International Expert Consensus on Switching Platelet P2Y 12 Receptor–Inhibiting Therapies

Recent advances in microfluidic technology of arterial thrombosis investigations

Microfluidic technology has emerged as a powerful tool in studying arterial thrombosis, allowing researchers to construct artificial blood vessels and replicate the hemodynamics of blood flow. This technology has led to significant advancements in understanding thrombosis and platelet adhesion and aggregation. Microfluidic models have various types and functions, and by studying the fabrication methods and working principles of microfluidic chips, applicable methods can be selected according to specific needs. The rapid development of microfluidic integrated system and modular microfluidic system makes arterial thrombosis research more diversified and automated, but its standardization still needs to be solved urgently. One key advantage of microfluidic technology is the ability to precisely control fluid flow in microchannels and to analyze platelet behavior under different shear forces and flow rates. This allows researchers to study the physiological and pathological processes of blood flow, shedding light on the underlying mechanisms of arterial thrombosis. In conclusion, microfluidic technology has revolutionized the study of arterial thrombosis by enabling the construction of artificial blood vessels and accurately reproducing hemodynamics. In the future, microfluidics will place greater emphasis on versatility and automation, holding great promise for advancing antithrombotic therapeutic and prophylactic measures.

Switching from cangrelor to oral P2Y12 inhibitors: a focused review on drug-drug interactions

INTRODUCTION

Cangrelor, the only intravenous platelet P2Y12 receptor inhibitor, is characterized by a prompt and potent platelet inhibition, with a rapid offset of action. Large-scale clinical trials have shown that cangrelor reduce peri-procedural thrombotic events among patients undergoing percutaneous coronary interventions and not pre-treated with an oral P2Y12 receptor inhibitor. However, high P2Y12 receptor occupancy provided by cangrelor raises concerns for drug-drug interactions (DDIs) when transitioning to oral P2Y12 inhibitors.

AREAS COVERED

An understanding of the pharmacology of cangrelor and oral P2Y12 inhibitors is essential to define the optimal approach to transition to oral P2Y12 inhibitors without incurring the risk of DDIs. This review, based on a thorough literature search in major scientific databases (PubMed, Cochrane Library, Web of Science), synthesizes the pharmacology of cangrelor and the oral P2Y12 receptor inhibitors, providing the rationale for the occurrence of DDIs and strategies to avoid such risk.

EXPERT OPINION

The timing of transition from cangrelor to oral P2Y12 inhibitors plays a crucial role in the occurrence of DDIs, especially with clopidogrel and prasugrel. Currently, no evidence suggests a DDI when transitioning to ticagrelor. Adhering to product labels and guideline recommendations is crucial for optimizing safety and efficacy of cangrelor.

Antithrombotic Therapy in Acute Coronary Syndrome

Early mechanical reperfusion, primarily via percutaneous coronary intervention, combined with timely antithrombotic drug administration, constitutes the main approach for managing acute coronary syndrome (ACS). Clinicians have access to a variety of antithrombotic agents, necessitating careful selection to balance reducing thrombotic events against increased bleeding risks. This review offers a comprehensive update on current antithrombotic therapy in ACS, emphasizing the need for individualized treatment strategies.

De-escalation of antithrombotic treatment after acute coronary syndrome, a new paradigm

After an acute coronary syndrome (ACS) it is imperative to balance the bleeding vs. the ischemic risk given the similar prognostic impact of the two events. Since the post-discharge bleeding risk is substantially stable over time whereas the ischemic risk accumulates in the first weeks to months, a strategy of de-escalation of antithrombotic treatment, consisting in the reduction of either the duration (i.e., early interruption of one antiplatelet agent) or the intensity (i.e., switching from the more potent P2Y12-inhibitors prasugrel or ticagrelor to clopidogrel) of dual antiplatelet therapy (DAPT), has been proposed. Reducing the intensity of DAPT can be carried out as a default strategy (unguided approach) or based on the results of either platelet function tests or genetic tests (guided approach). Overall, all de-escalation strategies have shown to consistently decrease bleeding events with no apparent increase in ischemic events as compared to 12-month standard-of-care DAPT. Owing however to several limitations and weaknesses of the available evidence, de-escalation strategies are currently not recommended as a routine, but should rather be considered for selected ACS patients, such as those at increased risk of bleeding.

CYP2C19 Genetic Testing for Oral P2Y12 Inhibitor Therapy: A Scientific Statement From the American Heart Association

There is significant variability in the efficacy and safety of oral P2Y12 inhibitors, which are used to prevent ischemic outcomes in common diseases such as coronary and peripheral arterial disease and stroke. Clopidogrel, a prodrug, is the most used oral P2Y12 inhibitor and is activated primarily after being metabolized by a highly polymorphic hepatic cytochrome CYP2C219 enzyme. Loss-of-function genetic variants in CYP2C219 are common, can result in decreased active metabolite levels and increased on-treatment platelet aggregation, and are associated with increased ischemic events on clopidogrel therapy. Such patients can be identified by CYP2C19 genetic testing and can be treated with alternative therapy. Conversely, universal use of potent oral P2Y12 inhibitors such as ticagrelor or prasugrel, which are not dependent on CYP2C19 for activation, has been recommended but can result in increased bleeding. Recent clinical trials and meta-analyses have demonstrated that a precision medicine approach in which loss-of-function carriers are prescribed ticagrelor or prasugrel and noncarriers are prescribed clopidogrel results in reducing ischemic events without increasing bleeding risk. The evidence to date supports CYP2C19 genetic testing before oral P2Y12 inhibitors are prescribed in patients with acute coronary syndromes or percutaneous coronary intervention. Clinical implementation of such genetic testing will depend on among multiple factors: rapid availability of results or adoption of the concept of performing preemptive genetic testing, provision of easy-to-understand results with therapeutic recommendations, and seamless integration in the electronic health record.

Preoperative antiplatelet therapy may be a risk factor for postoperative ischemic complications in intracranial hemorrhage patients

BACKGROUND AND PURPOSE

Spontaneous intracranial hemorrhage (ICH) patients are still at risk of postoperative ischemic complications (PICs) after surgery. In addition, the proportion of patients receiving antiplatelet therapy (APT) in ICH patients increased significantly with age. This study aims to evaluate the impact of preoperative antiplatelet therapy on PICs in ICH patients.

METHODS

This is a cohort study that retrospectively analyzed the data of ICH patients who underwent surgical treatment. PICs rate was compared between patients with preoperative ATP and those without preoperative ATP. Univariate and multivariate analyses were conducted to evaluate the impact of preoperative APT on PICs. In addition, Kaplan-Meier method was used for survival analysis and the impact of PICs on patients' postoperative outcomes was evaluated.

RESULTS

A total of 216 patients were included in this study. There were 47 patients (21.76%) with preoperative APT; 169 patients (78.24%) without preoperative APT. The incidence of PICs in the APT group was significantly higher when compared with that in the nAPT group (36.17% vs. 20.71%, p = 0.028＜0.05). Furthermore, significant differences were both observed in multivariate analysis (p = 0.035＜0.05) and survival analysis (log rank χ2 = 5.415, p = 0.020＜0.05). However, there was no significant difference between the outcomes of patients suffering from PICs and that of patients not suffering from PICs (p = 0.377 > 0.05).

CONCLUSIONS

In conclusion, preoperative APT may be a risk factor for PICs in ICH patients undergoing surgical treatment significantly.

From Atherosclerotic Plaque to Myocardial Infarction-The Leading Cause of Coronary Artery Occlusion

Cardiovascular disease (CVD) constitutes the most common cause of death worldwide. In Europe alone, approximately 4 million people die annually due to CVD. The leading component of CVD leading to mortality is myocardial infarction (MI). MI is classified into several types. Type 1 is associated with atherosclerosis, type 2 results from inadequate oxygen supply to cardiomyocytes, type 3 is defined as sudden cardiac death, while types 4 and 5 are associated with procedures such as percutaneous coronary intervention and coronary artery bypass grafting, respectively. Of particular note is type 1, which is also the most frequently occurring form of MI. Factors predisposing to its occurrence include, among others, high levels of low-density lipoprotein cholesterol (LDL-C) in the blood, cigarette smoking, chronic kidney disease (CKD), diabetes mellitus (DM), hypertension, and familial hypercholesterolaemia (FH). The primary objective of this review is to elucidate the issues with regard to type 1 MI. Our paper delves into, amidst other aspects, its pathogenesis, risk assessment, diagnosis, pharmacotherapy, and interventional treatment options in both acute and long-term conditions.

Enzalutamide: Understanding and Managing Drug Interactions to Improve Patient Safety and Drug Efficacy

Enzalutamide is an oral androgen receptor signaling inhibitor utilized in the treatment of men with prostate cancer. It is a moderate inducer of the cytochrome P450 (CYP) enzymes CYP2C9 and CYP2C19, and a strong inducer of CYP3A4. It was also shown to be a mild inhibitor of the efflux transporter P-glycoprotein in patients with prostate cancer. Enzalutamide is primarily metabolized by CYP3A4 and CYP2C8. The risk of enzalutamide drug interactions arises primarily when it is coadministered with other drugs that interact with these CYPs, including CYP3A4. In this review, we begin by providing an overview of enzalutamide including its dosing, use in special populations, pharmacokinetics, changes to its prescribing information, and potential for interaction with coadministered drugs. Enzalutamide interactions with drugs from a wide range of medication classes commonly prescribed to patients with prostate cancer are described, including oral androgen deprivation therapy, agents used to treat a range of cardiovascular diseases, antidiabetic drugs, antidepressants, anti-seizure medications, common urology medications, analgesics, proton pump inhibitors, immunosuppressants, and antigout drugs. Enzalutamide interactions with common vitamins and supplements are also briefly discussed. This review provides a resource for healthcare practitioners and patients that will help provide a basis for the understanding and management of enzalutamide drug-drug interactions to inform decision making, improve patient safety, and optimize drug efficacy.

Sex-Based Outcomes of Dual-Antiplatelet Therapy After Percutaneous Coronary Intervention: A Pairwise and Network Meta-Analysis

BACKGROUND

Although dual antiplatelet therapy (DAPT) improves the outcomes of patients undergoing percutaneous coronary intervention (PCI), sex-specific differences in efficacy and safety of DAPT remain unresolved. We compared sex differences for DAPT outcomes and DAPT durations (1-3 months [short-term], 6 months [mid-term], and >12 months [extended] vs. 12 months).

METHODS

We searched databases through 31 December 2023 for trials reporting DAPT after PCI. The endpoints were major adverse cardiovascular and cerebrovascular events (MACCE), net adverse clinical and cerebrovascular events (NACCE), and any bleeding. Extracted data were pooled in a frequentist network and pairwise, random-effects meta-analysis.

RESULTS

Twenty-two trials (99,591 participants, 25.2% female) were included. Female sex was significantly associated with a higher 1-year MACCE risk (hazard ratio 1.14 [95% confidence interval 1.02-1.28]) and bleeding (1.13 [1.00-1.28]), but not NACCE (1.12 [0.96-1.31]). In sub-analyses, the association between female sex and MACCE was related to use of clopidogrel as the second antiplatelet agent (1.11 [1.03-1.20]), whereas higher bleeding events were related to newer P2Y12 inhibitors (P2Y12i) (1.58 [1.01-2.46]). For DAPT duration, short-term DAPT followed by P2Y12i monotherapy was non-inferior for MACCE in females and males (0.95 [95% CI 0.83-1.10; and 0.96 [0.80-1.16]) but tended to be superior in males for NACCE versus 12-month DAPT (0.96 [0.91-1.01]); mid-term DAPT tended to be associated with a lower bleeding risk in males (0.43 [0.17-1.09]).

CONCLUSIONS

Female sex is associated with higher MACCE and bleeding when newer P2Y12i agents are used. Short-term DAPT followed by P2Y12i monotherapy is safe and effective in both sexes undergoing PCI.

CLINICAL TRIALS REGISTRATION

PROSPERO ID: CRD42021278663.

Antiplatelet Drugs Use in Pregnancy-Review of the Current Practice and Future Implications

When clinicians opt for antithrombotic therapy to manage or prevent thrombotic complications during pregnancy, it is imperative to consider the unique physiological state of the pregnant woman's body, which can influence the pharmacokinetics of the drug, its ability to traverse the placental barrier, and its potential teratogenic effects on the fetus. While the efficacy and safety of aspirin during pregnancy have been relatively well-established through numerous clinical studies, understanding the effects of newer, more potent antiplatelet agents has primarily stemmed from individual clinical case reports necessitating immediate administration of potent antiplatelet therapy during pregnancy. This review consolidates the collective experiences of clinicians confronting novel thrombotic complications during pregnancy, often requiring the use of dual antiplatelet therapy. The utilization of potent antiplatelet therapy carries inherent risks of bleeding, posing threats to both the pregnant woman and the fetus, as well as the potential for teratogenic effects on the fetus. In the absence of official guidelines regarding the use of potent antiplatelet drugs in pregnancy, a plethora of cases have demonstrated the feasibility of preventing recurrent thrombotic complications, mitigating bleeding risks, and successfully managing pregnancies, frequently culminating in cesarean deliveries, through meticulous selection and dosing of antiplatelet medications.

Ticagrelor enhances the cardioprotective effects of ischemic preconditioning in stable patients undergoing percutaneous coronary intervention: the TAPER-S randomized study

BACKGROUND

Ticagrelor improves clinical outcomes in patients with acute coronary syndromes compared with clopidogrel. Ticagrelor also inhibits cell uptake of adenosine and has been associated with cardioprotective effects in animal models. We sought to investigate the potential cardioprotective effects of ticagrelor, as compared with clopidogrel, in stable patients undergoing percutaneous coronary intervention (PCI).

METHODS AND RESULTS

This was a Prospective Randomized Open Blinded End-points (PROBE) trial enrolling stable patients with coronary artery disease (CAD) requiring fractional flow reserve-guided PCI of intermediate epicardial coronary lesions. ST-segment elevation at intracoronary electrocardiogram (IC-ECG) during a two-step sequential coronary balloon inflations in the reference vessel during PCI was used as an indirect marker of cardioprotection induced by ischemic preconditioning (IPC). The primary endpoint of the study was the comparison of the delta (Δ) (difference) ST-segment elevation measured by IC-ECG during two-step sequential coronary balloon inflations.

RESULTS

Fifty-three patients were randomized to either clopidogrel or ticagrelor. The study was stopped earlier because the primary endpoint was met at a pre-specified interim analysis. ΔST-segment elevation was significantly higher in ticagrelor as compared to clopidogrel arms (P < 0.0001). Ticagrelor was associated with lower angina score during coronary balloon inflations. There was no difference in coronary microvascular resistance between groups. Adenosine serum concentrations were increased in patients treated with ticagrelor as compared to those treated with clopidogrel.

CONCLUSIONS

Ticagrelor enhances the cardioprotective effects of IPC compared with clopidogrel in stable patients with CAD undergoing PCI. Further studies are warranted to fully elucidate the mechanisms through which ticagrelor may exert cardioprotective effects in humans.

CLINICAL TRIAL REGISTRATION

http://www.clinicaltrials.gov. Unique Identifier: NCT02701140.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Efficacy and safety of cangrelor as compared to ticagrelor in patients with ST-elevated myocardial infarction (STEMI): a systematic review and meta-analysis

BACKGROUND

This systematic review and meta-analysis aimed to compare the efficacy and safety of cangrelor as compared to ticagrelor in patients with ST-elevated myocardial infarction (STEMI) who underwent percutaneous intervention.

METHODS

PubMed, Embase, Scopus, Web of Science, Cochrane CENTRAL, and ClinicalTrials.gov databases were searched for relevant head-on-comparison or swapping studies. The primary outcome was the rate of high platelet reactivity (HPR) at specific time intervals after stopping cangrelor infusion during the first 24 h. Secondary outcomes were the risks of thrombosis, all-cause mortality and bleeding. Pooled odds ratios (ORs) were calculated using random-effects models.

RESULTS

A total of 1018 studies were screened and eight were included in the analysis. There were four head-on-comparison studies and four swapping studies. There was no significant difference in the proportion of patients achieving a high platelet reactivity in swapping studies [OR, 0.71 (95% CI 0.04, 13.87), p = 0.82, i2 = 88%]. In head-on-comparison studies, PRU from Fig. 2B shows there was no significant reduction in high platelet reactivity [mean difference - 77.83 (95% CI - 238.84, 83.18), p < 0.001, i2 = 100%]. PRU results from (Fig. 2C) show a mean difference of 7.38 (95% CI - 29.74, 44.51), p < 0.001, i2 = 97%. There was no significant difference in the risks of thrombosis [OR, 0.91 (95% CI 0.20, 4.13), p = 0.81, i2 = 0%], all-cause mortality [OR, 3.52 (95% CI 0.44, 27.91), p = 0.24, i2 = 26%] and bleeding [OR, 0.89 (95% CI 0.37, 2.17), p = 0.93, i2 = 0%] between the two groups as revealed in the head-on-comparison studies.

CONCLUSION

The efficacy and safety profiles of cangrelor and ticagrelor were similar in patients with STEMI.

Feasibility and Safety of Bridging Antiplatelet Therapy with Cangrelor in Neuro-Oncology: A Preliminary Experience

Antiplatelet therapy is mandatory for prevention of thrombotic events in patients with a recent history of acute coronary syndromes and/or percutaneous coronary interventions. However, if an urgent surgery is required during antiplatelet therapy, a compromise between the ischemic/thrombotic and hemorrhagic risk has to be reached. Different bridging schemes are reported in the literature, but there is no clear consensus on the optimal treatment strategy in terms of efficacy and safety. Although some indications about the perioperative management of antiplatelet therapy regarding specific surgical specializations are available, balancing the thrombotic and hemorrhagic risk on an individual basis, no evidence referring to neurosurgical or neuro-oncologic procedures is reported. Herein, we present our preliminary experience in the perioperative management of a patient who underwent a neurosurgical procedure for the resection of a primary malignant brain tumor using an intravenous P2Y12 inhibitor (cangrelor) as bridging therapy after a recent acute myocardial infarction treated with primary percutaneous coronary intervention and stenting. The oral P2Y12 inhibitor (clopidogrel) was withdrawn 5 days prior to the surgical procedure and continuous infusion of cangrelor was started 3 days before the surgery at a dose of 0.75 μg/kg/min. Cangrelor was discontinued 2 hours before surgery and resumed 72 hours after tumor resection for further 60 hours. Neither cangrelor-related bleeding nor cardiac ischemic events were observed in the perioperative period and the following 90 days, supporting data regarding the feasibility and safety of this bridging scheme. Further studies are needed to confirm our promising results.

Current Strategies to Guide the Antiplatelet Therapy in Acute Coronary Syndromes

The role of antiplatelet therapy in patients with acute coronary syndromes is a moving target with considerable novelty in the last few years. The pathophysiological basis of the treatment depends on platelet biology and physiology, and the interplay between these aspects and clinical practice must guide the physician in determining the best therapeutic options for patients with acute coronary syndromes. In the present narrative review, we discuss the latest novelties in the antiplatelet therapy of patients with acute coronary syndromes. We start with a description of platelet biology and the role of the main platelet signal pathways involved in platelet aggregation during an acute coronary syndrome. Then, we present the latest evidence on the evaluation of platelet function, focusing on the strengths and weaknesses of each platelet's function test. We continue our review by describing the role of aspirin and P2Y12 inhibitors in the treatment of acute coronary syndromes, critically appraising the available evidence from clinical trials, and providing current international guidelines and recommendations. Finally, we describe alternative therapeutic regimens to standard dual antiplatelet therapy, in particular for patients at high bleeding risk. The aim of our review is to give a comprehensive representation of current data on antiplatelet therapy in patients with acute coronary syndromes that could be useful both for clinicians and basic science researchers to be up-to-date on this complex topic.

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.

Efficacy and safety of low dose intravenous cangrelor in a consecutive cohort of patients undergoing neuroendovascular procedures

BACKGROUND

Cangrelor is an intravenous P2Y12 inhibitor with rapid onset and fast offset of antiplatelet action. Dose adjusted cangrelor based on platelet function testing is suggested to be advantageous for use during neuroendovascular procedures. In this study, we aimed to assess the efficacy and safety of this strategy.

METHODS

This retrospective study included consecutive patients who received low dose intravenous cangrelor (5 µg/kg; infusion 1 µg/kg/min) for ruptured (RIA) and unruptured (UIA) intracranial aneurysms, and acute ischemic stroke (AIS). Indications were acute stenting or intraluminal thrombus. Outcomes were assessed at 24 hours by brain CT and CT angiography. The primary efficacy outcome was the rate of stent occlusion or persistent intraluminal thrombus. The primary safety outcome was the rate of major hemorrhages.

RESULTS

101 patients (56 men; median age (IQR) 59 (51-70) years) received low dose cangrelor for acute stenting (79/101 (78%)) and intraprocedural thrombus (22/101 (22%)). Overall, 5 (4.9%) patients experienced stent occlusion within 24 hours (RIA 3/28; AIS 2/52). There were no cases of failure among UIA patients. Stent mis-opening (fish mouthing or stenosis >50%) was significantly associated with stent occlusion (P<0.001). The overall rate of major hemorrhage was 2% (2/101), which occurred in AIS patients. Platelet reactivity unit (PRU) values were lower in those presenting with major hemorrhage (PRU 4 (SD 1.4) vs PRU 60 (SD 63); P=0.043). Mortality rate after cangrelor related hemorrhage was 1%.

CONCLUSIONS

Low dose cangrelor appears to be effective in preventing stent thrombosis and arterial patency with a low hemorrhagic risk.

Parent artery occlusion after pipeline embolization device implantation of intracranial saccular and fusiform aneurysms

BACKGROUND

Studies reporting parent artery occlusion (PAO) after pipeline embolization device (PED) implantation are limited. The aim of this study was to investigate the incidence rate and risk factors of PAO after PED implantation.

METHODS

In this retrospective study, we enrolled consecutive patients with intracranial saccular and fusiform aneurysms treated with PED implantation at our institution. Multivariate logistic regression analysis was subsequently performed to determine the risk factors for PAO.

RESULTS

A total of 588 saccular and fusiform aneurysms were finally enrolled in the study. PAO was found in 14 (2.38%) aneurysms. The aneurysm complete occlusion rate was 79.6%. Compared with the non-PAO group, aneurysms in the PAO group were larger in size (20.08 vs 9.61 mm; p<0.001), had a greater neck diameter (9.92 vs 6.15 mm; p=0.001), and had higher frequencies of adjunctive coils (64.3% vs 35.7%; p=0.028). In the multivariate logistic analysis, aneurysm size (OR 1.12, 95% CI 1.02 to 1.24; p=0.016) and the presence of poor wall apposition after balloon angioplasty (OR 7.74, 95% CI 1.28 to 46.82; p=0.026) were associated with PAO occurrence after adjusting for confounding factors.

CONCLUSIONS

In this study, the incidence rate of PAO following PED implantation was 2.38% in intracranial saccular and fusiform aneurysms. Aneurysm size and residual presence of poor wall apposition after balloon angioplasty were risk factors for PAO. Further research is required to better understand the mechanisms of PAO.

Dyspnea-Related Ticagrelor Discontinuation After Percutaneous Coronary Intervention

BACKGROUND

Nearly 20% of patients on ticagrelor experience dyspnea, which may lead to treatment discontinuation in up to one-third of cases.

OBJECTIVES

The authors sought to evaluate the incidence, predictors, and outcomes of dyspnea-related ticagrelor discontinuation after percutaneous coronary intervention (PCI).

METHODS

In the TWILIGHT (Ticagrelor With Aspirin or Alone in High-Risk Patients After Coronary Intervention) trial, after 3 months of ticagrelor plus aspirin, patients were maintained on ticagrelor and randomized to aspirin or placebo for 1 year. The occurrence of dyspnea associated with ticagrelor discontinuation was evaluated among all patients enrolled in the trial. A landmark analysis was performed at 3 months after PCI, that is, the time of randomization. Predictors of dyspnea-related ticagrelor discontinuation were obtained from multivariable Cox regression with stepwise selection of candidate variables.

RESULTS

The incidence of dyspnea-related ticagrelor discontinuation was 6.4% and 9.1% at 3 and 15 months after PCI, respectively. Independent predictors included Asian race (lower risk), smoking, prior PCI, hypercholesterolemia, prior coronary artery bypass, peripheral artery disease, obesity, and older age. Among 179 patients who discontinued ticagrelor because of dyspnea after randomization, ticagrelor monotherapy was not associated with a higher risk of subsequent ischemic events (composite of all-cause death, myocardial infarction, or stroke) compared with ticagrelor plus aspirin (5.0% vs 7.1%; P = 0.566).

CONCLUSIONS

In the TWILIGHT trial, dyspnea-related ticagrelor discontinuation occurred in almost 1 in 10 patients and tended to occur earlier rather than late after PCI. Several demographic and clinical conditions predicted its occurrence, and their assessment may help identify subjects at risk for therapy nonadherence.

Switching From Cangrelor to Prasugrel in Patients Undergoing Percutaneous Coronary Intervention: The Switching Antiplatelet-6 (SWAP-6) Study

BACKGROUND

A drug-drug interaction (DDI) may occur when transitioning from intravenous P2Y12 inhibition with cangrelor to oral P2Y12 inhibition with prasugrel. However, this has never been tested in patients undergoing percutaneous coronary intervention (PCI).

OBJECTIVES

This study sought to rule out a DDI when cangrelor and prasugrel are concomitantly administered in PCI patients.

METHODS

SWAP-6 (Switching Antiplatelet-6) was a prospective, randomized, 3-arm, open-label pharmacokinetic (PK) and pharmacodynamic (PD) study. Patients (N = 77) were randomized to 1) prasugrel only at the start of PCI, 2) cangrelor plus prasugrel concomitantly at the start of PCI, or 3) cangrelor at the start of PCI plus prasugrel at the end of infusion. Cangrelor infusion was maintained for 2 hours. PK/PD assessments were performed at baseline and 6 time points postrandomization. The primary endpoint was noninferiority in VerifyNow (Werfen) P2Y12 reaction units measured at 4 hours after randomization between cangrelor plus prasugrel concomitantly administered vs prasugrel only. PK assessments included plasma levels of the active metabolite of prasugrel.

RESULTS

Compared with prasugrel, cangrelor further enhances P2Y12 inhibitory effects. At 4 hours postrandomization, P2Y12 reaction unit levels were significantly lower with prasugrel only compared to cangrelor and prasugrel concomitantly administered (least squares means difference = 130; 95% CI: 85-176), failing to meet the prespecified noninferiority margin. Findings were corroborated by multiple PD assays. The active metabolite of prasugrel levels were not affected by concomitant administration of cangrelor and were low at the end of cangrelor infusion.

CONCLUSIONS

In patients undergoing PCI, concomitant administration of prasugrel with cangrelor leads to a marked increase in platelet reactivity after stopping cangrelor infusion, supporting the presence of a DDI. (Switching Antiplatelet Therapy-6 [SWAP-6]; NCT04668144).

Aspirin microcrystals deposited on high-density microneedle tips for the preparation of soluble polymer microneedles

To reduce mucosal damage in the gastrointestinal tract caused by aspirin, aspirin microcrystals were loaded in soluble polymeric microneedle (MN) tips. Aspirin was prepared into aspirin microcrystals by jet milling. Aspirin microcrystals with particle sizes of 0.5-5 μm were loaded on MN tips with a height of 250 µm or 300 µm. The aspirin microcrystals suspended in a polymer solution were concentrated in the MN tips under negative pressure. The aspirin microcrystals had high stability in the MNs since they were not dissolved in solution during the fabrication process. The MN patch packaged in an aluminum-plastic bag containing silica gel desiccant can be stored at 4 °C. The MN tips implanted in the skin of Institute of Cancer Research (ICR) mice dissolved within 30 min. Isolated porcine ear skin was punctured by MNs with heights of 300 μm and 250 μm to depths of 130 μm and 90 μm, respectively. The fluorescent red (FR) release from MNs reached 98.59% within 24 h. The MNs delivered aspirin microcrystals to the epidermis and dermis, providing a smooth plasma concentration in rats. The MNs loaded with aspirin microcrystals did not evoke primary irritation on the dorsal skin of Japanese white rabbits. In summary, MNs loaded with aspirin microcrystals provide a new approach to improve the stability of aspirin in MN patches.

Mind the Gap: Model-Based Switching from Selatogrel to Maintenance Therapy with Oral P2Y12 Receptor Antagonists

Background: The P2Y12 receptor antagonist selatogrel is being developed for subcutaneous self-administration with a ready-to-use autoinjector at the onset of acute myocardial infarction (AMI) symptoms. The unique pharmacological profile of selatogrel (fast, potent, and short-acting) can bridge the time gap between the onset of AMI and first medical care. A clinical Phase 1 study showed a time-dependent pharmacodynamic interaction between selatogrel and loading doses of clopidogrel and prasugrel. As treatment switching is a common clinical practice, the assessment of subsequent switching from a clopidogrel loading dose to the first maintenance dose of oral P2Y12 receptor antagonists is highly relevant. Objectives: Model-based predictions of inhibition of platelet aggregation (IPA) for the drugs triggering pharmacodynamic interactions were to be derived to support clinical guidance on the transition from selatogrel to oral P2Y12 receptor antagonists. Methods: Scenarios with selatogrel 16 mg administration or placebo followed by a clopidogrel loading dose and, in turn, prasugrel or ticagrelor maintenance doses at different times of administration were studied. Population pharmacokinetic/pharmacodynamic modeling and simulations of different treatment scenarios were used to derive quantitative estimates for IPA over time. Results: Following selatogrel/placebo and a clopidogrel loading dose, maintenance treatment with ticagrelor or a prasugrel loading dose followed by maintenance treatment quickly achieved sustained IPA levels above 80%. Prior to maintenance treatment, a short time span from 18 to 24 h was identified where IPA levels were predicted to be lower with selatogrel than with placebo if clopidogrel was administered 12 h after selatogrel or placebo. Predicted IPA levels reached with placebo alone and a clopidogrel loading dose at 4 h were consistently lower than with selatogrel administration, followed by a clopidogrel loading dose at 12 h. If a clopidogrel loading dose is administered at 12 h, selatogrel maintains higher IPA levels up to 16 h. IPA levels are subsequently lower than on the placebo until the administration of the first maintenance dose. Conclusions: Model-based predictions informed the transition from selatogrel subcutaneous administration to oral P2Y12 therapy. The application of modeling techniques illustrates the value of employing pharmacokinetic and pharmacodynamic modeling for the simulation of various clinical scenarios of switching therapies.

Effect of prasugrel versus ticagrelor on coronary microcirculation in patients undergoing pharmacoinvasive strategy - acute and short-term results

INTRODUCTION

Both ticagrelor and prasugrel are class I recommendations for treatment of ST-elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI) [ 1 ]. But clinical outcomes with the two drugs are conflicting which might be due to differential effects on coronary microcirculation. No study to date had compared the effects of prasugrel or ticagrelor on coronary microcirculation in patients undergoing pharmacoinvasive PCI (pPCI).

AIM AND OBJECTIVE

To compare the effects of prasugrel and ticagrelor on coronary microcirculation in STEMI patients undergoing pPCI as assessed by Myocardial Blush Grade (MBG). The secondary aim was to assess flow in the infarct-related artery by corrected thrombolysis in myocardial infarction (TIMI) frame count (cTFC) and whether a differential effect if detected on coronary microcirculation translated in improvement in left ventricular ejection fraction assessed at 6 months.

MATERIAL AND METHODS

A total of 240 patients with STEMI were evaluated in this open-label randomized control trial who initially underwent thrombolysis and later PCI (from 24 to 48 h) post-successful thrombolysis. The study subjects were randomized to receive either ticagrelor ( n  = 120) or prasugrel ( n  = 120) in 1 : 1 ratio 2 h prior to elective PCI. Patients underwent PCI according to standard protocol and post-procedure cTFC and MBG were compared. Patients were also followed up for 6 months to compare ejection fractions in both groups. We also assessed the effect of the two drugs on bleeding complications during hospitalization and over 6-month follow-up period.

RESULTS

There were no significant differences between the two groups with respect to baseline characteristics. Prasugrel administration resulted in higher MBG Grade 3 (50.86% vs 33.89%, P  = 0.012) and lower cTFC (17.14 ± 4.08 vs 19.3 ± 4.06, P  < 0.01). Improvement in ejection fraction was significantly higher with prasugrel compared to ticagrelor (10.29% ± 15.2 vs 4.66% ± 13.5, P  = 0.003). Bleeding events at 6 months follow-up according to TIMI classification were similar in both the groups (11.86% vs 6.9%, P  = 0.39).

CONCLUSION

Prasugrel produces greater improvement in coronary microcirculation than Ticagrelor resulting in improved myocardial salvage in patients of STEMI undergoing pPCI.

Personalised antiplatelet therapies for coronary artery disease: what the future holds

Coronary artery disease (CAD) is one of the leading causes of death globally, and antiplatelet therapy is crucial for both its prevention and treatment. Antiplatelet drugs such as aspirin and P2Y12 inhibitors are commonly used to reduce the risk of thrombotic events, including myocardial infarction, stroke, and stent thrombosis. However, the benefits associated with the use of antiplatelet drugs also come with a risk of bleeding complications. The ever-growing understanding of the poor prognostic implications associated with bleeding has set the foundations for defining strategies that can mitigate such safety concern without any trade-off in antithrombotic protection. To this extent, personalised antiplatelet therapy has emerged as a paradigm that optimizes the balance between safety and efficacy by customizing treatment to the individual patient's needs and risk profile. Accurate risk stratification for both bleeding and thrombosis can aid in selecting the optimal antiplatelet therapy and prevent serious and life-threatening outcomes. Risk stratification has traditionally included clinical and demographic characteristics and has expanded to incorporate angiographic features and laboratory findings. The availability of bedside platelet function testing as well as rapid genotyping assays has also allowed for a more individualized selection of antiplatelet therapy. This review provides a comprehensive overview of the current state of the art and future trends in personalised antiplatelet therapy for patients with CAD, with emphasis on those presenting with an acute coronary syndrome and undergoing percutaneous coronary revascularization. The aim is to provide clinicians with a comprehensive understanding of personalised antiplatelet therapy and facilitate informed clinical decision-making.

Implementation of CYP2C19 genotyping and clinical outcomes following percutaneous coronary intervention in East Asian patients treated with oral P2Y12 inhibitors

BACKGROUND

The CYP2C19 loss-of-function variants have significant impact on response to clopidogrel. The efficacy and safety of tailored antiplatelet therapy under the guidance of CYP2C19 genetic polymorphisms remains elusive for patients undergoing percutaneous coronary intervention (PCI).

OBJECTIVES

The aims of the present study were to investigate the impact of clinical implementation of CYP2C19 genotyping on the selection of oral P2Y12 inhibitor therapy following PCI, and to estimate the risk of adverse outcomes for patients with different genotype status treated with alternative or traditional P2Y12 inhibitor.

METHODS

Data from a single-center registry enrolling 41,090 consecutive PCI patients treated with dual antiplatelet therapy after PCI were analyzed. Risk of major adverse cardiovascular events (MACEs) and bleeding events within 12 months after PCI were compared across CYP2C19 genotype and antiplatelet therapy groups using Cox proportional hazards models.

RESULTS

CYP2C19 genotyping was successfully achieved for 9081 patients, of whom baseline characteristics significantly differed from non-genotyped patients. A higher proportion of genotyped patients were prescribed ticagrelor compared with non-genotyped patients (27.0 % vs. 15.5 %, P < 0.001). CYP2C19 metabolic status was an independent predictor for use of ticagrelor (P < 0.001). Ticagrelor was significantly associated with a lower risk of MACEs in poor metabolizers (adjusted hazard ratio 0.62, 95 % confidence interval 0.42 to 0.92, P = 0.017), but not in intermediate metabolizers or normal metabolizers. The interaction was not statistically significant (P for interaction = 0.252).

CONCLUSIONS

Genotype information on CYP2C19 metabolic status was associated with an increase in the use of potent antiplatelet therapy in PCI patients. Patients prescribed with clopidogrel has a higher risk of MACEs among poor metabolizers, which suggested the potential application of genotype-guided P2Y12 inhibitor selection for improving clinical outcomes.

A novel de-escalation antiplatelet therapy for patients with acute coronary syndrome undergoing percutaneous coronary intervention

To investigate the effect of different DAPTs in patients with ACS undergoing PCI, and to identify the most efficient DAPT to reduce the risk of ischemia and bleeding after PCI. Between March 2017 and December 2021, 1598 patients with ACS who underwent PCI were included in the study. The DAPT protocol included the clopidogrel group (aspirin 100 mg + clopidogrel 75 mg), ticagrelor group (aspirin 100 mg + ticagrelor 90 mg), de-escalation Group 1 (reduced dose of ticagrelor [from 90 mg to 60 mg]) after 3 months of oral DAPT [aspirin 100 mg + ticagrelor 90 mg]), and de-escalation Group 2 (switched from ticagrelor to clopidogrel after 3 months of oral DAPT [aspirin 100 mg + ticagrelor 90 mg]). All patients received a 12-month follow-up. The primary endpoint was net adverse clinical events (NACEs) that included the composite endpoints of cardiac death, myocardial infarction, ischemia-driven revascularization, stroke, and bleeding events. There were 2 secondary endpoints, major adverse cardiovascular and cerebrovascular events (MACCEs) and bleeding. No statistically significant difference was found in the incidence of NACEs between the 4 groups at the average 12-month follow-up (15.7% vs 19.2% vs 16.7% vs 20.4%). Cox regression analysis revealed that DAPT ticagrelor group regimen (hazard ratio [HR] 0.547; 95% confidence interval [CI]: 0.334-0.896; P  = .017) were associated with a lower risk of MACCEs. Age (HR 1.024; 95% CI: 1.003-1.046; P  = .022). DAPT de-escalation Group 2 regimen (HR 1.665; 95% CI: 1.001-2.767; P  = .049) were marginally associated with a higher risk of MACCEs. Ticagrelor group regimen (HR 1.856; 95% CI: 1.376-2.504; P  < .001) was associated with higher risk of bleeding events. Ticagrelor group regimen (HR 1.606; 95% CI: 1.179-2.187; P  = .003) were associated with a higher risk of minor bleeding events. For patients with ACS underwent PCI, there were no significant difference in the incidence of NACEs between 3 and 12 months after PCI between de-escalation and non-de-escalation therapies. Compared with ticagrelor-based 12-month DAPT, there was no significant difference in MACCEs and bleeding events in patients receiving de-escalation treatment (ticagrelor reduction from 90 to 60 mg, 3 months after PCI).

Evaluating the pharmacokinetic and pharmacodynamic impact of different modes of ticagrelor administration

INTRODUCTION

Alternative administration modes for oral P2Y12 inhibitors, particularly ticagrelor, have emerged as a potential alternative to overcome the limitations associated with the delayed onset of action of these drugs in patients who are unable to swallow or with impaired absorption.

AREAS COVERED

This comprehensive literature review aims to provide an overview of the current state of knowledge on the pharmacokinetics and administration modes of ticagrelor, including factors that may affect its action. It also compares the pharmacokinetics of ticagrelor with that of other drugs with similar uses to provide a comprehensive understanding of the potential advantages and limitations of different modalities of P2Y12 administration. For this purpose, Embase, Medline, Web of Science Core Collection, Cochrane Central Register of Controlled Trials, Google Scholar, and ClinicalTrials.gov were searched from database inception to July 2023.

EXPERT OPINION

Among the different alternatives, crushed formulations, especially for ticagrelor, have emerged as the most promising option, showing early and robust platelet inhibition. However, important questions remain unanswered, such as the comparative clinical benefits of crushed ticagrelor versus standard administration, the cost-effectiveness of alternative modes compared to intravenous P2Y12 inhibitors such as cangrelor, and the important limitations associated with the concomitant use of opioids, who have been proven to impair even the action of crushed ticagrelor.

The Role of Antiplatelet in the Management of Sickle Cell Disease Patients

Sickle cell disease (SCD) is a genetic disorder characterized by abnormal hemoglobin, leading to red blood cell deformities and subsequent vaso-occlusive events. Platelet activation and adhesion play a significant role in the pathophysiology of SCD, contributing to the development of complications such as vaso-occlusive events, stroke, acute chest syndrome, and other manifestations. Antiplatelet therapy has emerged as a potential strategy to mitigate these complications by modulating the platelet function and reducing thrombotic events. This review article provides an overview of antiplatelet therapy's role in managing SCD patients. It discusses the pathophysiological abnormalities in the platelet function in SCD, the rationale for antiplatelet therapy, and the evidence supporting its use in various clinical scenarios. The article explores aspirin as the primary antiplatelet agent in SCD, including its mechanism of action, dosing considerations, and efficacy and safety data. Additionally, it highlights other antiplatelet agents, such as clopidogrel, prasugrel, ticagrelor, and emerging therapies under investigation. Clinical applications of antiplatelet therapy in primary and secondary prevention and the management of acute chest syndrome and other SCD complications are also discussed. Safety considerations are emphasized, including bleeding risk assessment, monitoring, and patient selection for antiplatelet therapy. Finally, the review highlights future research and clinical practice directions, including the development of novel antiplatelet agents, combination therapies, and the integration of antiplatelet therapy with other SCD treatments. Overall, this review provides a comprehensive understanding of the current role of antiplatelet therapy in SCD management, the challenges faced, and future directions for improving patient outcomes.

Cardiovascular precision medicine - A pharmacogenomic perspective

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

Defining Strategies of Modulation of Antiplatelet Therapy in Patients With Coronary Artery Disease: A Consensus Document from the Academic Research Consortium

Antiplatelet therapy is the mainstay of pharmacologic treatment to prevent thrombotic or ischemic events in patients with coronary artery disease treated with percutaneous coronary intervention and those treated medically for an acute coronary syndrome. The use of antiplatelet therapy comes at the expense of an increased risk of bleeding complications. Defining the optimal intensity of platelet inhibition according to the clinical presentation of atherosclerotic cardiovascular disease and individual patient factors is a clinical challenge. Modulation of antiplatelet therapy is a medical action that is frequently performed to balance the risk of thrombotic or ischemic events and the risk of bleeding. This aim may be achieved by reducing (ie, de-escalation) or increasing (ie, escalation) the intensity of platelet inhibition by changing the type, dose, or number of antiplatelet drugs. Because de-escalation or escalation can be achieved in different ways, with a number of emerging approaches, confusion arises with terminologies that are often used interchangeably. To address this issue, this Academic Research Consortium collaboration provides an overview and definitions of different strategies of antiplatelet therapy modulation for patients with coronary artery disease, including but not limited to those undergoing percutaneous coronary intervention, and consensus statements on standardized definitions.

Rescue of immediate post-transcarotid artery revascularization carotid stent thrombosis due to clopidogrel resistance using flow-reversal and aspiration thrombectomy

An 84-year-old patient developed immediate thrombosis of his carotid stent in recovery after transcarotid artery revascularization. In the present report, the technical details about intraoperative management for neurovascular rescue using the transcarotid artery revascularization flow-reversal system are described. The patient was determined to have clopidogrel resistance. Intraoperative medical management is also discussed. The current alternative intravenous and oral antiplatelet therapies such as glycoprotein IIb/IIIa and P2Y12 inhibitors are explored. The debate regarding preoperative antiplatelet resistance testing remains ambiguous, and increasing studies have demonstrated the safety and efficacy of alternatives to clopidogrel. Despite an unpredictable and devastating complication, the patient's outcome was successful using contemporary strategies.

Baseline P2Y12 reactivity, kidney function, and CYP2C19 genotype determine clopidogrel responsiveness in acute stroke

Clopidogrel is the most-widely used platelet P2Y12-inhibitor for secondary-prevention of ischemic stroke. Platelet P2Y12 reactivity before and after inhibitors can be measured with blood sampling by commercialized system. We aimed to evaluate (1) whether high-on-clopidogrel platelet P2Y12 reactivity (HCPR) is associated with short-term vascular events and (2) the predictors of HCPR in acute stroke. The inclusion criterion was patients with acute stroke who received clopidogrel within 12-48 h after the onset. Platelet reactivity was assayed at baseline and after clopidogrel treatment using the VerifyNow system. The primary endpoint was recurrent ischemic events within 21 days after stroke. Among 190 patients, 32(16.9%) had recurrent ischemic stroke. Multivariate analyses showed that HCPR was significantly associated with the short-term events with an odds-ratio of 2.5 (95% CI 1.1-5.7, p = 0.027). Patients with HCPR had significantly higher frequencies of high baseline platelet P2Y12 reactivity, impaired kidney function, and carrying one or two CYP2C19 loss-of-function alleles. A poor clopidogrel response score combining these factors was developed. Ten percent of patients with score 0, 20.3% of those with score 1, 38.3% of those with score 2, and 66.7% of those with score 3 had HCPR (χ²-test, p < 0.001). Multivariate analyses showed that, compared with the score-0 group, the score-2 and -3 groups had higher risks of HCPR with hazard-ratios of 5.4 (95% CI 1.5-20.3, p = 0.012) and 17.4 (95% CI 3.4-88.9, p = 0.001) for developing recurrent ischemic strokes. The study emphasized the role of HCPR in ischemic stroke. We also developed an HCPR risk score, which could be used in clinical practice or trials, potentially with more precision, to weigh the clinical benefit of a tailored antiplatelet-strategy for patients with stroke.

Antiplatelet Strategies Following PCI: A Review of Trials Informing Current and Future Therapies

Dual antiplatelet therapy (DAPT) has been paramount in preventing thrombosis following percutaneous coronary intervention for nearly 3 decades. However, over the years, DAPT has seen significant changes in the agents utilized and duration of therapy as trials have raced to keep up with advancements made in stent technology and our understanding of bleeding and ischemic risk. Recently, there have been a number of trials demonstrating significant reductions in bleeding events with shorter DAPT durations, which are not yet reflected in practice guidelines. Further, there has been a shift toward more individualized antiplatelet regimens to meet patient-specific risk profiles. This review provides a comprehensive summary of the major trials that have informed current DAPT strategies, puts into context recent trials driving a shift toward more tailored antiplatelet regimens, and highlights gaps in knowledge that remain and the ongoing trials designed to address them.

The Signaling Pathway of the ADP Receptor P2Y12 in the Immune System: Recent Discoveries and New Challenges

P2Y12 is a G-protein-coupled receptor that is activated upon ADP binding. Considering its well-established role in platelet activation, blocking P2Y12 has been used as a therapeutic strategy for antiplatelet aggregation in cardiovascular disease patients. However, receptor studies have shown that P2Y12 is functionally expressed not only in platelets and the microglia but also in other cells of the immune system, such as in monocytes, dendritic cells, and T lymphocytes. As a result, studies were carried out investigating whether therapies targeting P2Y12 could also ameliorate inflammatory conditions, such as sepsis, rheumatoid arthritis, neuroinflammation, cancer, COVID-19, atherosclerosis, and diabetes-associated inflammation in animal models and human subjects. This review reports what is known about the expression of P2Y12 in the cells of the immune system and the effect of P2Y12 activation and/or inhibition in inflammatory conditions. Lastly, we will discuss the major problems and challenges in studying this receptor and provide insights on how they can be overcome.

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

Importance

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

Objective

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

Design, Setting, and Participants

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

Exposures

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

Main Outcomes and Measures

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

Results

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

Conclusions and Relevance

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

Reduced-dose prasugrel monotherapy without aspirin after PCI with the SYNERGY stent in East Asian patients presenting with chronic coronary syndromes or non-ST-elevation acute coronary syndromes: rationale and design of the ASET Japan pilot study

The Acetyl Salicylic Elimination Trial (ASET) Japan pilot study is a multicentre, single-arm, open-label, proof-of-concept study with a stopping rule based on the occurrence of definite stent thrombosis. This study aims to demonstrate the feasibility and safety of low-dose prasugrel monotherapy following percutaneous coronary intervention (PCI) in Japanese patients presenting with chronic coronary syndromes (CCS) or non-ST-elevation acute coronary syndromes (NSTE-ACS). Four hundred patients with a SYNTAX score <23 requiring PCI due to CCS or NSTE-ACS will be screened and considered eligible for the study. The enrolment is planned in two phases: 1) 200 patients presenting with CCS, followed by 2) 200 patients presenting with NSTE-ACS. After optimal PCI with implantation of a SYNERGY (Boston Scientific) stent, patients will be enrolled and loaded with prasugrel 20 mg, followed by a maintenance dose of prasugrel 3.75 mg once daily without aspirin continued for 3 months in Phase 1 (CCS patients), and for 12 months in Phase 2 (NSTE-ACS patients). After these follow-up periods, prasugrel will be replaced by standard antiplatelet therapy according to local practice. The primary endpoint is a composite of cardiac death, target vessel myocardial infarction, or definite stent thrombosis after the index procedure. The primary bleeding endpoint is any Bleeding Academic Research Consortium type 3 or 5 bleeding occurring within 3 months of the index PCI for CCS patients, or 12 months for NSTE-ACS patients. The ASET Japan study is designed to demonstrate the feasibility and safety of reduced-dose prasugrel monotherapy after PCI in East Asian patients with acute and chronic coronary syndromes.

Platelet P2Y1 receptor exhibits constitutive G protein signaling and β-arrestin 2 recruitment

BACKGROUND

Purinergic P2Y₁ and P2Y₁₂ receptors (P2Y₁-R and P2Y₁₂-R) are G protein-coupled receptors (GPCR) activated by adenosine diphosphate (ADP) to mediate platelet activation, thereby playing a pivotal role in hemostasis and thrombosis. While P2Y₁₂-R is the major target of antiplatelet drugs, no P2Y₁-R antagonist has yet been developed for clinical use. However, accumulating data suggest that P2Y₁-R inhibition would ensure efficient platelet inhibition with minimal effects on bleeding. In this context, an accurate characterization of P2Y₁-R antagonists constitutes an important preliminary step.

RESULTS

Here, we investigated the pharmacology of P2Y₁-R signaling through Gq and β-arrestin pathways in HEK293T cells and in mouse and human platelets using highly sensitive resonance energy transfer-based technologies (BRET/HTRF). We demonstrated that at basal state, in the absence of agonist ligand, P2Y₁-R activates Gq protein signaling in HEK293T cells and in mouse and human platelets, indicating that P2Y₁-R is constitutively active in physiological conditions. We showed that P2Y₁-R also promotes constitutive recruitment of β-arrestin 2 in HEK293T cells. Moreover, the P2Y₁-R antagonists MRS2179, MRS2279 and MRS2500 abolished the receptor dependent-constitutive activation, thus behaving as inverse agonists.

CONCLUSIONS

This study sheds new light on P2Y₁-R pharmacology, highlighting for the first time the existence of a constitutively active P2Y₁-R population in human platelets. Given the recent interest of P2Y₁₂-R constitutive activity in patients with diabetes, this study suggests that modification of constitutive P2Y₁-R signaling might be involved in pathological conditions, including bleeding syndrome or high susceptibility to thrombotic risk. Thus, targeting platelet P2Y₁-R constitutive activation might be a promising and powerful strategy for future antiplatelet therapy.

Rationale and design of the TUXEDO-2 India study: Ultra-Thin strUt Supraflex Cruz versus XiencE in a Diabetic pOpulation with multi-vessel disease-2

BACKGROUND

The role of percutaneous coronary interventions (PCI) in patients with diabetes mellitus and multi-vessel disease has been questioned by the results of the FREEDOM trial, which showed superiority of coronary artery bypass graft(CABG) over first generation drug-eluting stents (DES) including a reduction in mortality. In the light of safer and more efficacious stents and significantly better medical management, those results that date back to 2012 need to be revisited. TUXEDO-2 is a study designed to compare two contemporary stents in Indian diabetic patients with multi-vessel disease.

AIMS

The primary objective of the TUXEDO-2 study is to compare the clinical outcomes of PCI with ultra-thin Supraflex Cruz vs Xience when combined with contemporary optimal medical therapy (OMT) in diabetic patients with multi-vessel disease. The secondary objective is to compare clinical outcomes between a pooled cohort from both arms of the study (Supraflex Cruz + Xience; PCI arm) vs CABG based on a performance goal derived from the CABG arm of the FREEDOM trial (historical cohort). The tertiary objective is a randomized comparison of ticagrelor vs prasugrel in addition to aspirin for the composite of ischemic and bleeding events.

METHODS

In this prospective, open-label, multi-centre, 2 × 2 factorial, randomized, controlled study, 1,800 patients with diabetes mellitus and multi-vessel disease (inclusion criteria similar to FREEDOM trial) with indication for coronary revascularization will be randomly assigned to Supraflex Cruz or Xience stents and also to ticagrelor- or prasugrel- based antiplatelet strategies. All patients will receive guideline directed OMT and optimal PCI including image- and physiology-guided complete revascularization where feasible. The patients will be followed through five years to assess their clinical status and major clinical events. The primary endpoint is a non-inferiority comparison of target lesion failure at one-year for Supraflex Cruz vs Xience (primary objective) with an expected event rate of 11% and a non-inferiority margin of 4.5%. For PCI vs CABG (secondary objective), the primary endpoint is major adverse cardiac events (MACE), defined as a composite of all cause death, nonfatal myocardial infarction, or stroke at one-year and yearly up to five years, with a performance goal of 21.6%. For ticagrelor vs prasugrel (tertiary objective), the primary endpoint is composite of death, myocardial infarction, stroke, and major bleeding as per the Bleeding Academic Research Consortium (BARC) at one-year with expected event rate of 15% and a non-inferiority margin of 5%.

CONCLUSIONS

The TUXEDO-2 study is a contemporary study involving state-of-the-art PCI combined with guideline directed OMT in a complex subset of patients with diabetes mellitus and multi-vessel disease. The trial will answer the question as to whether a biodegradable polymer coated ultra-thin Supraflex Cruz stent is an attractive option for PCI in diabetic patients with multi-vessel disease. It will also help address the question whether the results of FREEDOM trial would have been different in the current era of safer and more efficacious stents and modern medical therapy. In addition, the comparative efficacy and safety of ticagrelor vs prasugrel in addition to aspirin will be evaluated. (CTRI/2019/11/022088).

Parenteral Antiplatelet Drugs in ST-Elevation Myocardial Infarction: Current Status and Future Directions

Oral inhibitors of the platelet P2Y₁₂ receptor are indispensable in the treatment of ST-elevation myocardial infarction (STEMI), improving outcomes and even reducing mortality in some studies. However, these drugs are limited by delayed absorption and suboptimal platelet inhibition at the time of primary percutaneous coronary intervention. Despite efforts to achieve faster and more sustained platelet inhibition, strategies such as prehospital administration, higher loading doses, and crushed formulations have not led to improved coronary reperfusion. Parenteral glycoprotein IIb/IIIa inhibitors act sooner and are more potent than oral P2Y₁₂ inhibitors, but their use has been limited by the increased risk of major bleeding and thrombocytopenia. Hence, there is a clinical need to refine drugs that deliver rapid, effective, yet safe platelet inhibition in the setting of STEMI. Novel parenteral antiplatelet drugs, such as cangrelor, selatogrel, and zalunfiban, have been recently developed to achieve rapid, potent antiplatelet effects while preserving hemostasis. We provide a description of currently available parenteral antiplatelet agents and of those in clinical development for prehospital administration in STEMI patients.

Pharmacogenetics of P2Y12 receptor inhibitors

Oral P2Y12 inhibitors are commonly prescribed for cardiovascular disease and include clopidogrel, prasugrel, and ticagrelor. Each of these drugs has its strengths and weaknesses. Prasugrel and ticagrelor are more potent inhibitors of platelet aggregation and were shown to be superior to clopidogrel in preventing major adverse cardiovascular events after an acute coronary syndrome and percutaneous coronary intervention (PCI) in the absence of genotyping. However, both are associated with an increased risk for non-coronary artery bypass-related bleeding. Clopidogrel is a prodrug requiring bioactivation, primarily via the CYP2C19 enzyme. Approximately 30% of individuals have a CYP2C19 no function allele and decreased or no CYP2C19 enzyme activity. Clopidogrel-treated carriers of a CYP2C19 no function allele have decreased exposure to the clopidogrel active metabolite and lesser inhibition of platelet aggregation, which likely contributed to reduced clopidogrel efficacy in clinical trials. The pharmacogenetic data for clopidogrel are most robust in the setting of PCI, but evidence is accumulating for other indications. Guidance is available from expert consensus groups and regulatory agencies to assist with integrating genetic information into P2Y12 inhibitor prescribing decisions, and CYP2C19 genotype-guided antiplatelet therapy after PCI is one of the most common examples of clinical pharmacogenetic implementation. Herein, we review the evidence for pharmacogenetic associations with clopidogrel response and outcomes with genotype-guided P2Y12 inhibitor selection and describe guidance to assist with pharmacogenetic implementation. We also describe processes for applying genotype data for P2Y12 inhibitor therapy selection and remaining gaps in the field. Ultimately, consideration of both clinical and genetic factors may guide selection of P2Y12 inhibitor therapy that optimally balances the atherothrombotic and bleeding risks.

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.

Real-world evidence of switching P2Y12 receptor-inhibiting therapies to prasugrel after PCI in patients with ACS: results from EFF-K registry

BACKGROUND

Potent P2Y12 inhibitors are recommended for up to 12 months after percutaneous coronary intervention (PCI) in patients diagnosed with acute coronary syndrome (ACS). However, the prescription pattern is diverse in real world practice, which includes various switching between antiplatelet regimens. In this study, we analyzed the prescription patterns of prasugrel, and assessed the safety and effectiveness of P2Y12 inhibitors switching patterns in a real world registry of patients subjected to PCI after ACS.

METHODS

The EFF-K study included 3077 ACS patients receiving prasugrel-based dual antiplatelet therapy. The cohort was divided into those who were administered with prasugrel as the primary antiplatelet treatment (naïve cohort) or as a substitute agent after clopidogrel or ticagrelor pre-treatment (switch cohort). The primary endpoint was a net adverse clinical event (NACE; a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, or TIMI major bleeding unrelated to coronary-artery bypass grafting).

RESULTS

A total of 3077 patients diagnosed with ACS were included in the analysis. Among the total population, 726 patients (23.6%) were classed as the naïve cohort and 2351 patients (76.4%) as the switch cohort. Baseline characteristics showed that the switch cohort had more comorbidities, such as hypertension, diabetes mellitus, heart failure and previous PCI. The major cause of switching to prasugrel in the switch cohort was the necessity for a more potent antiplatelet agent (56.3%). During a 12-month follow-up period, 51 patients (1.7%) experienced at least one NACE. The incidence of NACE did not differ between the naïve and switch cohort (1.5% vs. 1.7%, Hazard ratio 1.17, 95% Confidence interval 0.56-2.43, P = 0.677). In subgroup analysis, no significant interaction was observed between the treatment strategy and the incidence of NACE across various subgroups.

CONCLUSIONS

Dual antiplatelet therapy with prasugrel seems to be safe and effective both as a primary treatment and as a substitute for other P2Y12 inhibitors in a real world registry of Asian ACS patients receiving PCI.

TRIAL REGISTRATION

KCT0002356, registered June 13, 2017.

Timing, Selection, Modulation, and Duration of P2Y12 Inhibitors for Patients With Acute Coronary Syndromes Undergoing PCI

Dual antiplatelet therapy with aspirin and the oral P2Y₁₂ inhibitor clopidogrel as the cornerstone of treatment for patients with an acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) was firstly established in 2001. Soon thereafter, the newer-generation P2Y₁₂ inhibitors prasugrel and ticagrelor became commercially available. The clinical management of ACS patients undergoing PCI has evolved significantly in the last 2 decades, with a shift toward more rapid invasive management, broader use of drug-eluting stents, and the increasing recognition that major bleeding due to antiplatelet therapy is detrimental. In this ever-changing scenario, numerous studies have addressed 4 main questions regarding P2Y₁₂ inhibition in ACS patients undergoing PCI: timing, selection, modulation, and duration. This paper reviews the latest evidence surrounding these topical questions, with a focus on efficacy and safety data, practice guidelines, and residual areas of uncertainty.

Cangrelor in Patients With Coronary Artery Disease Pretreated With Ticagrelor: The Switching Antiplatelet (SWAP)-5 Study

BACKGROUND

There are no studies specifically designed to rule out a drug-drug interaction (DDI) when cangrelor is used among patients who have been pretreated with ticagrelor.

OBJECTIVES

This study sought to rule out a DDI among cangrelor-treated patients who have been pretreated with ticagrelor.

METHODS

In this prospective, randomized, double-blind, placebo-controlled, crossover, pharmacokinetic (PK) and pharmacodynamic (PD) study, patients with coronary artery disease (N = 20) were pretreated with a 180-mg ticagrelor loading dose and after 1 hour randomized to placebo or cangrelor (bolus and infusion for 2 hours). Patients crossed over after 1 to 4 weeks of washout. PK analysis included ticagrelor plasma levels and its active metabolite. PD assessments included VerifyNow P2Y₁₂ reaction units (PRU), light transmittance aggregometry, vasodilator-stimulated phosphoprotein, and Total Thrombus-Formation Analysis System. PK/PD assessments were performed at 7 time points.

RESULTS

Compared with placebo, adding cangrelor to patients pretreated with ticagrelor resulted in a significant reduction in PRU at 30 minutes and 1 hour after starting infusion. At 2 hours after stopping cangrelor/placebo infusion, PRU were low and similar in both groups (16.9 vs 12.6; mean difference: 4.3; 95% CI: -28.6 to 37.3), meeting the noninferiority primary endpoint (predefined noninferiority margin 45 PRU). Consistent findings were shown with all PD assays. PK tracked PD findings with no differences between groups in plasma levels of ticagrelor and its metabolite.

CONCLUSIONS

Compared with placebo, the use of cangrelor in patients pretreated with ticagrelor results in enhanced platelet inhibition with no differences in PK/PD profiles after discontinuation of drug infusion indicating the absence of a DDI. (PD and PK Profiles of Switching Between Cangrelor and Ticagrelor Following Ticagrelor Pre-treatment [SWAP-5]; NCT04634162).

Dissolvable polymeric microneedles loaded with aspirin for antiplatelet aggregation

To reduce mucosal damage in the gastrointestinal tract caused by aspirin, we developed a dissolvable polymeric microneedle (MN) patch loaded with aspirin. Biodegradable polymers provide mechanical strength to the MNs. The MN tips punctured the cuticle of the skin and dissolved when in contact with the subcutaneous tissue. The aspirin in the MN patch is delivered continuously through an array of micropores created by the punctures, providing a stable plasma concentration of aspirin. The factors affecting the stability of aspirin during MNs fabrication were comprehensively analyzed, and the hydrolysis rate of aspirin in the MNs was less than 2%. Compared to oral administration, MN administration not only had a smoother plasma concentration curve but also resulted in a lower effective dose of antiplatelet aggregation. Aspirin-loaded MNs were mildly irritating to the skin, causing only slight erythema on the skin and recovery within 24 h. In summary, aspirin-loaded MNs provide a new method to reduce gastrointestinal adverse effects in patients requiring aspirin regularly.