Effect of CYP2C19 and ABCB1 single nucleotide polymorphisms on outcomes of treatment with ticagrelor versus clopidogrel for acute coronary syndromes: a genetic substudy of the PLATO trial

Efficacy of dual antiplatelet therapy after ischemic stroke according to hsCRP levels and CYP2C19 genotype

BACKGROUND

Both high-sensitive C-reactive protein (hsCRP) and CYP2C19 genotypes are independent predictors of clinical outcomes after ischemic stroke. We aim to evaluate the association of CYP2C19 loss-of-function alleles (LoFA) carrying status with the effects of dual/single antiplatelet therapy at different hsCRP levels using the CHANCE trial.

METHODS

Subjects with both of CYP2C19 major alleles information (*2, *3, and *17) and hsCRP measurements were enrolled from the prespecified subgroup. CYP2C19 LoFA carriers were defined as patients with either*2 or *3 allele. Cox proportional hazards models were used to assess the interaction of CYP2C19 LoFA carrying status with the effects of dual/single antiplatelet therapy at different hsCRP levels. The primary outcome was recurrent stroke within 90 days.

RESULTS

Among 2,801 patients, 1,646 (58.8%) were LoFA carriers, and 922 (32.9%) had elevated hsCRP. In patients with nonelevated hsCRP, there was a significant interaction effect between CYP2C19 LoFA carrying status and dual/single antiplatelet regimens for prevention of recurrent stroke and combined vascular events (P = .048, .048, respectively), but, not in patients with elevated hsCRP (P = .502, .472, respectively). Only among patients with nonelevated hsCRP and noncarrier of CYP2C19 LoFA, dual antiplatelets significantly reduced the risk of recurrent stroke compared with aspirin alone (hazard ratio = 0.44 [0.26-0.74], P = .003). No significant differences in bleeding were found.

CONCLUSIONS

Nonelevated hsCRP and noncarrier of CYP2C19 LoFA may predict a better response to dual antiplatelet therapy in reducing stroke recurrence and composite vascular events for patients with minor stroke and high-risk TIA.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00979589.

The first in-human study to evaluate the antiplatelet properties of the clopidogrel conjugate DT-678 in acute coronary syndrome patients and healthy volunteers

BACKGROUND AND PURPOSE

DT-678 is a novel antiplatelet prodrug, capable of releasing the antiplatelet active metabolite of clopidogrel (AM) upon exposure to glutathione. In this study, we investigated factors responsible for clopidogrel high on-treatment platelet reactivity (HTPR) in acute coronary syndrome (ACS) patients and evaluated the capacity of DT-678 to overcome HTPR.

EXPERIMENTAL APPROACH

A total of 300 consecutive ACS patients naive to P2Y12 receptor inhibitors were recruited and genotyped for CYP2C19 alleles. Blood samples were drawn before and after administration of 600-mg clopidogrel. Platelet reactivity index (PRI) and plasma AM concentrations were determined and grouped according to their CYP2C19 genotypes. DT-678 was applied ex vivo to whole blood samples to examine its inhibitory effects. To further examine the antiplatelet effectiveness of DT-678 in vivo, 20 healthy human subjects were recruited in a Phase I clinical trial, and each received a single dose of either 3-mg DT-678 or 75-mg clopidogrel. The pharmacokinetics and pharmacodynamics in different CYP2C19 genotype groups were compared.

KEY RESULTS

Statistical analyses revealed that CYP2C19 genotype, body mass index, hyperuricaemia, and baseline PRI were significantly associated with a higher risk of clopidogrel HTPR in ACS patients. The addition of DT-678 ex vivo decreased baseline PRI regardless of CYP2C19 genotypes, overcoming clopidogrel HTPR. This observation was further confirmed in healthy volunteers receiving 3 mg of DT-678.

CONCLUSION AND IMPLICATIONS

These results suggest that DT-678 effectively overcomes clopidogrel HTPR resulting from genetic and/or clinical factors in Chinese ACS patients, demonstrating its potential to improve antiplatelet therapy.

Comparative Efficacy and Safety of Different Low-Dose Platelet Inhibitors in Patients With Coronary Heart Disease: A Bayesian Network Meta-Analysis

OBJECTIVE

The optimal low-dose antiplatelet agents in patients with coronary heart disease (CHD) had not been determined. The objective of this study was to compare the impact of different low-dose antiplatelet agents on cardiovascular outcomes and bleeding risks in patients with CHD.

METHODS

We searched PubMed, Embase, the Cochrane Library, China National Knowledge Infrastructure, VIP, WanFang Data, and China Biology Medicine. Randomized controlled trials (RCTs) enrolling patients with CHD treated with different low-dose platelet aggregation inhibitors were included. The revised Cochrane Risk of Bias Tool for Randomized Trials Risk was used to assess risk of bias in RCTs. A Bayesian random network meta-analysis (NMA) was conducted, with odds ratios (OR) and 95% confidence intervals (CI) as effect estimates in R 4.2.2 software and Stata 15.0. The quality of evidence was assessed using the Confidence in NMA framework.

RESULTS

Sixteen RCTs involving 6350 patients were included. All participants were treated with a recommended dose of aspirin plus a low or standard dose of P2Y12 receptor antagonist. Low-level evidence indicated the risk of major adverse cardiovascular events (MACE) was similar among low doses of prasugrel, ticagrelor, standard doses of prasugrel, ticagrelor, and clopidogrel. Low- to moderate-level evidence suggested there was no difference in bleeding risk among low dose of prasugrel, ticagrelor, clopidogrel compared to standard dose of prasugrel, ticagrelor, and clopidogrel. NMA showed that low dose of prasugrel had the highest probability of being the best intervention in terms of MACE, myocardial infarction, and bleeding events leading to discontinuation.

CONCLUSION

Based on low-level evidence, low dose of prasugrel combined with standard dose of aspirin can be recommended for patients with CHD, low dose of ticagrelor was similar in terms of MACE and bleeding compared with standard dose of P2Y12 receptor antagonist.  : The systematic review was registered in PROSPERO with the registration number CRD42023438376.

Prolonged antithrombotic treatment after de-escalation of dual antiplatelet therapy in patients after acute coronary syndrome - which strategy should be applied? The ELECTRA-SIRIO 2 investigators standpoint

De-escalation of dual antiplatelet (DAPT) intensity may be considered in patients with high risk of bleeding after acute coronary syndrome. Some high risk patients after de-escalation may require antithrombotic therapy prolonged over 12 months. With the current guideline recommended strategies, there are some doubts and uncertainties with respect to the transition period. Herein we discuss these issues more extensively. De-escalation of DAPT, intended to decrease bleeding risk, may be accomplished by switching to a drug with reduced antiplatelet effect (de-escalation by switching), by reducing the dose (de-escalation by dose reduction), or by removing an antiplatelet agent (de-escalation by discontinuation). The dilemma concerns patients who have undergone scheduled, early de-escalation of DAPT to monotherapy with a P2Y12 receptor inhibitor at standard dose, as in the TWILIGHT study. The dilemma is even greater in patients whose de-escalation consisted of both reduction in dose of one and discontinuation of the other antiplatelet agent. This strategy is currently being tested in the ELECTRA-SIRIO 2 study. When making a therapeutic decision in patients who meet the criteria for prolonged dual antithrombotic therapy we suggest considering the previously applied DAPT de-escalation strategy. In general, unless the risk of ischemic events has increased since prior de-escalation, there is no scientific rationale for escalating antithrombotic treatment in a patient previously de-escalated (through reduction or discontinuation). Regardless of the treatment strategy, its effectiveness depends on the patient's adherence to medical recommendations.

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.

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.

Genetic Determinants of Response to P2Y12 Inhibitors and Clinical Implications

The CYP2C19 enzyme metabolizes clopidogrel, a prodrug, to its active form. Approximately 30% of individuals inherit a loss-of-function (LoF) polymorphism in the CYP2C19 gene, leading to reduced formation of the active clopidogrel metabolite. Reduced clopidogrel effectiveness has been well documented in patients with an LoF allele following an acute coronary syndrome or percutaneous coronary intervention. Prasugrel or ticagrelor is recommended in those with an LoF allele as neither is affected by CYP2C19 genotype. Although data demonstrate improved outcomes with a CYP2C19-guided approach to P2Y12 inhibitor selection, genotyping has not yet been widely adopted in 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.

Outcomes of Ticagrelor Versus High-dose Clopidogrel in CYP2C19 Intermediate Metabolizer Undergoing Percutaneous Coronary Intervention for Acute Coronary Syndromes

ABSTRACT

Guidelines on antiplatelet recommendation for CYP2C19 intermediate metabolizer (IM) have not come to an agreement. This study aimed to evaluate the clinical benefit of ticagrelor when compared with high-dose clopidogrel in CYP2C19 IM after percutaneous coronary intervention for acute coronary syndromes. Patients were enrolled according to CYP2C19 genotype and individual antiplatelet therapy. Patient characteristics and clinical outcomes were collected through electronic medical record system. The primary outcome was major adverse cardiac and cerebrovascular event (MACCE), namely a composite of death from cardiovascular causes, myocardial infarction, stroke, and stent thrombosis within 12 months. The secondary outcome was Bleeding Academic Research Consortium scale bleeding events within 12 months. The Cox proportional hazards regression model was performed, with inverse probability treatment weighting (IPTW) adjusting for potential confounders. A total of 532 CYP2C19 IM were enrolled in this retrospective single-center study. No statistically significant difference in incidence rate of MACCE was found between patients receiving ticagrelor versus clopidogrel (7.01 vs. 9.52 per 100 patient-years; IPTW-adjusted hazard ratio 0.71; 95% confidence interval: 0.32-1.58; adjusted log-rank P = 0.396), but the incidence rate of Bleeding Academic Research Consortium type 2, 3, or 5 bleeding events was statistically higher in the loss of function-ticagrelor group than in the loss of function-clopidogrel group (13.53 vs. 6.16 per 100 patient-years; IPTW-adjusted hazard ratio: 2.29; 95% confidence interval: 1.10-4.78; adjusted log-rank P = 0.027). Ticagrelor treatment in CYP2C19 IM resulted in a statistically higher risk of bleeding compared with high-dose clopidogrel, whereas a clear association between treatments and MACCE warrants further investigations.

Platelets in Thrombosis and Atherosclerosis: A Double-Edged Sword

This review focuses on the dual role of platelets in atherosclerosis and thrombosis, exploring their involvement in inflammation, angiogenesis, and plaque formation, as well as their hemostatic and prothrombotic functions. Beyond their thrombotic functions, platelets engage in complex interactions with diverse cell types, influencing disease resolution and progression. The contribution of platelet degranulation helps in the formation of atheromatous plaque, whereas the reciprocal interaction with monocytes adds complexity. Alterations in platelet membrane receptors and signaling cascades contribute to advanced atherosclerosis, culminating in atherothrombotic events. Understanding these multifaceted roles of platelets will lead to the development of targeted antiplatelet strategies for effective cardiovascular disease prevention and treatment. Understanding platelet functions in atherosclerosis and atherothrombosis at different stages of disease will be critical for designing targeted treatments and medications to prevent or cure the disease Through this understanding, platelets can be targeted at specific times in the atherosclerosis process, possibly preventing the development of atherothrombosis.

Stenting with dual-layer CGuard stent in acute sub-occlusive carotid artery stenosis and in tandem occlusions: a monocentric study

PURPOSE

Double-layer design carotid stents have been cast in a negative light since several investigations reported high rates of in-stent occlusions, at least in the acute setting of tandem occlusions. CGuard is a new generation double-layered stent that was designed to prevent periinterventional embolic events. The aim of this study was to analyze the safety and efficacy of the CGuard in emergent CAS and for the acute treatment of tandem occlusions in comparison with the single-layer Carotid Wallstent (CWS) system.

METHODS

All patients who underwent CAS with CGuard or CWS after intracranial mechanical thrombectomy (MT) between 11/2018 and 12/2022 were identified from our local thrombectomy registry. Clinical, interventional and neuroimaging data were analyzed. Patency of the stent was assessed within 72 h. Intracranial hemorrhage and modified Rankin score (mRS) at discharge were the main endpoints.

RESULTS

In total, 86 stent procedures in 86 patients were included (CWS: 44, CGuard: 42). CGuard had a lower, but not statistically significant rate (p = 0.431) of in-stent occlusions (n = 2, 4.8%) when compared to the CWS (n = 4, 9.1%). Significant in-stent stenosis was found in one case in each group. There was no statistically significant difference in functional outcome at discharge between the two groups with a median mRS for CGuard of 2 (IQR:1-5) vs. CWS 3 (IQR:2-4).

CONCLUSION

In our series, the rate of in-stent occlusions after emergent CAS was lower with the dual-layer CGuard when compared to the monolayer CWS. Further data are needed to evaluate the potential benefit of the design in more detail.

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.

Precision Antiplatelet Therapy after Percutaneous Coronary Intervention (Precision PCI) Registry - Informing optimal antiplatelet strategies

Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 receptor inhibitor (clopidogrel, prasugrel, or ticagrelor) is indicated after percutaneous coronary intervention (PCI) to reduce the risk of atherothrombotic events. Approximately 30% of the US population has a CYP2C19 no-function allele that reduces the effectiveness of clopidogrel, but not prasugrel or ticagrelor, after PCI. We have shown improved outcomes with the integration of CYP2C19 genotyping into clinical care to guide the selection of prasugrel or ticagrelor in CYP2C19 no-function allele carriers. However, the influence of patient-specific demographic, clinical, and other genetic factors on outcomes with genotype-guided DAPT has not been defined. In addition, the impact of genotype-guided de-escalation from prasugrel or ticagrelor to clopidogrel in patients without a CYP2C19 no-function allele has not been investigated in a diverse, real-world clinical setting. The Precision Antiplatelet Therapy after Percutaneous Coronary Intervention (Precision PCI) Registry is a multicenter US registry of patients who underwent PCI and clinical CYP2C19 testing. The registry is enrolling a diverse population, assessing atherothrombotic and bleeding events over 12 months, collecting DNA samples, and conducting platelet function testing in a subset of patients. The registry aims to define the influence of African ancestry and other patient-specific factors on clinical outcomes with CYP2C19-guided DAPT, evaluate the safety and effectiveness of CYP2C19-guided DAPT de-escalation following PCI in a real-world setting, and identify additional genetic influences of clopidogrel response after PCI, with the ultimate goal of establishing optimal strategies for individualized antiplatelet therapy that improves outcomes in a diverse, real-world population.

Pharmacogenomic Polygenic Model of Clopidogrel Predicts Recurrent Ischemic Events in Chinese Patients With Coronary Artery Disease

PURPOSE

Patients with coronary artery disease (CAD) need to take antiplatelet drugs regularly in order to prevent thrombosis; however, there is existing inter-individual variability in drug response. Pharmacogenomic studies indicate that drug response may also be influenced by genetic variants, and multiple genetic variants may work together. We assumed that patients carrying more risk alleles might have a worse clopidogrel drug response and that a polygenic model integrated different single variants might have the potential to explain clopidogrel drug response variability better. We aimed to investigate whether the polygenic model could be used to predict clopidogrel drug response.

METHODS

A total of 935 CAD patients were enrolled in the study. We investigated the association between 19 clopidogrel-related single-nucleotide polymorphisms (SNPs) and the incidence of recurrent ischemic events. Additionally, a polygenic model was constructed to assess the risk of ischemic events.

FINDINGS

There were only 2 SNPs of CYP2C8 gene (rs1934980 and rs17110453) that were nominally associated with incidence of recurrent ischemic events. We constructed a polygenic model integrated with 6 clopidogrel-related SNPs. When compared with patients carrying 6 or fewer risk alleles, patients with 7 or more risk alleles had a higher risk of ischemic events (hazard ratio = 1.87; P = 0.04).

IMPLICATIONS

The polygenetic model may be useful for clopidogrel drug response prediction in patients with CAD.

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.

Role of Cyp2c19 Genotype-Guided Antiplatelet Therapy After Percutaneous Coronary Intervention

PURPOSE OF REVIEW

Identification of a reliable discriminatory test to accurately stratify patient responses to antiplatelet therapy following coronary revascularization has become increasingly desirable to optimize therapeutic efficacy and safety.

RECENT FINDINGS

The expansion of platelet function testing to include genotype assessment has been an evolutionary journey, initially fraught with confounding results. However, more recent and rigorous data analysis suggests that genotype testing- guided, tailored antiplatelet therapy may hold promise in optimizing treatment of patients after coronary intervention. Current evidence increasingly supports the use of genotype guided CYP2C19 testing to better match the post coronary intervention patient with the most efficacious and least risky antiplatelet inhibitor. The risk stratification of poor, intermediate, and good metabolizers of these drugs with such testing promises to yield clinical dividends in terms of morbidity, mortality and cost control, in this growing patient population.

Clinical efficacy of clopidogrel and ticagrelor in patients undergoing off-pump coronary artery bypass grafting: a retrospective cohort study

BACKGROUND

Ticagrelor is reportedly more effective than clopidogrel in preventing atherothrombotic events in patients with percutaneous coronary intervention. However, the optimal antiplatelet therapy strategy after off-pump coronary artery bypass grafting (OPCABG) is yet to be established.

MATERIALS AND METHODS

This study was performed using the prospectively-maintained database at our institution. Patients who underwent OPCABG were divided into the clopidogrel and the ticagrelor groups. Propensity score matching analysis was performed between the two groups. The clinical outcome was the occurrence of major adverse cardiovascular event (MACE), defined as a composite of vascular death, myocardial infarction, or stroke 1-year after surgery.

RESULTS

In total, 545 patients completed the entire follow-up assessment. After propensity score matching, 232 patients each were included in the clopidogrel and ticagrelor groups. The primary outcome occurred in 7.8 and 4.3% of patients in the clopidogrel and ticagrelor groups, respectively ( P =0.113). CYP2C19 variants (*2, *3, and *17) did not impact the clinical outcomes, regardless of the use of clopidogrel or ticagrelor. The rates of MACE were significantly lower in patients carrying the ABCB1 C3435T CT/TT genotypes in the ticagrelor group than in those carrying the ABCB1 C3435T CC genotype in the clopidogrel group (1.4 vs. 9.1%, adjusted P =0.030), as well as those carrying the ABCB1 C3435T CC genotype in the ticagrelor group (1.4 vs. 8.9%, adjusted P =0.036). The ABCB1 C3435T CC genotype was significantly associated with the incidence of 1-year MACE (HR=1.558, 95% CI: 1.109-2.188, P =0.011). Patients who experienced severe perioperative bleeding exhibited a significantly higher incidence of MACE than those who did not experience severe perioperative bleeding (14.0 vs. 4.9%, adjusted P =0.007).

CONCLUSION

There was no significant difference in the 1-year MACE between patients receiving clopidogrel and those receiving ticagrelor after OPCABG. Notably, The ABCB1 C3435T CC genotype was related to a higher risk of MACE.

Is CYP2C Haplotype Relevant for Efficacy and Bleeding Risk in Clopidogrel-Treated Patients?

A recently discovered haplotype-CYP2C:TG-determines the ultrarapid metabolism of several CYP2C19 substrates. The platelet inhibitor clopidogrel requires CYP2C19-mediated activation: the risk of ischemic events is increased in patients with a poor (PM) or intermediate (IM) CYP2C19 metabolizer phenotype (vs. normal, NM; rapid, RM; or ultrarapid, UM). We investigated whether the CYP2C:TG haplotype affected efficacy/bleeding risk in clopidogrel-treated patients. Adults (n = 283) treated with clopidogrel over 3-6 months were classified by CYP2C19 phenotype based on the CYP2C19*2*17 genotype, and based on the CYP2C19/CYP2C cluster genotype, and regarding carriage of the CYP2:TG haplotype, and were balanced on a number of covariates across the levels of phenotypes/haplotype carriage. Overall, 45 (15.9%) patients experienced ischemic events, and 49 (17.3%) experienced bleedings. By either classification, the incidence of ischemic events was similarly numerically higher in PM/IM patients (21.6%, 21.8%, respectively) than in mutually similar NM, RM, and UM patients (13.2-14.8%), whereas the incidence of bleeding events was numerically lower (13.1% vs. 16.6-20.5%). The incidence of ischemic events was similar in CYP2C:TG carries and non-carries (14.1% vs. 16.1%), whereas the incidence of bleedings appeared mildly lower in the former (14.9% vs. 20.1%). We observed no signal to suggest a major effect of the CYP2C19/CYP2C cluster genotype or CYP2C:TG haplotype on the clinical efficacy/safety of clopidogrel.

Effectiveness of Clopidogrel vs Alternative P2Y12 Inhibitors Based on the ABCD-GENE Score

BACKGROUND

An ABCD-GENE (age, body mass index, chronic kidney disease, diabetes, and CYP2C19 genetic variants) score ≥10 predicts reduced clopidogrel effectiveness, but its association with response to alternative therapy remains unclear.

OBJECTIVES

The aim of this study was to evaluate the association between ABCD-GENE score and the effectiveness of clopidogrel vs alternative P2Y12 inhibitor (prasugrel or ticagrelor) therapy after percutaneous coronary intervention (PCI).

METHODS

A total of 4,335 patients who underwent PCI, CYP2C19 genotyping, and P2Y12 inhibitor treatment were included. The primary outcome was major atherothrombotic events (MAE) within 1 year after PCI. Cox regression was performed to assess event risk in clopidogrel-treated (reference) vs alternatively treated patients, with stabilized inverse probability weights derived from exposure propensity scores after stratifying by ABCD-GENE score and further by CYP2C19 loss-of-function (LOF) genotype.

RESULTS

Among patients with scores <10 (n = 3,200), MAE was not different with alternative therapy vs clopidogrel (weighted HR: 0.89; 95% CI: 0.65-1.22; P = 0.475). The risk for MAE also did not significantly differ by treatment among patients with scores ≥10 (n = 1,135; weighted HR: 0.75; 95% CI: 0.51-1.11; P = 0.155). Among CYP2C19 LOF allele carriers, MAE risk appeared lower with alternative therapy in both the group with scores <10 (weighted HR: 0.50; 95% CI: 0.25-1.01; P = 0.052) and the group with scores ≥10 (weighted HR: 0.48; 95% CI: 0.29-0.80; P = 0.004), while there was no difference in the group with scores <10 and no LOF alleles (weighted HR: 1.03; 95% CI: 0.70-1.51; P = 0.885).

CONCLUSIONS

These data support the use of alternative therapy over clopidogrel in CYP2C19 LOF allele carriers after PCI, regardless of ABCD-GENE score, while clopidogrel is as effective as alternative therapy in non-LOF patients with scores <10.

A disproportionality analysis of FDA adverse event reporting system (FAERS) events for ticagrelor

Background

Ticagrelor is a commonly used antiplatelet agent, but due to the stringent criteria for trial population inclusion and the limited sample size, its safety profile has not been fully elucidated.

Method

We utilized OpenVigil 2.1 to query the FDA Adverse Event Reporting System database and retrieved reports by the generic name "ticagrelor" published between 1 October 2010 and 31 March 2023. Adverse drug events (ADEs) were classified and described according to the preferred terms and system organ classes in the Medical Dictionary of Regulatory Activity. Proportional reporting ratio (PRR), reporting odds ratio (ROR) and Bayesian Confidence Propagation Neural Network (BCPNN) were used to detect signals.

Results

The number of ADE reports with ticagrelor as the primary suspect drug was 12,909. The top three ADEs were dyspnea [1824 reports, ROR 7.34, PRR 6.45, information component (IC) 2.68], chest pain (458 reports, ROR 5.43, PRR 5.27, IC 2.39), and vascular stent thrombosis (406 reports, ROR 409.53, PRR 396.68, IC 8.02). The highest ROR, 630.24, was found for "vascular stent occlusion". Cardiac arrest (137 reports, ROR 3.41, PRR 3.39, IC 1.75), atrial fibrillation (99 reports, ROR 2.05, PRR 2.04, IC 1.03), asphyxia (101 reports, ROR 23.60, PRR 23.43, IC 4.51), and rhabdomyolysis (57 reports, ROR 2.75, PRR 2.75, IC 1.45) were suspected new adverse events of ticagrelor.

Conclusion

The FAERS database produced potential signals associated with ticagrelor that have not been recorded in the package inserts, such as cardiac arrest, atrial fibrillation, asphyxia, and rhabdomyolysis. Further clinical surveillance is needed to quantify and validate potential hazards associated with ticagrelor-related adverse events.

Pharmacogenetic considerations in therapy with novel antiplatelet and anticoagulant agents

Antiplatelets and anticoagulants are extensively used in cardiovascular medicine for the prevention and treatment of thrombosis in the venous and arterial circulations. Wide inter-individual variability has been observed in response to antiplatelets and anticoagulants, which triggered researchers to investigate the genetic basis of this variability. Data from extensive pharmacogenetic studies pointed to strong evidence of association between polymorphisms in candidate genes and the pharmacokinetics and pharmacodynamic action and clinical response of the antiplatelets clopidogrel and the anticoagulant warfarin. In this review, we conducted an extensive search on Medline for the time period of 2009-2023. We also searched the PharmGKB website for levels of evidence of variant-drug combinations and for drug labels and clinical guidelines. We focus on the pharmacogenetics of novel antiplatelets and anticoagulants while excluding acetylsalicylic acid, warfarin and heparins, and discuss the current knowledge with emphasis on the level of evidence.

Development of a routine bedside CYP2C19 genotype assessment program for antiplatelet therapy guidance in a community hospital catheterization laboratory

Genotype based personalized antiplatelet therapy in the setting of percutaneous coronary intervention (PCI) has been studied in clinical trials. Despite the demonstrated risk associated with CYP2C19 loss-of-function (LoF) carriage in clopidogrel-treated PCI patients, real-world implementation of genotyping for PCI has been low. The goal of the current study was to provide CYP2C19 genotype information to the interventionalist prior to the completion of the catheterization to facilitate immediate personalized antiplatelet therapy. Routine personalization of P2Y12 inhibitor therapy for PCI in a community hospital cardiac catheterization laboratory by POC genotyping with the SpartanRx system was first offered in February 2017. A best practice advisory (BPA) based on the Clinical Pharmacogenetics Implementation Consortium Guideline for CYP2C19 genotype and clopidogrel therapy was placed in the electronic health record prescription medication ordering system. By December 2019, 1,052 patients had CYP2C19 genotype testing, 429 patients underwent PCI with genotype guided antiplatelet therapy, and 250 patients underwent PCI without genotype testing and received antiplatelet therapy at the discretion of the treating physician. BPA compliance was 93. 87% of LoF allele carriers were prescribed ticagrelor or prasugrel whereas 96% of non-LoF allele carriers were prescribed clopidogrel. The genotyping results were available within 1 h and made immediately available for decision making by the interventional cardiologist. POC CYP2C19 genotyping is feasible in a community hospital catheterization laboratory and is associated with high rate of best practice compliance.Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT03040622.

Net clinical benefit of clopidogrel versus ticagrelor in elderly patients carrying CYP2C19 loss-of-function variants with acute coronary syndrome after percutaneous coronary intervention

BACKGROUND AND AIMS

Elderly patients with acute coronary syndrome (ACS) tend to choose clopidogrel over potent P2Y12 receptor inhibitor such as ticagrelor after percutaneous coronary intervention (PCI) in China considering higher risks of bleeding. CYP2C19 genotype is regarded as a major factor influencing the efficacy of clopidogrel. The present study aims to investigate the efficacy and safety of ticagrelor relative to clopidogrel in elderly ACS patients after PCI in China with reduced CYP2C19 metabolism.

METHODS

Between January 2016 and March 2019, 2751 ACS patients over 65 years old with CYP2C19 loss-of-function (LOF) variants after PCI were enrolled. All patients were treated with aspirin and P2Y12 receptor inhibitor, among whom 2056 received clopidogrel and 695 received ticagrelor. Net adverse clinical events (NACE), a composite of cardiac death, myocardial infarction (MI), ischemic stroke, target vessel revascularization and clinically relevant bleeding including Bleeding Academic Research Consortium (BARC) types 2, 3, 5 bleeding, were compared between the two groups at 12 months after PCI. Propensity score matching (PSM) was conducted to balance the baseline characteristics between the two groups.

RESULTS

Before and after PSM, NACE was significantly increased in ticagrelor group compared with clopidogrel group at 12 months post PCI (Before PSM, 15.18% vs. 25.61% p<0.001; After PSM, 11.66% vs. 26.01% p<0.001). MACE was comparable between the two groups (Before PSM, 5.45% vs. 5.32% p>0.999; After PSM, 3.59% vs. 5.38% p=0.146). BARC types 2, 3, 5 bleeding events were significantly increased in patients treated with ticagrelor relative to clopidogrel (Before PSM, 10.31% vs. 21.01% p<0.001; After PSM, 8.22% vs. 21.38% p<0.001), which was mainly attributed to a higher incidence of BARC type 2 bleeding events in ticagrelor group (Before PSM, 8.12% vs. 18.56% p<0.001; After PSM, 6.43% vs. 18.83% p<0.001).

CONCLUSIONS

In the present real-world study, selection of ticagrelor over clopidogrel showed a significant increase in NACE with a higher incidence of bleeding and similar ischemic events in elderly ACS patients carrying CYP2C19 LOF variants after PCI.

Pharmacogenomic biomarkers in coronary artery disease: a narrative review

Coronary artery disease (CAD) has a high mortality rate. Despite various therapeutic targets, non-responsiveness to drugs remains a prevalent issue. Pharmacogenomics assesses the way an individual's genetic attributes affect their likely response to drug therapy. Single-nucleotide polymorphisms play a crucial role in determining these outcomes. This review offers an overview of single-nucleotide polymorphisms investigated in clinical studies and their associations with drug response/nonresponse in the treatment of CAD. A total of 104 studies of whole sets of chromosomes and several genes were explored. A total of 161 polymorphisms exhibited associations with drug response/nonresponse in CAD across diverse ethnic populations. This pool can serve as a pharmacogenomic biomarker for predicting response to drug therapy in patients with CAD.

Empiric treatment with aspirin and ticagrelor is the most cost-effective strategy in patients with minor stroke or transient ischemic attack

BACKGROUND

Patients with minor ischemic stroke or transient ischemic attacks (TIAs) are often treated with dual antiplatelet therapy regimens as part of secondary stroke prevention. Clopidogrel, an antiplatelet used in these regimens, is metabolized into its active form by the CYP2C19 enzyme. Patients with loss of function (LOF) mutations in CYP2C19 are at risk for poorer secondary outcomes when prescribed clopidogrel.

AIMS

We aimed to determine the cost-effectiveness of three different treatment antiplatelet regimens in ischemic stroke populations with minor strokes or TIAs and how these treatment regimens are influenced by the LOF prevalence in the population.

METHODS

Markov models were developed to look at the cost-effectiveness of empiric treatment with aspirin and clopidogrel versus empiric treatment with aspirin and ticagrelor, versus genotype-guided therapy for either 21 or 30 days. Effect ratios were obtained from the literature, and incidence rates and costs were obtained from the national data published by the Singapore Ministry of Health. The primary endpoints were the incremental cost-effectiveness ratios (ICERs).

RESULTS

Empiric treatment with aspirin and ticagrelor was the most cost-effective treatment. Genotype-guided therapy was more cost-effective than empiric aspirin and clopidogrel if the LOF was above 48%. Empiric ticagrelor and aspirin was cost saving when compared to genotype-guided therapy. Results in models of dual antiplatelet therapy for 30 days were similar.

CONCLUSION

This study suggests that in patients with minor stroke and TIA planned for dual antiplatelet regimens, empiric ticagrelor and aspirin is the most cost-effective treatment regimen. If ticagrelor is not available, genotype-guided therapy is the most cost-effective treatment regimen if the LOF prevalence in the population is more than 48%.

Effect of cytochrome P450 2C19 (CYP2C19) gene polymorphism and clopidogrel reactivity on long term prognosis of patients with coronary heart disease after PCI

Objective

To investigate the impact of CYP2C19 gene polymorphism on clopidogrel reactivity and its association with long-term clinical outcome in patients with coronary heart disease (CHD) undergoing percutaneous coronary intervention (PCI).

Methods

In total, 675 patients were enrolled. Based on the platelet inhibition rate, patients were categorized into two groups: clopidogrel low responsiveness (CLR) and normal clopidogrel responsiveness (NCR). The CLR group was divided into ticagrelor and clopidogrel group based on the antiplatelet drugs used in the follow-up treatment. Patients were classified into three groups (normal metabolizer, intermediate metabolizer, and poor metabolizer) based on the CYP2C19 genotype. We aimed to evaluate the impact of CYP2C19 gene polymorphism on clopidogrel reactivity. The cumulative rates of 12-month all-cause deaths, major adverse cardiovascular events (MACCEs), and bleeding events were calculated.

Results

CLR was observed in 44.4% of the overall population. Significant differences were observed in the platelet inhibition rate of clopidogrel among the three metabolic genotypes (P < 0.05). At the 12-month follow-up, 13 patients (1.9%) died and 96 patients (14.2%) experienced MACCEs. Patients with CLR (9.6% vs. 11.7% vs. 22.1%, P < 0.05) or poor metabolizer (10.7% vs. 16.4% vs. 22.6%, P = 0.026) experienced a higher rate of MACCEs. A MACCEs risk score between zero and two was calculated. The highest incidence of MACCEs significantly increased with the 2-positive results, and the area under the curve (AUC) was 0.712 (95% CI: 0.650-0.774, P < 0.05). There was no significant difference between the group with a score of one and the occurrence of MACCEs (P > 0.05).

Conclusions

Low response to clopidogrel in CHD patients is correlated with CYP2C19 gene polymorphism. CYP2C19 genotyping combined with platelet reactivity is an independent predictor of 12-months MACCEs in patients with clopidogrel treatment after PCI, which is better than either test alone.

A systematic study to evaluate the safety of ticagrelor combined with aspirin in the treatment of PCI patients in Chinese population: A single nucleotide polymorphisms study

The aim of this study was to identify genes and their associated loci related to ticagrelor pharmacokinetics and pharmacodynamics in Chinese patients with acute coronary syndrome (ACS) after percutaneous coronary intervention (PCI). The study included 1115 patients with ACS who received a drug-eluting stent implantation between October 2019 and January 2021. Among them, 98 cases of adverse reactions were observed; thus, 97 cases without adverse reactions were selected as the comparison group. The steady-state serum drug concentration was determined via high-performance liquid chromatography-mass spectrometry, and 15 single nucleotide polymorphism (SNP) loci were genotyped using the SNaPshot SNP Multiplex System. Our results showed that age and sex may affect ticagrelor serum concentration in patients with ACS. In particular, the SNPs CYP3A4∗1 (rs2242480 C > T), IGT2B (rs5911 A > C), P2Y12 (rs6787801) and CYP3A5 (rs776746 C > T) may affect the steady-state blood concentration of ticagrelor after PCI in ACS patients, and CYP3A4∗1 may also be related to adverse events. In addition, we found that the SNPs PEAR1 (rs4661012 T > G) and P2Y12 (rs6787801 A > G) may be associated with dyspnea. These findings can provide a useful reference to establish guidelines for future clinical individualized dosage regimens of ticagrelor after PCI.

Advances and Perspectives in methods for identifying high platelet reactivity

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

Pharmacogenomics of Cardiovascular Drugs for Atherothrombotic, Thromboembolic and Atherosclerotic Risk

PURPOSE OF REVIEW

Advances in pharmacogenomics have paved the way for personalized medicine. Cardiovascular diseases still represent the leading cause of mortality in the world. The aim of this review is to summarize the background, rationale, and evidence of pharmacogenomics in cardiovascular medicine, in particular, the use of antiplatelet drugs, anticoagulants, and drugs used for the treatment of dyslipidemia.

RECENT FINDINGS

Randomized clinical trials have supported the role of a genotype-guided approach for antiplatelet therapy in patients with coronary heart disease undergoing percutaneous coronary interventions. Numerous studies demonstrate how the risk of ineffectiveness of new oral anticoagulants and vitamin K anticoagulants is linked to various genetic polymorphisms. Furthermore, there is growing evidence to support the association of some genetic variants and poor adherence to statin therapy, for example, due to the appearance of muscular symptoms. There is evidence for resistance to some drugs for the treatment of dyslipidemia, such as anti-PCSK9.

SUMMARY

Pharmacogenomics has the potential to improve patient care by providing the right drug to the right patient and could guide the identification of new drug therapies for cardiovascular disease. This is very important in cardiovascular diseases, which have high morbidity and mortality. The improvement in therapy could be reflected in the reduction of healthcare costs and patient mortality.

Insight into Risk Factors, Pharmacogenetics/Genomics, and Management of Adverse Drug Reactions in Elderly: A Narrative Review

The European Medicine Agency (EMA) has defined Adverse Drug Reactions (ADRs) as "a noxious and unintended response to a medicine", not including poisoning, accidental, or intentional overdoses. The ADR occurrence differs based on the approach adopted for defining and detecting them, the characteristics of the population under study, and the research setting. ADRs have a significant impact on morbidity and mortality, particularly among older adults, and represent a financial burden for health services. Between 30% and 60% of ADRs might be predictable and preventable, emerging as a result of inappropriate prescription, drug chemistry inherent toxicity, cell-specific drug toxicity, age- and sex-related anomalies in drug absorption, distribution, metabolism, and elimination (ADME), and drug-drug interactions (DDIs) in combination therapies or when a patient is treated with different drugs for concomitant disorders. This is particularly important in chronic diseases which require long-term treatments. Rapid developments in pharmacogenetics/genomics have improved the understanding of ADRs accompanied by more accurate prescriptions and reduction in unnecessary costs. To alleviate the burden of ADRs, especially in the elderly, interventions focused on pharmaceutical principles, such as medication review and reconciliation, should be integrated into a broader assessment of patients' characteristics, needs, and health priorities. Digital health interventions could offer valuable solutions to assist healthcare professionals in identifying inappropriate prescriptions and promoting patient adherence to pharmacotherapies.

Ticagrelor vs Clopidogrel in Acute Myocardial Infarction Patients With a History of Ischemic Stroke

OBJECTIVE

To investigate whether use of ticagrelor compared to clopidogrel is associated with different risks for thrombotic events or major bleeding among acute myocardial infarction (AMI) patients with a prior history of acute ischemic stroke.

PATIENTS AND METHODS

This retrospective cohort study used the Health and Welfare Database in Taiwan. Stroke patients prescribed ticagrelor plus aspirin or clopidogrel plus aspirin after a primary hospitalization for AMI between July 1, 2013, and December 31, 2018, were included. Inverse probability of treatment weighting was applied to balance covariates between treatment groups. The primary effectiveness outcome included a composite measure of AMI, acute ischemic stroke, or all-cause mortality. The primary safety outcome included a composite measure of intracranial hemorrhage (ICH) and major gastrointestinal bleeding. The secondary effectiveness and safety outcomes comprised each of the individual components that make up the primary effectiveness and safety outcomes, respectively.

RESULTS

A total of 1691 eligible patients were included in the study, of whom 734 (43.4%) received ticagrelor plus aspirin and 957 received clopidogrel plus aspirin. There were no significant differences observed in the primary and secondary effectiveness outcomes between the two study groups. However, the use of ticagrelor was associated with a higher risk of ICH (ticagrelor: 8.68 per 1000 person-year; clopidogrel: 2.17 per 1,000 person-year; HR, 3.34; 95% CI, 1.27 to 8.81, P = .01) compared with clopidogrel.

CONCLUSION

In AMI patients with a history of acute ischemic stroke, the risks of cardiovascular events were comparable between ticagrelor plus aspirin and clopidogrel plus aspirin. However, ticagrelor was associated with a higher risk of ICH. Ticagrelor should be used cautiously in AMI patients with a history of acute ischemic stroke.

CYP2C19 Polymorphisms and Clinical Outcomes Following Percutaneous Coronary Intervention (PCI) in the Million Veterans Program

Background

CYP2C19 loss-of-function (LOF) alleles decrease the antiplatelet effect of clopidogrel following percutaneous coronary intervention (PCI) in patients presenting with acute coronary syndrome (ACS). The impact of genotype in stable ischemic heart disease (SIHD) is unclear.

Objectives

Determine the association of CYP2C19 genotype with major adverse cardiac events (MACE) after PCI for ACS or SIHD.

Methods

Million Veterans Program (MVP) participants age <65 years with a PCI documented in the VA Clinical Assessment, Reporting and Tracking (CART) Program between 1/1/2009 to 9/30/2017, treated with clopidogrel were included. Time to MACE defined as the composite of all-cause death, stroke or myocardial infarction within 12 months following PCI.

Results

Among 4,461 Veterans (mean age 59.1 ± 5.1 years, 18% Black); 44% had ACS, 56% had SIHD and 29% carried a CYP2C19 LOF allele. 301 patients (6.7%) experienced MACE while being treated with clopidogrel, 155 (7.9%) in the ACS group and 146 (5.9%) in the SIHD group. Overall, MACE was not significantly different between LOF carriers vs. noncarriers (adjusted hazard ratio [HR] 1.18, confidence interval [95%CI] 0.97-1.45, p=0.096). Among patients presenting with ACS, MACE risk in LOF carriers versus non-carriers was numerically higher (HR 1.30, 95%CI 0.98-1.73, p=0.067). There was no difference in MACE risk in patients with SIHD (HR 1.09, 95%CI 0.82-1.44; p=0.565).

Conclusions

CYP2C19 LOF carriers presenting with ACS treated with clopidogrel following PCI experienced a numerically greater elevated risk of MACE events. CYP2C19 LOF genotype is not associated with MACE among patients presenting with SIHD.

Genotype-guided dual antiplatelet therapy in cerebrovascular disease: assessing the risk and benefits for ethnic populations

INTRODUCTION

Cerebrovascular disease is a leading cause of morbidity and mortality in the world and antiplatelet therapy is a main pharmacologic means of secondary prevention. Clinical information has accumulated about benefit of dual antiplatelet therapy in certain clinical scenarios, genetic causes of antiplatelet resistance and its effect on clinical outcomes, and ethnic and geographic distributions of genetic polymorphisms.

AREAS COVERED

This review covers literature related to the pharmacogenomics of antiplatelet agents with a focus on ethnic variability, antiplatelet resistance, and dual antiplatelet therapy in cerebrovascular disease.

EXPERT OPINION

Selecting patients for dual antiplatelet therapy and specific agents require consideration of multiple factors. Ethnic factors should be considered in certain circumstances, but additional research is needed to determine the generalizability of the findings.

An update on novel therapies for treating patients with arterial thrombosis

INTRODUCTION

Antithrombotic therapy field is undergoing rapid and significant changes during the past decade. In addition to new therapeutic strategies with existing targets, investigators are exploring the potential use of new targets to address unmet needs to treat patients with arterial diseases.

AREAS COVERED

We aim to provide an update on and a comprehensive review of the antithrombic agents that are being explored in patients with arterial diseases. We discuss latest developments with respect to upstream antiplatelet agents, and collagen and thrombin pathway inhibitors. We searched PubMed databases for English language articles using keywords: antiplatelet agents, thrombin pathway inhibitors, collagen receptors, arterial disease.

EXPERT OPINION

Despite implementation of potent P2Y12 inhibitors, there are numerous unmet needs in the treatment of arterial diseases including ceiling effect of currently available antiplatelet agents along with and an elevated risk of bleeding. The latter observations encouraged investigators to explore new targets that can attenuate the generation of platelet-fibrin clot formation and subsequent ischemic event occurrences with minimal effect on bleeding. These targets include collagen receptors on platelets and thrombin generation including FXa, FXIa, and FXIIa. In addition, investigators are studying novel antiplatelet agents/strategies to facilitate upstream therapy in high-risk patients.

Cardiovascular precision medicine - A pharmacogenomic perspective

Precision medicine envisages the integration of an individual's clinical and biological features obtained from laboratory tests, imaging, high-throughput omics and health records, to drive a personalised approach to diagnosis and treatment with a higher chance of success. As only up to half of patients respond to medication prescribed following the current one-size-fits-all treatment strategy, the need for a more personalised approach is evident. One of the routes to transforming healthcare through precision medicine is pharmacogenomics (PGx). Around 95% of the population is estimated to carry one or more actionable pharmacogenetic variants and over 75% of adults over 50 years old are on a prescription with a known PGx association. Whilst there are compelling examples of pharmacogenomic implementation in clinical practice, the case for cardiovascular PGx is still evolving. In this review, we shall summarise the current status of PGx in cardiovascular diseases and look at the key enablers and barriers to PGx implementation in clinical practice.

Clopidogrel Use in CYP2C19 Loss-of-Function Carriers With High Bleeding Risk After Percutaneous Coronary Intervention

BACKGROUND

It is not known whether clopidogrel use in cytochrome P450 (CYP) 2C19 loss-of-function (LOF) carriers with high bleeding risk (HBR) contributes to adverse outcomes after percutaneous coronary intervention (PCI).

METHODS AND RESULTS

This retrospective observational study included 618 consecutive patients with available CYP2C19 polymorphism information who underwent PCI between September 2014 and August 2021. Patients with HBR (319 [52%] met the Academic Research Consortium definition) were divided into 2 groups according to P2Y12inhibitor action, namely decreased (i.e., clopidogrel in CYP2C19 LOF carriers) and retained (i.e., clopidogrel in CYP2C19 LOF non-carriers or prasugrel regardless of CYP2C19 polymorphisms), and clinical outcomes at 1 year were compared using inverse probability-weighted Cox proportional hazard regression. The primary ischemic outcome (a composite of cardiovascular death, myocardial infarction, or ischemic stroke) was significantly higher in the decreased than retained group (10.2% vs. 3.0%; adjusted hazard ratio [aHR] 2.78; 95% confidence interval [CI] 1.40-5.52; P=0.004). The primary bleeding outcome (Bleeding Academic Research Consortium 3 or 5) did not differ significantly between the decreased and retained groups (3.4% vs. 6.9%, respectively; aHR 0.48; 95% CI 0.22-1.01; P=0.054). There were no interactions between the treatment groups and HBR status in primary ischemic and bleeding outcomes.

CONCLUSIONS

Among patients with HBR, clopidogrel use in CYP2C19 LOF carriers was significantly associated with increased ischemic events after PCI.

Assessing the Clinical Treatment Dynamics of Antiplatelet Therapy Following Acute Coronary Syndrome and Percutaneous Coronary Intervention in the US

Importance

A platelet ADP P2Y12 receptor (P2Y12) inhibitor plus aspirin is standard therapy for patients undergoing percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS). Compared with clopidogrel, prasugrel and ticagrelor are associated with superior antiatherothrombotic effects but increased bleeding risk; with recent guideline updates, it is important to describe current treatment patterns and the role of bleeding risk in treatment choice.

Objective

To describe secular trends and determinants of initial P2Y12 inhibitor choice and switching, including deescalation (switch from prasugrel or ticagrelor to clopidogrel).

Design, Setting, and Participants

This retrospective cohort study used MarketScan Commercial Claims Data from 2010 to 2019 for patients aged 18 years or older who underwent PCI for ACS, had no P2Y12 inhibitor use in the past year, and filled a P2Y12 inhibitor prescription within 30 days after PCI hospitalization discharge. Data were analyzed from February to May 2022.

Exposures

Clopidogrel, prasugrel, and ticagrelor, with determinants including bleeding risk measured using Academic Research Consortium for High Bleeding Risk criteria, sociodemographic characteristics, P2Y12 inhibitor copays, and bleeding events during follow-up.

Main Outcomes and Measures

The prevalence of each P2Y12 inhibitor among patients who initiated the drugs and the prevalence of switching within 12 months after PCI were evaluated. The association between baseline bleeding risk and bleeding manifestations during follow-up and initial treatment and deescalation were calculated using multivariable logistic and Cox proportional hazards regression models.

Results

Between 2010 and 2019, 62 423 patients were identified who initiated P2Y12 inhibitors (females, 22.4%; males, 77.6%; mean [SD] age, 54.32 [7.13] years). The prevalence of clopidogrel as initial therapy decreased from 77.5% in 2010 to 29.6% in 2019, while initial use of prasugrel or ticagrelor increased from 22.5% to 60.4%. Within 1 year after PCI, 11.0% of patients switched therapy, mostly for deescalation. Deescalation prevalence increased from 1.8% in 2010 to 12.6% in 2018. Between 2016 and 2018, 8588 of 22 886 (37.5%) patients had major baseline bleeding risk, which decreased the selection of prasugrel or ticagrelor as initial therapy (adjusted odds ratio, 0.78; 95% CI, 0.74-0.84). Among 11 285 patients who initiated prasugrel or ticagrelor, major bleeding risk at baseline (adjusted hazard ratio, 1.11; 95% CI, 1.00-1.23) and the occurrence of bleeding during follow-up (adjusted hazard ratio, 4.42; 95% CI, 3.62-5.93) were associated with deescalation.

Conclusions and Relevance

A strong shift in preference for prasugrel and ticagrelor as initial therapy following PCI for ACS was observed. Deescalation increased over the study period. Major bleeding risk at baseline was moderately associated with initial treatment choice but had a limited association with deescalation. The increasing use of more potent P2Y12 inhibitors emphasizes opportunities to enhance preemptive patient-centered treatment strategies to maintain optimal antiplatelet activity while reducing bleeding risk during the subacute period following PCI for ACS.

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.

Platelet P2Y12 Inhibitor Monotherapy after Percutaneous Coronary Intervention: An Emerging Option for Antiplatelet Therapy De-escalation

Antiplatelet therapy is considered essential for secondary prevention of ischemic heart disease. After percutaneous coronary intervention (PCI), temporary dual antiplatelet therapy (DAPT), a combination consisting of aspirin and an oral P2Y12 receptor blocker, is recommended. In the long term, this strategy results in more bleeding than antiplatelet therapy with aspirin alone. Therefore, to reduce bleeding, an increasing trend has been to keep DAPT as short as clinically acceptable, after which aspirin monotherapy is continued. Another option to diminish bleeding is to discontinue aspirin at the moment of DAPT cessation after PCI, and to continue on P2Y12 blocker monotherapy. This survey reviews the evidence on P2Y12 blocker monotherapy. Some clinical guidance will be provided on when and in whom P2Y12 inhibitor monotherapy may be applied after DAPT cessation following PCI.

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.

Pharmacogenetics of Antiplatelet Therapy

Antiplatelet therapy is used in the treatment of patients with acute coronary syndromes, stroke, and those undergoing percutaneous coronary intervention. Clopidogrel is the most widely used antiplatelet P2Y12 inhibitor in clinical practice. Genetic variation in CYP2C19 may influence its enzymatic activity, resulting in individuals who are carriers of loss-of-function CYP2C19 alleles and thus have reduced active clopidogrel metabolites, high on-treatment platelet reactivity, and increased ischemic risk. Prospective studies have examined the utility of CYP2C19 genetic testing to guide antiplatelet therapy, and more recently published meta-analyses suggest that pharmacogenetics represents a key treatment strategy to individualize antiplatelet therapy. Rapid genetic tests, including bedside genotyping platforms that are validated and have high reproducibility, are available to guide selection of P2Y12 inhibitors in clinical practice. The aim of this review is to provide an overview of the background and rationale for the role of a guided antiplatelet approach to enhance patient care.

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.

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.

Clinical Pharmacogenetics Implementation Consortium Guideline for CYP2C19 Genotype and Clopidogrel Therapy: 2022 Update

CYP2C19 catalyzes the bioactivation of the antiplatelet prodrug clopidogrel, and CYP2C19 genotype impacts clopidogrel active metabolite formation. CYP2C19 intermediate and poor metabolizers who receive clopidogrel experience reduced platelet inhibition and increased risk for major adverse cardiovascular and cerebrovascular events. This guideline is an update to the 2013 Clinical Pharmacogenetics Implementation Consortium (CPIC) guideline for the use of clopidogrel based on CYP2C19 genotype and includes expanded indications for CYP2C19 genotype-guided antiplatelet therapy, increased strength of recommendation for CYP2C19 intermediate metabolizers, updated CYP2C19 genotype to phenotype translation, and evidence from an expanded literature review (updates at www.cpicpgx.org).

Evaluation of race and ethnicity disparities in outcome studies of CYP2C19 genotype-guided antiplatelet therapy

Dual antiplatelet therapy with a P2Y12 inhibitor (clopidogrel, prasugrel, or ticagrelor) and aspirin remains the standard of care for all patients undergoing percutaneous coronary intervention (PCI). It is well-established that patients carrying CYP2C19 no function alleles have impaired capacity to convert clopidogrel into its active metabolite and thus, are at higher risk of major adverse cardiovascular events (MACE). The metabolism and clinical effectiveness of prasugrel and ticagrelor are not affected by CYP2C19 genotype, and accumulating evidence from multiple randomized and observational studies demonstrates that CYP2C19 genotype-guided antiplatelet therapy following PCI improves clinical outcomes. However, most antiplatelet pharmacogenomic outcome studies to date have lacked racial and ethnic diversity. In this review, we will (1) summarize current guideline recommendations and clinical outcome evidence related to CYP2C19 genotype-guided antiplatelet therapy, (2) evaluate the presence of potential racial and ethnic disparities in the major outcome studies supporting current genotype-guided antiplatelet therapy recommendations, and (3) identify remaining knowledge gaps and future research directions necessary to advance implementation of this precision medicine strategy for dual antiplatelet therapy in diverse, real-world clinical settings.

Precision medicine in interventional cardiology: implications for antiplatelet therapy in patients undergoing percutaneous coronary intervention

Precision medicine is a medical model that proposes the customization of medical treatments to the individual patient, as opposed to a one-drug-fits-all model. Such a "personalized medicine" approach has been widely adopted in several medical fields, such as cancer medicine, but the implementation of precision medicine in cardiovascular medicine has not been similarly straightforward. Because pharmacogenomics plays an important role in the safety and efficacy of cardiovascular drug therapy, there has been a great interest in the use of tools aiming at personalizing antiplatelet therapy. Moreover, antiplatelet therapy is essential for the treatment of cardiovascular patients to reduce the risk of thrombotic complications, particularly those undergoing percutaneous coronary intervention, but it is inevitably associated with increased bleeding risk. In this review, the authors discuss the rationale, summarize the evidence and discuss the current and future directions for the personalization of antiplatelet treatment regimens in patients undergoing percutaneous coronary intervention.