Application of Age, Body Mass Index, Chronic Kidney Disease, Diabetes, and Genotyping Score for Efficacy of Clopidogrel: Secondary Analysis of the CHANCE Trial

The pharmacology of antiplatelet agents for primary, secondary, and tertiary prevention of ischemic stroke

INTRODUCTION

Ischemic etiology accounts for two thirds of all strokes in which platelet activation and aggregation play a major role. A variety of antiplatelet therapies have been tested for primary, secondary, and tertiary prevention, with certain patient subtypes benefiting more than others from a specific regimen.

AREAS COVERED

This review aims at synthetizing current evidence on pharmacology of antiplatelet agents approved for primary, secondary, and tertiary stroke prevention and their application among possible patient subtypes that may benefit more from their administration.

EXPERT OPINION

Management of ischemic stroke has largely evolved over the past decades. A better understanding of stroke pathophysiology has allowed to identify patients who can benefit most from antiplatelet therapies, with varying degrees of benefit depending on whether these agents are being used for primary, secondary, or tertiary prevention. Importantly, the antiplatelet treatment regimens currently available have expanded and no longer limited to aspirin but include other drugs such as P2Y12 and phosphodiesterase inhibitors, also used in combination, as well as precision medicine approaches using genetic testing aiming at optimizing the safety and efficacy in this population.

Utility of the ACD-GENE-CLI Score in Asian Patients with Critical Limb Ischemia Undergoing Endovascular Interventions

AIMS

Critical limb ischemia (CLI) is an emerging public health threat and lacks a reliable score for predicting the outcomes. The Age, Body Mass Index, Chronic Kidney Disease, Diabetes, and Genotyping (ABCD-GENE) risk score helps identify patients with coronary artery disease who have cytochrome P450 2C19 (CYP2C19) polymorphism-related drug resistance and are at risk for cardiovascular adverse events. However, its application to CLI remains unknown. In this study, we aim to validate a modified ACD-GENE-CLI score to improve the prediction of major adverse limb events (MALEs) in patients with CLI receiving clopidogrel.

METHODS

Patients with CLI receiving clopidogrel post-endovascular intervention were enrolled prospectively in two medical centers. Amputation and revascularization as MALEs were regarded as the outcomes.

RESULTS

A total of 473 patients were recruited, with a mean follow-up duration of 25 months. Except for obesity, old age, diabetes, chronic kidney disease (CKD), and CYP2C19 polymorphisms were significantly associated with MALEs. Using bootstrap regression analysis, we established a modified risk score (ACD-GENE-CLI) that included old age (≥ 65 years), diabetes, CKD, and CYP2C19 polymorphisms. At a cutoff value of 8, the ACD-GENE-CLI score was superior to the CYP2C19 deficiency only, and the conventional ABCD-GENE score in predicting MALEs (area under the curve: 0.69 vs. 0.59 vs. 0.67, p=0.01). The diagnostic ability of the ACD-GENE-CLI score was consistent in the external validation. Also, Kaplan-Meier curves showed that in CYP2C19 deficiency, the ABCD-GENE and ACD-GENE-CLI scores could all differentiate patients with CLI who are free from MALEs.

CONCLUSIONS

The modified ACD-GENE-CLI score could differentiate patients with CLI receiving clopidogrel who are at risk of MALEs. Further studies are required to generalize the utility of the score.

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.

Differential Impact of Clinical Factors for Predicting High Platelet Reactivity on Clinical Outcomes in Acute Myocardial Infarction Patients Treated With Clopidogrel and Prasugrel

AIMS

Several scoring systems, including the ABCD-GENE and HHD-GENE scores incorporating clinical and genetic factors, have been developed to identify patients likely to have high platelet reactivity on P2Y12 inhibitors, leading to increased risks of ischemic events. However, genetic testing is not widely available in daily practice. We aimed to evaluate the differential impact of clinical factors in the scores on ischemic outcomes in patients treated with clopidogrel and prasugrel.

METHODS

This bi-center registry included 789 patients with acute myocardial infarction (MI) undergoing percutaneous coronary intervention and treated with either clopidogrel or prasugrel at discharge. The relations of the number of clinical factors included in the ABCD-GENE (age ≥ 75 years, body mass index ＞30 kg/m2, chronic kidney disease, and diabetes) and HHD-GENE (hypertension, hemodialysis, and diabetes) scores to the primary endpoint of major cardiovascular events after discharge, a composite of death, recurrent MI, and ischemic stroke, were evaluated.

RESULTS

The number of clinical factors in the ABCD-GENE score was not predictive of ischemic outcomes after discharge in patients treated with clopidogrel and/or prasugrel, while the increase in the number of clinical factors of the HHD-GENE score was associated with an increased risk of the primary endpoint in a stepwise manner in patients on a P2Y12 inhibitor.

CONCLUSIONS

Clinical factors listed in the HHD-GENE score may help stratify ischemic risks in patients with acute MI treated with clopidogrel and prasugrel, whereas risk stratification without genetic testing in patients treated with clopidogrel may be challenging.

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.

Impact of CYP2C19 Genotype on Efficacy and Safety of Clopidogrel-based Antiplatelet Therapy in Stroke or Transient Ischemic Attack Patients: An Updated Systematic Review and Meta-analysis of Non-East Asian Studies

PURPOSE

Inconclusive and limited results have been reported on the clinical utility of CYP2C19 genotyping in stroke/TIA patients of non-East Asian ancestries. We herein performed an updated systematic review and meta-analysis to quantitatively estimate the association of CYP2C19 loss-of function (LOF) status with efficacy and safety of clopidogrel-based antiplatelet therapy in non-East Asian patients affected by stroke or TIA.

METHODS

A comprehensive search was performed up to July 2023 using PubMed, Web of Knowledge, and Cochrane Library databases. The clinical outcomes investigated were stroke, composite vascular events and bleeding. Pooled estimates were calculated as risk ratios (RR) with 95% CI using the Mantel- Haenszel random-effects model. The quality of evidence was assessed using the GRADEpro tool.

RESULTS

A total number of 1673 stroke/TIA patients from 8 non-East Asian studies, published between 2014 and 2022, were included in the systematic review. Clopidogrel-treated carriers of CYP2C19 LOF alleles were found at increased risk of stroke compared to non-carriers (RR: 1.68, 95%CI: 1.04-2.71, P = 0.03). However, no significant association was observed with the risk of composite vascular events (RR: 1.15, 95%CI: 0.58-2.28, P = 0.69) or bleeding (RR: 0.84, 95%CI: 0.38-1.86, P = 0.67). Similarly, European ancestry patients carrying CYP2C19 LOF alleles displayed a higher risk of stroke (RR: 2.69 (1.11-6.51, P = 0.03), but not of composite vascular events or bleeding.

CONCLUSION

The present updated meta-analysis provides moderate quality evidence of association between CYP2C19 LOF alleles and an increased risk of stroke in non-East Asian patients with stroke/TIA after receiving clopidogrel therapy. Further large pharmacogenetic studies are still warranted to corroborate these findings.

The ABCD-GENE score influences vascular event rates in both users of clopidogrel and aspirin, as well as non-users of either drug in a population-based cohort study

Background and Objectives

Clopidogrel is an antiplatelet used in both primary and secondary prevention of cardiovascular diseases. It is a prodrug, requiring CYP2C19 for its metabolism to the active metabolite. The ABCD-GENE score, combining clinical attributes (age, body mass index, chronic kidney disease, diabetes mellitus), with genetic information (presence of 1 or 2 loss of function (LOF) alleles in the CYP2C19 gene) has been shown to identify patients with higher risk of recurrent cardiovascular events in high-risk populations undergoing percutaneous coronary intervention. We aimed to determine if the ABCD-GENE score or LOF alleles were associated with an increased risk of vascular events among clopidogrel users in a general population.

Methods

We conducted a population based cohort study with UK Biobank's primary care prescription records to identify clopidogrel users. ABCD-GENE scores were calculated with closest available data from the first date of clopidogrel prescription. The number of LOF alleles present, and the clinical component ABCD, were separate exposures. The outcome of interest was a composite endpoint of vascular events comprised of myocardial infarction, ischemic stroke, and death due to either of these. We performed Cox proportional hazards models with clopidogrel as a time varying exposure to predict hazards of these outcomes. In order to determine the drug specificity of these exposures, the analyses were repeated in aspirin users, and in non-users of either aspirin or clopidogrel.

Results

Among 11,248 clopidogrel users, 3,365 (30%) developed a vascular event over a mean follow-up of 5.95±3.94 years. ABCD-GENE score ≥10 was associated with an increased risk of vascular events (HR 1.13, 95% CI 1.03-1.23). In aspirin users, and in non-users of either aspirin or clopidogrel, the ABCD-GENE score was also associated with increased risk of vascular events. In clopidogrel users, aspirin users, and non-users of either drug, the ABCD score was associated with increased risk of vascular events. The presence of two CYP2C19 LOF alleles was associated with an increased risk of vascular events in aspirin and non-users but not in clopidogrel users.

Discussion

In this population-based cohort study, the ABCD-GENE score was associated with an increased risk of vascular events in clopidogrel users, aspirin users, and in non-users of either drug. The clinical component, ABCD was also associated with an increased risk of vascular events in all three groups. This suggests that the ABCD-GENE score is not specific to clopidogrel users in identifying persons at high risk of vascular events in a general sample with low baseline CYP2C19 LOF allele frequency.

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.

Performance of the ABCD-GENE Score for Predicting Clinical Outcomes in Clopidogrel-Treated Patients with ACS

The ABCD-GENE score was constructed to identify patients with high platelet reactivity (HPR) after 30 days of clopidogrel treatment. In our study, 1297 eligible patients with acute coronary syndrome (ACS) were included, and 44 (3.4%) major adverse cardiovascular events (MACEs) occurred during the 12-month clopidogrel treatment. The score with a cutoff of ≥ 10 was independently associated with the risk of 5-day HPR (adjusted HR: 1.73, 95% CI: 1.09-2.74, P = 0.020) and MACEs (adjusted HR: 2.25, 95% CI: 1.19-4.25, P = 0.013). The risk of MACEs increased when the multivariable model with the score (≥ 10) plus 5-day HPR was used (adjusted HR: 4.37, 95% CI: 1.90-10.10, P = 0.001). The c-statistic for MACEs was 0.60 when using the score threshold of ≥ 10 and 0.63 when using the model with the score plus 5-day HPR. As a simple tool, the ABCD-GENE score could identify clopidogrel-treated Chinese patients with ACS who are at increased risk of MACEs. The addition of 5-day HPR could slightly improve the diagnostic ability of the score.

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.

Impact of the ABCD-GENE Score on Clopidogrel Clinical Effectiveness after PCI: A Multi-Site, Real-World Investigation

The Age, Body mass index, Chronic kidney disease, Diabetes mellitus, and CYP2C19 GENEtic variants (ABCD-GENE) score was developed to identify patients at risk for diminished antiplatelet effects with clopidogrel after percutaneous coronary intervention (PCI). The objective of this study was to validate the ability of the ABCD-GENE score to predict the risk for atherothrombotic events in a diverse, real-world population of clopidogrel-treated patients who underwent PCI and received clinical CYP2C19 genotyping to guide antiplatelet therapy. A total of 2,341 adult patients who underwent PCI, were genotyped for CYP2C19, and received treatment with clopidogrel across four institutions were included (mean age 64 ± 12 years, 35% women, and 20% Black). The primary outcome was major atherothrombotic events, defined as the composite of all-cause death, myocardial infarction, ischemic stroke, stent thrombosis, or revascularization for unstable angina within 12 months following PCI. Major adverse cardiovascular events (MACE), defined as the composite of cardiovascular death, myocardial infarction, ischemic stroke, or stent thrombosis, was assessed as the secondary outcome. Outcomes were compared between patients with an ABCD-GENE score ≥ 10 vs. < 10. The risk of major atherothrombotic events was higher in patients with an ABCD-GENE score ≥ 10 (n = 505) vs. < 10 (n = 1,836; 24.6 vs. 14.7 events per 100 patient-years, adjusted hazard ratio (HR) 1.66, 95% confidence interval (CI), 1.23-2.25, P < 0.001). The risk for MACE was also higher among patients with a score ≥ 10 vs. < 10 (16.7 vs. 10.1 events per 100 patient-years, adjusted HR 1.59, 95% CI 1.11-2.30, P = 0.013). Our diverse, real-world data demonstrate diminished clopidogrel effectiveness in post-PCI patients with an ABCD-GENE score ≥ 10.