Derivation, Validation, and Prognostic Utility of a Prediction Rule for Nonresponse to Clopidogrel

Derivation of a Novel Scoring System Predicting High Platelet Reactivity on Prasugrel in Patients with Coronary Artery Disease

AIMS

High platelet reactivity (HPR) has been associated with an increased risk of thrombotic events in patients undergoing percutaneous coronary intervention. HPR has been well examined in patients treated with clopidogrel; however, HPR on prasugrel is poorly investigated.

METHODS

Four prospective studies were pooled, in which platelet reactivity on prasugrel was measured using VerifyNow assay; genotyping of CYP2C19 was also performed. Factors associated with HPR on prasugrel were identified using multivariable analysis to develop a risk prediction model.

RESULTS

In total, 180 patients were examined in this study, of whom 51 (28%) had HPR on prasugrel. The multivariable analysis indicated that hypertension, diabetes, hemodialysis, and the number of CYP2C19 loss-of-function (LOF) alleles are significant factors for HPR on prasugrel. These four factors were then incorporated to develop the HHD-GENE score. The receiver operating characteristic curve analysis showed that the HHD-GENE score predicted HPR on prasugrel (area under the curve (AUC) 0.74, best cutoff value 5, p＜0.001). With the best cutoff value, patients with the HHD-GENE score ≥ 5 had a significantly increased risk of HPR on prasugrel than their counterpart (50% vs. 18%, p＜0.001).

CONCLUSIONS

The HHD-GENE score consisting of hypertension, diabetes, hemodialysis, and CYP2C19 LOF alleles may be useful in identifying patients on prasugrel who are at high risk for HPR. External validation is needed to define the clinical utility of this novel scoring system.

Escalation and De-Escalation of Antiplatelet Therapy after Acute Coronary Syndrome or PCI: Available Evidence and Implications for Practice

Dual antiplatelet therapy (DAPT) is the gold standard for the antithrombotic management of patients with an acute coronary syndrome (ACS) or undergoing percutaneous coronary intervention (PCI). Implementation of intensified or prolonged DAPT regimens has proven to lower the risk of ischemic events but at the expense of increased bleeding. Importantly, bleeding is a predictor of poor prognosis. Risk stratification and selection of tailored antiplatelet strategies to maximize the net clinical benefit in individual patients with ACS or undergoing PCI is therefore potentially beneficial. Recently, novel approaches including DAPT de-escalation or escalation have been proposed as possible alternatives to standard DAPT. These strategies, which are generally based on patient's risk profile, genetics, and/or platelet function have been proposed to offer more tailored treatments in patients with ACS or PCI, with the ultimate goal of providing adequate ischemic protection while mitigating the risk of bleeding. This review summarizes the available evidence on DAPT de-escalation or escalation (both guided and unguided) and discusses the practical implications of these strategies in the contemporary management of patients with ACS and/or undergoing PCI.

P2Y12 Inhibitor Monotherapy after Percutaneous Coronary Intervention

In patients with acute and chronic coronary artery disease undergoing percutaneous coronary intervention (PCI), dual antiplatelet therapy (DAPT) has been the cornerstone of pharmacotherapy for the past two decades. Although its antithrombotic benefit is well established, DAPT is associated with an increased risk of bleeding, which is independently associated with poor prognosis. The improvement of the safety profiles of drug-eluting stents has been critical in investigating and implementing shorter DAPT regimens. The introduction into clinical practice of newer generation oral P2Y₁₂ inhibitors such as prasugrel and ticagrelor, which provide more potent and predictable platelet inhibition, has questioned the paradigm of standard DAPT durations after coronary stenting. Over the last five years, several trials have assessed the safety and efficacy of P2Y₁₂ inhibitor monotherapy after a short course of DAPT in patients treated with PCI. Moreover, ongoing studies are testing the role of P2Y₁₂ inhibitor monotherapy immediately after PCI in selected patients. In this review, we provide up-to-date evidence on the efficacy and safety of P2Y₁₂ inhibitor monotherapy after a short period of DAPT compared to DAPT in patients undergoing PCI as well as outcomes associated with P2Y₁₂ inhibitor monotherapy compared to aspirin for long-term prevention.

Elevated serum C1q is an independent predictor of high residual platelet reactivity in CAD patients receiving clopidogrel therapy

Background

Inflammation increases the risk of thrombosis in coronary artery disease (CAD) patients and affects the antiplatelet efficacy of clopidogrel. C1q interacts with platelets to activate platelets and induce thrombosis by participating in and regulating the inflammatory response. Whether C1q affects adenosine diphosphate (ADP)-induced platelet reactivity during clopidogrel therapy was unclear and our study aimed to explore the issue.

Method

We enrolled 1,334 CAD patients receiving clopidogrel therapy and evaluated the association between C1q level and high residual platelet reactivity (HRPR) using logistic regression and restricted cubic spline (RCS). HRPR was defined as ADP-induced maximum amplitude (MA_ADP) > 47 mm plus ADP-induced platelet aggregation (ADP_i) < 50%.

Results

A total of 516 patients (38.7%) performed HRPR. The frequency of HRPR increases with the increase in C1q level (26.3%, 38.4%, 43.2%, and 46.7% for the 1st to 4th quartile of C1q). The result of multivariate logistic regression demonstrated elevated C1q as an independent predictor for HRPR (2^nd quartile: OR = 1.722, 95% CI 1.215–2.440; 3^rd quartile: OR = 2.015, 95% CI 1.413–2.874; 4^th quartile: OR = 2.362, 95% CI 1.631–3.421, compared to the 1st quartile). RCS depicted the nonlinear relationship between C1q and HRPR risk (p for non-linear < 0.05).

Conclusion

The current research is the first to explore the association of C1q and ADP-induced platelet reactivity and to demonstrate elevated C1q as an independent risk factor for HRPR in CAD patients during clopidogrel therapy.

Body mass index and efficacy and safety of ticagrelor versus prasugrel in patients with acute coronary syndromes

INTRODUCTION AND OBJECTIVES

The efficacy and safety of ticagrelor vs prasugrel in patients with acute coronary syndromes (ACS) according to body mass index (BMI) remain unstudied. We assessed the efficacy and safety of ticagrelor vs prasugrel in patients with ACS according to BMI.

METHODS

Patients (n=3987) were grouped into 3 categories: normal weight (BMI <25kg/m²; n=1084), overweight (BMI ≥ 25 to <30kg/m²; n=1890), and obesity (BMI ≥ 30kg/m²; n=1013). The primary efficacy endpoint was the 1 year incidence of all-cause death, myocardial infarction, or stroke. The secondary safety endpoint was the 1 year incidence of Bleeding Academic Research Consortium type 3 to 5 bleeding.

RESULTS

The primary endpoint occurred in 63 patients assigned to ticagrelor and 39 patients assigned to prasugrel in the normal weight group (11.7% vs 7.5%; HR, 1.62; 95%CI, 1.09-2.42; P=.018), 78 patients assigned to ticagrelor and 58 patients assigned to prasugrel in the overweight group (8.3% vs 6.2%; HR, 1.36; 95%CI, 0.97-1.91; P=.076), and 43 patients assigned to ticagrelor and 37 patients assigned to prasugrel in the obesity group (8.6% vs 7.3%; HR, 1.18; 95%CI, 0.76-1.84; P=.451). The 1-year incidence of bleeding events did not differ between ticagrelor and prasugrel in patients with normal weight (6.5% vs 6.6%; P=.990), overweight (5.6% vs 5.0%; P=.566) or obesity (4.4% vs 2.8%; P=.219). There was no significant treatment arm-by-BMI interaction regarding the primary endpoint (P_int=.578) or secondary endpoint (P_int=.596).

CONCLUSIONS

In patients with ACS, BMI did not significantly impact the treatment effect of ticagrelor vs prasugrel in terms of efficacy or safety.

CLINICAL TRIAL REGISTRATION

NCT01944800.

Impact of diabetes mellitus on the pharmacodynamic effects of prasugrel and ticagrelor after switching from clopidogrel in patients with coronary artery disease

Switching P2Y₁₂ inhibitors is common in clinical practice. However, data on the pharmacodynamic (PD) effects of switching in clinical settings characterized by high platelet reactivity, such as diabetes mellitus (DM), are limited. This is a post-hoc analysis from a prospective, randomized, open-label study conducted in coronary artery disease patients comparing the PD effects of loading dose (LD) and maintenance dose regimens of prasugrel vs ticagrelor according to DM status. A total of 110 patients were enrolled: 42 (38%) with DM and 68 (62%) without DM. All patients were on maintenance dual antiplatelet therapy with aspirin and clopidogrel. PD assessments were performed using whole blood vasodilator-stimulated phosphoprotein (VASP), with results quantified by the platelet reactivity index (PRI), VerifyNow P2Y12 (VN-P2Y12) with results reported as P2Y12 reaction units (PRU), and light transmittance aggregometry (LTA) following 20 and 5 µM adenosine diphosphate stimuli with results reported as maximum platelet aggregation (MPA). PD assessments were performed at baseline (while on clopidogrel), 30 min after LD, 2 h after LD, and 1 week after LD. Overall, platelet reactivity was higher in DM than in non-DM patients while on clopidogrel therapy. After switching to either prasugrel or ticagrelor, platelet reactivity dropped but remained significantly higher among patients with DM at 30 min with all tests (VN-PRU p < 0.01, MPA 20 µM p < 0.01, VASP-PRI p = 0.02) and at 2 h with VN-PRU (p < 0.01) and LTA-MPA 20 µM (p < 0.01) but not with VASP-PRI (p = 0.19). There were no significant differences between prasugrel and ticagrelor both among patients with or without DM, except for lower LTA-MPA 20 at 30 min (p < 0.01) among non-DM patients treated with prasugrel. Patients with DM treated with clopidogrel have higher platelet reactivity compared to patients without DM. Although platelet reactivity markedly reduces to a similar extent after switching to prasugrel or ticagrelor, patients with DM persist with increased platelet reactivity compared to patients without DM.Study registration: ClinicalTrials.gov identifier: NCT01852175.

De-escalation of antiplatelet therapy in acute coronary syndromes: Why, how and when?

The synergistic blockade of the key platelet signaling pathways of cyclooxygenase-1 blockade and P2Y12 signaling by combining aspirin plus a potent P2Y12 inhibitor (prasugrel or ticagrelor), the so called dual antiplatelet treatment (DAPT), has represented the antithrombotic regimen of choice in patients with acute coronary syndrome (ACS) for nearly a decade. Nevertheless, the use of such antiplatelet treatment regimen, while reduced the risk of thrombotic complications, it is inevitably associated with increased bleeding and this risk may outweigh the benefit of a reduction of ischemic events in specific subgroup of patients. In light of the adverse prognostic implications of a bleeding complication, there has been a great interest in the development of antiplatelet regimens aimed at reducing bleeding without any trade-off in ischemic events. The fact that the ischemic risk is highest in the early phase after an ACS while the risk of bleeding remains relatively stable over time has represented the rationale for the implementation of a more intense antithrombotic regimen early after an ACS, followed by a less intense antithrombotic regimen thereafter. This practice, known as a "de-escalation" strategy, represents one of the more promising approaches for personalization of antithrombotic therapy in ACS. In this review we discuss the rationale, appraise the evidence and provide practical recommendations on the use of a de-escalation strategy of antiplatelet therapy in patients with an ACS.

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.

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.

Differential Impact of Clinical and Genetic Factors on High Platelet Reactivity in Patients with Coronary Artery Disease Treated with Clopidogrel and Prasugrel

AIM

High platelet reactivity (HPR) is associated with increased risks of thrombotic events in patients with coronary artery disease. The recently developed ABCD-GENE score identified five clinical and genetic factors (age, body mass index, chronic kidney disease, diabetes, and the CYP2C19 loss-of-function allele) for HPR, although the significance of various stages of each factor is unclear.

METHODS

Four prospective studies were pooled, in which platelet reactivity was measured using the VerifyNow assay with clopidogrel and prasugrel; genotyping of CYP2C19 was also performed. Each component of the ABCD-GENE score was divided into three subcategories. VerifyNow P2Y12 reactivity units ＞208 were defined as HPR.

RESULTS

A total of 184 patients were included, of which 111 (60%) and 51 (28%) had HPR with clopidogrel and prasugrel. Chronic kidney disease had an impact on HPR on both clopidogrel and prasugrel, whereas the impact of diabetes was more evident in patients treated with prasugrel. Although the number of CYP2C19 loss-of-function alleles was clearly associated with a likelihood of HPR with clopidogrel, P2Y12 reactivity units with prasugrel treatment were also significantly and progressively higher in patients with more CYP2C19 loss-of-function alleles.

CONCLUSIONS

Clinical and genetic factors had a differential effect on a P2Y12 inhibitor reactivity with clopidogrel and prasugrel in patients with coronary artery disease. The severity of the factors also had a different impact on HPR.

P2Y12 inhibition by clopidogrel increases adverse clinical events after transcatheter aortic valve replacement

BACKGROUND

Dual antiplatelet therapy (DAPT) has been proposed to explain the increased occurrence of bleeding events after transcatheter aortic valve replacement (TAVR) despite no relevant study exploring the extent of platelet inhibition. In the present study, we sought to assess whether P2Y₁₂ inhibition by clopidogrel impacts clinical outcomes in TAVR patients.

METHODS

Patients were enrolled in a prospective registry at Nouvel Hôpital Civil, Strasbourg, France between February 2010 and May 2019. Vasodilator-stimulated phosphoprotein (VASP) flow cytometry test was assessed 24 h after the procedure. Responder to clopidogrel was defined by a platelet reactivity index ≤50%. The primary endpoint was 90-day major adverse cardiac and cerebrovascular events (MACCE), including all-cause death, myocardial infarction, stroke, and heart failure hospitalization.

RESULTS

Of the 828 patients with available VASP monitoring, 491 TAVR patients received preprocedural clopidogrel therapy. Responders were identified in 22% (n = 110) and low responders in 78% (n = 381) of patients. By multivariate Cox regression analysis, responders to clopidogrel (hazard ratio [HR]: 2.09; 95% confidence interval [CI]: 1.13 to 3.79: p = 0.02) and previous PCI (HR: 2.16; 95% CI: 1.02 to 4.68; p = 0.04) were identified as independent predictors of 90-day MACCE. The cumulative event-free survival rate at 90-day was significantly lower in the responder group (p = 0.008; log rank test).

CONCLUSIONS

In conclusion, appropriate P2Y₁₂ inhibition by clopidogrel is a major determinant of MACCE at 90 days after TAVR. The present data challenge DAPT as a standard therapy during TAVR.

Development and Validation of a Novel Tool for the Prediction of Clopidogrel Response in Chinese Acute Coronary Syndrome Patients: The GeneFA Score

Aim: Growing evidence indicated that CYP2C19 genotypes could only explain a fraction of the pharmacodynamic response to clopidogrel, while a number of clinical factors also have contributing roles. Our objective was to develop a new risk score to improve prognostication of ischemic events in Chinese patients treated with clopidogrel. Methods: A new risk score was developed and internally validated in 445 patients with acute coronary syndrome (ACS) undergoing coronary stenting. The final score was named the GeneFA score based on the inclusion of CYP2C19 genotype, fibrinogen, and age. External validation of the GeneFA score and comparison with the ABCD-GENE score were performed in an independent ACS cohort. Results: Based on the observed frequencies of high platelet reactivity (HRPR) in relation to the GeneFA risk score, a relatively higher clinical HRPR was observed in the upper quintile with a representative score of 3 (52.90%) and 4 (59.10%), whereas it was found less frequently in groups with scores 0 (6.70%), 1 (15.10%), and 2 (16.70%). Participants with a GeneFA score >2 had an increased risk of HRPR (54.3 vs. 14.7%, p < 0.001) and ischemic recurrence (20.7 vs. 5.4%, p < 0.001). The GeneFA score exhibited a better prediction for high HRPR patients as compared to the ABCD-GENE score (p < 0.001). In the validation population, GeneFA illustrated a similarly high prognostic value for HRPR incidence (C-statistic: 0.855 for GeneFA and 0.843 for ABCD-GENE) and ischemic recurrence (C-statistic: 0.726 for GeneFA and 0.724 for ABCD-GENE) on clopidogrel as compared to ABCD-GENE. Conclusion: The GeneFA risk score had a moderate predictive ability for HRPR on clopidogrel for CAD patients in Chinese populations. The predictive value of the GeneFA score was consistent with the ABCD-GENE score for HRPR identification.

Antiplatelet therapy after percutaneous coronary intervention

Antiplatelet therapy is key to reducing local thrombotic complications and systemic ischaemic events among patients undergoing percutaneous coronary interventions (PCI), but it is inevitably associated with increased bleeding. The continuous refinement in stent technologies, together with the high incidence of ischaemic recurrences after PCI and the understanding of prognostic implications associated with bleeding, have led to a substantial evolution in antiplatelet treatment regimens over the past decades. Numerous investigations have been conducted to better stratify patients undergoing PCI according to their ischaemic and bleeding risks and to implement antithrombotic regimens accordingly. Evidence from these investigations have resulted in a number of antithrombotic treatment options as recommended by recent guidelines. In this State-of-the-Art review we provide the rationale, summarise the evidence, and discuss current and future directions of antiplatelet treatment regimens after PCI.

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.

ABCD-GENE Score and Clinical Outcomes Following Percutaneous Coronary Intervention: Insights from the TAILOR-PCI Trial

Background In TAILOR-PCI, genotype-guided selection of P2Y₁₂ inhibitors after percutaneous coronary intervention did not significantly reduce the risk of ischemic events at 12 months. The Age, Body Mass Index, Chronic Kidney Disease, Diabetes, and Genotyping (ABCD-GENE) score identifies patients with high platelet reactivity on clopidogrel at increased risk of ischemic events. The aim of this study was to investigate the value of the ABCD-GENE score for tailoring P2Y₁₂ inhibitor selection after percutaneous coronary intervention. Methods and Results In a post hoc analysis of the TAILOR-PCI, outcomes were analyzed by ABCD-GENE score and allocation to genotype-guided or conventional P2Y₁₂ inhibitor selection. Primary (death, myocardial infarction, or stroke) and secondary (cardiovascular death, myocardial infarction, stroke, stent thrombosis, or severe recurrent ischemia) outcomes were assessed. Among 3883 patients discharged on clopidogrel in the genotype-guided and conventional therapy groups, 15.8% and 84.2% had high (≥10 points) or low (<10) ABCD-GENE scores, respectively. At 12 months, both the primary (5.2% versus 2.6%, P<0.001) and secondary outcomes (7.7% versus 4.6%, P=0.001) were significantly increased in patients with high ABCD-GENE score. Among 4714 patients allocated to genotype-guided or conventional therapy, the former did not significantly reduce the 12-month risk of the primary and secondary outcomes in both the high and low ABCD-GENE score groups (p_interaction=0.48 and 0.27, respectively). Conclusions Among patients with percutaneous coronary intervention on clopidogrel, the ABCD-GENE score was helpful in identifying those at higher risk. The ABCD-GENE score may potentially enhance the precision of tailored selection of P2Y₁₂ inhibitors, which needs to be confirmed in prospective investigations. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique Identifier: NCT01742117.

Role of platelet function and genetic testing in patients undergoing percutaneous coronary intervention

Dual antiplatelet therapy (DAPT) represents the standard of care for patients undergoing percutaneous coronary intervention (PCI). Increasing evidence indicates that a "one-size-fits-all" approach with the use of a standard DAPT regimen for all patients undergoing PCI could lead to either suboptimal efficacy or prohibitively high bleeding in specific cohorts of patients. Moreover, the broad interindividual variability in response to P2Y₁₂ inhibitors can impact outcomes and resource utilization. Among the strategies proposed to provide a more balanced trade-off between bleeding and ischemic events at a single patient level, a guided selection of P2Y₁₂ inhibitors, by using platelet function or genetic testing, has shown promising results. In this review, we provide a focused summary of the rationale and evidence on the use of platelet function and genetic testing-guided antiplatelet therapy, and we explore the implications for their use in the modern setting of patients undergoing PCI.

Clopidogrel monotherapy in patients with and without on-treatment high platelet reactivity: a SMART-CHOICE substudy

BACKGROUND

Although P2Y12 inhibitor monotherapy has emerged as a promising alternative for dual antiplatelet therapy (DAPT), there remains concern regarding the safety of clopidogrel monotherapy.

AIMS

We sought to investigate clinical outcomes of clopidogrel monotherapy in patients with and without on-treatment high platelet reactivity (HPR).

METHODS

In the SMART-CHOICE study, three-month DAPT followed by P2Y12 inhibitor monotherapy was compared with 12-month DAPT in patients undergoing percutaneous coronary intervention. A platelet function test was performed for 833 patients with clopidogrel-based therapy. The primary endpoint was major adverse cardiovascular and cerebrovascular events (MACCE: a composite of all-cause death, myocardial infarction, or stroke) at 12 months.

RESULTS

Overall, 108 (13.0%) patients had HPR on clopidogrel. Patients with HPR had a significantly higher rate of MACCE than patients without HPR (8.7% vs 1.5%, adjusted HR 3.036, 95% CI: 1.060-8.693, p=0.038). The treatment effect of clopidogrel monotherapy for the 12-month MACCE was not significantly different compared with DAPT among patients with HPR (8.0% vs 9.4%, adjusted HR 0.718, 95% CI: 0.189-2.737, p=0.628) and without HPR (2.2% vs 0.9%, adjusted HR 2.587, 95% CI: 0.684-9.779, p=0.161; adjusted p for interaction=0.170).

CONCLUSIONS

Clopidogrel monotherapy showed treatment effects comparable to DAPT for MACCE in patients with or without HPR. However, HPR was significantly associated with an increased risk of MACCE in clopidogrel-treated patients regardless of maintenance of aspirin.

CLINICAL TRIAL REGISTRATION

Comparison Between P2Y12 Antagonist Monotherapy and Dual Antiplatelet Therapy After DES (SMART-CHOICE) (ClinicalTrials.gov: NCT02079194).

Impact of Pancreatic β-Cell Function on Clopidogrel Responsiveness and Outcomes in Chinese Nondiabetic Patients Undergoing Elective Percutaneous Coronary Intervention

PURPOSE

Insulin resistance and β-cell dysfunction are fundamental defects contributing to type 2 diabetes development. Prior studies indicated that insulin resistance may be correlated with low responsiveness to clopidogrel. This study aimed to investigate the effects of β-cell function on clopidogrel-induced platelet P2Y12 inhibition and the clinical outcomes of nondiabetic patients undergoing elective percutaneous coronary intervention (PCI).

METHODS

Patients scheduled to undergo elective PCI and receive clopidogrel in addition to aspirin were recruited for this study. Homeostatic model assessment 2 of β-cell function (HOMA2-β%) was used to classify participants into quartiles. Thromboelastography (TEG) was used to calculate the quantitative platelet inhibition rate to assess clopidogrel-induced antiplatelet reactivity. The clinical outcome was major adverse cardiovascular and cerebrovascular events (MACCEs).

RESULTS

Of the 784 participants evaluated, 21.3% of them (169 of 784) had low responsiveness to clopidogrel. According to multivariate linear regression analysis, the first quartile of HOMA2-β% (19.9-78.1), indicating greater β-cell dysfunction, was independently associated with low responsiveness to clopidogrel compared with the fourth quartile (126.8-326.2) after adjustment for potential covariates [odds ratio 2.140, 95% confidence interval (CI) (1.336 to 3.570), P = 0.038]. In addition, at one year, the first quartile of HOMA2-β% was associated with an increased risk of 1-year MACCE occurrence compared with the fourth quartile [adjusted hazard ratio 4.989, 95% CI (1.571 to 15.845), P = 0.006].

CONCLUSION

Increased β-cell dysfunction, indicated by a low HOMA2-β%, was associated with low responsiveness to clopidogrel and an increased risk of one-year MACCEs in nondiabetic patients undergoing elective PCI.

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

BACKGROUND AND PURPOSE

The age, body mass index, chronic kidney disease, diabetes, and genotyping (ABCD-GENE) score is a validated risk score integrating CYP2C19 genotypes with clinical risk factors influencing clopidogrel response that would allow the more precise identification of subjects at risk for high platelet reactivity and adverse clinical outcomes. Our objective was to further verify application of the ABCD-GENE score and investigate appropriate cutoff value in patients with minor stroke or transient ischemic attack.

METHODS

In this post-analysis of the CHANCE trial (Clopidogrel in High-Risk Patients With Acute Nondisabling Cerebrovascular Events), the ABCD-GENE score was calculated for all patients enrolled in this study. By using the proposed cutoff of 10, patients were stratified as being at high risk for high platelet reactivity or not. We further categorized the ABCD-GENE score to 0 to 5, 6 to 24, and >24 to investigate the cutoff value of this scale in clinical application. Stroke recurrence at 3 months was considered as the primary outcome.

RESULTS

Among a total of 2923 patients with minor stroke/transient ischemic attack, there were 2273 (77.76%) with ABCD-GENE score <10 and 650 (22.24%) patients with ABCD-GENE score ≥10. Compared with the aspirin alone, hazard ratios (95% CIs) of the clopidogrel-aspirin therapy for stroke recurrence were 0.70 (0.54-0.91) and 0.76 (0.46-1.24), among patients of ABCD-GENE scores <10 and ABCD-GENE scores ≥10, respectively. Stratified analyses by ABCD-GENE score 0 to 5, 6 to 24, and >24, hazard ratios of the clopidogrel-aspirin therapy for stroke recurrence were 0.57 (95% CI, 0.38-0.85), 0.78 (0.58-1.06), and 1.20 (0.44-3.28) (P value for trend=0.0052).

CONCLUSIONS

Among Chinese minor stroke/transient ischemic attack population, the efficacy of clopidogrel-aspirin therapy was decreased in patients with higher ABCD-GENE score. Our study suggests that CYP2C19 genotypes and clinical risk factors can be integrated by ABCD-GENE score to estimate the efficacy of clopidogrel-aspirin therapy.

Pharmacogenetics to guide cardiovascular drug therapy

Over the past decade, pharmacogenetic testing has emerged in clinical practice to guide selected cardiovascular therapies. The most common implementation in practice is CYP2C19 genotyping to predict clopidogrel response and assist in selecting antiplatelet therapy after percutaneous coronary intervention. Additional examples include genotyping to guide warfarin dosing and statin prescribing. Increasing evidence exists on outcomes with genotype-guided cardiovascular therapies from multiple randomized controlled trials and observational studies. Pharmacogenetic evidence is accumulating for additional cardiovascular medications. However, data for many of these medications are not yet sufficient to support the use of genotyping for drug prescribing. Ultimately, pharmacogenetics might provide a means to individualize drug regimens for complex diseases such as heart failure, in which the treatment armamentarium includes a growing list of medications shown to reduce morbidity and mortality. However, sophisticated analytical approaches are likely to be necessary to dissect the genetic underpinnings of responses to drug combinations. In this Review, we examine the evidence supporting pharmacogenetic testing in cardiovascular medicine, including that available from several clinical trials. In addition, we describe guidelines that support the use of cardiovascular pharmacogenetics, provide examples of clinical implementation of genotype-guided cardiovascular therapies and discuss opportunities for future growth of the field.

Guided and unguided de-escalation from potent P2Y12 inhibitors among patients with ACS: a meta-analysis

AIM

Optimal dual antiplatelet therapy (DAPT) in patients undergoing percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS) intends to balance ischemic and bleeding risks. Various DAPT de-escalation strategies, defined as switching from a full-dose potent to a reduced dose or less potent P2Y12 inhibitor, have been evaluated in several ACS-PCI trials. We aimed to compare DAPT de-escalation to standard DAPT with full dose potent P2Y12 inhibitors in ACS patients who underwent PCI.

METHODS & RESULTS

PubMed, Google Scholar and Cochrane Central Register of Controlled Trials were searched for eligible randomised controlled trials. Aspirin monotherapy trials were excluded. Five randomised trials (n = 10,779 patients) that assigned DAPT de-escalation (genetically guided to clopidogrel n = 1,242; platelet function guided to clopidogrel n = 1,304; unguided to clopidogrel n = 1,672; unguided to lower dose n = 1,170) versus standard DAPT (control group n = 5,391) were included in this analysis. DAPT de-escalation was associated with a significant reduction in Bleeding Academic Research Consortium ≥ 2 bleeding (HR 0.57, 95% CI 0.42-0.78; I2 = 77%) as well as major adverse cardiac events, represented in most trials by the composite of cardiovascular mortality, myocardial infarction, stent thrombosis and stroke (HR 0.77, 95% CI 0.62-0.96; I2 = 0%). Notwithstanding the limited power, consistency was noted across various de-escalation strategies.

CONCLUSION

De-escalation of DAPT after PCI for ACS, both unguided and guided by genetic or platelet function testing, was associated with lower rates of clinically relevant bleeding and ischemic events as compared to standard DAPT with potent P2Y12 inhibitors based on five open-label RCTs reviewed.

Clopidogrel versus Ticagrelor in CYP2C19 Loss-of-Function Allele Noncarriers: A Real-World Study in China

OBJECTIVE

 This article compares the clinical outcomes of clopidogrel and ticagrelor in patients with acute coronary syndrome (ACS) without cytochrome P450 (CYP)2C19 loss-of-function (LOF) alleles and investigates whether clopidogrel could be an alternative P2Y12 inhibitor without increasing the risk of ischemic events.

METHODS

 Patients were divided into the clopidogrel-treated group and the ticagrelor-treated group. Inverse probability of treatment weighting (IPTW) calculated by propensity scores was used to adjust confounding covariates. The primary outcome was major adverse cardiovascular or cerebrovascular events (MACCEs) within 12 months. The secondary outcomes were MACCEs plus unstable angina, and clinically significant bleeding events.

RESULTS

 Finally, 2,199 patients were included. Of them, 1,606 were treated with clopidogrel, and 593 were treated with ticagrelor. The mean age of the original cohort was 59.92 ± 9.81 years. During the 12-month follow-up period, MACCEs occurred in 89 patients (4.0%). No significant differences were observed in MACCEs (IPTW-adjusted hazard ratio [HR], 0.87; 95% confidence interval [CI], 0.65-1.18), MACCEs plus unstable angina (IPTW-adjusted HR, 1.20; 95% CI, 0.91-1.59), or clinically significant bleeding events (IPTW-adjusted HR, 0.81; 95% CI, 0.53-1.23) between the clopidogrel- and ticagrelor-treated groups.

CONCLUSION

 In patients with ACS without CYP2C19 LOF alleles, clopidogrel was not associated with a higher risk of MACCEs when compared with ticagrelor. The main findings of this study support use of clopidogrel in CYP2C19 LOF noncarriers as an alternative P2Y12 inhibitor, which may reduce medical expenses and adverse reactions caused by more potent P2Y12 inhibitors in these patients.

CYP2C19 genotype has prognostic value in specific populations following coronary stenting

Background

The prognostic value of the CYP2C19 genotype in post-percutaneous coronary intervention (PCI) patients remains controversial. The recently-published, limited-sample PHARMCLO trial indicates a personalized pharmacogenomic approach may reduce adverse events. This study aimed to determine the prognostic value of CYP2C19 genotypes.

Methods

The original cohort consisted of 10,724 PCI patients in 2013. 756 patients with genotyped CYP2C19 were included in our analysis. The CYP2C19 genotype prognostic value was tested based on different clinical factors. The primary endpoint was major adverse cardio- and cerebro-vascular event (MACCE).

Results

MACCE 2-years post-PCI occurred in 19 patients (17.4%) in poor metabolizers (PM, CYP2C19 *2/*2, *2/*3, *3/*3), 43 patients (12.2%) in intermediate metabolizers (IM, CYP2C19 *1/*2 or *1/*3) and 27 patients (9.2%) in extensive metabolizers (EM, CYP2C19 *1/*1). PM was an independent MACCE predictor compared with EM (HR: 1.960, 95% CI: 1.139–3.372), but the difference between IM and PM was not significant (HR: 1.314, 95% CI: 0.843–2.048). Major bleeding (BARC grade ≥3) was not significantly different between the three groups (2.5% vs. 2.1% vs. 0.8%, P=0.133). Subgroup analysis showed that the CYP2C19 genotype prognostic value was present in the following subgroups: male, age >60 years, body mass index (BMI) >24 kg/m², SYNTAX score >15, current smokers, and patients without chronic kidney disease.

Conclusions

Utilizing CYP2C19 genotype to guide post-PCI antiplatelet therapy might be appropriate in patients with the following characteristics: male, age >60 years, BMI >24 kg/m², SYNTAX score >15, current smokers, and non-chronic kidney disease (CKD) patients.

Platelet Function Testing and Genotyping for Tailoring Treatment in Complex PCI Patients

Dual antiplatelet therapy (DAPT), comprising aspirin and a P2Y12 receptor inhibitor, is considered the cornerstone of treatment in patients who have undergone percutaneous coronary intervention (PCI). Patients with complex PCI (C-PCI) constitute a special PCI subpopulation, characterized by increased ischemic risk. Identifying the optimal DAPT strategy is often challenging and remains controversial in this setting. In an attempt to balance ischemic and bleeding risks in C-PCI patients receiving DAPT, treatment individualization regarding potency and duration has evolved as a feasible approach. Platelet function testing and genotyping have been evaluated in several trials with conflicting and mostly neutral results. The aim of this review is to critically appreciate the role of these tools for antiplatelet treatment tailoring specifically in C-PCI patients. Because existing evidence is limited, dedicated future studies are warranted to elucidate the utility of platelet function testing and genotyping in C-PCI.

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.

Ticagrelor or Clopidogrel After an Acute Coronary Syndrome in the Elderly: A Propensity Score Matching Analysis from 16,653 Patients Treated with PCI Included in Two Large Multinational Registries

PURPOSE

Higher risk of bleeding with ticagrelor over clopidogrel in elderly patients with acute coronary syndrome (ACS) who underwent percutaneous coronary intervention (PCI) has been suggested. We assessed the incidence of major bleedings (MB), reinfarction (re-MI), and all-cause death to evaluate safety and efficacy of ticagrelor versus clopidogrel in such population.

METHODS

Real-world registries RENAMI and BleeMACS were merged. The pooled cohort was divided into two groups, clopidogrel versus ticagrelor. Statistical analysis considered patients <75 versus ≥75 years old. Endpoints were BARC 3-5 MB, re-MI, and all-cause death at 1-year follow-up. The study included 16,653 patients (13,153 < 75 and 3500 ≥ 75 years). Ticagrelor was underused in elderly patients (16.3% versus 20.8%, P < 0.001). Using propensity score matching (PSM), two treatment groups of 1566 patients were included in the final analysis.

RESULTS

Ticagrelor was able to prevent re-MI (hazard ratio [HR], 0.31; 95% confidence interval [CI], 0.2-0.6; P < 0.001) and all-cause death (HR, 0.60; 95% CI, 0.4-0.9; P = 0.026) irrespective of age. In patients ≥75 years, ticagrelor reduced all-cause death (HR, 0.32; 95% CI, 0.1-0.8; P = 0.012) and re-MI (HR, 0.25; 95% CI, 0.1-1.1, P = 0.072). Moreover, even with the limit of the low number of events, ticagrelor did not significantly increase the incidence of MB (HR, 1.49; 95% CI, 0.70-3.0; P = 0.257). At multiple Cox regression, age (HR, 1.03; 95% CI, 1.02-1.05; P < 0.001) resulted an independent risk factor for bleeding.

CONCLUSION

In our study, reflecting the results from two large retrospective, real-world registries, Ticagrelor did not significantly increase MB compared with clopidogrel in elderly patients with ACS treated with PCI, while significantly improving 1-year survival. Further studies on elderly patients are suggested.

Impact of Age on the Safety and Efficacy of Ticagrelor Monotherapy in Patients Undergoing PCI

OBJECTIVES

The aim of this study was to assess the impact of age on the safety and efficacy of ticagrelor monotherapy after percutaneous coronary intervention (PCI).

BACKGROUND

As the risk for bleeding and ischemic complications after PCI increases with age, the authors conducted a pre-specified analysis of the TWILIGHT (Ticagrelor With Aspirin or Alone in High-Risk Patients After Coronary Intervention) trial to evaluate the possible benefits of ticagrelor monotherapy according to age.

METHODS

The TWILIGHT trial enrolled patients undergoing PCI with drug-eluting stents who fulfilled at least 1 clinical and 1 angiographic high-risk criterion. Age ≥65 years was a clinical entry criterion. After 3 months of dual-antiplatelet therapy with ticagrelor, event-free patients were randomized to ticagrelor plus placebo or ticagrelor plus aspirin for an additional 12 months. The primary endpoint was Bleeding Academic Research Consortium type 2, 3, or 5 bleeding. The key secondary endpoint was the composite of all-cause death, myocardial infarction, or stroke.

RESULTS

A total of 3,113 patients (47.7%) were ≥65 years of age. At 1 year after randomization, ticagrelor monotherapy significantly reduced BARC type 2, 3, or 5 bleeding (4.5% vs. 8.2%; hazard ratio: 0.53; 95% confidence interval: 0.40 to 0.71) without increasing ischemic events (4.2% vs. 4.4%; hazard ratio: 0.96; 95% confidence interval: 0.68 to 1.35) compared with ticagrelor plus aspirin among patients ≥65 years of age. These findings were consistent in patients <65 years of age with respect to the primary (p_interaction = 0.62) and key secondary (p_interaction = 0.77) endpoints and across different age categories.

CONCLUSIONS

A strategy of ticagrelor monotherapy following 3 months of dual-antiplatelet therapy significantly reduced clinically relevant bleeding compared with ticagrelor plus aspirin without an increase in ischemic events, irrespective of age.

MiR-126 Is an Independent Predictor of Long-Term All-Cause Mortality in Patients with Type 2 Diabetes Mellitus

MicroRNAs are endogenous non-coding RNAs that are involved in numerous biological processes through regulation of gene expression. The aim of our study was to determine the ability of several miRNAs to predict mortality and response to antiplatelet treatment among T2DM patients. Two hundred fifty-two patients with diabetes were enrolled in the study. Among the patients included, 26 (10.3%) patients died within a median observation time of 5.9 years. The patients were receiving either acetylsalicylic acid (ASA) 75 mg (65%), ASA 150 mg (15%) or clopidogrel (19%). Plasma miR-126, miR-223, miR-125a-3p and Let-7e expressions were assessed by quantitative real time PCR and compared between the patients who survived and those who died. Adjusted Cox-regression analysis was used for prediction of mortality. Differential miRNA expression due to different antiplatelet treatment was analyzed. After including all miRNAs into one multivariate Cox regression model, only miR-126 was predictive of future occurrence of long-term all-cause death (HR = 5.82, 95% CI: 1.3–24.9; p = 0.024). Furthermore, miR-126, Let-7e and miR-223 expressions in the clopidogrel group were significantly higher than in the ASA group (p = 0.014; p = 0.013; p = 0.028, respectively). To conclude, miR-126 expression is a strong and independent predictor of long-term all-cause mortality among patients with T2DM. Moreover, miR-223, miR-126 and Let-7e present significant interactions with antiplatelet treatment regimens and clinical outcomes.

Evolution of antithrombotic therapy in patients undergoing percutaneous coronary intervention: a 40-year journey

Since its introduction in 1977, percutaneous coronary intervention has become one of the most commonly performed therapeutic procedures worldwide. Such widespread diffusion, however, would have not been possible without a concomitant evolution of the pharmacotherapies associated with this intervention. Antithrombotic agents are fundamental throughout the management of patients undergoing coronary stent implantation, starting from the procedure itself to the long-term prevention of cardiovascular events. The last 40 years of interventional cardiology have seen remarkable improvements in both drug therapies and device technologies, which largely reflected a progressive understanding of the pathophysiological mechanisms of coronary artery disease, as well as procedure- and device-related adverse events. The purpose of this article is to provide an overview of the important milestones in antithrombotic pharmacology that have shaped clinical practice of today while also providing insights into knowledge gaps and future directions.

Guided versus standard antiplatelet therapy in patients undergoing percutaneous coronary intervention: a systematic review and meta-analysis

BACKGROUND

Whether guided selection of antiplatelet therapy in patients undergoing percutaneous coronary intervention (PCI) is effective in improving outcomes compared with standard antiplatelet therapy remains controversial. We assessed the safety and efficacy of guided versus standard selection of antiplatelet therapy in patients undergoing PCI.

METHODS

For this systematic review and meta-analysis, from Aug 20 to Oct 25, 2020, we searched MEDLINE (via PubMed), Cochrane, Embase, and Web of Science databases for randomised controlled trials and observational studies published in any language that compared guided antiplatelet therapy, by means of platelet function testing or genetic testing, versus standard antiplatelet therapy in patients undergoing PCI. Two reviewers independently assessed study eligibility, extracted the data, and assessed risk of bias. Risk ratios (RRs) and 95% CIs were used with random-effects or fixed-effect models according to the estimated heterogeneity among studies assessed by the I² index. Coprimary endpoints were trial-defined primary major adverse cardiovascular events and any bleeding. Key secondary endpoints were all-cause death, cardiovascular death, myocardial infarction, stroke, definite or probable stent thrombosis, and major and minor bleeding. This study is registered with PROSPERO (CRD42021215901).

FINDINGS

3656 potentially relevant articles were screened. Our analysis included 11 randomised controlled trials and three observational studies with data for 20 743 patients. Compared with standard therapy, guided selection of antiplatelet therapy was associated with a reduction in major adverse cardiovascular events (RR 0·78, 95% CI 0·63-0·95, p=0·015) and reduced bleeding, although not statistically significant (RR 0·88, 0·77-1·01, p=0·069). Cardiovascular death (RR 0·77, 95% CI 0·59-1·00, p=0·049), myocardial infarction (RR 0·76, 0·60-0·96, p=0·021), stent thrombosis (RR 0·64, 0·46-0·89, p=0·011), stroke (RR 0·66, 0·48-0·91, p=0·010), and minor bleeding (RR 0·78, 0·67-0·92, p=0·0030) were reduced with guided therapy compared with standard therapy. Risks of all-cause death and major bleeding did not differ between guided and standard approaches. Outcomes varied according to the strategy used, with an escalation approach associated with a significant reduction in ischaemic events without any trade-off in safety, and a de-escalation approach associated with a significant reduction in bleeding, without any trade-off in efficacy.

INTERPRETATION

Guided selection of antiplatelet therapy improved both composite and individual efficacy outcomes with a favourable safety profile, driven by a reduction in minor bleeding, supporting the use of platelet function or genetic testing to optimise the choice of agent in patients undergoing PCI.

FUNDING

None.

Effect of CYP2C19 Genotype on Ischemic Outcomes During Oral P2Y12 Inhibitor Therapy: A Meta-Analysis

OBJECTIVES

The aim of this study was to examine the effect of CYP2C19 genotype on clinical outcomes in patients with coronary artery disease (CAD) who predominantly underwent percutaneous coronary intervention (PCI), comparing those treated with ticagrelor or prasugrel versus clopidogrel.

BACKGROUND

The effect of CYP2C19 genotype on treatment outcomes with ticagrelor or prasugrel compared with clopidogrel is unclear.

METHODS

Databases through February 19, 2020, were searched for studies reporting the effect of CYP2C19 genotype on ischemic outcomes during ticagrelor or prasugrel versus clopidogrel treatment. Study eligibility required outcomes reported for CYP2C19 genotype status and clopidogrel and alternative P2Y12 inhibitors in patients with CAD with at least 50% undergoing PCI. The primary analysis consisted of randomized controlled trials (RCTs). A secondary analysis was conducted by adding non-RCTs to the primary analysis. The primary outcome was a composite of cardiovascular death, myocardial infarction, stroke, stent thrombosis, and severe recurrent ischemia. Meta-analysis was conducted to compare the 2 drug regimens and test interaction with CYP2C19 genotype.

RESULTS

Of 1,335 studies identified, 7 RCTs were included (15,949 patients, mean age 62 years; 77% had PCI, 98% had acute coronary syndromes). Statistical heterogeneity was minimal, and risk for bias was low. Ticagrelor and prasugrel compared with clopidogrel resulted in a significant reduction in ischemic events (relative risk: 0.70; 95% confidence interval: 0.59 to 0.83) in CYP2C19 loss-of-function carriers but not in noncarriers (relative risk: 1.0; 95% confidence interval: 0.80 to 1.25). The test of interaction on the basis of CYP2C19 genotype status was statistically significant (p = 0.013), suggesting that CYP2C19 genotype modified the effect. An additional 4 observational studies were found, and adding them to the analysis provided the same conclusions (p value of the test of interaction <0.001).

CONCLUSIONS

The effect of ticagrelor or prasugrel compared with clopidogrel in reducing ischemic events in patients with CAD who predominantly undergo PCI is based primarily on the presence of CYP2C19 loss-of-function carrier status. These results support genetic testing prior to prescribing P2Y12 inhibitor therapy.

Antithrombotic Management of Elderly Patients With Coronary Artery Disease

Antithrombotic therapy represents the mainstay of treatment in patients with coronary artery disease (CAD), including elderly patients who are at increased risk for ischemic recurrences. However, the elderly population is also more vulnerable to bleeding complications. Numerous mechanisms, including abnormalities in the vasculature, thrombogenicity, comorbidities, and altered drug response, contribute to both increased thrombotic and bleeding risk. Age-related organ changes and drug-drug interactions secondary to polypharmacy lead to distinct pharmacokinetic and pharmacodynamic profiles of antithrombotic drugs. Overall these factors contribute to the risk-benefit profiles of antithrombotic therapies in elderly subjects and underscore the need for treatment regimens that can reduce bleeding while preserving efficacy. Given that the prevalence of CAD, as well as concomitant diseases with thromboembolic potential, such as atrial fibrillation, increases with age and that the elderly population is in continuous growth, understanding the safety and efficacy of different antithrombotic regimens is pivotal for patient-centered care. In the present overview the authors appraise the available data on the use of antithrombotic therapy in older patients with CAD to assist with the management of this high-risk population and define knowledge gaps that can set the basis for future research.

Patient-tailored antithrombotic therapy following percutaneous coronary intervention

Dual antiplatelet therapy has long been the standard of care in preventing coronary and cerebrovascular thrombotic events in patients with chronic coronary syndrome and acute coronary syndrome undergoing percutaneous coronary intervention, but choosing the optimal treatment duration and composition has become a major challenge. Numerous studies have shown that certain patients benefit from either shortened or extended treatment duration. Furthermore, trials evaluating novel antithrombotic strategies, such as P2Y12 inhibitor monotherapy, low-dose factor Xa inhibitors on top of antiplatelet therapy, and platelet function- or genotype-guided (de-)escalation of treatment, have shown promising results. Current guidelines recommend risk stratification for tailoring treatment duration and composition. Although several risk stratification methods evaluating ischaemic and bleeding risk are available to clinicians, such as the use of risk scores, platelet function testing , and genotyping, risk stratification has not been broadly adopted in clinical practice. Multiple risk scores have been developed to determine the optimal treatment duration, but external validation studies have yielded conflicting results in terms of calibration and discrimination and there is limited evidence that their adoption improves clinical outcomes. Likewise, platelet function testing and genotyping can provide useful prognostic insights, but trials evaluating treatment strategies guided by these stratification methods have produced mixed results. This review critically appraises the currently available antithrombotic strategies and provides a viewpoint on the use of different risk stratification methods alongside clinical judgement in current clinical practice.

Stent Thrombosis Risk Over Time on the Basis of Clinical Presentation and Platelet Reactivity: Analysis From ADAPT-DES

OBJECTIVES

The aim of this study was to determine the risk period for increased stent thrombosis (ST) after percutaneous coronary intervention (PCI) in patients with acute coronary syndromes (ACS) and whether this increased risk is related to high platelet reactivity (HPR).

BACKGROUND

ST risk after PCI is higher among patients with ACS than those with stable ischemic heart disease. When ST risk is highest in patients with ACS and how that is affected by HPR is unknown.

METHODS

Using the ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) registry, ST rates during 2-year follow-up post-PCI with drug-eluting stents were compared among patients presenting with ACS (myocardial infarction [MI] or unstable angina) or stable ischemic heart disease (non-ACS). Landmark analyses were done at 30 days and 1 year post-PCI. Platelet reactivity on aspirin and clopidogrel post-PCI was assessed using VerifyNow assays.

RESULTS

Of 8,582 patients, 2,063 presented with MI, 2,370 with unstable angina, and 4,149 with non-ACS. Incidence rates of HPR were 48.0%, 43.3%, and 39.8%, respectively (p < 0.001). Within the first 30 days post-PCI, patients presenting with MI had increased ST risk compared with patients with non-ACS (hazard ratio [HR]: 4.52; 95% confidence interval [CI]: 2.01 to 10.14; p < 0.001). After 30 days, relative ST risks were progressively lower and no longer significant between groups (31 days to 1 year post-PCI: HR: 1.97; 95% CI: 0.80 to 4.85; >1 year post-PCI: HR: 0.89; 95% CI: 0.27 to 2.92). The elevated ST risk in patients with MI within 30 days was largely confined to those with HPR on clopidogrel (HR: 5.77; 95% CI: 2.13 to 15.63; p < 0.001).

CONCLUSIONS

Among patients undergoing PCI, rates of ST during 2-year follow-up were highest in those with MI and lowest in those with non-ACS. Increased ST risk in patients with MI was greatest in the first 30 days post-PCI and was observed predominantly among those with increased HPR on clopidogrel. These findings emphasize the importance of adequate P2Y₁₂ inhibition after MI, especially within the first 30 days after stent implantation.

Safety and efficacy of P2Y12 inhibitor monotherapy in patients undergoing percutaneous coronary interventions

Introduction: Antiplatelet therapy represents a key strategy for the prevention of thrombotic complications in patients with both acute and chronic coronary syndromes, particularly those undergoing percutaneous coronary intervention (PCI). Nevertheless, dual antiplatelet therapy (DAPT) is associated with a bleeding risk proportionate to its duration. Ever growing appreciation of the prognostic implications associated with bleeding and the development of safer stent platforms over the past years have led to a number of novel antiplatelet treatment strategies being tested among patients undergoing PCI. Areas covered: P2Y₁₂ inhibitor monotherapy after ashort course DAPT has emerged as ableeding reduction strategy to mitigate such risk while still preventing thrombotic complications. In this review we describe the latest evidence regarding the safety and efficacy of P2Y₁₂ inhibitor monotherapy in patients undergoing PCI in different clinical settings. Expert opinion: P2Y₁₂ inhibitor monotherapy after a brief period of DAPT has emerged as an effective approach to reduce the risk of bleeding without any tradeoff in efficacy (i.e., thrombotic complications). This strategy has shown consistent findings in a number of different clinical settings of patients undergoing PCI. Nevertheless, unanswered questions on the ideal patient and the precise P2Y₁₂ monotherapy regimen warrant further investigation.

Validation of the ABCD-GENE score to identify high platelet reactivity in east Asian patients undergoing percutaneous coronary intervention

BACKGROUND

High platelet reactivity (HPR) is associated with subsequent thrombotic events in patients undergoing percutaneous coronary intervention (PCI). Recently, the ABCD-GENE score was developed to identify patients at risk for HPR, incorporating both clinical and genetic factors. However, this score was derived and validated in mostly Caucasian subjects and it has not been validated in an East Asian population.

METHOD

Individual patient data from 4 prospective studies were pooled, in which platelet reactivity was measured using the VerifyNow assay on clopidogrel and genotyping of CYP2C19 was performed after PCI. Study populations included patients with general stable coronary artery disease, hemodialysis, age ≥75 and/or body weight <50 kg, and acute coronary syndrome. VerifyNow P2Y12 reactivity units >208 was defined as HPR.

RESULTS

Of 184 patients, 111 (60%) had HPR on clopidogrel. In the receiver operating characteristics curve analyses, the ABCD-GENE score significantly predicted HPR on clopidogrel (AUC 0.78, best cut-off value 9, p < 0.001). Across the 4 studies and their combinations, the diagnostic ability and cut-off values of ABCD-GENE score for HPR on clopidogrel were consistent.

CONCLUSIONS

The ABCD-GENE score had significant and moderate diagnostic ability for HPR on clopidogrel in Japanese patients undergoing PCI. The predictivity was consistent across a broad spectrum of patient populations, suggesting the applicability of this novel scoring system in clinical practice worldwide.

Safety and efficacy of double vs. triple antithrombotic therapy in patients with atrial fibrillation with or without acute coronary syndrome undergoing percutaneous coronary intervention: a collaborative meta-analysis of non-vitamin K antagonist oral anticoagulant-based randomized clinical trials

Aims

Safety and efficacy of antithrombotic regimens in patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI) may differ based on clinical presentation. We sought to compare double vs. triple antithrombotic therapy (DAT vs. TAT) in AF patients with or without acute coronary syndrome (ACS) undergoing PCI.

Methods and results

A systematic review and meta-analysis was performed using PubMed to search for non-vitamin K antagonist oral anticoagulant (NOAC)-based randomized clinical trials. Data on subgroups of ACS or elective PCI were obtained by published reports or trial investigators. A total of 10 193 patients from four NOAC trials were analysed, of whom 5675 presenting with ACS (DAT = 3063 vs. TAT = 2612) and 4518 with stable coronary artery disease (SCAD; DAT = 2421 vs. TAT = 2097). The primary safety endpoint of ISTH major bleeding or clinically relevant non-major bleeding was reduced with DAT compared with TAT in both ACS (12.2% vs. 19.4%; RR 0.63, 95% CI 0.56–0.71; P < 0.0001; I² = 0%) and SCAD (14.6% vs. 22.0%; RR 0.68, 95% CI 0.55–0.85; P = 0.0008; I² = 66%), without interaction (P-int = 0.54). Findings were consistent for secondary bleeding endpoints, including intra-cranial haemorrhage. In both subgroups, there was no difference between DAT and TAT for all-cause death, major adverse cardiovascular events, or stroke. Myocardial infarction and stent thrombosis were numerically higher with DAT vs. TAT consistently in ACS and SCAD (P-int = 0.60 and 0.86, respectively). Findings were confirmed by multiple sensitivity analyses, including a separate analysis on dabigatran regimens and a restriction to PCI population.

Conclusions

DAT, compared with TAT, is associated with lower bleeding risks, including intra-cranial haemorrhage, and a small non-significant excess of cardiac ischaemic events in both patients with or without ACS.