Non-ST-elevation acute coronary syndromes with previous coronary artery bypass grafting: a meta-analysis of invasive vs. conservative management

BACKGROUND AND AIMS

A routine invasive strategy is recommended in the management of higher risk patients with non-ST-elevation acute coronary syndromes (NSTE-ACSs). However, patients with previous coronary artery bypass graft (CABG) surgery were excluded from key trials that informed these guidelines. Thus, the benefit of a routine invasive strategy is less certain in this specific subgroup.

METHODS

A systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted. A comprehensive search was performed of PubMed, EMBASE, Cochrane, and ClinicalTrials.gov. Eligible studies were RCTs of routine invasive vs. a conservative or selective invasive strategy in patients presenting with NSTE-ACS that included patients with previous CABG. Summary data were collected from the authors of each trial if not previously published. Outcomes assessed were all-cause mortality, cardiac mortality, myocardial infarction, and cardiac-related hospitalization. Using a random-effects model, risk ratios (RRs) with 95% confidence intervals (CIs) were calculated.

RESULTS

Summary data were obtained from 11 RCTs, including previously unpublished subgroup outcomes of nine trials, comprising 897 patients with previous CABG (477 routine invasive, 420 conservative/selective invasive) followed up for a weighted mean of 2.0 (range 0.5-10) years. A routine invasive strategy did not reduce all-cause mortality (RR 1.12, 95% CI 0.97-1.29), cardiac mortality (RR 1.05, 95% CI 0.70-1.58), myocardial infarction (RR 0.90, 95% CI 0.65-1.23), or cardiac-related hospitalization (RR 1.05, 95% CI 0.78-1.40).

CONCLUSIONS

This is the first meta-analysis assessing the effect of a routine invasive strategy in patients with prior CABG who present with NSTE-ACS. The results confirm the under-representation of this patient group in RCTs of invasive management in NSTE-ACS and suggest that there is no benefit to a routine invasive strategy compared to a conservative approach with regard to major adverse cardiac events. These findings should be validated in an adequately powered RCT.

Association of Age- and Body Mass Index-Stratified High On-Treatment Platelet Reactivity With Coronary Intervention Outcomes in East Asian Patients

BACKGROUND

Although age and body mass index (BMI) significantly affect platelet reactivity units and clinical outcomes after percutaneous coronary intervention, there are limited data on the relationship between high on-treatment platelet reactivity (HPR) and clinical outcomes on age and BMI differences. Thus, we investigated the association of HPR with clinical outcomes according to age and BMI.

METHODS AND RESULTS

The study analyzed 11 714 patients who underwent platelet function tests after percutaneous coronary intervention. The primary end point was the occurrence of major adverse cardiac and cerebrovascular events (MACCEs), whereas the secondary end point was major bleeding. HPR was defined as platelet reactivity units ≥252. Patients were categorized by age (<67 years of age or ≥67 years of age) and BMI (≤22.6 kg/m2 or >22.6 kg/m2). Patients <67 years of age with HPR had increases in both MACCEs (adjusted hazard ratio [HR], 1.436 [95% CI, 1.106-1.867]; P=0.007) and major bleeding (adjusted HR, 1.584 [95% CI, 1.095-2.290]; P=0.015) compared with the those with non-HPR, respectively. In patients ≥67 years of age with HPR, there were no differences in MACCEs, but there was a decrease in major bleeding (adjusted HR, 0.721 [95% CI, 0.542-0.959]; P=0.024). Meanwhile, patients with HPR with BMI >22.6 kg/m2 had increases in MACCEs (adjusted HR, 1.387 [95% CI, 1.140-1.688]; P=0.001). No differences were shown in major bleeding.

CONCLUSIONS

HPR was linked to an increase in MACCEs or a decrease in major bleeding in patients after percutaneous coronary intervention, depending on age and BMI. This study is the first to observe that clinical outcomes in patients with HPR after percutaneous coronary intervention may vary based on age and BMI. Because the study is observational, the results should be viewed as hypothesis generating and emphasize the need for randomized clinical trials.

A novel machine learning model to predict high on-treatment platelet reactivity on clopidogrel in Asian patients after percutaneous coronary intervention

BACKGROUND

Various genetic and nongenetic variables influence the high on-treatment platelet reactivity (HTPR) in patients taking clopidogrel.

AIM

This study aimed to develop a novel machine learning (ML) model to predict HTPR in Chinese patients after percutaneous coronary intervention (PCI).

METHOD

This cohort study collected information on 507 patients taking clopidogrel. Data were randomly divided into a training set (90%) and a testing set (10%). Nine candidate Machine learning (ML) models and multiple logistic regression (LR) analysis were developed on the training set. Their performance was assessed according to the area under the receiver operating characteristic curve, precision, recall, F1 score, and accuracy on the test set. Model interpretations were generated using importance scores by transforming model variables into scaled features and representing in radar plots. Finally, we established a prediction platform for the prediction of HTPR.

RESULTS

A total of 461 patients (HTPR rate: 19.52%) were enrolled in building the prediction model for HTPR. The XGBoost model had an optimized performance, with an AUC of 0.82, a precision of 0.80, a recall of 0.44, an F1 score of 0.57, and an accuracy of 0.87, which was superior to those of LR. Furthermore, the XGBoost method identified 7 main predictive variables. To facilitate the application of the model, we established an XGBoost prediction platform consisting of 7 variables and all variables for the HTPR prediction.

CONCLUSION

A ML-based approach, such as XGBoost, showed optimum performance and might help predict HTPR on clopidogrel after PCI and guide clinical decision-making. Further validated studies will strengthen this finding.

Platelet RNA Biomarker of Ticagrelor-Responsive Genes Is Associated With Platelet Function and Cardiovascular Events

BACKGROUND

Identifying patients with the optimal risk:benefit for ticagrelor is challenging. The aim was to identify ticagrelor-responsive platelet transcripts as biomarkers of platelet function and cardiovascular risk.

METHODS

Healthy volunteers (n=58, discovery; n=49, validation) were exposed to 4 weeks of ticagrelor with platelet RNA data, platelet function, and self-reported bleeding measured pre-/post-ticagrelor. RNA sequencing was used to discover platelet genes affected by ticagrelor, and a subset of the most informative was summarized into a composite score and tested for validation. This score was further analyzed (1) in CD34+ megakaryocytes exposed to an P2Y12 inhibitor in vitro, (2) with baseline platelet function in healthy controls, (3) in peripheral artery disease patients (n=139) versus patient controls (n=30) without atherosclerosis, and (4) in patients with peripheral artery disease for correlation with atherosclerosis severity and risk of incident major adverse cardiovascular and limb events.

RESULTS

Ticagrelor exposure differentially expressed 3409 platelet transcripts. Of these, 111 were prioritized to calculate a Ticagrelor Exposure Signature score, which ticagrelor reproducibly increased in discovery and validation cohorts. Ticagrelor's effects on platelets transcripts positively correlated with effects of P2Y12 inhibition in primary megakaryocytes. In healthy controls, higher baseline scores correlated with lower baseline platelet function and with minor bleeding while receiving ticagrelor. In patients, lower scores independently associated with both the presence and extent of atherosclerosis and incident ischemic events.

CONCLUSIONS

Ticagrelor-responsive platelet transcripts are a biomarker for platelet function and cardiovascular risk and may have clinical utility for selecting patients with optimal risk:benefit for ticagrelor use.

The Impact of CYP2C19 Genotype on the Platelet Reactivity Index (PRI) among Chronic Coronary Syndromes (CCS) Patients Undergoing Percutaneous Coronary Intervention (PCI): Affectability of Rapid Genetic Testing

BACKGROUND

In the Asian population, the presence of the CYP2C19 loss-of-function (LOF) allele is a known genetic variation. This allele is associated with a reduced capacity to metabolize clopidogrel into its active forms through the CYP2C19 enzyme, resulting in diminished platelet inhibition and an elevated risk of recurrent cardiovascular events. Regulatory authorities have recommended an alternative P2Y12 inhibitor, ticagrelor, for individuals carrying the LOF allele. Consequently, this study seeks to assess the impact of the CYP2C19 genotype on the Platelet reactivity index (PRI) using a rapid genetic testing approach in Asian patients with chronic coronary syndromes (CCS) who undergo percutaneous coronary intervention (PCI).

METHODS

This prospective study employed a parallel design, single-center design, and randomized approach. Genotyping for the CYP2C19*2 and *3 polymorphisms was conducted using the Nested Allele-Specific Multiplex PCR (NASM-PCR) technique. Patients meeting the inclusion criteria underwent genotyping for CYP2C19 polymorphisms. Following PCI, patients were randomly assigned to receive either ticagrelor or clopidogrel. PRI assessments were performed four hours after loading dose administration. The trial was registered with ClinicalTrials.gov under the identifier NCT05516784.

RESULTS

Among the 94 patients recruited for the study, 40 (42.55%) were identified as carriers of the LOF allele for CYP2C19*2 and *3 (*1/*2, *2/*2, *1/*3). Out of the 84 patients evaluated for PRI (44 receiving clopidogrel and 40 receiving ticagrelor), 21 (47.7%) of the clopidogrel group and 39 (97.5%) of the ticagrelor group exhibited a favorable response to antiplatelet therapy (PRI < 50). Patients treated with ticagrelor demonstrated superior antiplatelet responses compared to those receiving clopidogrel, regardless of LOF carrier status (P = 0.005 and < 0.001 for non-LOF and LOF carriers, respectively).

CONCLUSION

NASM-PCR as a rapid genetic test holds promise for personalizing antiplatelet therapy in Asian CCS patients.

De-escalation or abbreviation of dual antiplatelet therapy in acute coronary syndromes and percutaneous coronary intervention: a Consensus Statement from an international expert panel on coronary thrombosis

Conventional dual antiplatelet therapy (DAPT) for patients with acute coronary syndromes undergoing percutaneous coronary intervention comprises aspirin with a potent P2Y purinoceptor 12 (P2Y12) inhibitor (prasugrel or ticagrelor) for 12 months. Although this approach reduces ischaemic risk, patients are exposed to a substantial risk of bleeding. Strategies to reduce bleeding include de-escalation of DAPT intensity (downgrading from potent P2Y12 inhibitor at conventional doses to either clopidogrel or reduced-dose prasugrel) or abbreviation of DAPT duration. Either strategy requires assessment of the ischaemic and bleeding risks of each individual. De-escalation of DAPT intensity can reduce bleeding without increasing ischaemic events and can be guided by platelet function testing or genotyping. Abbreviation of DAPT duration after 1-6 months, followed by monotherapy with aspirin or a P2Y12 inhibitor, reduces bleeding without an increase in ischaemic events in patients at high bleeding risk, particularly those without high ischaemic risk. However, these two strategies have not yet been compared in a head-to-head clinical trial. In this Consensus Statement, we summarize the evidence base for these treatment approaches, provide guidance on the assessment of ischaemic and bleeding risks, and provide consensus statements from an international panel of experts to help clinicians to optimize these DAPT approaches for individual patients to improve outcomes.

Impact of body mass on P2Y12-inhibitor de-escalation in acute coronary syndromes-a substudy of the TROPICAL-ACS trial

AIMS

Clinical guidelines recommend de-escalation antiplatelet strategies to reduce bleeding risk in acute coronary syndrome (ACS) patients, albeit with a weak recommendation. This substudy of the TROPICAL-ACS trial aimed to determine the impact of body mass on the efficacy of a platelet function testing-guided de-escalation regimen in ACS patients after percutaneous coronary intervention.

METHODS AND RESULTS

Patients were randomized to prasugrel (control group) or a platelet function testing-guided regimen with clopidogrel or prasugrel defined after 1-week clopidogrel. The primary endpoint was the net clinical benefit [cardiovascular death, myocardial infarction, stroke, or Bleeding Academic Research Consortium (BARC) 2-5 bleeding] for 12 months. Overweight was defined as a body mass index >25 kg/m2.Patients without overweight showed a significant net clinical benefit from the de-escalation strategy, while in overweight cases de-escalation was comparable to prasugrel treatment [hazard ratio (HR): 0.52; 95% confidence interval (CI): 0.31-0.88; P = 0.013 and HR: 0.95; 95% CI: 0.69-1.31, P = 0.717, P-non-inferiority = 0.03, respectively, P-interaction = 0.053]. The benefit of de-escalation in terms of the risk of bleeding or of the ischaemic events did not reach statistical significance. Bleeding events with de-escalation were less frequent in non-overweight patients but comparable in overweight patients (HR: 0.55; 95% CI: 0.30-1.03; P = 0.057 and HR: 0.95; 95% CI: 0.64-1.41, respectively, P-interaction = 0.147). Non-overweight patients had lower ischaemic event rates with de-escalation, while overweight cases had slightly less (HR: 0.47; 95% CI: 0.18-1.25; P = 0.128 and HR: 0.89; 95% CI: 0.53-1.50, respectively, P-interaction = 0.261).

CONCLUSION

The strategy of guided dual antiplatelet therapy de-escalation was associated with a significant net clinical benefit in non-overweight patients, while the two strategies were equivalent in overweight patients.

Abatement of potent P2Y12 antagonist-based dual antiplatelet therapy after coronary intervention: A network meta-analysis of randomized controlled trials

Introduction

Dual antiplatelet therapy (DAPT) including prasugrel or ticagrelor is recommended in patients with acute coronary syndromes (ACS) treated with coronary intervention (PCI). Acknowledging the importance of bleeding, multiple trials tested abatement schemes including uniform or guided de-escalation from the potent P2Y12 inhibitor (P2Y12-De) or P2Y12 inhibitor monotherapy (P2Y12-Mo) with heterogeneous results. We aimed to perform a systematic review and network meta-analysis of the impact of DAPT abatement strategies in patients with PCI.

Methods

Electronic databases were searched for relevant randomized clinical studies evaluating clinical outcomes of patients after PCI. The rate of adverse events was evaluated using a frequentist network metanalysis. The random-effects model was used to combine risk estimates across trials and risk ratio (RR) with 95% confidence intervals (95% CIs) served as summary statistics. The primary endpoints of interest were the rate of major cardiac adverse events (MACE, defined as the composite of cardiovascular mortality, myocardial infarction and stroke) and bleeding.

Results

Ten studies were identified randomizing 42511 patients. 6359 switched to the P2Y12-De and 13062 switched to the P2Y12-Mo. The risk of MACE, reflected a 24% reduction in the P2Y12-De and a 14% in the P2Y12-Mo in comparison with the DAPT strategy using potent P2Y12 inhibitors (RR: 0.76 [0.62, 0.94], and RR: 0.86 [0.75, 0.99], p < 0.05 both). A 35% risk reduction of major bleeding was seen with monotherapy (RR: 0.65 [0.46, 0.91],) contrasting the de-escalation trials where this effect was not significant (RR: 0.84 [0.57, 1.22]). All bleeding and minor bleeding events were reduced with both strategies. Indirect P2Y12-Mo versus P2Y12-De comparisons exhibited them as similar alternatives without significant differences.

Conclusion

Our analysis suggests that both P2Y12-De and P2Y12-Mo reduce ischemic events and bleeding among PCI-treated ACS patients. Ischemic benefit was more expressed with P2Y12-De, however, reduction of major bleeding was only significant with P2Y12-Mo strategy.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021258502, identifier CRD42021258502.

Resistance on the Latest Oral and Intravenous P2Y12 ADP Receptor Blockers in Patients with Acute Coronary Syndromes: Fact or Myth?

Novel P2Y12 ADP receptor blockers (ADPRB) should be preferred in dual-antiplatelet therapy in patients with acute coronary syndrome. Nevertheless, there are still patients who do not respond optimally to novel ADP receptor blocker therapy, and this nonoptimal response (so-called "high on-treatment platelet reactivity" or "resistance") could be connected with increased risk of adverse ischemic events, such as myocardial re-infarction, target lesion failure and stent thrombosis. In addition, several risk factors have been proposed as factors associated with the phenomenon of inadequate response on novel ADPRB. These include obesity, multivessel coronary artery disease, high pre-treatment platelet reactivity and impaired metabolic status for prasugrel, as well as elderly, concomitant therapy with beta-blockers, morphine and platelet count for ticagrelor. There is no literature report describing nonoptimal therapeutic response on cangrelor, and cangrelor therapy seems to be a possible approach for overcoming HTPR on prasugrel and ticagrelor. However, the optimal therapeutic management of "resistance" on novel ADPRB is not clear and this issue requires further research. This narrative review article discusses the phenomenon of high on-treatment platelet reactivity on novel ADPRB, its importance in clinical practice and approaches for its therapeutic overcoming.

Short dual antiplatelet therapy and dual antiplatelet therapy de-escalation after primary percutaneous intervention: For whom and how

Dual antiplatelet therapy (DAPT) for 6-12 months, followed by lifelong aspirin monotherapy is considered an effective standard therapy for the prevention of thrombo-ischemic events in patients with acute and chronic coronary syndrome (ACS, CCS) undergoing percutaneous coronary intervention (PCI) or after a primarily conservative treatment decision. In ACS patients, the stronger P2Y12-inhibitors ticagrelor or prasugrel are recommended in combination with aspirin unless the individual bleeding risk is high and shortening of DAPT is warranted or clopidogrel is preferred. However, also in patients at low individual bleeding risk, DAPT is associated with a higher risk of bleeding. In recent years, new antithrombotic treatment strategies, such as shortening DAPT followed by early P2Y12-inhibitor monotherapy and de-escalating DAPT from potent P2Y12-inhibitors to clopidogrel by maintaining DAPT duration time, have been investigated in clinical trials and shown to reduce bleeding complications in cardiovascular high-risk patients without negative effects on ischemic events. In this review, we summarize the current knowledge and discuss its implication on future antithrombotic strategies in terms of a personalized medicine.

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.

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.

Neutrophil-Derived Protein S100A8/A9 Alters the Platelet Proteome in Acute Myocardial Infarction and Is Associated With Changes in Platelet Reactivity

Supplemental Digital Content is available in the text.

Objective:

Platelets are central to acute myocardial infarction (MI). How the platelet proteome is altered during MI is unknown. We sought to describe changes in the platelet proteome during MI and identify corresponding functional consequences.

Approach and Results:

Platelets from patients experiencing ST-segment–elevation MI (STEMI) before and 3 days after treatment (n=30) and matched patients with severe stable coronary artery disease before and 3 days after coronary artery bypass grafting (n=25) underwent quantitative proteomic analysis. Elevations in the proteins S100A8 and S100A9 were detected at the time of STEMI compared with stable coronary artery disease (S100A8: FC, 2.00; false discovery rate, 0.05; S100A9: FC, 2.28; false discovery rate, 0.005). During STEMI, only S100A8 mRNA and protein levels were correlated in platelets (R=0.46, P=0.012). To determine whether de novo protein synthesis occurs, activated platelets were incubated with 13C-labeled amino acids for 24 hours and analyzed by mass spectrometry. No incorporation was confidently detected. Platelet S100A8 and S100A9 was strongly correlated with neutrophil abundance at the time of STEMI. When isolated platelets and neutrophils were coincubated under quiescent and activated conditions, release of S100A8 from neutrophils resulted in uptake of S100A8 by platelets. Neutrophils released S100A8/A9 as free heterodimer, rather than in vesicles or extracellular traps. In the community-based Bruneck study (n=338), plasma S100A8/A9 was inversely associated with platelet reactivity—an effect abrogated by aspirin.

Conclusions:

Leukocyte-to-platelet protein transfer may occur in a thromboinflammatory environment such as STEMI. Plasma S100A8/A9 was negatively associated with platelet reactivity. These findings highlight neutrophils as potential modifiers for thrombotic therapies in coronary artery disease.

Similar Inflammatory Biomarkers Reflect Different Platelet Reactivity in Percutaneous Coronary Intervention Patients Treated With Clopidogrel: A Large-Sample Study From China

Background: Platelet reactivity is closely associated with adverse events in percutaneous coronary intervention (PCI) patients. Inflammation plays a crucial role in the development of coronary heart disease (CHD).

Aim: To investigate the association of inflammatory biomarkers such as leukocyte count and high-sensitivity C reactive proteins (hs-CRP) with platelet reactivity in PCI patients treated with clopidogrel.

Method: We examined 10,724 consecutive PCI patients in Fuwai hospital from January 2013 to December 2013. High on-treatment platelet reactivity (HTPR) was defined as adenosine diphosphate (ADP)-induced platelet maximum amplitude [MA(ADP)] of thromboelastogram (TEG) > 47 mm, and low on-treatment platelet reactivity (LTPR) MA(ADP) < 31 mm.

Results: Finally, 6,772 PCI patients treated with clopidogrel who had the results of postoperative TEG were enrolled. Among them, 2,070 (30.57%) presented HTPR and 2,568 (37.92%) presented LTPR. As for LTPR, multivariate logistic regression showed that leukocyte count (OR: 1.153, 95% CI 1.117–1.191) and hs-CRP (OR: 0.920, 95% CI 0.905–0.936) were independent predictors, along with diabetes mellites, hemoglobin, platelet count and glucose. As for HTPR, multivariate logistic regression showed that leukocyte count (OR: 0.885, 95% CI 0.854–0.917) and hs-CRP (OR: 1.094, 95% CI 1.077–1.112) were independent predictors, along with sex, hemoglobin, platelet count and glucose.

Conclusions: This was the first large real-world study reporting that both leukocyte count and hs-CRP were the independent factors for platelet reactivity in PCI populations treated with clopidogrel, among which higher leukocyte count was associated with more LTPR while higher hs-CRP was associated with more HTPR, providing new insights on individualized antiplatelet therapy.

The Current Role of Platelet Function Testing in Clinical Practice

Platelet dysfunction, whether hereditary or acquired, may increase an individual's risk of spontaneous, posttraumatic, or postoperative bleeding. Conversely, increased platelet reactivity on antiplatelet agents following vascular (in particular, coronary vascular) intervention may increase the risk of thrombosis and adverse vascular events. The aim of platelet function testing is to identify and characterize platelet dysfunction in these settings to inform bleeding/ thrombosis risk and guide perioperative prophylactic management strategies. A vast array of screening and diagnostic tests is available for this purpose. The successful clinical application of platelet function tests depends on the knowledge of their analytical strengths and limitations and the correct extrapolation of derived results to a particular clinical scenario. This review critically appraises traditional and contemporary platelet function testing focusing on their role in clinical practice.

The year in cardiology: acute coronary syndromes

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Analysis of individualized antiplatelet therapy for patients of acute coronary syndrome after percutaneous coronary intervention under the guidance of platelet function: A one-center retrospective cohort study

There is controversy in clinical application of antiplatelet drugs by monitoring platelet function. Therefore, we explored whether early and dynamic medication could bring better clinical outcomes for patients under the guidance of platelet function tests (PFT).In this retrospective cohort study, we analyzed the prognostic events of 1550 patients with acute coronary syndrome (ACS) at Tianjin People's Hospital in China. They received dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) from January 2017 to December 2018. The primary endpoint was based on the Bleeding Academic Research Consortium (BARC) 3 or 5 major bleeding. Secondary endpoints included MACCE (all-cause death, nonfatal myocardial infarction, stroke, stent thrombosis, and unplanned target vessel reconstruction) and BARC 1 to 2 minor bleeding. The endpoint events within 1 year after PCI were recorded. Patients were divided into a guided group and a control group according to the drug adjustment by PFT results. After the propensity scores matched, the end points of 2 groups were compared, and subgroup analysis was performed on major bleeding events.After propensity score matching, there were 511 cases in the guided group and the control group, respectively. The primary endpoint events occurred in 10 patients (1.96%) in the guided group and 23 patients (4.5%) in the control group (HR: 0.45; 95% CI, 0.21-0.95; P = .037). After the guided group adjusted drug doses, the risk of major bleeding was lower than standard DAPT of the control group. Although some patients in the guided group reduced doses earlier, the incidence of MACCE events did not increase in the guided group compared with the control group (4.89% vs 6.07%; P = .41). There was no statistical difference in BARC 1 to 2 minor bleeding (P = .22). Subgroup analysis showed that PFT was more effective in patients with diabetes and multivessel disease.Early observation of dynamic PFT in ACS patients after PCI can guide individualized antiplatelet therapy to reduce the risk of major bleeding without increasing the risk of ischemia.

Viscoelastic Hemostatic Assays and Platelet Function Testing in Patients with Atherosclerotic Vascular Diseases

Platelets play crucial role in acute vascular atherosclerotic diseases, including myocardial infarction and stroke. Additionally, platelet aggregation is a key target of antiplatelet agents, forming the keystone of pharmacotherapy of various atherosclerotic cardiovascular diseases. Thromboelastography and thromboelastometry, representing currently available viscoelastic hemostatic assays (VHA), are designed as whole blood, real-time analyzers of clot formation and clot resolution. These assays could, in theory, overcome some limitations of currently available platelet function testing assays. This article reviews the current experience with the use of VHA for platelet function testing and for monitoring of the response to antiplatelet therapy.

Pharmacodynamic Profile and Prevalence of Bleeding Episode in East Asian Patients with Acute Coronary Syndromes Treated with Prasugrel Standard-Dose versus De-escalation Strategy: A Randomized A-MATCH Trial

Compared with Caucasian patients, East Asian patients have the unique risk-benefit trade-off and different responsiveness to antithrombotic regimens. The aim of this study was to compare pharmacodynamic profile in East Asian patients with acute coronary syndromes (ACSs) treated with prasugrel standard-dose versus a de-escalation strategy. Before discharge, ACS patients with age <75 years or weight ≥60 kg (n = 255) were randomly assigned to the standard-dose (10-mg group) or de-escalation strategy (5-mg group or platelet function test [PFT]-guided group). After 1 month, VerifyNow P2Y12 assay-based platelet reactivity (P2Y12 reaction unit [PRU]) and bleeding episodes were evaluated. Primary endpoint was the percentage of patients with the therapeutic window (85 ≤ PRU ≤ 208). The 250 patients completed 1-month treatment. The percentage of patients within the therapeutic window was significantly lower in the 10-mg group (n = 85) compared with the 5-mg (n = 83) and PFT-guided groups (n = 82) (35.3 vs. 67.5 vs. 65.9%) (odds ratio [OR]: 3.80 and 3.54; 95% confidence interval [CI]: 2.01-7.21 and 1.87-6.69, respectively). Compared with the 10-mg group, the bleeding rate was tended to be lower with de-escalation strategies (35.3 vs. 24.1% vs. 23.2%) (hazard ratio [HR]: 0.58 and 0.55; 95% CI: 0.30-1.14 and 0.28-1.09, respectively). "PRU < 127" was the optimal cut-off for predicting 1-month bleeding events (area under the curve: 0.616; 95% CI: 0.543-0.689; p = 0.005), which criteria was significantly associated with early discontinuation of prasugrel treatment (HR: 2.00; 95% CI: 1.28-3.03; p = 0.001). In conclusion, compared with the standard-dose prasugrel, the prasugrel de-escalation strategy in East Asian patients presented with ACS showed a higher chance within the therapeutic window and a lower tendency toward bleeding episodes. REGISTRATION:  URL: https://clinicaltrials.gov. Unique identifier:NCT01951001.

Detailed thrombogenicity phenotyping and 1 year outcomes in patients undergoing WATCHMAN implantation: (TARGET-WATCHMAN) a case-control study

The relation of device related thrombosis (DRT) and major bleeding after left atrial appendage closure (LAAC) to laboratory thrombosis and hemostasis markers has not been studied. We performed a prospective case control study to identify clinical characteristics and laboratory markers in patients who developed DRT and major bleeding following WATCHMAN LAAC. Thromboelastography, platelet aggregation (PA), urinary 11-dehydrothromboxane B₂ (UTX), fibrinogen, D-dimer, thrombin time and von Willebrand factor activity were determined at baseline, immediately following, and at 45 and 180 days post-LAAC (n = 32) and outcomes were followed for 1 year. Baseline characteristics and thrombogenic profiles of patients with and without DRT and/or BARC bleeding were compared. Mean age was 76 ± 8 years and CHADS2 VASc score was 4.4 ± 1.4. There were 3 DRTs (2 within 6 months, and 1 at 12 months), 4 Type 3A BARC bleeds, and 2 non-cardiac deaths. Patients with DRT had higher baseline thrombin-induced platelet-fibrin clot strength (68.0 ± 1.8 vs. 62.7 ± 4.7 mm, p = 0.06); FCS (35.6 ± 6.0 vs. 24.4 ± 6.6 mm, p = 0.009); and D-dimer (1712 ± 2330 vs. 283 ± 213 ng/mL, p = 0.001). At baseline, 5 patients had all 3 factors associated with high thrombotic risk and 2 experienced a DRT within 6 months. Patients with Type 3A BARC bleeding had lower baseline collagen-induced and 45-day ADP-induced PA (p < 0.01 for both). DRT following LAAC was associated with a baseline prothrombogenic profile whereas bleeding was associated with low platelet reactivity. These preliminary findings warrant further validation and have future implications on patient selection and adjunctive antithrombotic therapy following LAAC.Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT03040622 .

Relationship Between Platelet Reactivity and Ischemic and Bleeding Events After Percutaneous Coronary Intervention in East Asian Patients: 1-Year Results of the PENDULUM Registry

Background The balance between ischemic and bleeding events and their association with platelet reactivity in patients receiving antiplatelet therapy after percutaneous coronary intervention (PCI), which differs among regions, is not fully evaluated for East Asians. We examined ischemic/bleeding events and platelet reactivity in Japanese patients undergoing PCI and determined associations between high/low platelet reactivity and clinical outcomes. Methods and Results PENDULUM (Platelet Reactivity in Patients with Drug Eluting Stent and Balancing Risk of Bleeding and Ischemic Event) is a prospective, multicenter registry of Japanese patients with PCI. Primary end points were incidence of first major adverse cardiac and cerebrovascular events (MACCE) and first major bleeding events at 12 months post-PCI. Platelet reactivity (P2Y₁₂ reaction unit [PRU] value) was measured at 12 to 48 hours post-PCI; patients were grouped as having high PRU (>208), optimal PRU (>85 to ≤208), and low PRU (≤85). MACCE and major bleeding occurred in 4.4% and 2.8% of 6267 patients, respectively. The mean±SD PRU value was 182.1±77.1. MACCE was significantly higher in the high PRU (5.7%; n=2227) versus the optimal PRU group (3.6%; n=3002). The hazard ratio (HR) for high PRU versus optimal PRU level was significantly higher for MACCE (adjusted HR, 1.53; 95% CI, 1.14-2.06 [P=0.004]); stent thrombosis followed the same trend. Incidence of major bleeding did not differ significantly between groups. A high PRU level was significantly associated with MACCE in both patients with and patients without acute coronary syndrome. Conclusions These real-world data suggest an association between high platelet reactivity and cardiovascular events in Japanese patients undergoing PCI. The trend was the same in both patients with and patients without acute coronary syndrome. REGISTRATION URL: https://www.umin.ac.jp/ctr. Unique identifier: UMIN 000020332.

Prasugrel Versus Ticagrelor in Patients With CYP2C19 Loss-of-Function Genotypes: Results of a Randomized Pharmacodynamic Study in a Feasibility Investigation of Rapid Genetic Testing

The feasibility of rapid genetic testing in patients undergoing percutaneous coronary intervention (PCI) and the comparison of the pharmacodynamic effects of prasugrel versus ticagrelor among carriers of cytochrome P450 2C19 loss-of-function alleles treated with PCI has been poorly explored. Rapid genetic testing using the Spartan assay was shown to be feasible and provides results in a timely fashion in a real-world setting of patients undergoing coronary angiography (n = 781). Among patients (n = 223, 28.5%), carriers of at least 1 loss-of-function allele treated with PCI (n = 65), prasugrel, and ticagrelor achieve similar levels of platelet inhibition. (A Pharmacodynamic Study Comparing Prasugrel Versus Ticagrelor in Patients Undergoing PCI With CYP2C19 Loss-of-function [NCT02065479]).

Smoking and outcomes following guided de-escalation of antiplatelet treatment in acute coronary syndrome patients: a substudy from the randomized TROPICAL-ACS trial

Aims

Prior analyses disclosed variations in antiplatelet drug response and clinical outcomes between smokers and non-smokers, thus the safety and efficacy of any dual antiplatelet therapy (DAPT) de-escalation strategy may differ in relation to smoking status. Hence, we assessed the impact of smoking on clinical outcomes and adenosine diphosphate-induced platelet aggregation following guided de-escalation of DAPT in invasively managed acute coronary syndrome (ACS) patients.

Methods and results

The multicentre TROPICAL-ACS trial randomized 2610 biomarker-positive ACS patients 1:1 to standard treatment with prasugrel for 12 months (control group) or a platelet function testing guided de-escalation of DAPT. Current smokers (n = 1182) showed comparable event rates between study groups [6.6% vs. 6.6%; hazard ratio (HR) 1.0, 95% confidence interval (CI) 0.64–1.56, P &gt; 0.99]. In non-smokers (n = 1428), a guided DAPT de-escalation was associated with a lower 1-year incidence of the primary endpoint [cardiovascular death, myocardial infarction, stroke, or bleeding ≥ Grade 2 according to Bleeding Academic Research Consortium (BARC) criteria] compared with control group patients (7.9% vs. 11.0%; HR 0.71, 95% CI 0.50–0.99, P = 0.048). This reduction was mainly driven by a lower rate of BARC ≥ Grade 2 bleedings (5.2% vs. 7.7%; HR 0.68, 95% CI 0.45–1.03, P = 0.066). There was no significant interaction of smoking status with treatment effects of guided DAPT de-escalation (Pint = 0.23). Adenosine diphosphate-induced platelet aggregation values were higher in current smokers [median 28 U, interquartile range (IQR: 20–40)] vs. non-smoker [median 24 U (16–25), P &lt; 0.0001] in the control group and in current smokers [median 42 U, IQR (27–68)] vs. non-smoker [median 37 U, IQR (25–55), P &lt; 0.001] in the monitoring group.

Conclusion

Guided DAPT de-escalation appears to be equally safe and effective in smokers and non-smokers. Regardless of smoking status and especially for those patients deemed unsuitable for 1 year of potent platelet inhibition this DAPT strategy might be used as an alternative antiplatelet treatment regimen.

Whole blood platelet aggregation kinetics under cardiopulmonary bypass: A pilot study

Assessing the platelets' functional status during surgery on cardiopulmonary bypass is challenging. This study used multiple electrode impedance aggregometry (Multiplate^®) to create a timeline of platelet aggregation changes as induced by cardiopulmonary bypass in antiplatelet-naive patients undergoing elective surgery for mitral valve regurgitation. We performed six consecutive measurements (T1: pre-operatively, T2: after heparinization, T3: 3 min after establishment of cardiopulmonary bypass, T4: immediately after administration of cardioplegia, T5: 5 min after administration of cardioplegia, and T6: 45 min after administration of cardioplegia). Platelet aggregation was determined after stimulation with 3.2-μg/mL collagen, 6.4-μM adenosine diphosphate, and 32-μM thrombin receptor activating peptide. Five patients were included (age: 64 ± 10 years, one female). We observed a decrease in hematocrit levels by -17.1% ± 3.7% (T1 vs T6) with a drop after establishment of cardiopulmonary bypass (T2 vs T3) and slightly decreasing platelet counts by -6.2% ± 7.7% (T1 vs T6). Immediately after establishment of cardiopulmonary bypass (T2 vs T3), we observed reduced platelet aggregation responses for stimulation with adenosine diphosphate (-19.7% ± 12.8%) and thrombin receptor activating peptide (-19.3% ± 6.3%). Interestingly, we found augmented platelet aggregation for all stimuli 45 min after administration of cardioplegia (T5 vs T6) with the strongest increase for collagen (+83.4% ± 42.8%; adenosine diphosphate: +39.0% ± 37.2%; thrombin receptor activating peptide: +34.5% ± 18.5%). Thus, after an initial drop due to hemodilution upon establishment of cardiopulmonary bypass, platelet reactivity increased over time which was not outweighed by decreasing platelet counts due to mechanical platelet destruction and absorption. These findings have implications for rational transfusion, peri-operative antiplatelet therapy, and for the management of patients on other extracorporeal support, such as extracorporeal life support or extracorporeal membrane oxygenation.

Pharmacodynamics During Transition Between Platelet P2Y12 Inhibiting Therapies

Several platelet P2Y₁₂ inhibiting agents, both oral and intravenous, are available for clinical use. The oral P2Y₁₂ inhibitors comprise clopidogrel, prasugrel, and ticagrelor. Cangrelor is the only intravenous P2Y₁₂ inhibitor. Numerous pharmacodynamic studies have been performed to assess the impact of P2Y₁₂ inhibitor switching on platelet reactivity profiles and to define the optimal strategy if switching is needed, with the goal of minimizing the risk of having inadequate platelet inhibition due to potential drug-drug interactions occurring during the drug overlap phase. This article provides an overview of pharmacodynamic studies assessing switching between P2Y₁₂ inhibitors and recommendations on switching modalities based on these findings.