results from November 1, 2013 to November 2, 2018 in our hospital, which were checked in the electronic medical record system. The main outcome measures were the number and type of pharmacogenetic testing across five years.

Results

A total of 47,265 (56.9% male, mean age = 51.5 years) pharmacogenetic testing results were obtained with an average annual rate of growth of 63.0% across five years. A 50.2% (23,748/47,265) of all the pharmacogenetic testing results were for the determination of cytochrome P450 2C19 (CYP2C19) *2, *3 genotypes, and 41.7% were for the methylene tetrahydrofolate reductase (MTHFR) C677T genotype. The number of departments performing the pharmacogenetic testing was 35, 63, 55, 52, 52 and 39 for 2013–2018, respectively, and the main top five departments were cardiology, psychiatry, ICU, cardiac surgery and intervention.

Conclusion

Clinical implementation of pharmacogenetic testing in China is growing rapidly, but the types and implementing departments of pharmacogenetic testing were limited. Our present study reported the real-world implementation modality of pharmacogenomic tests in China. It will help us to understand the testing of pharmacogenetics in China in order to promote the rational development of pharmacogenetics.

Genotype-Guided P2Y 12 Inhibitor Therapy After Percutaneous Coronary Intervention: A Bayesian Analysis

Background:

Among patients receiving percutaneous coronary intervention (PCI), the role of a genotype-guided approach for antiplatelet therapy compared with usual care is unclear. We conducted a Bayesian analysis of the entire TAILOR-PCI (Tailored Antiplatelet Initiation to Lessen Outcomes Due to Decreased Clopidogrel Response After Percutaneous Coronary Intervention) randomized clinical trial population to evaluate the effect of the genotype-guided antiplatelet therapy post-PCI compared with the usual care on the risk of major adverse cardiovascular events (MACE).

Methods:

The primary outcome for our study was the composite of MACE (myocardial infarction, stroke, and cardiovascular death). Secondary outcomes included cardiovascular death, stroke, myocardial infarction, stent thrombosis, and major/minor bleeding. Bayesian modeling was used to estimate the probability of clinical benefit of genotype-guided therapy using (1) noninformative priors (ie, analyzing the TAILOR-PCI trial) and (2) informative priors derived from the ADAPT, POPular Genetics, IAC-PCI, and PHARMCLO trials (ie, analyzing TAILOR-PCI trial in the context of prior evidence). Risk ratio (RR: ratio of cumulative outcome incidence between genotype-guided and conventional therapy group) and 95% credible interval (CrI) were estimated for the study outcomes, and probability estimates for RR <1 were computed.

Results:

Using noninformative priors, in TAILOR-PCI the RR for MACE was 0.78 (95% CrI, 0.55–1.07) in genotype-guided therapy after PCI, and the probability of RR <1 was 94%. Using noninformative priors, the probability of RR <1 for cardiovascular death (RR, 0.95 [95% CrI, 0.52–1.74]), stroke (RR, 0.68 [95% CrI, 0.44–1.06]), myocardial infarction (RR, 0.84 [95% CrI, 0.37–1.89]), stent thrombosis (RR, 0.75 [95% CrI, 0.37–1.45]), and major or minor bleeding (RR, 1.22 [95% CrI, 0.84–1.77]) were 57%, 96%, 67%, 81%, and 15%, respectively. Using informative priors, the posterior probability of RR <1 for MACE, from genotype-guided therapy, was 99% (RR, 0.69 [95% CrI, 0.57–0.84]). Using informative priors, the posterior probability of RR <1 for cardiovascular death (RR, 0.86 [95% CrI, 0.61–1.19]), stroke (RR, 0.69 [95% CrI, 0.48–0.99]), myocardial infarction (RR:0.56 [95% CrI, 0.40–0.78]), stent thrombosis (RR, 0.59 [95% CrI, 0.38–0.94]), and major or minor bleeding (RR, 0.84 [95% CrI, 0.70–0.99]) were 81%, 99%, 99%, 99%, and 99%, respectively.

Conclusions:

Bayesian analysis of the TAILOR-PCI trial provides clinically meaningful data on the posterior probability of reducing MACE using genotype-guided P2Y 12 inhibitor therapy after PCI.

Risk of stroke in CYP2C19 LoF polymorphism carrier coronary artery disease patients undergoing clopidogrel therapy: An ethnicity-based updated meta-analysis

BACKGROUND

Antiplatelet agent clopidogrel has been widely used for stroke management for many years, although resistance to clopidogrel may increase the chance of stroke recurrence. CYP2C19 loss-of-function (LoF) polymorphism is assumed to be responsible for the poor metabolism of clopidogrel that ultimately turns to resistance. Previous publications could not provide firm evidence due to highly conflicting and heterogeneous outcomes.

AIM

To get clear evidence from an updated meta-analysis on CYP2C19 LoF polymorphism association with stroke risk in clopidogrel treated patients, this study has been performed.

METHODS

We conducted a meta-analysis with 72 selected studies from authentic databases, including 40,035 coronary artery disease patients treated with clopidogrel.

RESULTS

This analysis showed that the worldwide carrier of one or more CYP2C19 LoF alleles had a significantly higher risk of stroke and composite events than the non-LoF carriers (RR=1.78, 95% CI=1.52-2.07, p<0.00001 and RR=1.39, 95% CI=1.26-1.54, p<0.00001, respectively). Besides, subgroup analysis showed that Asian CYP2C19 LoF carriers had a significantly increased risk of stroke (RR=1.91, 95% CI=1.60-2.28, p<0.00001) while the risk of composite events was significantly higher in all ethnic populations (Asian: RR=1.58, 95% CI=1.32-1.89, p<0.00001; Caucasian: RR=1.27, 95% CI=1.08-1.50, p=0.003; Hispanic and others: RR=1.21, 95% CI=1.09-1.34, p=0.0003).

CONCLUSION

Our meta-analysis confirmed that the presence of CYP2C19 LoF alleles increases the risk of stroke and composite events recurrence in the worldwide population, especially in Asians undergoing clopidogrel treatment. Alternative antiplatelet therapy should be investigated thoroughly for the intermediate and poor metabolizers.

Effects of aging on clinical outcomes in patients receiving genotype-guided P2Y12 inhibitor selection after percutaneous coronary intervention

STUDY OBJECTIVE

To compare the clinical effectiveness of genotype-guided P2Y12 inhibitor selection following PCI in older patients (≥70 years) and younger patients (<70 years).

DESIGN AND SETTING

Single-center, retrospective, cohort study. Risk of major adverse cardiovascular or cerebrovascular events (MACCE), defined as stent thrombosis, ischemic stroke, transient ischemic attack, non-fatal acute coronary syndrome, or cardiovascular death during 12 months after PCI, was compared across genotype and antiplatelet therapy groups by proportional hazards regression in patients ≥70 years and <70 years.

PATIENTS

1,469 patients who underwent PCI and had CYP2C19 genotype testing at a single academic medical center.

MEASUREMENTS AND MAIN RESULTS

The study population was comprised of 402 (27.4%) ≥70 years (older group) and 1067 (72.6%) <70 years (younger group). Alternative P2Y12 inhibitors (prasugrel or ticagrelor) were used less often in the older group than the younger group in patients with a CYP2C19 no function allele (55% vs. 67%; p = 0.02) and in patients without a no function allele (10% vs. 35%, p < 0.001). For patients treated with clopidogrel, MACCE was significantly higher in no function allele carriers compared to those without a no function allele in the older group (19.2% vs. 12.7%; adjusted HR 2.32; 95% CI 1.07-5.05; p = 0.03) and the younger group (17.4% vs. 10.4%; adjusted HR 2.01; 95% CI 1.17-3.46; p = 0.01). In patients without a no function allele, MACCE risk was similar with clopidogrel compared to prasugrel or ticagrelor in the older group (adjusted HR 0.99; 95% CI 0.44-2.21; p = 0.98) and the younger group (adjusted HR 1.12; 95% CI 0.72-1.74; p = 0.61).

CONCLUSION

This study suggests important clinical benefits of CYP2C19 genotype-guided antiplatelet therapy after PCI in both younger and older patients.

Pharmacogenomics in Cardiovascular Diseases

Cardiovascular pharmacogenomics is the study and identification of genomic markers that are associated with variability in cardiovascular drug response, cardiovascular drug-related outcomes, or cardiovascular drug-related adverse events. This overview presents an introduction and historical background to cardiovascular pharmacogenomics, and a protocol for designing a cardiovascular pharmacogenomics study. Important considerations are also included for constructing a cardiovascular pharmacogenomics phenotype, designing the replication or validation strategy, common statistical approaches, and how to put the results in context with the cardiovascular drug or cardiovascular disease under investigation. © 2021 Wiley Periodicals LLC. Basic Protocol: Designing a cardiovascular pharmacogenomics study.

Platelet transfusion for patients with platelet dysfunction: effectiveness, mechanisms, and unanswered questions

PURPOSE OF REVIEW

In this review, we discuss current clinical guidelines and potential underlying mechanisms regarding platelet transfusion therapy in patients at risk of bleeding, comparing management of patients with thrombocytopenia versus those with qualitative platelet disorders.

RECENT FINDINGS

Platelet transfusion therapy is highly effective in managing bleeding in patients with hypoproliferative thrombocytopenia. Clinical trials have demonstrated that platelet transfusion can be used at a lower trigger threshold and reduced platelet doses, and may be used therapeutically rather than prophylactically in some situations, although additional data are needed. In patients with inherited platelet disorders such as Glanzmann's Thrombasthenia or those with RASGRP2 mutations, platelet transfusion may be ineffective because of competition between transfused and endogenous platelets at the site of vascular injury. Successful management of these patients may require transfusion of additional platelet units, or mechanism-driven combination therapy with other pro-hemostatic agents. In patients on antiplatelet therapy, timing of transfusion and inhibitor mechanism-of-action are key in determining therapeutic success.

SUMMARY

Expanding our understanding of the mechanisms by which transfused platelets exert their pro-hemostatic function in various bleeding disorders will improve the appropriate use of platelet transfusion.

The Role of Genetic Polymorphism and Other Factors on Clopidogrel Resistance (CR) in an Asian Population with Coronary Heart Disease (CHD)

Clopidogrel is a widely-used antiplatelet drug. It is important for the treatment and prevention of coronary heart disease. Clopidogrel can effectively reduce platelet activity and therefore reduce stent thrombosis. However, some patients still have ischemic events despite taking the clopidogrel due to the alteration in clopidogrel metabolism attributable to various genetic and non-genetic factors. This review aims to summarise the mechanisms and causes of clopidogrel resistance (CR) and potential strategies to overcome it. This review summarised the possible effects of genetic polymorphism on CR among the Asian population, especially CYP2C19 *2 / *3 / *17, where the prevalence rate among Asians was 23.00%, 4.61%, 15.18%, respectively. The review also studied the effects of other factors and appropriate strategies used to overcome CR. Generally, CR among the Asian population was estimated at 17.2-81.6%. Therefore, our overview provides valuable insight into the causes of RC. In conclusion, understanding the prevalence of drug metabolism-related genetic polymorphism, especially CYP2C19 alleles, will enhance clinical understanding of racial differences in drug reactions, contributing to the development of personalised medicine in Asia.

CYP2C19 genotype-directed P2Y12 inhibitor antiplatelet therapy normalizes risk for major adverse cardiovascular events after percutaneous coronary intervention

Objective

To study the use of CYP2C19 genotyping to guide P2Y₁₂ inhibitor selection to maximize efficacy, and attenuate risk in appropriate patients who underwent PCI for CAD.

Methods

We performed a retrospective analysis of 868 patients with CAD who received CYP2C19 genotyping after PCI and changed P2Y₁₂ inhibitor based on the results. Patients were divided into two groups based on clopidogrel metabolizer status. Group I: Intermediate (IM) and poor metabolizers (PM). Group II: Ultra-rapid (UM), rapid (RM) and normal metabolizers (NM). Each group was then categorized to one of two treatment arms guided by CYP2C19 genotype. Category 1: IM/PM started on clopidogrel, switched to ticagrelor or prasugrel; 2:IM/PM started on ticagrelor/prasugrel, continued these medications; 3: UM/RM/NM started on ticagrelor/prasugrel, switched to clopidogrel; 4: UM/RM/NM started on clopidogrel, continued clopidogrel. Death due to cardiac causes, bleeding events, non-fatal MI, target vessel revascularization (TVR), and MACE in all four categories were considered at 1, 6 and 12 months.

Results

We did not observe significant difference between phenotypes for MACE at 1 (p = 0.274), 6 (p = 0.387), and 12 months (p = 0.083). Death due to cardiac causes, MI, and bleeding events were not significant at 1, 6, and 12 months. There was no significant difference in TVR at 6 (p = 0.491), and 12 months (p = 0.423) except at 1 month (p = 0.012).

Conclusion

CYP2C19 genotype-based intervention can be implemented effectively and reliably to guide selection of P2Y₁₂ inhibitor to optimize patient quality and safety when appropriate in post PCI patients.

Impact of Implementing CYP2C19 Genotype-Guided Antiplatelet Therapy on P2Y12 Inhibitor Selection and Clinical Outcomes in Acute Coronary Syndrome Patients After Percutaneous Coronary Intervention: A Real-World Study in China

Background: CYP2C19 loss-of-function (LOF) alleles reduce the effectiveness of clopidogrel in patients undergoing percutaneous coronary intervention for acute coronary syndrome. However, the clinical impact of implementing CYP2C19 gene-guided pharmacotherapy is unclear, especially among the Chinese population. The purpose of this study was to evaluate P2Y12 receptor inhibitor selection and clinical outcomes upon implementation of CYP2C19 genotype-guided pharmacotherapy in current clinical practice.

Methods: This was a single-center observational cohort study. Adult percutaneous coronary intervention patients who received CYP2C19 genetic testing (*2, *3, *17 alleles) were included. Ticagrelor was recommended for patients with a LOF allele. Factors related to P2Y12 inhibitor selection were determined by logistic regression. The primary endpoint was major cardiac or cerebrovascular adverse events (MACCE) within 12 months. MACCE and clinically significant bleeding events (BARC ≥2) in the LOF-clopidogrel group, non-LOF-clopidogrel group, and non-LOF-ticagrelor group were compared with those in the LOF-ticagrelor group. The inverse probability of treatment weighting (IPTW) was adjusted in a Cox regression analysis to eliminate confounding factors.

Results: Among 1,361 patients, 826 (60.7%) had a LOF allele. Patients with a LOF allele were more likely to be prescribed ticagrelor (multivariate-adjusted OR 1.349; 95% CI 1.040 to 1.751; p = 0.024). The MACCE rate was higher in the LOF-clopidogrel group than in the LOF-ticagrelor group (7.8 vs. 4.0%; log-rank p = 0.029; IPTW-adjusted HR 2.138; 95% CI 1.300–3.515). Compared with the LOF-ticagrelor group, the non-LOF-clopidogrel group showed no significant difference in MACCE rate (5.8 vs. 4.0%; log-rank p = 0.272; IPTW-adjusted HR 1.531; 95% CI 0.864–2.714). Among the patients treated with ticagrelor, there was no significant difference in the MACCE rate between the LOF group and non-LOF group (4.3 vs. 4.0%; log-rank p = 0.846; IPTW-adjusted HR 1.184; 95% CI 0.582–2.410). There was no significant difference in the incidence of clinically significant bleeding events among the four groups.

Conclusion: This study confirms that efficiently returned CYP2C19 genotype results did partially guide cardiologists to prescribe ticagrelor for patients with a LOF allele, and that clopidogrel had a higher risk of MACCE than ticagrelor in these patients, which provides support for the implementation of CYP2C19 gene-guided antiplatelet therapy in clinical practice.

Implementation and Initial Evaluation of a Research and Scholarship Training Pathway in a Doctor of Pharmacy Curriculum

Objective. To design, implement, and assess the initial impact of a pharmacy student research and scholarship training pathway.Methods. The Research and Scholarship in Pharmacy (RASP) pathway was designed to create a longitudinal, elective pathway within a Doctor of Pharmacy (PharmD) curriculum at a single institution. The pathway consisted of three elective courses built around a faculty-mentored scholarly project where students framed an answerable question, generated and interpreted relevant data, and communicated their findings in oral and written form. Following implementation, a retrospective, multi-method analysis was conducted to evaluate the impact of the program on the initial two student cohorts that completed it and assess their perceptions of the value of the pathway.Results. Fifty students (25 in each of two cohorts) completed the three-course sequence. Students were supported by 33 distinct faculty mentors. Thirty-eight (76%) students presented an abstract derived from their project at a national meeting. The first cohort exit survey (96% response rate) revealed positive student perceptions regarding the value of and satisfaction with the research pathway. Twenty-three (96%) students were satisfied with their research experience, 21 (88%) were satisfied with their faculty mentor, and 24 (100%) were satisfied with their development of project management skills. In the first cohort, 10 (40%) students published an original research manuscript within one year of graduation.Conclusion. The Research and Scholarship in Pharmacy pathway feasibly and effectively provided a mechanism for students to engage in a faculty-mentored longitudinal research experience within a PharmD curriculum that promoted skill development and opportunities for scholarship. Initial implementation demonstrated high rates of student satisfaction, low rates of student attrition, and high rates of scholarly output.

Impact of the CYP2C19*17 Allele on Outcomes in Patients Receiving Genotype-Guided Antiplatelet Therapy After Percutaneous Coronary Intervention

Genotyping for CYP2C19 no function alleles to guide antiplatelet therapy after percutaneous coronary intervention (PCI) improves clinical outcomes. Although results for the increased function CYP2C19*17 allele are also reported, its clinical relevance in this setting remains unclear. A collaboration across nine sites examined antiplatelet therapy prescribing and clinical outcomes in 3,342 patients after implementation of CYP2C19-guided antiplatelet therapy. Risk of major atherothrombotic and bleeding events over 12 months after PCI were compared across cytochrome P450 2C19 isozyme (CYP2C19) metabolizer phenotype and antiplatelet therapy groups by proportional hazards regression. Clopidogrel was prescribed to a similar proportion of CYP2C19 normal (84.5%), rapid (82.9%), and ultrarapid metabolizers (80.6%) (P = 0.360). Clopidogrel-treated normal metabolizers (20.4 events/100 patient-years; adjusted hazard ratio (HR) 1.00, 95% confidence interval (CI), 0.75-1.33, P = 0.993) and clopidogrel-treated rapid or ultrarapid metabolizers (19.1 events/100 patient-years; adjusted HR 0.95, 95% CI, 0.69-1.30, P = 0.734) exhibited no difference in major atherothrombotic events compared with patients treated with prasugrel or ticagrelor (17.6 events/100 patient-years). In contrast, clopidogrel-treated intermediate and poor metabolizers exhibited significantly higher atherothrombotic event risk compared with prasugrel/ticagrelor-treated patients (adjusted HR 1.56, 95% CI, 1.12-2.16, P = 0.008). When comparing clopidogrel-treated rapid or ultrarapid metabolizers to normal metabolizers, no difference in atherothrombotic (adjusted HR 0.97, 95% CI, 0.73-1.29, P = 0.808) or bleeding events (adjusted HR 1.34, 95% CI, 0.83-2.17, P = 0.224) were observed. In a real-world setting of genotype-guided antiplatelet therapy, the CYP2C19*17 allele did not significantly impact post-PCI prescribing decisions or clinical outcomes. These results suggest the CYP2C19 *1/*17 and *17/*17 genotypes have limited clinical utility to guide antiplatelet therapy after PCI.

Incidence of major adverse cardiovascular events with genotype test guided antiplatelet treatment strategy after percutaneous coronary intervention

Objective

To estimate the incidence of major adverse cardiovascular events (MACE) with genotype test-guided antiplatelet therapy in patients undergoing percutaneous coronary intervention (PCI) for acute coronary syndrome.

Methods

Patients who had undergone PCI for acute coronary syndrome as well as stable coronary artery disease were recruited. Salivary samples were obtained from these patients and genotyped for CYP2C19∗2, CYP2C19∗3 variations by sequencing method (GAAP x method). Patients were categorized as normal (GG, GG) (29%), intermediate (AG) (52%) or poor metabolizes (homozygous variant AA) (19%). Dual antiplatelets were given based on the genotyping data. Poor metabolizes received newer agent (ticagrelor), intermediate metabolizes received double-dose of clopidogrel and normal metabolizes received therapeutic doses of clopidogrel. All subjects were followed-up for six months.

Results

Based on the genotyping data of CYP2C19∗2 and CYP2C19∗3 variations, it was found that most patients were categorized as ‘intermediate’ (78, 51.65%), followed by ‘normal’ (43, 28.48%) and ‘poor’ metabolizes (30, 19.87%). Only 3 (1.5%) of 151 patients reported MACE at follow-up.

Conclusions

Genotyping for CYP2C19 variations to assess clopidogrel resistance in patients undergoing PCI and subsequent drug selection helps reduce MACE after coronary intervention.

Clinical Utility of CYP2C19 Genotype-Guided Antiplatelet Therapy in Patients at Risk of Adverse Cardiovascular and Cerebrovascular Events: A Review of Emerging Evidence

In patients undergoing percutaneous coronary intervention (PCI), the standard of care is dual antiplatelet therapy with a P2Y₁₂ inhibitor (clopidogrel, prasugrel, or ticagrelor) and aspirin. Current clinical practice guidelines now recommend more potent P2Y₁₂ inhibitors (prasugrel or ticagrelor) over clopidogrel in acute coronary syndrome (ACS). However, clopidogrel remains the most commonly prescribed P2Y₁₂ inhibitor in the setting of PCI and is also the preferred agent in the treatment and secondary prevention of stroke. Clopidogrel is a prodrug that requires bioactivation by the CYP2C19 enzyme. It has been shown that clopidogrel use in patients who are CYP2C19 no function allele carriers are associated with impaired antiplatelet inhibition and a higher risk of major adverse cardiovascular and cerebrovascular events. Compared to clopidogrel, prasugrel and ticagrelor clinical response is not impacted by CYP2C19 genotype. Even with a demonstrated increased risk of adverse outcomes in CYP2C19 no function allele carriers treated with clopidogrel, routine implementation of CYP2C19 genotyping to guide antiplatelet therapy selection has remained controversial and has not been widely adopted. Recent results from multiple prospective randomized and nonrandomized clinical trials investigating the use of CYP2C19 genotype-guided antiplatelet therapy following PCI have advanced the evidence base demonstrating the clinical utility of this strategy. Multiple recent studies have examined the effects of CYP2C19 genotype on clopidogrel outcomes in the setting of stroke and neurointerventional procedures. In this review, we discern the clinical utility of using CYP2C19 genotype testing to guide antiplatelet therapy prescribing by evaluating the impact of CYP2C19 genotype-guided selection of antiplatelet therapy on clinical outcomes, summarizing emerging data from cardiovascular and neurology clinical studies, and discussing implications for clinical practice guidelines, remaining knowledge gaps and future research directions.

Risk of major adverse cardiovascular events of CYP2C19 loss-of-function genotype guided prasugrel/ticagrelor vs clopidogrel therapy for acute coronary syndrome patients undergoing percutaneous coronary intervention: a meta-analysis

The most effective antiplatelet treatments for acute coronary syndrome (ACS) patients carrying CYP2C19 loss-of-function (LoF) alleles undergoing percutaneous coronary intervention (PCI) is still debating and conflicting. It was aimed to compare the efficacy and safety endpoints for these patients treated with alternative P2Y12 receptor blockers (e.g. prasugrel or ticagrelor) against clopidogrel. Literature was searched in PubMed, Cochrane library, Synapse and 1000 Genomes databases following PRISMA guidelines for identifying relevant studies. Aggregated risk was estimated by RevMan software using either fixed/random-effects models where P values<0.05 (two-sided) were considered statistically significant. Nine studies comprising 16,132 ACS patients undergoing PCI were included in this analysis in which 2,746 and 2,640 patients were in the CYP2C19 LoF clopidogrel and alternatives treatment group, respectively. It was demonstrated that patients treated with prasugrel or ticagrelor significantly reduced the risk of MACEs (RR 0.58; 95% CI 0.45-0.76; P<0.0001) as compared to patients with clopidogrel where both groups carrying CYP2C19 LoF alleles. Subgroup analysis showed that prasugrel or ticagrelor significantly reduced the risk of cardiovascular death (RR 0.44; 95% CI: 0.25-0.74; P=0.002) and MI (RR 0.60; 95% CI: 0.44-0.81; P=0.0008) while other clinical outcomes were not found statistically significant between these two groups; stroke (RR 0.77; 95% CI: 0.43-1.38; P =0.39), stent thrombosis (RR 0.67; 95% CI: 0.38-1.18; P =0.17), unstable angina (RR 0.55; 95% CI: 0.13-2.33; P =0.42), revascularisation (RR 0.79; 95% CI: 0.28-2.24; P=0.66). Bleeding events were not found significantly different between these groups (RR 1.06; 95% CI: 0.88-1.28; P=0.55). Considering efficacy and safety, alternative antiplatelets (e.g. prasugrel or ticagrelor) may be regarded as better treatment option as compared to clopidogrel for ACS patients undergoing PCI.

Perioperative management of antiplatelet therapy in noncardiac surgery

PURPOSE OF REVIEW

Perioperative management of antiplatelet agents (APAs) in the setting of noncardiac surgery is a controversial topic of balancing bleeding versus thrombotic risks.

RECENT FINDINGS

Recent data do not support a clear association between continuation or discontinuation of APAs and rates of ischemic events, bleeding complications, and mortality up to 6 months after surgery. Clinical factors, such as indication and urgency of the operation, time since stent placement, invasiveness of the procedure, preoperative cardiac optimization, underlying functional status, as well as perioperative control of supply-demand mismatch and bleeding may be more responsible for adverse outcome than antiplatelet management.

SUMMARY

Perioperative management of antiplatelet therapy (APT) should be individually tailored based on consensus among the anesthesiologist, cardiologist, surgeon, and patient to minimize both ischemic/thrombotic and bleeding risks. Where possible, surgery should be delayed for a minimum of 1 month but ideally for 3-6 months from the index cardiac event. If bleeding risk is acceptable, dual APT (DAPT) should be continued perioperatively; otherwise P2Y12 inhibitor therapy should be discontinued for the minimum amount of time possible and aspirin monotherapy continued. If bleeding risk is prohibitive, both aspirin and P2Y12 inhibitor therapy should be interrupted and bridging therapy may be considered in patients with high thrombotic risk.

Use of Real-World Evidence in US Payer Coverage Decision-Making for Next-Generation Sequencing-Based Tests: Challenges, Opportunities, and Potential Solutions

OBJECTIVES

Given the potential of real-world evidence (RWE) to inform understanding of the risk-benefit profile of next-generation sequencing (NGS)-based testing, we undertook a study to describe the current landscape of whether and how payers use RWE as part of their coverage decision making and potential solutions for overcoming barriers.

METHODS

We performed a scoping literature review of existing RWE evidentiary frameworks for evaluating new technologies and identified barriers to clinical integration and evidence gaps for NGS. We synthesized findings as potential solutions for improving the relevance and utility of RWE for payer decision-making.

RESULTS

Payers require evidence of clinical utility to inform coverage decisions, yet we found a relatively small number of published RWE studies, and these are predominately focused on oncology, pharmacogenomics, and perinatal/pediatric testing. We identified 3 categories of innovation that may help address the current undersupply of RWE studies for NGS: (1) increasing use of RWE to inform outcomes-based contracting for new technologies, (2) precision medicine initiatives that integrate clinical and genomic data and enable data sharing, and (3) Food and Drug Administration reforms to encourage the use of RWE. Potential solutions include development of data and evidence review standards, payer engagement in RWE study design, use of incentives and partnerships to lower the barriers to RWE generation, education of payers and providers concerning the use of RWE and NGS, and frameworks for conducting outcomes-based contracting for NGS.

CONCLUSIONS

We provide numerous suggestions to overcome the data, methodologic, infrastructure, and policy challenges constraining greater integration of RWE in assessments of NGS.

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

Current guidelines recommend dual antiplatelet therapy (DAPT) consisting of aspirin and a P2Y12 inhibitors following percutaneous coronary intervention (PCI). CYP2C19 genotype can guide DAPT selection, prescribing ticagrelor or prasugrel for loss-of-function (LOF) allele carriers (genotype-guided escalation). Cost-effectiveness analyses (CEA) are traditionally grounded in clinical trial data. We conduct a CEA using real-world data using a 1-year decision-analytic model comparing primary strategies: universal empiric clopidogrel (base case), universal ticagrelor, and genotype-guided escalation. We also explore secondary strategies commonly implemented in practice, wherein all patients are prescribed ticagrelor for 30 days post PCI. After 30 days, all patients are switched to clopidogrel irrespective of genotype (nonguided de-escalation) or to clopidogrel only if patients do not harbor an LOF allele (genotype-guided de-escalation). Compared with universal clopidogrel, both universal ticagrelor and genotype-guided escalation were superior with improvement in quality-adjusted life years (QALY's). Only genotype-guided escalation was cost-effective ($42,365/QALY) and demonstrated the highest probability of being cost-effective across conventional willingness-to-pay thresholds. In the secondary analysis, compared with the nonguided de-escalation strategy, although genotype-guided de-escalation and universal ticagrelor were more effective, with ICER of $188,680/QALY and $678,215/QALY, respectively, they were not cost-effective. CYP2C19 genotype-guided antiplatelet prescribing is cost-effective compared with either universal clopidogrel or universal ticagrelor using real-world implementation data. The secondary analysis suggests genotype-guided and nonguided de-escalation may be viable strategies, needing further evaluation.