Correlations among different platelet aggregation pathways in a group of healthy volunteers

Platelet aggregation is a complicated process mediated by different signaling pathways. As the process is highly complex and apparently redundant, the relationships between these pathways are not yet fully known. The aim of this project was to study the interconnections among seven different aggregation pathways in a group of 53 generally healthy volunteers aged 20 to 66 years. Platelet aggregation was induced with thrombin receptor activating peptide 6 (TRAP), arachidonic acid (AA), platelet activating factor 16 (PAF), ADP, collagen, thromboxane A2 analogue U46619 or ristocetin (platelet agglutination) ex vivo in fasting blood samples according to standardized timetable protocol. Additionally, some samples were pre-treated with known clinically used antiplatelet drugs (vorapaxar, ticagrelor or acetylsalicylic acid (ASA)). Significant correlations among all used inducers were detected (Pearson correlation coefficients (rP): 0.3 to 0.85). Of all the triggers, AA showed to be the best predictor of the response to other inducers with rP ranging from 0.66 to 0.85. Interestingly, the antiplatelet response to ticagrelor strongly predicted the response to unrelated drug vorapaxar (rP = 0.71). Our results indicate that a response to one inducer can predict the response for other triggers or even to an antiplatelet drug. These data are useful for future testing but should be also confirmed in patients.

Computer-directed rational design enhanced the thermostability of carbonyl reductase LsCR for the synthesis of ticagrelor precursor

Carbonyl reductases are useful for producing optically active alcohols from their corresponding prochiral ketones. Herein, we applied a computer-assisted strategy to increase the thermostability of a previously constructed carbonyl reductase, LsCRM4 (N101D/A117G/F147L/E145A), which showed an outstanding activity in the synthesis of the ticagrelor precursor (1S)-2-chloro-1-(3,4-difluorophenyl)ethanol. The stability changes introduced by mutations at the flexible sites were predicted using the computational tools FoldX, I-Mutant 3.0, and DeepDDG, which demonstrated that 12 virtually screened mutants could be thermally stable; 11 of these mutants exhibited increased thermostability. Then a superior mutant LsCRM4-V99L/D150F was screened out from the library that was constructed by iteratively combining the beneficial sites, which showed a 78% increase in activity and a 17.4°C increase in melting temperature compared to LsCRM4. Our computer-assisted design and combinatorial strategy dramatically increased the efficiency of thermostable enzyme production.

Antithrombotic drug removal with hemoadsorption during off-pump coronary artery bypass grafting

BACKGROUND

Patients requiring coronary artery bypass grafting (CABG) are often loaded with antithrombotic drugs (AT) and are at an increased risk for perioperative bleeding complications. Active AT removal by a hemoadsorption cartridge integrated in the cardiopulmonary bypass circuit is increasingly used in this setting to reduce bleeding, and herein we describe the extension of this application in patients on AT undergoing off-pump coronary artery bypass (OPCAB).

METHODS

Ten patients (80% male; mean age: 67.4 ± 9.2years) were treated with ticagrelor (eight patients), rivaroxaban and ticagrelor (one patient), and rivaroxaban (one patient) prior to OPCAB surgery. AT's were discontinued one day before surgery in nine patients and on the day of surgery in one patient, and all patients were also on aspirin. The cohort mean EuroSCORE-II was 2.9 ± 1.5%. A hemoadsorption cartridge was integrated into a dialysis device (n=4) or a stand-alone apheresis pump (n=6) periprocedural, for a treatment time of 145 ± 33 min. Outcome measures included bleeding according to Bleeding Academic Research Consortium (BARC)-4 and 24-hour chest-tube-drainage (CTD).

RESULTS

Mean operation time was 184 ± 35 min. All patients received a left internal thoracic artery with a mean of 2.3 ± 0.9 total grafts. One patient had a BARC-4 bleeding event and there were no surgical re-explorations for bleeding. Mean 24-hours CTD was 680 ± 307mL. During follow-up of 19.5 ± 17.0 months, none of the patients died or required further reinterventions. No device-related adverse events were reported.

CONCLUSIONS

Hemoadsorption via a stand-alone apheresis pump during OPCAB surgery was feasible and safe. This innovative and new approach showed favorable bleeding rates in patients on antithrombotic drugs requiring bypass surgery.

Impact of hemodialysis on efficacies of the antiplatelet agents in coronary artery disease patients complicated with end-stage renal disease

It is controversial whether hemodialysis affects the efficacy of the antiplatelet agents. We aimed to investigate the impact of hemodialysis on efficacies of the antiplatelet agents in coronary artery disease (CAD) patients complicated with end-stage renal disease (ESRD). 86 CAD patients complicated with ESRD requiring hemodialysis were consecutively enrolled. After 5-day treatment with aspirin and clopidogrel or ticagrelor, the platelet aggregations induced by arachidonic acid (PLAA) or adenosine diphosphate (PLADP), and the P2Y12 reaction unit (PRU) were measured before and after hemodialysis. The propensity matching score method was adopted to generate a control group with normal renal function from 2439 CAD patients. In patients taking aspirin, the PLAA remained unchanged after hemodialysis. In patients taking clopidogrel, the PLADP (37.26 ± 17.04 vs. 31.77 ± 16.09, p = 0.029) and corresponding clopidogrel resistance (CR) rate (23 [48.9%] vs. 14 [29.8%], p = 0.022) significantly decreased after hemodialysis, though PRU remained unchanged. Subgroup analysis indicated that PLADP significantly decreased while using polysulfone membrane (36.8 ± 17.9 vs. 31.1 ± 14.5, p = 0.024). In patients taking ticagrelor, PLADP, and PRU remained unchanged after hemodialysis. ESRD patients had higher incidences of aspirin resistance (AR) and CR compared to those with normal renal function (AR: 16.1% vs. 0%, p = 0.001; CR: 48.4% vs. 24.8%, p = 0.024). Hemodialysis does not have negative effect on the efficacies of aspirin, clopidogrel and ticagrelor in ESRD patients with CAD. ESRD patients have higher incidences of AR and CR compared with those with normal renal function.Trial registration ClinicalTrials.gov Identifier: NCT03330223, first registered January 4, 2018.

Ticagrelor monotherapy after a short course of dual antiplatelet therapy with ticagrelor plus aspirin following percutaneous coronary intervention in patients with versus without diabetes mellitus: a meta-analysis of randomized trials

BACKGROUND

Cardiovascular disease (CVD) is one among the major causes of mortality all round the globe. Several anti-platelet regimens have been proposed following percutaneous coronary intervention (PCI). In this analysis, we aimed to show the adverse clinical outcomes associated with ticagrelor monotherapy after a short course of dual antiplatelet therapy (DAPT) with ticagrelor and aspirin following PCI in patients with versus without diabetes mellitus (DM).

METHODS

Electronic databases were searched by four authors from September to November 2023. Cardiovascular outcomes and bleeding events were the endpoints of this analysis. Revman 5.4 software was used to conduct this meta-analysis. Risk ratio (RR) and 95% confidence intervals (CI) were used to represent the results which were generated.

RESULTS

Three studies with a total number of 22,574 participants enrolled from years 2013 to 2019 were included in this analysis. Results of this analysis showed that DM was associated with significantly higher risks of major adverse cardiovascular events (RR: 1.73, 95% CI: 1.49 - 2.00; P = 0.00001), all-cause mortality (RR: 2.15, 95% CI: 1.73 - 2.66; P = 0.00001), cardiac death (RR: 2.82, 95% CI: 1.42 - 5.60; P = 0.003), stroke (RR: 1.78, 95% CI: 1.16 - 2.74; P = 0.009), myocardial infarction (RR: 1.63, 95% CI: 1.17 - 2.26; P = 0.004) and stent thrombosis (RR: 1.74, 95% CI: 1.03 - 2.94; P = 0.04) when compared to patients without DM. However, thrombolysis in myocardial infarction (TIMI) defined minor and major bleedings, bleeding defined according to the academic research consortium (BARC) type 3c (RR: 1.31, 95% CI: 0.14 - 11.90; P = 0.81) and BARC type 2, 3 or 5 (RR: 1.17, 95% CI: 0.85 - 1.62; P = 0.34) were not significantly different.

CONCLUSION

In patients who were treated with ticagrelor monotherapy after a short course of DAPT with ticagrelor and aspirin, DM was an independent risk factor for the significantly increased adverse cardiovascular outcomes. However, TIMI and BARC defined bleeding events were not significantly different in patients with versus without DM.

Population Pharmacokinetic/Pharmacodynamic Models for P2Y12 Inhibitors: A Systematic Review and Clinical Appraisal Using Exposure Simulation

BACKGROUND AND OBJECTIVE

Recent research indicates a correlation between plasma concentration of P2Y12 inhibitors and clinical events, particularly bleeding, which significantly impeded their clinical therapeutic performance. It is therefore vital to delve into the factors that might affect the plasma concentration. The study aims to summarize population pharmacokinetics/pharmacodynamics (PopPKPD) models for commonly prescribed P2Y12 inhibitors (clopidogrel, prasugrel, and ticagrelor) and assess bleeding risk in specific individual groups.

METHODS

The PopPKPD models of P2Y12 inhibitors were collected and summarized based on predetermined inclusion and exclusion criteria. The collected models were replicated in simulations, which were used to assess factors affecting plasma concentrations of P2Y12 inhibitors. Simulation results for special populations were compared to therapeutic window based on reported exposure-effect relationships (PK/PD-related bleeding and thrombotic clinical outcomes) to predict bleeding risk in special populations with different dosing regimens and cumulative covariates.

RESULT

Finally, 12 studies were included for PK simulation, 7 of which that also included PD data were subjected to further analysis, with the majority being based on Phase I or II trials. Simulations showed that several covariates such as female gender, weight, elderly can significantly impact on exposure, with special populations reaching up to 179% of the general population. However, after dose adjustment, blood concentrations for special populations can reach approximately ±20% of general population exposure. Therefore, lowering the maintenance dose of ticagrelor from 90 to 60 mg bid was first recommended to reduce bleeding risk without significantly increasing ischemic risk, particularly in elderly, small-weight Asian females.

CONCLUSION

Lowering the maintenance dose of ticagrelor from 90 to 60 mg bid effectively reduces bleeding risk without increasing thrombotic infarction risk in elderly, small-weight Asian females.

Assessing the impact of a financial incentive and refill reminder program on medication adherence and costs

BACKGROUND

Improving medication adherence remains an important goal to improve therapeutic outcomes and lower health care costs. Point-of-sale prescription costs and forgetfulness remain top reasons why patients do not adhere to medications. Programs using both text message-based reminders and financial incentives may encourage patients to refill their prescriptions on time by reducing copays through discounts at the point of sale. Sempre Health, the subject of our analysis, provides both text message refill reminders and a dynamic discount incentive program to improve medication adherence.

OBJECTIVE

To evaluate the impact of a financial incentive/refill reminder program on medication adherence and total cost of care for patients taking the antithrombotic agents ticagrelor, apixaban, or rivaroxaban in a large regional health plan.

METHODS

After propensity-score matching on demographics, socioeconomic status, baseline copay, prior pharmacy/medical spend, and morbidity, we compared-using a difference-in-differences analytic approach-adherence (measured by proportion of days covered), unplanned health care utilization, and costs (total cost of care, medical, and pharmacy cost) of health plan members who did and did not enroll in the financial incentive/refill reminder program between February 1, 2019, and October 31, 2021, over 1 and 2 years. Because of differences in patient characteristics, we analyzed patients on ticagrelor (the antiplatelet group), apixaban, and rivaroxaban (the anticoagulant group) separately.

RESULTS

There were a total of 1,292 one-to-one program and control propensity-matched patients: 166 each for the antiplatelet group and 480 each for the anticoagulant group. The average age of the anticoagulant group was 62 years; more than 60% were male, and approximately 45% had no prior unplanned care events. In contrast, the average age of the antiplatelet group was 57 years; more than 70% were male, and approximately 21% had no prior unplanned care events. In the antiplatelet group, the proportions adherent (proportion of days covered ≥80%) were 63.3% vs 42.8% (P = 0.0002) for program vs controls. Similarly, in the anticoagulant group, the proportion adherent was 77.9% vs 60.2% (P < 0.0001) for program vs controls. Reflecting improved adherence, costs of apixaban and rivaroxaban increased by $79 per member per month (PMPM) (P < 0.0001), with no statistically significant differences in other costs. Similarly, the cost of ticagrelor increased by $77 PMPM (P = 0.0102) with no statistically significant differences in other costs. Finally, there was a 16% (P = 0.032) reduction in emergency department use for those in the program.

CONCLUSIONS

The financial incentive and refill reminder program was associated with improved adherence to antithrombotic medications, reduced emergency department use, and increased medication costs, but not in total pharmacy, medical, or total cost of care in both subgroups.

Ticagrelor Increases Exposure to the Breast Cancer Resistance Protein Substrate Rosuvastatin

Ticagrelor and rosuvastatin are often used concomitantly after atherothrombotic events. Several cases of rhabdomyolysis during concomitant ticagrelor and rosuvastatin have been reported, suggesting a drug-drug interaction. We showed recently that ticagrelor inhibits breast cancer resistance protein (BCRP) and organic anion transporting polypeptide (OATP) 1B1, 1B3, and 2B1-mediated rosuvastatin transport in vitro. The aim of this study was to investigate the effects of ticagrelor on rosuvastatin pharmacokinetics in humans. In a randomized, crossover study, 9 healthy volunteers ingested a single dose of 90 mg ticagrelor or placebo, followed by a single 10 mg dose of rosuvastatin 1 hour later. Ticagrelor 90 mg or placebo were additionally administered 12, 24, and 36 hours after their first dose. Ticagrelor increased rosuvastatin area under the plasma concentration-time curve (AUC) and peak plasma concentration 2.6-fold (90% confidence intervals: 1.8-3.8 and 1.7-4.0, P = 0.001 and P = 0.003), and prolonged its half-life from 3.1 to 6.6 hours (P = 0.009). Ticagrelor also decreased the renal clearance of rosuvastatin by 11% (3%-19%, P = 0.032). The N-desmethylrosuvastatin:rosuvastatin AUC0-10h ratio remained unaffected by ticagrelor. Ticagrelor had no effect on the plasma concentrations of the endogenous OATP1B substrates glycodeoxycholate 3-O-glucuronide, glycochenodeoxycholate 3-O-glucuronide, glycodeoxycholate 3-O-sulfate, and glycochenodeoxycholate 3-O-sulfate, or the sodium-taurocholate cotransporting polypeptide substrate taurocholic acid. These data indicate that ticagrelor increases rosuvastatin concentrations more than twofold in humans, probably mainly by inhibiting intestinal BCRP. Because the risk for rosuvastatin-induced myotoxicity increases along with rosuvastatin plasma concentrations, using ticagrelor concomitantly with high doses of rosuvastatin should be avoided.

Facile fabrication of an extended-release tablet of Ticagrelor using three dimensional printing technology

The objective of the study was to fabricate tailored extended-release tablets of blood thinner Ticagrelor as once-daily dosing using additive manufacturing for better compliance in heart failure therapy. The solid work design of the tablet was printed using hot melt extrusion (HME) based 3D printing by optimized mixture of Eudragit RS-100, plasticizer and drug for producing extrudable and printable filaments. FTIR and TGA results showed no covalent interaction among ingredients and no decomposition during HME process, respectively. Friability, weight variation, assay and content uniformity tests met USP requirements, while the mean hardness of the tablets was calculated in a value between 40 and 50 kg. According to DSC and XRD results, the crystallinity state of the Ticagrelor was converted to an amorphous one in the tablet matrix. Smooth surfaces with multiple deposited layers were observed using SEM. In comparison, the maximum Ticagrelor release of 100% after 120 min from Brilinta® tablets was decreased to 97% in 400 min from the 3D tablet at infill of 90%. Korsmeyer-Peppas kinetic model showed the drug release mechanism is affected by diffusion and swelling. In general, fabrication of the extended-release 3D printed tablet of Ticagrelor using HME-based-additive manufacturing has the potential to provide specific doses with tailored kinetic release for personalized medicine, improving adherence at point-of-care.

The Prognostic impact of treatments evolution in STEMI

OBJECTIVE

To evaluate in a real-world primary percutaneous coronary intervention (pPCI) registry the impact of the evolution of evidence-based treatments on prognosis.

METHODS

STEMI patients undergoing pPCI at the University Hospital of Trieste, Italy, were enrolled. The first cohort (old treatments cohort) included STEMI patients treated between January-2007 and December-2012, and the second cohort (new treatments cohort), between January-2013 and December-2020. Inverse Probability of Treatment Weighting (IPTW) Cox regression models as well as multivariable Cox regression models were performed to assess the risk of a composite primary endpoint (PE) of all cause death, reinfarction and re-PCI at 5 years.

RESULTS

A total of 2425 STEMI patients were enrolled. At multivariable Cox regression, the new-treatments cohort had lower risk of PE and mortality. Weighted (IPTW) Cox proportional hazard models confirmed the lower risk of the new treatments cohort for PE (HR 0.72; 95% CI 0.56-0.91, p = 0.007) and 5-year mortality (HR 0.70, 95%CI 0.54-0.91, p = 0.009). When considering both clinical and procedural variables, complete revascularization (HR 0.46, 95%CI 0.27-0.80, p = 0.006) and the administration of prasugrel or ticagrelor (HR 0.72, 95%CI 0.52-0.99, p = 0.013) were independent predictors of PE as well as of 5-year mortality. Patients receiving prasugrel or ticagrelor or drug eluting stent were at lower risk of 1-year stent thrombosis (HR 0.50, 95%CI 0.28-0.90, p = 0.021).

CONCLUSIONS

In a real-word STEMI population the prognosis of patients has improved in the last decades, and this was associated to the use of new antithrombotic treatments and to the implementation of complete revascularization.

An eco-friendly ultra-performance liquid chromatography-mass spectrometry method for quantification of rivaroxaban and ticagrelor in rat plasma: grapefruit interactions

Aim: An eco-friendly ultra-performance liquid chromatography-tandem mass spectrometry method was developed to study the pharmacokinetics of rivaroxaban and ticagrelor in rat plasma, utilizing moxifloxacin as an internal standard. The food-drug interaction between grapefruit juice and these drugs was also investigated. Methods: Liquid-liquid extraction was used. A nonporous stationary phase Agilent® Poroshell 120EC C18 column was used with methanol: 0.1% aqueous formic acid (95:5 v/v) as a mobile phase. The detection was performed in multiple reaction monitoring mode using positive electrospray ionization. The method's validation was conducted in accordance with US FDA and European Medicines Agency guidelines. Results & conclusion: Grapefruit juice should be ingested with caution in patients treated with antithrombotic medications as it may increase their plasma concentration, inducing bleeding, and requires close clinical monitoring.

Refractory drug-induced systemic small-vessel vasculitis with two varied extracutaneous manifestations: a case report and review of the literature

BACKGROUND

Clopidogrel and ticagrelor are rarely reported to cause vasculitis via drug hypersensitivity reaction, largely mediated by T cells and immunoglobulin E (IgE). Despite therapeutic advances, the etiology of refractory vasculitides remains incompletely understood. Recently, (non)immunological mechanisms bypassing T cells and IgE have been proposed to explain resistance to standard immunosuppressants. Herein, we report a case of refractory drug-induced systemic small-vessel vasculitis with varied extracutaneous manifestations and incorporate multiple sources of data to provide detailed accounts of complex (non)immunological phenomena involved in this case. Study objectives are to provide an insight about rare presentations of commonly used drugs, upgrade the pathophysiological concepts of drug-induced vasculitis, raise need for further investigation to define causes and risk factors for refractory vasculitis, and discuss most of the current knowledge suggesting novel therapeutic approaches to treat this vasculitis. To our knowledge, this is the first case of the two flares of systemic small-vessel vasculitis in a single patient in response to clopidogrel and ticagrelor exposure, respectively. However, this report is limited by attribution/observer bias.

CASE PRESENTATION

We herein report a 24-year-old Caucasian male student with a medical history of mild seasonal allergic rhinoconjunctivitis, tension-type headaches, posttraumatic arterial stenosis, and previous exposure to ibuprofen, acetylsalicylic acid, and mRNA coronavirus disease 2019 (COVID-19) vaccine who suffered largely from acute urticaria and dyspnea after 20 days of acetylsalicylic acid and clopidogrel introduction. A skin punch biopsy confirmed leukocytoclastic vasculitis. Serologic antibody testing, complement analysis, microbiologic testing, and cancer biomarkers revealed no abnormalities. Regarding the patient's medical history, both acetylsalicylic acid and clopidogrel were exchanged for ticagrelor. Furthermore, the addition of naproxen, cyclosporine, bilastine, prednisolone, and montelukast resulted in complete recovery. After 7 days, diarrhea and hematuria occurred. Urinalysis and computed tomography showed reversible proteinuria with gross hematuria and hypodense changes in kidney medulla, respectively, associated with discontinuation of ticagrelor and naproxen. In addition, the patient recovered completely without any immunosuppression up-titration.

CONCLUSIONS

This case highlights the role of clopidogrel and ticagrelor as possible triggering agents for systemic small-vessel vasculitis and offers an insight into novel therapeutic strategies for refractory vasculitides. Further research is needed to build on the findings of a current report.

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.

Platelet Inhibition with Ticagrelor 60 mg Versus 90 mg Twice Daily in Elderly Patients with Acute Coronary Syndrome: Rationale and Design of the PLINY THE ELDER Trial

BACKGROUND

Elderly status is steadily increasing among patients with acute coronary syndrome (ACS). Dual antiplatelet therapy (DAPT) with aspirin and a potent P2Y12 receptor inhibitor is the cornerstone of treatment to prevent recurrent thrombotic complications in patients with ACS. However, DAPT in older patients is challenged by a concurrent heightened risk of ischemia and bleeding. The aim of this study is to evaluate the pharmacodynamic and pharmacokinetic profile of a lower dose of ticagrelor (60 mg twice daily) among elderly patients during the early phase of ACS.

STUDY DESIGN

PLINY THE ELDER (PLatelet INhibition with two different doses of potent P2y12 inhibitors in THE ELDERly population) (NCT04739384) is a prospective, randomized, open-label, crossover trial to evaluate the non-inferiority of a lower dose of ticagrelor (60 mg twice daily) compared with a standard dose (90 mg twice daily) among elderly patients with ACS undergoing percutaneous coronary intervention (PCI). A total of 50 patients, aged 75 years or more, with indication to potent P2Y12 receptor inhibitors will be randomized within 3 days from PCI for the index ACS. Patients with indication to oral anticoagulant therapy, treatment with glycoprotein IIb/IIIa inhibitors, or active bleeding will be excluded. The primary endpoint is platelet reactivity determined by P2Y12 reaction units (PRU) (VerifyNow, Accumetrics, San Diego, CA, USA) after treatment with ticagrelor 60 or 90 mg twice daily for 14 days. Secondary endpoints will include other pharmacodynamic tests of ADP-induced aggregation (light transmittance aggregometry and multiple electrode aggregometry) and determination of pharmacokinetic profile (plasma levels of ticagrelor and its metabolite AR-C124910XX) by high performance liquid chromatography-tandem mass spectrometry.

CONCLUSIONS

The PLINY THE ELDER trial will determine whether a lower dose of ticagrelor confers non-inferior platelet inhibition compared with the standard dose in the early phase of ACS among elderly patients undergoing PCI, informing future clinical investigation.

A Machine Learning-Based Image Segmentation Method to Quantify In Vitro Osteoclast Culture Endpoints

Quantification of in vitro osteoclast cultures (e.g. cell number) often relies on manual counting methods. These approaches are labour intensive, time consuming and result in substantial inter- and intra-user variability. This study aimed to develop and validate an automated workflow to robustly quantify in vitro osteoclast cultures. Using ilastik, a machine learning-based image analysis software, images of tartrate resistant acid phosphatase-stained mouse osteoclasts cultured on dentine discs were used to train the ilastik-based algorithm. Assessment of algorithm training showed that osteoclast numbers strongly correlated between manual- and automatically quantified values (r = 0.87). Osteoclasts were consistently faithfully segmented by the model when visually compared to the original reflective light images. The ability of this method to detect changes in osteoclast number in response to different treatments was validated using zoledronate, ticagrelor, and co-culture with MCF7 breast cancer cells. Manual and automated counting methods detected a 70% reduction (p < 0.05) in osteoclast number, when cultured with 10 nM zoledronate and a dose-dependent decrease with 1-10 μM ticagrelor (p < 0.05). Co-culture with MCF7 cells increased osteoclast number by ≥ 50% irrespective of quantification method. Overall, an automated image segmentation and analysis workflow, which consistently and sensitively identified in vitro osteoclasts, was developed. Advantages of this workflow are (1) significantly reduction in user variability of endpoint measurements (93%) and analysis time (80%); (2) detection of osteoclasts cultured on different substrates from different species; and (3) easy to use and freely available to use along with tutorial resources.

Cell Surface Platelet Tissue Factor Expression: Regulation by P2Y12 and Link to Residual Platelet Reactivity

BACKGROUND

ADP-induced platelet activation leads to cell surface expression of several proteins, including TF (tissue factor). The role of ADP receptors in platelet TF modulation is still unknown. We aimed to assess the (1) involvement of P2Y1 and P2Y12 receptors in ADP-induced TF exposure; (2) modulation of TFpos-platelets in anti-P2Y12-treated patients with coronary artery disease. Based on the obtained results, we revisited the intracellular localization of TF in platelets.

METHODS

The effects of P2Y1 or P2Y12 antagonists on ADP-induced TF expression and activity were analyzed in vitro by flow cytometry and thrombin generation assay in blood from healthy subjects, P2Y12-/-, and patients with gray platelet syndrome. Ex vivo, P2Y12 inhibition of TF expression by clopidogrel/prasugrel/ticagrelor, assessed by VASP (vasodilator-stimulated phosphoprotein) platelet reactivity index, was investigated in coronary artery disease (n=238). Inhibition of open canalicular system externalization and electron microscopy (TEM) were used for TF localization.

RESULTS

In blood from healthy subjects, stimulated in vitro by ADP, the percentage of TFpos-platelets (17.3±5.5%) was significantly reduced in a concentration-dependent manner by P2Y12 inhibition only (-81.7±9.5% with 100 nM AR-C69931MX). In coronary artery disease, inhibition of P2Y12 is paralleled by reduction of ADP-induced platelet TF expression (VASP platelet reactivity index: 17.9±11%, 20.9±11.3%, 40.3±13%; TFpos-platelets: 10.5±4.8%, 9.8±5.9%, 13.6±6.3%, in prasugrel/ticagrelor/clopidogrel-treated patients, respectively). Despite this, 15% of clopidogrel good responders had a level of TFpos-platelets similar to the poor-responder group. Indeed, a stronger P2Y12 inhibition (130-fold) is required to inhibit TF than VASP. Thus, a VASP platelet reactivity index <20% (as in prasugrel/ticagrelor-treated patients) identifies patients with TFpos-platelets <20% (92% sensitivity). Finally, colchicine impaired in vitro ADP-induced TF expression but not α-granule release, suggesting that TF is open canalicular system stored as confirmed by TEM and platelet analysis of patients with gray platelet syndrome.

CONCLUSIONS

Data show that TF expression is regulated by P2Y12 and not P2Y1; P2Y12 antagonists downregulate the percentage of TFpos-platelets. In clopidogrel good-responder patients, assessment of TFpos-platelets highlights those with residual platelet reactivity. TF is stored in open canalicular system, and its membrane exposure upon activation is prevented by colchicine.

Clinical Updates on Antiplatelet Therapy for Secondary Prevention in Acute Ischemic Stroke

Antiplatelet therapy is the first-line management for noncardioembolic transient ischemic attack (TIA) and acute ischemic stroke (IS). Herein, we review the safety and efficacy of antiplatelet therapies in patients with IS and TIA, primarily focusing on the acute stage. We discuss current antiplatelet monotherapy and the factors influencing efficacy and continuation rate according to clinical trial data. Aspirin remains the most commonly used first-line antiplatelet agent for preventing noncardioembolic stroke recurrence, and clopidogrel, cilostazol, and ticagrelor are feasible alternatives. Various short-term dual antiplatelet therapies (including clopidogrel-aspirin and ticagrelor-aspirin combination therapy) for minor stroke and high-risk TIA are also reviewed. For selected patients with specific stroke etiologies, short-term dual antiplatelet therapy with aspirin combined with clopidogrel or ticagrelor can significantly reduce the risk of stroke. However, insufficient evidence supports the benefits of triple antiplatelet therapy for recurrent noncardioembolic stroke prevention, and this treatment substantially increases the rate of bleeding complications. Keyword: antiplatelet therapy, acute ischemic stroke, secondary prevention, transient ischemic attack.

Influence of early dose reduction of ticagrelor on clinical outcomes following percutaneous coronary intervention for complex lesions

Ticagrelor-based dual antiplatelet therapy (DAPT) provides potent antiplatelet inhibition but may increase the bleeding risk in Asian populations. We investigated the influence of early ticagrelor dose reduction (120 mg) on clinical outcomes in Korean patients undergoing percutaneous coronary intervention (PCI). A multicenter prospective clinical cohort study was conducted with patients who received standard-dose ticagrelor-based DAPT (180 mg) after PCI for complex lesions. Major adverse cardiovascular event (MACE: a composite of cardiovascular death, myocardial infarction, stroke, and repeat revascularization), bleeding, and net adverse clinical events (NACE: a composite of MACE and bleeding) were assessed. Among the 772 patients on standard-dose ticagrelor-based DAPT, 115 (14.8%) switched to low-dose ticagrelor-based DAPT (120 mg) within 6 months. Common reasons for the regimen changes were switching as planned (38.8%), dyspnea (25.5%), and bleeding (23.6%). A multivariable Cox proportional hazard model (CPH) showed that the risks of MACE, bleeding, and NACE were not different between the low-dose and standard-dose groups throughout the entire follow-up period and the period beyond 6 months post-PCI. Time-varying multivariable CPH models of the ticagrelor dose reduction yielded similar results. A reduction of the ticagrelor dose within 6 months after PCI is feasible and safe even in patients with complex lesions harboring a high ischemic event risk.

Sample pretreatment and HPLC determination of antiplatelet drug ticagrelor in blood plasma from patients with acute coronary syndromes

A simple HPLC method was developed for the determination of antiplatelet drug ticagrelor (TCG) in blood. Sample preparation and extraction conditions were investigated and optimized. The preparation of blood plasma was investigated by protein precipitation using perchloric acid, methanol, acetonitrile (ACN), and trifluoroacetic acid. Protein precipitation using ACN was found to be the most suitable. Chromatographic separation of TCG was performed on a C18 column with a mobile phase consisting of ACN and 15 mM ammonium acetate buffered at pH 8.0. The method was applied to determine TCG in blood plasma of patients who had a heart attack. Blood samples were collected 1.5 h after the administration of the initial loading dose of the antiplatelet drug. The average concentration of TCG was found to be 0.97 ± 0.53 μg/ml. The developed method proved to be very selective, without interferences from other endogenous substances and the influences of possible coadministered drugs. The limits of detection and quantification estimated by the signal-to-noise ratio in real samples were 0.24 and 0.4 μg/ml, respectively. The developed method is simple and can be easily applied in clinics and emergency cardiac situations after the initial loading dose of TCG in the first few hours of a heart attack.

Comparison of Different Chronic Maintenance Antithrombotic Strategies in Patients with Coronary Artery Disease: A Systematic Review and Network Meta-Analysis

Background

Optimal antithrombotic therapy during the chronic maintenance period in patients with coronary artery disease (CAD) is unknown. We compared five kinds of mainstream chronic maintenance antithrombotic strategies at least one year after the acute phase: aspirin alone, clopidogrel alone, ticagrelor alone, continued dual antiplatelet therapy (DAPT) for a period of time, and maintenance with aspirin combined with a low-dose anticoagulant such as rivaroxaban.

Methods

Ten randomized, controlled trials were selected using PubMed, Ovid MEDLINE, Embase, and Cochrane library through February 2023. The primary outcome was main adverse cardiac events (MACEs), and secondary outcomes include net adverse clinical events (NACEs), cardiac death, all-cause death, ischemic stroke, stent thrombosis, total bleeding, and major bleeding. A network meta-analysis was conducted with a random-effects model. Data extraction was performed by three independent reviewers.

Results

Our search identified ten eligible randomized controlled trials enrolling a total of 82,084 patients comparing different chronic maintenance antithrombotic strategies. As for the primary endpoint, there was no statistical difference in MACE outcomes between any two of the five methods. As for the secondary endpoint, there was no statistical difference in NACE, major bleeding, all-cause death, cardiac death, and stent thrombosis between any two methods. The aspirin plus low-dose rivaroxaban group had a lower incidence of ischemic stroke compared to the aspirin group (OR = 0.49, 95% CrI 0.26-0.91). And the prolonged DAPT group had a higher total bleeding rate compared to aspirin group (OR = 2.4, 95% CrI 1.1-5.9).

Conclusions

In terms of MACE, NACE, all-cause death, cardiac death, stent thrombosis, and major bleeding, there were no significant differences between using aspirin alone, clopidogrel alone, and ticagrelor alone; extending DAPT duration; and using aspirin combined with low-dose rivaroxaban for chronic maintenance antithrombotic regimens. However, choosing aspirin combined with low-dose rivaroxaban can reduce the incidence of ischemic stroke, and prolonged DAPT may have a higher rate of total bleeding. However, it is important to note that this study is based on indirect comparisons, and there is currently a lack of direct evidence comparing various maintenance antiplatelet therapy regimens. Further high-quality studies are needed to address this gap and provide more conclusive evidence on the comparative effectiveness of different maintenance antiplatelet strategies.

Dual Antiplatelet Therapy with 3rd Generation P2Y12 Inhibitors in STEMI Patients: Impact of Body Mass Index on Loading Dose-Response

PURPOSE

This study aims to assess the association between body mass index (BMI) and platelet reactivity in STEMI patients treated with oral 3rd generation P2Y12 inhibitors.

METHODS

Overall, 429 STEMI patients were enrolled in this study. Patients were divided into two groups according to BMI (BMI < 25 vs ≥ 25 kg/m2). A propensity score matching (1:1) was performed to balance potential confounders in patient baseline characteristics. Platelet reactivity was assessed by VerifyNow at baseline and after 3rd generation P2Y12 inhibitor (ticagrelor or prasugrel) loading dose (LD). Blood samples were obtained at baseline (T0), 1 h (T1), 2 h (T2), 4-6 h (T3), and 8-12 h (T4) after the LD. High on-treatment platelet reactivity (HTPR) was defined as a platelet reactivity unit value ≥ 208 units.

RESULTS

After propensity score matching, patients with BMI ≥ 25 had similar values of baseline platelet reactivity, while they had higher level of platelet reactivity at 1 and 2 h after the LD and higher rate of HRPT. Furthermore, multivariate analysis demonstrated that BMI ≥ 25 was an independent predictor of HTPR at 2 h (OR 2.01, p = .009). Conversely, starting from 4 h after the LD, platelet reactivity values and HRPT rates were comparable among the two study groups.

CONCLUSIONS

A BMI ≥ 25 kg/m2 is associated with delayed pharmacodynamic response to oral 3rd generation P2Y12 inhibitor LD, and it is a strong predictor of HTPR in STEMI patients treated by dual antiplatelet therapy with ticagrelor or prasugrel.

Biolimus-eluting vs. other limus-eluting stents in NSTE-ACS: A pooled analysis of GLASSY and TWILIGHT

BACKGROUND

Biodegradable polymer biolimus-eluting stents (BP-BES) may be associated with better outcomes in patients with acute coronary syndromes (ACS) undergoing percutaneous coronary intervention (PCI) compared to other current-generation limus-eluting stents (LES).

AIMS

To compare BP-BES with other current-generation LES in ACS patients undergoing PCI.

METHODS

We pooled individual data of Non-ST-segment elevation (NSTE)-ACS patients from two large randomized controlled trials (GLASSY and TWILIGHT). The BP-BES groups consisted mostly of GLASSY patients, while the control group (other current-generation LES) included exclusively TWILIGHT patients. The primary outcome was major adverse cardiovascular events (MACE), including cardiovascular death, myocardial infarction, or stent thrombosis; the key secondary outcome was target-vessel failure (TVF). To account for trial design differences, outcomes were assessed at 3 months (short-term) and between 3 and 12 months (long-term) after PCI and subsequently pooled to estimate the 12-month hazards.

RESULTS

Of 7107 and 6053 NSTE-ACS patients included in the short- and long-term analysis, 32.7% and 36.5% received a BP-BES, respectively. Risk of MACE associated with BP-BES versus other LES was similar at short-term (1.1% vs 1.3%, adjusted HR 0.86, 95%CI 0.53-1.38), lower at long-term (1.7% vs 3.1%, adjusted HR 0.49, 95%CI 0.34-0.72), and lower in the entire 12-month period (pooled adjusted HR 0.61, 95%CI 0.45-0.82). The cumulative 12-month risk of TVF was reduced with BP-BES (adjusted HR 0.52, 95%CI 0.38-0.70).

CONCLUSION

BP-BES was associated with lower 12-month risks of MACE and TVF compared to other current generation LES among NSTE-ACS patients treated with abbreviated or standard ticagrelor-based DAPT. These non-randomized findings are hypothesis-generating.

CONDENSED ABSTRACT

Differences in clinical outcomes may exist between biodegradable polymer biolimus-eluting stents (BP-BES) and other current-generation limus-eluting stent (LES) in patients with acute coronary syndrome (ACS). We pooled individual data of about 7000 Non-ST-segment elevation ACS patients undergoing PCI and treated with ticagrelor with or without aspirin from two large randomized controlled trials (GLASSY and TWILIGHT). BP-BES patients derived very largely from GLASSY and other LES patients from TWILIGHT. In this population, BP-BES compared to other current generation LES, were associated with a lower 12-month risk of major adverse cardiovascular events and target-vessel failure.

Antiplatelet Therapy in Neurointervention

The aim of this review is to provide an overview of the use of antiplatelet medication in neurointervention, with a focus on the clinical indications for antiplatelet use in both preventing and reducing platelet aggregation. This review will cover current antiplatelet medications, pharmacokinetics, and pharmacodynamics. We will provide an overview of different endovascular devices and discuss the antiplatelet regimes in neurointervention, highlighting gaps in evidence and scope for future studies.Two randomized controlled trials have evaluated antiplatelet use in the setting of acute large vessel occlusion stroke, with neither demonstrating benefit in their overall cohorts. Evidence on antiplatelet medication for both acute and elective stenting for acute stroke and treatment of cerebral aneurysms is currently based on large case series, and practice in neurointervention has increasingly utilized dual antiplatelet regimes with clopidogrel and second-line agents like prasugrel and ticagrelor. Clopidogrel function testing has an increasing role in neurointerventional procedures, particularly for high metal surface area stents such as the braided flow diverter type stents. Intravenous glycoprotein IIB/IIIA inhibitors have been utilized for both acute bridging and rescue therapy.Antiplatelet decision making is complex, and there are few randomized control trials to guide clinical practice. Comparative trials to guide decision making remain important in both the acute and elective settings. Standardised protocols incorporating platelet function testing may play a role in assisting decision making until more robust clinical evidence is available, particularly in the context of acute neurointerventional stenting for stroke and ruptured cerebral aneurysms.

Bleeding risk in patients prescribed dual antiplatelet therapy and triple therapy after coronary interventions: the ADAPTT retrospective population-based cohort studies

Background

Bleeding among populations undergoing percutaneous coronary intervention or coronary artery bypass grafting and among conservatively managed patients with acute coronary syndrome exposed to different dual antiplatelet therapy and triple therapy (i.e. dual antiplatelet therapy plus an anticoagulant) has not been previously quantified.

Objectives

The objectives were to estimate hazard ratios for bleeding for different antiplatelet and triple therapy regimens, estimate resources and the associated costs of treating bleeding events, and to extend existing economic models of the cost-effectiveness of dual antiplatelet therapy.

Design

The study was designed as three retrospective population-based cohort studies emulating target randomised controlled trials.

Setting

The study was set in primary and secondary care in England from 2010 to 2017.

Participants

Participants were patients aged ≥ 18 years undergoing coronary artery bypass grafting or emergency percutaneous coronary intervention (for acute coronary syndrome), or conservatively managed patients with acute coronary syndrome.

Data sources

Data were sourced from linked Clinical Practice Research Datalink and Hospital Episode Statistics.

Interventions

Coronary artery bypass grafting and conservatively managed acute coronary syndrome: aspirin (reference) compared with aspirin and clopidogrel. Percutaneous coronary intervention: aspirin and clopidogrel (reference) compared with aspirin and prasugrel (ST elevation myocardial infarction only) or aspirin and ticagrelor.

Main outcome measures

Primary outcome: any bleeding events up to 12 months after the index event. Secondary outcomes: major or minor bleeding, all-cause and cardiovascular mortality, mortality from bleeding, myocardial infarction, stroke, additional coronary intervention and major adverse cardiovascular events.

Results

The incidence of any bleeding was 5% among coronary artery bypass graft patients, 10% among conservatively managed acute coronary syndrome patients and 9% among emergency percutaneous coronary intervention patients, compared with 18% among patients prescribed triple therapy. Among coronary artery bypass grafting and conservatively managed acute coronary syndrome patients, dual antiplatelet therapy, compared with aspirin, increased the hazards of any bleeding (coronary artery bypass grafting: hazard ratio 1.43, 95% confidence interval 1.21 to 1.69; conservatively-managed acute coronary syndrome: hazard ratio 1.72, 95% confidence interval 1.15 to 2.57) and major adverse cardiovascular events (coronary artery bypass grafting: hazard ratio 2.06, 95% confidence interval 1.23 to 3.46; conservatively-managed acute coronary syndrome: hazard ratio 1.57, 95% confidence interval 1.38 to 1.78). Among emergency percutaneous coronary intervention patients, dual antiplatelet therapy with ticagrelor, compared with dual antiplatelet therapy with clopidogrel, increased the hazard of any bleeding (hazard ratio 1.47, 95% confidence interval 1.19 to 1.82), but did not reduce the incidence of major adverse cardiovascular events (hazard ratio 1.06, 95% confidence interval 0.89 to 1.27). Among ST elevation myocardial infarction percutaneous coronary intervention patients, dual antiplatelet therapy with prasugrel, compared with dual antiplatelet therapy with clopidogrel, increased the hazard of any bleeding (hazard ratio 1.48, 95% confidence interval 1.02 to 2.12), but did not reduce the incidence of major adverse cardiovascular events (hazard ratio 1.10, 95% confidence interval 0.80 to 1.51). Health-care costs in the first year did not differ between dual antiplatelet therapy with clopidogrel and aspirin monotherapy among either coronary artery bypass grafting patients (mean difference £94, 95% confidence interval -£155 to £763) or conservatively managed acute coronary syndrome patients (mean difference £610, 95% confidence interval -£626 to £1516), but among emergency percutaneous coronary intervention patients were higher for those receiving dual antiplatelet therapy with ticagrelor than for those receiving dual antiplatelet therapy with clopidogrel, although for only patients on concurrent proton pump inhibitors (mean difference £1145, 95% confidence interval £269 to £2195).

Conclusions

This study suggests that more potent dual antiplatelet therapy may increase the risk of bleeding without reducing the incidence of major adverse cardiovascular events. These results should be carefully considered by clinicians and decision-makers alongside randomised controlled trial evidence when making recommendations about dual antiplatelet therapy.

Limitations

The estimates for bleeding and major adverse cardiovascular events may be biased from unmeasured confounding and the exclusion of an eligible subgroup of patients who could not be assigned an intervention. Because of these limitations, a formal cost-effectiveness analysis could not be conducted.

Future work

Future work should explore the feasibility of using other UK data sets of routinely collected data, less susceptible to bias, to estimate the benefit and harm of antiplatelet interventions.

Trial registration

This trial is registered as ISRCTN76607611.

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 27, No. 8. See the NIHR Journals Library website for further project information.

DO THE GUIDELINES GUIDE THE BELGRADE EMERGENCY MEDICAL SERVICE PHYSICIANS THROUGH THE MANAGEMENT OF ACUTE ST-ELEVATION MYOCARDIAL INFARCTION?

The aim of the study was to assess whether current guidelines for diagnosis and treatment of acute ST-elevation myocardial infarction (STEMI) in daily clinical practice are adequately applied in the Belgrade Emergency Medical Service (EMS). A retrospective research included 2,982 STEMI patients who were cared for by EMS teams. Therapy consisting of morphine, oxygen, nitroglycerin and aspirin (MONA) was applied. Dual antiaggregation therapy (aspirin 325 mg + ticagrelor 180 mg or clopidogrel 600 mg) was administered to patients with primary percutaneous coronary intervention (PCI) indicated. With electrocardiographic monitoring included, the patients were transported directly to PCI unit with announcement of the arrival. Response times I-V were measured. There was an increasing trend in the number of STEMI patients. A rapid increase in the use of dual antiaggregation therapy (MONA and clopidogrel or MONA and ticagrelor) was reported from year to year, as well as a dramatic increase in the use of ticagrelor compared to clopidogrel. The time from receiving the call to the arrival on the scene was 13.72 minutes, and the time from receiving the call to hospital arrival was 52.83 minutes. Our physicians care for STEMI patients in accordance with the current international and local recommendations.

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).

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).

Fabrication of ticagrelor bioadhesive solid dispersion based on coaxial electrostatic spray to improve drug release and enhance oral bioavailability

Due to the low solubility and poor bioavailability of Ticagrelor (TIC), the current study developed a structured bioadhesive core-shell drug delivery system to address it. Ticagreior solid dispersion (T-SD) was fabricated using the uniaxial electrostatic spray method. Ticagrelor bio adhesive solid dispersion (T-BSD) was also prepared using the coaxial electrostatic spray technique. The adhesion of T-BSD to each intestinal segment was determined using biological adhesion test. The compartment model was used to study the plasma concentration-time curve and related pharmacokinetic parameters. The results of bioadhesion tests showed a positive adhesion effect of T-BSD in each intestinal segment. The maximum plasma concentration (C_max) of T-BSD was increased to 777.08ng/mL compared with the free drug (367ng/mL). Similarly, t_1/2, MRT and T_max of T-BSD (12.1h, 9.4h, 4h) were higher than the free drug (11.2h, 8.6h, 1h), respectively. The relative bioavailability of T-BSD was further increased to 430% compared with the free drug. The findings collectively revealed that the coaxial-electrospray technique could be a promising way to improve the bioavailability of TIC.

Ticagrelor with and without aspirin in patients with a prior coronary artery bypass graft undergoing percutaneous coronary intervention: the TWILIGHT-CABG study

BACKGROUND

Prior coronary artery bypass graft surgery (CABG) patients undergoing percutaneous coronary intervention (PCI) are often older and present with multiple comorbidities. Ticagrelor monotherapy after a short course of dual antiplatelet therapy (DAPT) has emerged as an effective bleeding-avoidance strategy among high-risk patients.

AIMS

We aimed to examine the effects of ticagrelor with or without aspirin in prior CABG patients undergoing PCI within the TWILIGHT trial.

METHODS

After 3 months of ticagrelor plus aspirin, patients were randomised to either aspirin or placebo, in addition to ticagrelor, for 12 months and compared by prior CABG status. The primary endpoint was Bleeding Academic Research Consortium (BARC) type 2, 3 or 5 bleeding. The key secondary endpoint was all-cause death, myocardial infarction (MI), or stroke.

RESULTS

Out of 7,119 patients, a total of 703 (10.8%) patients had prior CABG within the randomised cohort. Prior CABG patients had more comorbidities and a higher incidence of BARC type 2, 3, or 5 bleeding and death, MI or stroke at 1 year after randomisation, compared with patients without prior CABG. Ticagrelor monotherapy was associated with significantly less BARC 2, 3, or 5 bleeding among prior CABG patients compared with DAPT (4.9% vs 9.6%, hazard ratio [HR] 0.50, 95% confidence interval [CI]: 0.28 to 0.90; pinteraction=0.676) and similar rates of death, MI or stroke (10.0% vs 8.7%, HR 1.14, 95% CI: 0.70 to 1.87; pinteraction=0.484). When comparing target vessel type, treatment effects were consistent among graft- and native-vessel interventions.

CONCLUSIONS

In high-risk patients with prior CABG, ticagrelor monotherapy reduced bleeding without compromising ischaemic outcomes compared with ticagrelor plus aspirin.

Amiodarone attenuates cardiac Rubidium-82 in consecutive PET/CT scans in a rodent model

BACKGROUND

Risk stratification and diagnosis using Rubidium-82 (82Rb) positron emission tomography (PET) is a routine clinical approach in coronary artery disease (CAD). Various drugs are used to treat CAD; however, whether any of them change the uptake of 82Rb in the heart has not been investigated. The aim of this study is to determine whether drugs used in treatment of CAD affect the uptake of 82Rb in the heart in healthy rats.

METHODS

Seventy-seven Sprague-Dawley rats were included in the cross-sectional study. All rats underwent baseline 82Rb PET/CT and divided into eleven groups treated with different drugs. One group was control group (no treatment), eight groups were treated with monotherapy (amiodarone, acetylsalicylic acid (ASA), clopidogrel, ticagrelor, atorvastatin, enalapril, amlodipine, metoprolol succinate), and two groups were treated with polypharmacy (ASA, ticagrelor, atorvastatin, amlodipine or ASA, clopidogrel, atorvastatin, amlodipine). Once a day, they were administered pharmacological therapy through oral gavage, and on day seven, follow-up scanned with 82Rb PET/CT.

RESULTS

In the control group without pharmacological treatment, no difference in the standard uptake value (SUV) ratio between heart and muscle from baseline to follow-up (5.8 vs 7.0, P = .3) was found. The group treated with amiodarone had a significantly reduced SUV ratio from baseline to follow-up (5.8 vs 5.1, P = .008). All other drugs investigated had no difference in SUV ratio from baseline to follow-up.

CONCLUSION

In this study, we showed that drugs normally used to treat CAD do not affect the uptake of 82Rb. However, amiodarone result in a significantly lowered 82Rb uptake, compared to control. This information about amiodarone would probably not change the size assessment of a myocardial perfusion defect in a clinical setting. However, it could change the kinetic parameters when assessing absolute myocardial blood flow in patients treated with amiodarone.

Temporal patterns, characteristics, and predictors of clinical outcomes in patients undergoing percutaneous coronary intervention for stent thrombosis

BACKGROUND

There are limited data on the outcomes of percutaneous coronary intervention (PCI) following stent thrombosis (ST) and differences exist based on timing.

AIMS

Our aim was to study the rates of PCI procedures for an ST indication among all patients admitted for PCI at a national level and to compare their characteristics and procedural outcomes based on ST timing.

METHODS

All PCI procedures in England and Wales (2014-2020) were retrospectively analysed and stratified by the presence of ST into four groups: non-ST, early ST (0-30 days), late ST (>30-360 days), very late ST (>360 days). Multivariable logistic regression models were performed to assess the odds ratios (OR) of in-hospital MACCE (major adverse cardiovascular and cerebrovascular events, a composite of mortality, acute stroke and reinfarction) and mortality.

RESULTS

Overall, 7,923 (1.4%) procedures were for ST indication, most commonly for early ST (n=4,171; 52.6%), followed by very late ST (n=2,801; 35.4%) and late ST (n=951; 12.0%). The rate of PCI for ST declined between 2014 and 2020 (1.7 to 1.4%; p<0.001). Early ST was the only subgroup associated with increased odds of MACCE (OR 1.22, 95% CI: 1.05-1.41), all-cause mortality (OR 1.21, 95% CI: 1.07-1.36) and reinfarction (OR 2.48, 95% CI: 1.48-4.14), compared with non-ST indication. The odds of mortality were significantly reduced in ST patients with the use of intravascular imaging (OR 0.66, 95% CI: 0.48-0.92) and newer P2Y12 inhibitors (ticagrelor: OR 0.69, 95% CI: 0.49-0.95; prasugrel: OR 0.54, 95% CI: 0.30-0.96).

CONCLUSIONS

PCI for ST has declined in frequency over a 7-year period, with most procedures performed for early ST. Among the different times of ST onset, only early ST is associated with worse clinical outcomes after PCI. Routine use of intravascular imaging and newer P2Y12 inhibitors could further improve outcomes in this high-risk procedural group.

Comparison of ticagrelor and clopidogrel on platelet function and prognosis in unstable angina

PURPOSE

This study aims to compare the effects of ticagrelor and clopidogrel on platelet function, cardiovascular prognosis, and bleeding in patients with unstable angina pectoris.

METHODS

Patients with unstable angina pectoris undergoing percutaneous coronary intervention (PCI) were enrolled (January 2018-December 2019). In total, 212 patients were treated with ticagrelor (90 mg twice daily) and 210 patients were treated with clopidogrel (75 mg once daily). Thromboelastography and light transmission aggregometry were used to measure the platelet aggregation rate (PAR). High-sensitivity troponin T (hs-TnT), pro-brain natriuretic peptide (NT-proBNP), high-sensitivity C-reactive protein (CRP), and heart-type fatty acid-binding protein (h-FABP) were measured to assess myocardial injury after PCI. Cardiovascular prognosis and bleeding events were evaluated in hospital and 12 months after discharge.

RESULTS

The PAR was significantly slower with ticagrelor (P < 0.001). hs-TnT, NT-proBNP, CRP, and h-FABP increased after compared with before PCI in both groups (P < 0.05). hs-TnT (P < 0.001) and h-FABP (P < 0.001) increased more significantly with clopidogrel. The in-hospital and 12-month major adverse cardiovascular event (MACE) rates were not significantly different between the two groups. The in-hospital total bleeding event rate was higher with ticagrelor (P < 0.05). Minor bleeding and total bleeding were more frequent at the 12-month follow-up in the ticagrelor group (P < 0.05).

CONCLUSION

Ticagrelor was more effective in suppressing the PAR than clopidogrel and reduced PCI-induced myocardial injury in patients with unstable angina pectoris. However, it increased in-hospital and 12-month bleeding events and had no benefit on in-hospital and 12-month MACEs.

Anticoagulants as Potential SARS-CoV-2 Mpro Inhibitors for COVID-19 Patients: In Vitro, Molecular Docking, Molecular Dynamics, DFT, and SAR Studies

In this article, 34 anticoagulant drugs were screened in silico against the main protease (M^pro) of SARS-CoV-2 using molecular docking tools. Idraparinux, fondaparinux, eptifibatide, heparin, and ticagrelor demonstrated the highest binding affinities towards SARS-CoV-2 M^pro. A molecular dynamics study at 200 ns was also carried out for the most promising anticoagulants to provide insights into the dynamic and thermodynamic properties of promising compounds. Moreover, a quantum mechanical study was also conducted which helped us to attest to some of the molecular docking and dynamics findings. A biological evaluation (in vitro) of the most promising compounds was also performed by carrying out the MTT cytotoxicity assay and the crystal violet assay in order to assess inhibitory concentration 50 (IC₅₀). It is worth noting that ticagrelor displayed the highest intrinsic potential for the inhibition of SARS-CoV-2 with an IC₅₀ value of 5.60 µM and a safety index of 25.33. In addition, fondaparinux sodium and dabigatran showed promising inhibitory activities with IC₅₀ values of 8.60 and 9.40 µM, respectively, and demonstrated safety indexes of 17.60 and 15.10, respectively. Moreover, the inhibitory potential of the SARS-CoV-2 M^pro enzyme was investigated by utilizing the SARS-CoV-2 M^pro assay and using tipranavir as a reference standard. Interestingly, promising SARS-CoV-2 M^pro inhibitory potential was attained for fondaparinux sodium with an IC₅₀ value of 2.36 µM, surpassing the reference tipranavir (IC₅₀ = 7.38 µM) by more than three-fold. Furthermore, highly eligible SARS-CoV-2 M^pro inhibitory potential was attained for dabigatran with an IC₅₀ value of 10.59 µM. Finally, an SAR was discussed, counting on the findings of both in vitro and in silico approaches.

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

Background

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

Method

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

Results

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

Conclusion

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

A ROS-Responsive Simvastatin Nano-Prodrug and its Fibronectin-Targeted Co-Delivery System for Atherosclerosis Treatment

Nanoprodrugs with responsive release properties integrate the advantages of stimuli-responsive prodrugs and nanotechnology. They would provide ultimate opportunity in fighting atherosclerosis. In this study, we synthesized a redox-responsive nanoprodrug of simvastatin (TPTS) by conjugating α-tocopherol polyethylene glycol derivative to the pharmacophore of simvastatin with a thioketal linker. TPTS formed nanoparticles and released parent simvastatin in the presence of hydrogen peroxide. Moreover, by taking advantage of the self-assembly behavior of TPTS, we developed a fibronectin-targeted delivery system (TPTS/C/T) to codelivery simvastatin prodrug and ticagrelor. In vitro and in vivo experiments indicated that TPTS and TPTS/C/T had good stability, which could reduce off-target leakage of drugs. They greatly inhibited the M1-type polarization of macrophages; reduced intracellular reactive oxygen species level and inflammatory cytokine; and TNF-α, MCP-1, and IL-1β were secreted by macrophage cells, thus providing enhanced anti-inflammatory and antioxidant effects compared with free simvastatin. TPTS/C/T realized targeted drug release to plaques and synergistic therapeutic effects of simvastatin and ticagrelor on atherosclerosis treatment in an ApoE-/- mouse model, resulting in excellent atherosclerosis therapeutic efficacy and a promising biosafety profile. Therefore, this study provides a new method for manufacturing statin nanodrugs and a new design idea for related responsive drug release nanosystems for atherosclerosis.

Pre-Percutaneous Coronary Intervention TIMI Flow Grade in STEMI Patients Treated with Pre-Hospital Ticagrelor Loading

Aim We hypothesised that pre-hospital ticagrelor loading would result in a higher proportion of STEMI patients presenting with pre percutaneous coronary intervention TIMI flow grade (ppTFG) 3 than had previously been reported in the clopidogrel era. Methods Retrospective observational analysis of all STEMI patients attending our centre from 01/01/2016 to 31/12/2019. Patients presenting with STEMI were required to have received pre-hospital load-ing with 180 mg ticagrelor. The coronary angiography images were assessed for each patient to determine the ppTFG in the infarct related artery. Results 590 patients met the inclusion criteria. 125 patients (21.2%) presented with ppTFG 3 on pre-PCI angiography with the remaining 465 patients (78.8%) presenting with ppTFG ≤ 2. In-hospital mor-tality was comparable between the two groups (4% vs 5.6%, p=0.48). Conclusion In STEMI patients loaded with ticagrelor in the field, over one-fifth present with ppTFG 3 on angi-ography pre-PCI. This data is comparable to data from the clopidogrel era.

Rationale and design of the safe and timely antithrombotic removal - ticagrelor (STAR-T) trial: A prospective, multi-center, double-blind, randomized controlled trial evaluating reductions in postoperative bleeding with intraoperative removal of ticagrelor by the drugsorb™-ATR device in patients undergoing cardiothoracic surgery within 48 hours from last ticagrelor dose

BACKGROUND

Ticagrelor is often administered to patients with acute coronary syndromes. However, when these patients require urgent or emergent cardiothoracic (CT) surgery the presence of ticagrelor significantly increases surgical bleeding. The goal of the current trial is to evaluate the effectiveness and safety of the DrugSorb-ATR hemoadsorption device for the intraoperative removal of ticagrelor to reduce postoperative bleeding in the above patient population. The Safe and Timely Antithrombotic Removal - Ticagrelor (STAR-T) Trial is a multi-center, double-blind, randomized, controlled trial enrolling patients who require cardiothoracic surgery on cardiopulmonary bypass (CPB) within 48 hours of last ticagrelor dose.

METHODS

Subjects will be randomized 1:1 to receive either the DrugSorb-ATR device or an identical sham device during CPB. The study will enroll up to 120 subjects at 20 U.S centers, and the primary outcome is the composite of fatal perioperative bleeding, moderate/severe/massive bleeding according to the Universal Definition of Perioperative Bleeding in Cardiac Surgery (UDPB), and 24 hours chest tube drainage. The components of the composite are hierarchically ranked according to clinical significance and the primary analysis will utilize the Win Ratio method. Percent change in ticagrelor levels before and after CPB (drug removal) will be the key secondary endpoint. An independent Clinical Events Committee will adjudicate all clinical endpoints including safety endpoints relating to postoperative thrombotic events. Subjects will be followed through 30 days after the index operation.

CONCLUSIONS

The results from STAR-T, if positive, will potentially support FDA market approval for DrugSorb-ATR, and provide a solution to an important unmet clinical need.

Utility of a pharmacogenetic-driven algorithm in guiding dual antiplatelet therapy for patients undergoing coronary drug-eluting stent implantation in China

PURPOSES

The POPular Risk Score (PRiS), a pharmacogenetic-driven algorithm consisting of CYP2C19 genotype, platelet reactivity, and clinical risk factors, is developed to evaluate ischemic risk and guide dual antiplatelet therapy (DAPT). This study aimed to evaluate the efficacy and safety of DAPT in accordance with the PRiS in patients undergoing drug-eluting stent (DES) implantation.

METHODS

A total of 1757 patients recruited in this cohort study were divided into four groups according to the PRiS and type of P2Y12 receptor inhibitor treatment at discharge. The primary endpoint was major adverse cardiovascular events (MACE, a composite of cardiovascular death, myocardial infarction, stroke, definite or probable stent thrombosis, and target vessel revascularization) during 1-year follow-up. The safety endpoints were defined by Bleeding Academic Research Consortium (BARC) criteria as major bleeding (BARC 3a, 3b, 3c, and 5) and clinically relevant bleeding (BARC 2, 3a, 3b, 3c, and 5).

RESULTS

Among 1046 patients with PRiS < 2 and 711 patients with PRiS ≥ 2, 34.2% and 38.3% of them were treated with ticagrelor, respectively. The PRiS ≥ 2 was an independent predictor for the 1-year incidence of MACE (HR(95%CI): 2.09 (1.37-3.20), p = 0.001). Multivariable Cox regression indicated that in the PRiS ≥ 2 group, ticagrelor was superior to clopidogrel in reducing the risk of MACE (HR(95%CI): 0.53 (0.29-0.98), p = 0.042), without increasing the bleeding risk. On the other hand, in the PRiS < 2 group, clopidogrel treatment was related to a remarkably lower rate of BARC class ≥ 2 bleeding (HR(95%CI): 0.39 (0.20-0.72), p = 0.003), but comparable incidences of MACE and BARC class ≥ 3 bleeding during 1-year follow-up. Similar associations between P2Y12 receptor inhibitors and 1-year endpoints in the PRiS < 2 and PRiS ≥ 2 group could also be identified in propensity score-weighted analysis and propensity score-matched analysis.

CONCLUSION

Tailored DAPT based on the PRiS could assist in improving the prognosis of patients undergoing DES implantation. Further randomized controlled trials are required to provide more evidence for PRiS-guided DAPT.

Modified ticagrelor loading doses according to the vasodilator-stimulated phosphoprotein phosphorylation index improve the clinical outcome in ST-elevation myocardial infarction patients with high on-treatment platelet reactivity

BACKGROUND

Current guidelines recommend a standard ticagrelor loading dose (LD) in ST-segment elevation myocardial infarction (STEMI) patients. However, antiplatelet therapy in STEMI patients at high risk of thrombotic events is suboptimal. The study was conducted to validate whether vasodilatorstimulated phosphoprotein (VASP)-guided ticagrelor dosing individual therapy may result in more effective platelet inhibition and better clinical outcomes.

METHODS

This trial included 374 STEMI patients with a low platelet response after ticagrelor LD. The patients were randomized into a control group and a VASP-guided group, where the ticagrelor pretreatment was individually adjusted before and after percutaneous coronary intervention (PCI) to obtain a VASP index < 50%. Up to 2 additional boluses of ticagrelor (every additional dosing was 90 mg) were prescribed after the first LD, and the VASP index was assessed 2 hours after each administration until a VASP index < 50% was obtained or up to 3 dosages (360 mg). The primary endpoint was major adverse cardiovascular events (MACEs) at 30 days. The secondary endpoints were thrombolysis in myocardial infarction (TIMI) major and minor bleeding.

RESULTS

The characteristics were similar in the two groups. After the ticagrelor doses increased, the platelet reactivity index (PRI) decreased, and 98.4% of patients reached PRI < 50% in the VASP-guided group. The adenosine concentration increased, and the rate of MACE was significantly lower in the VASP-guided group (10 [5.3%] vs. 20 [10.8%], hazard ratio 2.38, 95% confidence interval 1.21-3.28, p = 0.007). There were no major hemorrhagic complications (0 vs. 0, p = 1.0). The rate of minor bleeding in the VASP-guided group was higher than that in the control group, but the difference was not significant (24 [12.8%] vs. 16 [8.6%], p = 0.068).

CONCLUSIONS

The incremental ticagrelor dosing strategy decreases the rate of MACE after PCI without increasing major and minor bleeding.

Effect of Ticagrelor on Left Ventricular Remodeling in Patients With ST-Segment Elevation Myocardial Infarction (HEALING-AMI)

OBJECTIVES

The aim of this study was to evaluate the effect of ticagrelor versus clopidogrel on left ventricular (LV) remodeling after reperfusion of ST-segment elevation myocardial infarction (STEMI) in humans.

BACKGROUND

Animal studies have demonstrated that ticagrelor compared with clopidogrel better protects myocardium against reperfusion injury and improves remodeling after myocardial infarction.

METHODS

In this investigator-initiated, randomized, open-label, assessor-blinded trial performed at 10 centers in Korea, patients were enrolled if they had naive STEMI successfully treated with primary percutaneous coronary intervention (PCI) and at least 6-month planned duration of dual-antiplatelet treatment. The coprimary endpoints were LV remodeling index (LVRI) (a relative change of LV end-diastolic volume) measured on 3-dimensional echocardiography and N-terminal pro-B-type natriuretic peptide level at 6 months.

RESULTS

Among initially enrolled patients with STEMI (n = 336), 139 in each group completed the study. LVRI at 6 months was numerically lower with ticagrelor versus clopidogrel (0.6 ± 18.6% vs. 4.5 ± 16.5%; p = 0.095). Ticagrelor significantly reduced the 6-month level of N-terminal pro-B-type natriuretic peptide (173 ± 141 pg/ml vs. 289 ± 585 pg/ml; p = 0.028). These differences were prominent in patients with pre-PCI TIMI (Thrombolysis In Myocardial Infarction) flow grade 0. By multivariate analysis, ticagrelor versus clopidogrel reduced the risk for positive LV remodeling (LVRI >0%) (odds ratio: 0.56; 95% confidence interval: 0.33 to 0.95; p = 0.030). The LV end-diastolic volume index remained unchanged during ticagrelor treatment (from 54.7 ± 12.2 to 54.2 ± 12.2 ml/m²; p = 0.629), but this value increased over time during clopidogrel treatment (from 54.6 ± 11.3 to 56.4 ± 13.9 ml/m²; p = 0.056) (difference -2.3 ml/m²; 95% confidence interval: -4.8 to 0.2 ml/m²; p = 0.073). Ticagrelor reduced LV end-systolic volume index (from 27.0 ± 8.5 to 24.7 ± 8.4 ml/m²; p < 0.001), whereas no reduction was seen with clopidogrel (from 26.2 ± 8.9 to 25.6 ± 11.0 ml/m²; p = 0.366) (difference -1.8 ml/m²; 95% confidence interval: -3.5 to -0.1 ml/m²; p = 0.040).

CONCLUSIONS

Ticagrelor was superior to clopidogrel for LV remodeling after reperfusion of STEMI with primary PCI. (High Platelet Inhibition With Ticagrelor to Improve Left Ventricular Remodeling in Patients With ST Segment Elevation Myocardial Infarction [HEALING-AMI]; NCT02224534).

Clinical validation of AggreGuide A-100 ADP, a novel assay for assessing the antiplatelet effect of oral P2Y12 antagonists

In this prospective, 3-arm, repeated-measure multicenter investigation in 280 patients with cardiovascular risk factors, platelet aggregation was measured with the novel AggreGuide A-100 ADP (A-100 ADP) and VerifyNow (VN)-PRU assays at baseline, and after United States Food and Drug Administration approved loading and 7 days maintenance doses of clopidogrel (n = 94), prasugrel (n = 43) or ticagrelor, (n = 143). Based on the predetermined cutoff values of < 4.7 platelet activity index with A-100 ADP assay to indicate antiplatelet response, more than 91% of patients met the criteria following loading and maintenance doses of prasugrel and more than 84% patients met the criteria following loading and maintenance doses of ticagrelor whereas only 32% and 51% of patients met the criteria following loading and maintenance doses of clopidogrel, respectively. The total percent agreement between the A-100 ADP and VN-PRU assays was 89%. The A-100 ADP assay, which includes whole blood in motion, performs comparably to the VN-PRU assay in a study of patients with cardiovascular risk factors treated with P2Y₁₂ inhibitors possessing known differences in antiplatelet potencies. Trial registration ClinicalTrials.gov Identifier: NCT3111420.

Formulation and In Vivo Evaluation of Ticagrelor Self-nanoemulsifying Drug Delivery Systems

BACKGROUND

Ticagrelor (TGR), being an antiplatelet agent, belongs to BCS class IV drug with low solubility and permeability that undergoes first-pass metabolism, leading to reduced bioavailability of 36%.

OBJECTIVE

The main objective of this study is to develop TGR SNEDDS for enhancing solubility and oral bioavailability.

METHODS

An oil, surfactant and co-surfactant (miglyol 810, brij 35 and lauro glycol FCC) are chosen based on the maximum solubility of TGR. The selected vehicles are mixed in different ratios and are agitated mildly. Transmittance values that are more than 80 were noted and are used for constructing pseudo ternary phase diagram. Formulations that passed stability testing were evaluated for % transmission, drug content and in vitro drug release analysis. In vivo bioavailability studies of optimized SNEDDS are performed in Wistar rats.

RESULTS

From evaluation studies of TGR, formulation F13 with maximum drug release of 98.99% in 60 minutes, that is higher than 31.99% of the pure drug is considered as an optimised formulation. The particle size, Z average and zeta potential of the optimized TGR formulation F13 was 289.6 nm, 185.1 nm and -18.3 mV respectively. The FTIR and SEM studies do not indicate any drug excipient interaction and confirm nano size which is stable for 3 months. From in vivo bioavailability studies in rats, the C_max of optimized TGR SNEDDS (302.43±4.78 ng/ml) is higher than pure TGR suspension (47.32±2.75 ng/ml) and optimized SNEDDS exhibited 5 folds increase in oral bioavailability when compared to pure drug.

CONCLUSION

Hence the results reveal that, application of SNEDDS formulation technique for TGR Increases solubility and oral bioavailability.