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.

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

BACKGROUND

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

METHODS AND RESULTS

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

CONCLUSIONS

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

Prevalence of CYP2C19*2 and CYP2C19*3 Allelic Variants and Clopidogrel Use in Patients with Cardiovascular Disease in Trinidad & Tobago

INTRODUCTION

Trinidad & Tobago has the highest prevalence of cardiovascular disease (CVD) in the Caribbean and clopidogrel is a ubiquitously used treatment. Yet, the extent of genetically mediated clopidogrel resistance is unknown. To determine this, we investigated whether the association between CYP2C19*2 and CYP2C19*3 genetic variants and clopidogrel resistance holds, and calculated the frequencies of these in the Trinidadian CVD population.

METHODS

Demographic data, clinical data, and a saliva sample were collected under informed consent from 22 patients with CVD on dual anti-platelet therapy whose biochemical resistance to clopidogrel is known, and a further 162 patients accessing the main public CVD clinic in Trinidad and who are either currently being treated or are likely to be treated with clopidogrel. A polymerase chain reaction (PCR) and restriction enzyme digestion procedure was used to genotype each patient for the CYP2C19*2 and CYP2C19*3 allelic variants. Genotype was compared to known clopidogrel resistance in the 22 patients, and to disease status and clopidogrel usage in the larger cohort.

RESULTS

CYP2C19*2 genotype was concordant with clopidogrel resistance. CYP2C19*2 was detected in 61.1% (99/162) of patients and CYP2C19*3 was undetected. Clopidogrel was the most prescribed antiplatelet therapy (42%). A total of 120 people presented with coronary artery disease (CAD) and 52.5% of these (n = 63/120) are currently prescribed clopidogrel. 63.5% (40/63) of patients with CAD who are prescribed clopidogrel carry the CYP2C19*2 allele; ten homozygous and 30 heterozygous. Indian patients comprised 65% of the cohort and were four times more likely to carry the CYP2C19*2 allele than African patients.

CONCLUSIONS

A large proportion of Trinidadian patients with CVD who are prescribed or may be prescribed clopidogrel carry genetic variants associated with clopidogrel resistance. These results emphasize the clinical need for further investigation into whether CYP2C19*2 genotype should guide clopidogrel use for the cardiovascular disease population in Trinidad & Tobago. A slide deck is available for this article.

Cost-effectiveness analysis of CYP2C19 genotype-guided antiplatelet therapy for patients with acute minor ischemic stroke and high-risk transient ischemic attack in China

AIMS

The study aimed to estimate the cost-effectiveness of CYP2C19 genotype-guided antiplatelet therapy using cilostazol and ticagrelor as an alternative to clopidogrel, compared to conventional antiplatelet therapy with clopidogrel and aspirin.

METHODS

A 90-day decision tree and 30-year Markov model were employed to assess the costs and quality-adjusted life years (QALYs) of personalized antiplatelet therapy for patients with minor ischemic stroke and high-risk transient ischemic attack, compared to conventional antiplatelet therapy in the Chinese healthcare system. The primary outcome was the incremental cost-effectiveness ratio (ICER). The data sources included clinical trials, published literature, official documents and local prices. One-way sensitivity analysis and probabilistic sensitivity analysis were performed to confirm the robustness of the findings.

RESULTS

The base-case analysis indicated that the CYP2C19 genotype-guided antiplatelet strategy was cost-effective, and cilostazol group and ticagrelor group yielded an ICER of 3327.40 US dollars (USD)/QALY and 3426.92 USD/QALY, respectively, which were less than threshold. The one-way sensitivity analysis showed the results were robust, where the most sensitive parameter was the disability distribution in the modified Rankin scale 3-5. The probabilistic analysis showed that the CYP2C19 genotype-guided antiplatelet therapy with either cilostazol or ticagrelor was 100% cost-effective under the willingness-to-pay threshold.

CONCLUSIONS

CYP2C19 genotype-guided antiplatelet therapy using cilostazol and ticagrelor as an alternative to clopidogrel appeared to be more cost-effective than conventional antiplatelet therapy for acute minor ischemic stroke and high-risk transient ischemic attack patients over 30 years in China.

CYP2C19 Polymorphism in Ischemic Heart Disease Patients Taking Clopidogrel After Percutaneous Coronary Intervention in Egypt

BACKGROUND

Cardiovascular diseases (CVDs) are considered a leading cause of death worldwide. Allelic variation in the CYP2C19 gene leads to a dysfunctional enzyme, and patients with this loss-of-function allele will have an impaired clopidogrel metabolism, which eventually results in major adverse cardiovascular events (MACE). Ischemic heart disease patients (n = 102) who underwent percutaneous cardiac intervention (PCI) followed by clopidogrel were enrolled in the present study.

METHODS

The genetic variations in the CYP2C19 gene were identified using the TaqMan chemistry-based qPCR technique. Patients were followed up for 1 year to monitor MACE, and the correlations between the allelic variations in CYP2C19 and MACE were recorded.

RESULTS

During the follow-up, we reported 64 patients without MACE (29 with unstable angina (UA), 8 with myocadiac infarction (MI), 1 patient with non-STEMI, and 1 patient with ischemic dilated cardiomyopathy (IDC)). Genotyping of CYP2C19 in the patients who underwent PCI and were treated with clopidogrel revealed that 50 patients (49%) were normal metabolizers for clopidogrel with genotype CYP2C19*1/*1 and 52 patients (51%) were abnormal metabolizers, with genotypes CYP2C19*1/*2 (n = 15), CYP2C19*1/*3 (n = 1), CYP2C19*1/*17 (n = 35), and CYP2C19*2/*17 (n = 1). Demographic data indicated that age and residency were significantly associated with abnormal clopidogrel metabolism. Moreover, diabetes, hypertension, and cigarette smoking were significantly associated with the abnormal metabolism of clopidogrel. These data shed light on the inter-ethnic variation in metabolizing clopidogrel based on the CYP2C19 allelic distribution.

CONCLUSION

This study, along with other studies that address genotype variation of clopidogrel-metabolizing enzymes, might pave the way for further understanding of the pharmacogenetic background of CVD-related drugs.

Cost-effectiveness of CYP2C19-guided P2Y12 inhibitors in Veterans undergoing percutaneous coronary intervention for acute coronary syndromes

AIMS

CYP2C19-guided P2Y12 inhibitor selection can reduce cardiovascular (CV) events and bleeding in patients with acute coronary syndromes (ACSs) post-percutaneous coronary intervention (PCI). The 12-month cost-effectiveness of CYP2C19-guided P2Y12 inhibitor selection for Veterans post-ACS/PCI was evaluated from the Veterans Health Administration's (VHA) perspective.

METHODS AND RESULTS

Using average annualized PCI volumes and P2Y12 inhibitor use from VA data, a decision-analytic model simulated CYP2C19 testing vs. no testing outcomes in 2800 hypothetical Veterans receiving PY212 inhibitor for 12 months post-ACS/PCI (74% clopidogrel, 5% prasugrel, and 21% ticagrelor use at baseline without testing). CYP2C19 loss-of-function (LOF) carrier prevalence was 28%. Model inputs were from studies (bleeding/ischaemic events, CYP2C19-guided therapy effect, health state utilities, CYP2C19 LOF carrier prevalence) and VHA administrative data (costs of events, drugs, CYP2C19 testing; PCI volumes, and P2Y12 inhibitor prescriptions). The primary outcome was cost (2020 US${\$}$) per quality-adjusted life year (QALY) gained. Base-case scenarios, probabilistic sensitivity analyses, and scenario analyses were completed. CYP2C19-guided therapy resulted in 496 (24%) escalations (clopidogrel to prasugrel/ticagrelor) and 465 (65%) de-escalations (prasugrel/ticagrelor to clopidogrel). CYP2C19 testing averted 1 stroke, 27 myocardial infarctions, 8 CV-related deaths, and caused 3 bleeds. CYP2C19 testing (vs. no testing) was dominant in the base-case scenario (0.0027 QALYs gained, ${\$}$527 saved/person) and in 97.1% of simulations, making it cost-effective and high-value. In scenario analyses, de-escalation in conjunction with escalation is required for CYP2C19 testing to be cost-effective and high-value.

CONCLUSION

In Veterans post-ACS/PCI, CYP2C19-guided P2Y12 inhibitor selection can improve CV outcomes and lower costs for the VHA within 12 months of implementation.

Revascularization and Medical Therapy for Chronic Coronary Syndromes: Lessons Learnt from Recent Trials, a Literature Review

Stable coronary artery disease (CAD) has recently been replaced by a new entity described as chronic coronary syndrome (CCS). This new entity has been developed based on a better understanding of the pathogenesis, the clinical characteristics, and the morbi-mortality associated to this condition as part of the dynamic spectrum of CAD. This has significant implications in the clinical management of CCS patients, that ranges from lifestyle adaptation, medical therapy targeting all the elements contributing to CAD progression (i.e., platelet aggregation, coagulation, dyslipidaemia, and systemic inflammation), to invasive strategies (i.e., revascularization). CCS is the most frequent presentation of coronary artery disease which is the first cardiovascular disease worldwide. Medical therapy is the first line therapy for these patients; however, revascularization and especially percutaneous coronary intervention remains beneficial for some of them. European and American guidelines on myocardial revascularization were released in 2018 and 2021, respectively. These guidelines provide different scenarios to help physicians choose the optimal therapy for CCS patients. Recently, several trials focusing on CCS patients have been published. We sought to synthetize the place of revascularization in CCS patients according to the latest guidelines, the lessons learnt from recent trials on revascularization and medical therapy, and future perspectives.

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.

Implementation of pharmacogenomic clinical decision support for health systems: a cost-utility analysis

We constructed a cost-effectiveness model to assess the clinical and economic value of a CDS alert program that provides pharmacogenomic (PGx) testing results, compared to no alert program in acute coronary syndrome (ACS) and atrial fibrillation (AF), from a health system perspective. We defaulted that 20% of 500,000 health-system members between the ages of 55 and 65 received PGx testing for CYP2C19 (ACS-clopidogrel) and CYP2C9, CYP4F2 and VKORC1 (AF-warfarin) annually. Clinical events, costs, and quality-adjusted life years (QALYs) were calculated over 20 years with an annual discount rate of 3%. In total, 3169 alerts would be fired. The CDS alert program would help avoid 16 major clinical events and 6 deaths for ACS; and 2 clinical events and 0.9 deaths for AF. The incremental cost-effectiveness ratio was $39,477/QALY. A PGx-CDS alert program was cost-effective, under a willingness-to-pay threshold of $100,000/QALY gained, compared to no alert program.

A Japanese Dose of Prasugrel versus a Standard Dose of Clopidogrel in Patients with Acute Myocardial Infarction from the K-ACTIVE Registry

BACKGROUND

Dual antiplatelet therapy (DAPT) with aspirin plus P2Y12 inhibitor is used as a standard therapy for patients with acute myocardial infarction (AMI) treated with drug-eluting stents (DESs). In Japan, clopidogrel was the major P2Y12 inhibitor used for a decade until the new P2Y12 inhibitor, prasugrel, was introduced. Based on clinical studies considering Japanese features, the set dose for prasugrel was reduced to 20 mg as a loading dose (LD) and 3.75 mg as a maintenance dose (MD); these values are 60 and 10 mg, respectively, globally. Despite this dose discrepancy, little real-world clinical data regarding its efficacy and safety exist.

METHODS

From the K-ACTIVE registry, based on the DAPT regimen, patients were divided into a prasugrel group and a clopidogrel group. The ischemic event was a composite of cardiovascular death, non-fatal MI, and non-fatal stroke. The bleeding event was type 3 or 5 bleeding based on the Bleeding Academic Research Consortium (BARC) criteria.

RESULTS

Substantially more patients were prescribed prasugrel (n = 2786) than clopidogrel (n = 890). Clopidogrel tended to be selected over prasugrel in older patients with numerous comorbidities. Before adjustments were made, the cumulative incidence of ischemic events at 1 year was significantly greater in the clopidogrel group than in the prasugrel group (p = 0.007), while the cumulative incidence of bleeding events at 1 year was comparable between the groups (p = 0.131). After adjustments were made for the age, sex, body weight, creatine level, type of AMI, history of MI, approach site, oral anticoagulation therapy, presence of multivessel disease, Killip classification, and presence of intra-aortic balloon pumping, both ischemic and bleeding events became comparable between the groups.

CONCLUSION

A Japanese dose of prasugrel was commonly used in AMI patients in the real-world database. Both the prasugrel and clopidogrel groups showed comparable rates of 1 year ischemic and bleeding events.

Genotype-Guided Use of P2Y12 Inhibitors: A Review of Current State of the Art

The pharmacodynamics of the purinergic receptor type Y, subtype 12 (P2Y12) inhibitors has evolved. Our understanding of the metabolism of P2Y12 inhibitors has revealed polymorphisms that impact drug metabolism and antiplatelet efficacy, leading to genetic testing guided therapy. In addition, assays of platelet function and biochemistry have provided insight into our understanding of the efficacy of "antiplatelet" therapy, identifying patients with high or low platelet reactivity on P2Y12 therapy. Despite the data, the implementation of these testing modalities has not gained mainstream adoption across hospital systems. Given differences in potency between the three clinically available P2Y12 inhibitors, the balance between thrombotic and bleeding complications must be carefully considered, especially for the large proportion of patients at higher risk for bleeding. Here we review the current data for genetic and functional testing, risk assessment strategies, and guidelines for P2Y12 inhibitors guided therapy.

Increased frequency of CYP2C19 loss-of-function alleles in clopidogrel-treated patients with recurrent cerebral ischemia

AIM

Clopidogrel is used as secondary prevention after cerebral ischemia. Previous - mainly Asian - studies have shown that genetic variations in CYP2C19 are associated with an increased risk of recurrent stroke in clopidogrel-treated patients. Evidence on the impact of this drug-gene interaction in European neurology patients is currently limited. Aim of this study is to compare the prevalence of CYP2C19 loss-of-function (LoF) alleles in a population with recurrent cerebral ischemia to 2 reference groups from the same region.

METHODS

CYP2C19-genotyping (*2 and *3) was performed in clopidogrel-treated patients who presented with a recurrent ischemic stroke/TIA. Genotype distributions were compared with two reference groups; a cohort of consecutive patients who underwent elective coronary stent implantation and a cohort of healthy Dutch volunteers.

RESULTS

In total, 188 cases with a recurrent ischemic event were identified, of whom 38 (20.2%) with an early recurrent event (24 hours to 90 days after previous event). Among the total case group, 43.6% of the patients carried at least one CYP2C19 LoF allele, compared with 27.6% and 24.7% in respectively the cardiology and the healthy volunteers reference group (p<0.001 for both comparisons). Among the cases with an early recurrent event, 55.2% of patients were carriers of ≥ 1 CYP2C19 LoF allele (p<0.0001).

CONCLUSION

In this clopidogrel-treated population with recurrent cerebral ischemia the frequency of CYP2C19 LoF alleles was significantly higher than in reference groups, especially in early recurrent events. This study adds to the growing body of evidence that genotype-guided antiplatelet therapy could improve patient outcomes.

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

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

Applying Pharmacogenomic Guidelines to Combat Medical Care

Pharmacogenomics is a pillar of personalized medicine that has the potential to deliver optimized treatment in many medical settings. Military medicine in the deployed setting is unique and therefore warrants separate assessment pertaining to its potential capabilities and impact. Pharmacogenomics for United States Active Duty Service Members medical care in the deployed setting has not, to our knowledge, been previously reviewed. We present potential applications of pharmacogenomics to forward medical care through two comprehensive references for deployed medical care, the Tactical Combat Casualty Care Guidelines (TCCC) and Emergency War Surgery (EWS) fifth edition. All drugs within the deployment manuals, TCCC guidelines and EWS book, were identified and the list was cross-referenced to the Clinical Pharmacogenetics Implementation Consortium guidelines and genes-drugs interactions list as well as the Food and Drug Administration Table of Pharmacogenomics Biomarkers in Drug Labeling. Ten pharmacologic categories were identified, consisting of 15 drugs, along with the classes, aminogylcosides, beta-blockers, and volatile anesthetics. Drugs and pharmacogenomics liabilities were tabulated. Eight specific drugs or classes are expounded upon given the belief of the authors of their potential for impacting future treatment on the battlefield in the setting of prolonged field care. This review outlines several genes with liabilities in the prolonged field care setting and areas that may produce improved care with further study.

Comparative effects of guided vs. potent P2Y12 inhibitor therapy in acute coronary syndrome: a network meta-analysis of 61 898 patients from 15 randomized trials

AIMS

Guidelines recommend the use of potent P2Y12 inhibitors over clopidogrel for the reduction of ischaemic events in patients with acute coronary syndrome (ACS). However, this comes at the expense of increased bleeding. A guided selection of P2Y12 inhibiting therapy has the potential to overcome this limitation. We aimed at evaluating the comparative safety and efficacy of guided vs. routine selection of potent P2Y12 inhibiting therapy in patients with ACS.

METHODS AND RESULTS

We performed a network meta-analysis of randomized controlled trials (RCTs) comparing different oral P2Y12 inhibitors currently recommended for the treatment of patients with ACS (clopidogrel, prasugrel, and ticagrelor). RCTs including a guided approach (i.e. platelet function or genetic testing) vs. standard selection of P2Y12 inhibitors among patients with ACS were also included. Incidence rate ratios (IRR) and associated 95% confidence intervals (CIs) were estimated. P-scores were used to estimate hierarchies of efficacy and safety. The primary efficacy endpoint was major adverse cardiovascular events (MACE) and the primary safety endpoint was all bleeding. A total of 61 898 patients from 15 RCTs were included. Clopidogrel was used as reference treatment. A guided approach was the only strategy associated with reduced MACE (IRR: 0.80, 95% CI: 0.65-0.98) without any significant trade-off in all bleeding (IRR: 1.22, 95% CI: 0.96-1.55). A guided approach and prasugrel were associated with reduced myocardial infarction. A guided approach, prasugrel, and ticagrelor were associated with reduced stent thrombosis. Ticagrelor was also associated with reduced total and cardiovascular mortality. Prasugrel was associated with increased major bleeding. Prasugrel and ticagrelor were associated with increased minor bleeding. The incidence of stroke did not differ between treatments.

CONCLUSION

In patients with an ACS, compared with routine selection of potent P2Y12 inhibiting therapy (prasugrel or ticagrelor), a guided selection of P2Y12 inhibiting therapy is associated with the most favourable balance between safety and efficacy. These findings support a broader adoption of guided approach for the selection of P2Y12 inhibiting therapy in patients with ACS.

STUDY REGISTRATION NUMBER

This study is registered in PROSPERO (CRD42021258603).

KEY QUESTION

A guided selection of P2Y12 inhibiting therapy using platelet function or genetic testing improves outcomes among patients undergoing percutaneous coronary intervention. Nevertheless, the comparative safety and efficacy of a guided versus routine selection of potent P2Y12-inhibiting therapy in acute coronary syndrome has not been explored.

KEY FINDING

In a comprehensive network meta-analysis including the totality of available evidence and using clopidogrel as treatment reference, a guided approach was the only strategy associated with reduced major adverse cardiovascular events without any significant trade-off in bleeding. Prasugrel and ticagrelor increased bleeding and only ticagrelor reduced mortality.

TAKE HOME MESSAGE

A guided selection of P2Y12-inhibiting therapy represents the strategy associated with the most favourable balance between safety and efficacy. These findings support a broader adoption of guided P2Y12 inhibiting therapy in patients with acute coronary syndrome.

Genetic testing in patients undergoing percutaneous coronary intervention: rationale, evidence and practical recommendations

INTRODUCTION

Clopidogrel is the most frequently utilized P2Y12 inhibitor and is characterized by broad interindividual response variability resulting in impaired platelet inhibition and increased risk of thrombotic complications in a considerable number of patients. The potent P2Y12 inhibitors, prasugrel and ticagrelor, can overcome this limitation but at the expense of an increased risk of bleeding. Genetic variations of the cytochrome P450 (CYP) 2 C19 enzyme, a key determinant in clopidogrel metabolism, have been strongly associated with clopidogrel response profiles prompting investigations of genetic-guided selection of antiplatelet therapy.

AREAS COVERED

The present manuscript focuses on the rationale for the use of genetic testing to guide the selection of platelet P2Y12 inhibitors among patients undergoing percutaneous coronary intervention (PCI). Moreover, a comprehensive appraisal of the available evidence and practical recommendations is provided.

EXPERT COMMENTARY

Implementation of genetic testing as a strategy to guide the selection of therapy can result in escalation (i.e. switching to prasugrel or ticagrelor) or de-escalation (i.e. switching to clopidogrel) of P2Y12 inhibiting therapy. Most recent investigations support the clinical benefit of a genetic guided selection of antiplatelet therapy in patients undergo PCI. Integrating the results of genetic testing with clinical and procedural variables represents a promising strategy for a precision medicine approach for the selection of antiplatelet therapy among patients undergoing PCI.

P2Y12 inhibitors in neuroendovascular surgery: An opportunity for precision medicine

INTRODUCTION

Dual antiplatelet therapy (DAPT), primarily the combination of aspirin with a P2Y12 inhibitor, in patients undergoing intravascular stent or flow diverter placement remains the primary strategy to reduce device-related thromboembolic complications. However, selection, timing, and dosing of DAPT is critical and can be challenging given the existing significant inter- and intraindividual response variations to P2Y12 inhibitors.

METHODS

Assessment of indexed, peer-reviewed literature from 2000 to 2020 in interventional cardiology and neuroendovascular therapeutics with critical, peer-reviewed appraisal and extraction of evidence and strategies to utilize DAPT in cardio- and neurovascular patients with endoluminal devices.

RESULTS

Both geno- and phenotyping for DAPT are rapidly and conveniently available as point-of-care testing at a favorable cost-benefit ratio. Furthermore, systematic inclusion of a quantifying clinical risk score combined with an operator-linked, technical risk assessment for potential adverse events allows a more precise and individualized approach to new P2Y12 inhibitor therapy.

CONCLUSIONS

The latest evidence, primarily obtained from cardiovascular intervention trials, supports that combining patient pharmacogenetics with drug response monitoring, as part of an individually tailored, precision medicine approach, is both predictive and cost-effective in achieving and maintaining individual target platelet inhibition levels. Indirect evidence supports that this gain in optimizing drug responses translates to reducing main adverse events and overall treatment costs in patients undergoing DAPT after intracranial stent or flow diverting treatment.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Genotype-guided antiplatelet treatment versus conventional therapy: A systematic review and meta-analysis

AIM

This meta-analysis was carried out to explore if a personalized antiplatelet strategy based on genotyping is superior to conventional therapy.

METHODS

PubMed, Web of Science, EMBASE and the Cochrane Library were searched from the inception of each database to 5 May 2020. Studies reporting endpoints in genotype-guided treatment group and conventional treatment group were included. The endpoint results were presented as the risk ratio (RR), with 95% confidence interval (CI).

RESULTS

A total of 10 561 patients from 16 studies (eight randomized controlled trials [RCT] and eight cohort studies) were included in the meta-analysis. The rates of major adverse cardiovascular events (MACE), stent thrombosis and myocardial infarction (MI) were significantly lower in the genotype-guided group than in the conventional treatment group (RR 0.56, 95% CI 0.44-0.73, P < .0001; RR 0.40, 95% CI 0.24-0.67, P = .0005; RR 0.45, 95% CI 0.35-0.58, P < .00001, respectively). A significant difference was found between the two groups in major bleeding (RR 0.73, 95% CI 0.55-0.98, P = .04), which was not robust after sensitivity analysis.

CONCLUSION

Genotype-guided antiplatelet treatment could decrease the risk of MACE, stent thrombosis and MI in patients with coronary artery disease or undergoing percutaneous coronary intervention, without increasing the risk of bleeding over a long follow-up period. The decreased risk of efficacy outcomes was more obvious in cohort studies. Well-organized RCTs and clinical trials are required to verify the benefit of genotype-guided therapy.