Compounding and Characterization of a Selfmicroemulsifying System of Ticagrelor Tablets for Enhanced Solubility.

Ticagrelor is used to inhibit acute coronary syndrome, but its poor solubility and low bioavailability limit its in-vivo efficacy. The purpose of this study was to manufacture an optimized ticagrelor-loaded self-microemulsifying drug-delivery system in the form of tablets to enhance the solubility and dissolution of that drug. A preliminary study was conducted to determine the extent of turbidity of oils for this study, and a pseudoternaryphase diagram was used to identify the region of formation of microemulsion with 3 ratios (1:1,1:2, and 1:3). The solubility of ticagrelor was determined with the selected oil and a surfactant-and-cosurfactant mixture. A simplex lattice mixture design was used to compound the microemulsion. The microemulsion was converted to granules by the use of an adsorbent (aerosol) after a precipitation study. After characterization, the resultant granules were compressed into tablets for an in-vitro release study. The optimized formulation was subjected to various characterization procedures to determine the zeta potential, particle size, and surface morphology. The solubility of the drug was found to have increased manyfold in all formulations, and the optimized formulation was found to be 221.37 mg/mL. With respect to the ticagrelor tablets, aerosol up to 30% was needed as an adsorbent in the self-microemulsifying drug-delivery system. The compression of the ticagrelor granules was satisfactory for tablet formation. In all formulations, the release of the active drug was more than 80% within 30 minutes of dissolution time. The optimized icagrelorloaded self-microemulsifying drug-delivery system formulation consisted of medium-chain triglyceride oil (47.88.0%), surfactant (28.25%), and cosurfactant (23.85%), which significantly improved the dissolution of ticagrelor. The results of analysis via scanning electron microscopy revealed that the surface and size of the drug and the zeta potential were also satisfactory and suggested that the optimized ticagrelor-loaded self-microemulsifying drug-delivery system described in this report could be successfully used as an efficient method for achieving enhanced dissolution of ticagrelor.

Assessment of platelet functional activity in healthy individuals and patients receiving antiplatelet therapy. Possible inconsistencies between aggregation and flow cytometry tests.

Platelet functional activity was assessed in healthy volunteers (HV, n=92), patients with stable angina pectoris (SA, n=42) and acute coronary syndrome (ACS, n=73), treated with acetylsalicylic acid (ASA) + clopidogrel and ASA + ticagrelor, respectively. In all HV and patients we have compared parameters of platelet aggregation (maximum light transmission and velocity, Tmax and Vmax) and parameters, characterizing exposure of platelet activation markers, evaluated by flow cytometry. HV platelets were activated by 10 µM, 1 µM TRAP, and 20 µM, 5 µM, 2.5 µM ADP; patient platelets were activated by 10 µM TRAP and by 20 µM and 5 µM ADP. Strong and significant correlations between the aggregation and flow cytometry parameters (the r correlation coefficient from 0.4 up to >0.6) most frequently were registered in HV platelet during activation by 1 µM TRAP and in SA patients during platelet activation by 20 µM and 5 µM ADP. However, in many other cases these correlations were rather weak (r < 0.3) and sometimes statistically insignificant. In HV the differences in PAC-1 binding parameters between platelets activated by 10 µM TRAP (the strongest agonist) and all ADP concentrations were negligible (≤ 10%), while CD62P binding (at all ADP concentrations) and LTA parameters for (5 µM and 2.5 µM ADP) were significantly lower (by 40-60%). Antiplatelet therapy in patients decreased all parameters as compared to HV, but to varying extents. For 10 µM TRAP the MFI index for PAC-1 binding (40-50% decrease) and for both ADP concentrations the Tmax values (60-85% decrease) appeared to be the most sensitive in comparison with the other parameters that decreased to a lesser extent. The data obtained indicate a possibility of inconsistency between different LTA and flow cytometry parameters in assessing platelet activity and efficacy of antiplatelet drugs.

Impact of Society Guidelines on Trends in Use of Newer P2Y12 Inhibitors for Patients With Acute Coronary Syndromes Undergoing Percutaneous Coronary Intervention.

BACKGROUND: Over the past decade, major society guidelines have recommended the use of newer P2Y12 inhibitors over clopidogrel for those undergoing percutaneous coronary intervention for acute coronary syndrome. It is unclear what impact these recommendations had on clinical practice. METHODS AND RESULTS: All percutaneous coronary intervention procedures (n=534 210) for acute coronary syndrome in England and Wales (April 1, 2010, to March 31, 2022) were retrospectively analyzed, stratified by choice of preprocedural P2Y12 inhibitor (clopidogrel, ticagrelor, and prasugrel). Multivariable logistic regression models were used to examine odds ratios of receipt of ticagrelor and prasugrel (versus clopidogrel) over time, and predictors of their receipt. Overall, there was a significant increase in receipt of newer P2Y12 inhibitors from 2010 to 2020 (2022 versus 2010: ticagrelor odds ratio, 8.12 [95% CI, 7.67-8.60]; prasugrel odds ratio, 6.14 [95% CI, 5.53-6.81]), more so in ST-segment-elevation myocardial infarction than non-ST-segment-elevation acute coronary syndrome indication. The most significant increase in odds of receipt of prasugrel was observed between 2020 and 2022 (P<0.001), following a decline/plateau in its use in earlier years (2011-2019). In contrast, the odds of receipt of ticagrelor significantly increased in earlier years (2012-2017, Ptrend<0.001), after which the trend was stable (Ptrend=0.093). CONCLUSIONS: Over a 13-year-period, there has been a significant increase in use of newer P2Y12 inhibitors, although uptake of prasugrel use remained significantly lower than ticagrelor. Earlier society guidelines (pre-2017) were associated with the highest rates of ticagrelor use for non-ST-segment-elevation acute coronary syndrome and ST-segment-elevation myocardial infarction cases while the ISAR-REACT 5 (Prospective, Randomized Trial of Ticagrelor Versus Prasugrel in Patients With Acute Coronary Syndrome) trial and later society guidelines were associated with higher prasugrel use, mainly for ST-segment-elevation myocardial infarction indication.

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.

What is the context?• Platelet activation is a complicated process with multiple signaling cascades involved.• A total of seven common platelet triggers (ADP, collagen, TRAP-6, PAF, arachidonic acid/AA/, ristocetin and U46619) were tested.• The process is dependent on many factors including sex, age, concomitant disease(s), pharmacotherapy.What is new?• There were significant correlations between all tested aggregatory cascades.• AA has the highest rate of response predictability in our heterogeneous generally healthy volunteer group.• There was no correlation between impedance aggregometry in whole blood and turbidimetric measurement with platelet-rich plasma.What is the impact?• The effect of antiplatelet drugs can be assessed from the reaction to different trigger(s) at least in this group of healthy patients.• Future studies must test these relationships in patients with different diseases.

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.

Ticagrelor, but Not Clopidogrel, Attenuates Hepatic Steatosis in a Model of Metabolic Dysfunction-Associated Steatotic Liver Disease.

BACKGROUND: Previous studies have suggested that platelets are associated with inflammation and steatosis and may play an important role in liver health. Therefore, we evaluated whether antiplatelet agents can improve metabolic disorder-related fatty liver disease (MASLD). METHODS: The mice used in the study were fed a high-fat-diet (HFD) and were stratified through liver biopsy at 18 weeks. A total of 22 mice with NAFLD activity scores (NAS) ≥ 4 were randomly divided into three groups (HFD-only, clopidogrel (CLO; 35 mg/kg/day), ticagrelor (TIC; 40 mg/kg/day) group). And then, they were fed a feed mixed with the respective drug for 15 weeks. Blood and tissue samples were collected and used in the study. RESULTS: The TIC group showed a significantly lower degree of NAS and steatosis than the HFD group (p = 0.0047), but no effect on the CLO group was observed. Hepatic lipogenesis markers' (SREBP1c, FAS, SCD1, and DGAT2) expression and endoplasmic reticulum (ER) stress markers (CHOP, Xbp1, and GRP78) only reduced significantly in the TIC treatment group. Inflammation genes (MCP1 and TNF-α) also decreased significantly in the TIC group, but not in the CLO group. Nile red staining intensity and hepatic lipogenesis markers were reduced significantly in HepG2 cells following TIC treatment. CONCLUSION: Ticagrelor attenuated NAS and hepatic steatosis in a MASLD mice model by attenuating lipogenesis and inflammation, but not in the CLO group.

Ticagrelor alone versus ticagrelor plus aspirin from month 1 to month 12 after percutaneous coronary intervention in patients with acute coronary syndromes (ULTIMATE-DAPT): a randomised, placebo-controlled, double-blind clinical trial.

BACKGROUND: Following percutaneous coronary intervention with stent placement to treat acute coronary syndromes, international clinical guidelines generally recommend dual antiplatelet therapy with aspirin plus a P2Y12 receptor inhibitor for 12 months to prevent myocardial infarction and stent thrombosis. However, data on single antiplatelet therapy with a potent P2Y12 inhibitor earlier than 12 months after percutaneous coronary intervention for patients with an acute coronary syndrome are scarce. The aim of this trial was to assess whether the use of ticagrelor alone, compared with ticagrelor plus aspirin, could reduce the incidence of clinically relevant bleeding events without an accompanying increase in major adverse cardiovascular or cerebrovascular events (MACCE). METHODS: In this randomised, placebo-controlled, double-blind clinical trial, patients aged 18 years or older with an acute coronary syndrome who completed the IVUS-ACS study and who had no major ischaemic or bleeding events after 1-month treatment with dual antiplatelet therapy were randomly assigned to receive oral ticagrelor (90 mg twice daily) plus oral aspirin (100 mg once daily) or oral ticagrelor (90 mg twice daily) plus a matching oral placebo, beginning 1 month and ending at 12 months after percutaneous coronary intervention (11 months in total). Recruitment took place at 58 centres in China, Italy, Pakistan, and the UK. Patients were required to remain event-free for 1 month on dual antiplatelet therapy following percutaneous coronary intervention with contemporary drug-eluting stents. Randomisation was done using a web-based system, stratified by acute coronary syndrome type, diabetes, IVUS-ACS randomisation, and site, using dynamic minimisation. The primary superiority endpoint was clinically relevant bleeding (Bleeding Academic Research Consortium [known as BARC] types 2, 3, or 5). The primary non-inferiority endpoint was MACCE (defined as the composite of cardiac death, myocardial infarction, ischaemic stroke, definite stent thrombosis, or clinically driven target vessel revascularisation), with an expected event rate of 6·2% in the ticagrelor plus aspirin group and an absolute non-inferiority margin of 2·5 percentage points between 1 month and 12 months after percutaneous coronary intervention. The two co-primary endpoints were tested sequentially; the primary superiority endpoint had to be met for hypothesis testing of the MACCE outcome to proceed. All principal analyses were assessed in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT03971500, and is completed. FINDINGS: Between Sept 21, 2019, and Oct 27, 2022, 3400 (97·0%) of the 3505 participants in the IVUS-ACS study were randomly assigned (1700 patients to ticagrelor plus aspirin and 1700 patients to ticagrelor plus placebo). 12-month follow-up was completed by 3399 (>99·9%) patients. Between month 1 and month 12 after percutaneous coronary intervention, clinically relevant bleeding occurred in 35 patients (2·1%) in the ticagrelor plus placebo group and in 78 patients (4·6%) in the ticagrelor plus aspirin group (hazard ratio [HR] 0·45 [95% CI 0·30 to 0·66]; p<0·0001). MACCE occurred in 61 patients (3·6%) in the ticagrelor plus placebo group and in 63 patients (3·7%) in the ticagrelor plus aspirin group (absolute difference -0·1% [95% CI -1·4% to 1·2%]; HR 0·98 [95% CI 0·69 to 1·39]; pnon-inferiority<0·0001, psuperiority=0·89). INTERPRETATION: In patients with an acute coronary syndrome who had percutaneous coronary intervention with contemporary drug-eluting stents and remained event-free for 1 month on dual antiplatelet therapy, treatment with ticagrelor alone between month 1 and month 12 after the intervention resulted in a lower rate of clinically relevant bleeding and a similar rate of MACCE compared with ticagrelor plus aspirin. Along with the results from previous studies, these findings show that most patients in this population can benefit from superior clinical outcomes with aspirin discontinuation and maintenance on ticagrelor monotherapy after 1 month of dual antiplatelet therapy. FUNDING: The Chinese Society of Cardiology, the National Natural Scientific Foundation of China, and the Jiangsu Provincial & Nanjing Municipal Clinical Trial Project. TRANSLATION: For the Mandarin translation of the abstract see Supplementary Materials section.

Ticagrelor Versus Clopidogrel in Acute Large-Vessel Ischemic Stroke: A Randomized Controlled Single-Blinded Trial.

BACKGROUND: Large-vessel ischemic stroke represents about 25-40% of all ischemic strokes. Few clinical trials compared ticagrelor versus clopidogrel in ischemic stroke patients; all these studies included only patients with a transient ischemic attack or minor stroke; moreover, none of these studies included patients from North Africa. OBJECTIVES: We aimed to compare ticagrelor versus clopidogrel in the first-ever large-vessel occlusion (LVO) acute ischemic stroke in Egypt. METHODS: Our trial involved 580 first-ever LVO ischemic stroke patients who were randomly assigned to administer loading and maintenance doses of ticagrelor or clopidogrel. Screening, randomization, and start of treatment occurred during the first 24 hours of the stroke. RESULTS: 580 patients were included in the intention-to-treat analysis. Thirty patients in the ticagrelor group and 49 patients in the clopidogrel group experienced a new ischemic or hemorrhagic stroke at 90 days (hazard ratio [HR] 0.61; 95% confidence interval [CI] 0.38-0.98; p-value = 0.04), 36 patients in the ticagrelor group, and 57 in the clopidogrel group experienced composite of a new stroke, myocardial infarction, or death due to vascular insults (HR 0.56; 95% CI 0.37-0.87; p = 0.009). Patients who received ticagrelor had better clinical outcomes regarding National Institutes of Health Stroke Scale (NIHSS) reduction and a favorable modified Rankin scale (mRS) score. There were no differences between ticagrelor and clopidogrel regarding hemorrhagic and non-hemorrhagic complications. CONCLUSION: Patients with acute large-vessel ischemic stroke who received ticagrelor within the first 24 hours after ischemic stroke had better clinical outcomes based on recurrent stroke rates, NIHSS reduction, and favorable mRS rates compared with those who received clopidogrel. There were no differences between ticagrelor and clopidogrel regarding hemorrhagic and non-hemorrhagic complications. TRIAL REGISTRATION: Clinical trials.gov (NCT06120725).

Limb Outcomes With Ticagrelor Plus Aspirin in Patients With Diabetes Mellitus and Atherosclerosis.

BACKGROUND: Ticagrelor reduced major adverse cardiovascular events (MACE) and increased bleeding in patients with type 2 diabetes mellitus (T2DM) and coronary artery disease. Limb events including revascularization, acute limb ischemia (ALI), and amputation are major morbidities in patients with T2DM and atherosclerosis. OBJECTIVES: This study sought to determine the effect of ticagrelor on limb events. METHODS: Patients were randomized to ticagrelor or placebo on top of aspirin and followed for a median of 3 years. MACE (cardiovascular death, myocardial infarction, or stroke), limb events (ALI, amputation, revascularization), and bleeding were adjudicated by an independent and blinded clinical events committee. The presence of peripheral artery disease (PAD) was reported at baseline. RESULTS: Of 19,220 patients randomized, 1,687 (8.8%) had PAD at baseline. In patients receiving placebo, PAD was associated with higher MACE (10.7% vs 7.3%; HR: 1.48; P < 0.001) and limb (9.5% vs 0.8%; HR: 10.67; P < 0.001) risk. Ticagrelor reduced limb events (1.6% vs 1.3%; HR: 0.77; 95% CI: 0.61-0.96; P = 0.022) with significant reductions for revascularization (HR: 0.79; 95% CI: 0.62-0.99; P = 0.044) and ALI (HR: 0.24; 95% CI: 0.08-0.70; P = 0.009). The benefit was consistent with or without PAD (HR: 0.80; 95% CI: 0.58-1.11; and HR: 0.76; 95% CI: 0.55-1.05, respectively; Pinteraction = 0.81). There was no effect modification of ticagrelor vs placebo based on PAD for MACE (Pinteraction = 0.40) or TIMI major bleeding (Pinteraction = 0.3239). CONCLUSIONS: Patients with T2DM and atherosclerosis are at high risk of limb events. Ticagrelor decreased this risk, but increased bleeding. Future trials evaluating the combination of ticagrelor and aspirin would further elucidate the benefit/risk of such therapy in patients with PAD, including those without coronary artery disease. (A Study Comparing Cardiovascular Effects of Ticagrelor Versus Placebo in Patients With Type 2 Diabetes Mellitus [THEMIS]: NCT01991795).

Safety of Clopidogrel vs. Ticagrelor in Dual Antiplatelet Therapy Regimens for High-Bleeding Risk Acute Coronary Syndrome Patients: A Comprehensive Meta-analysis of Adverse Outcomes.

INTRODUCTION: Patients of acute coronary syndrome (ACS) at a high-bleeding risk (HBR) often require dual antiplatelet therapy (DAPT) to reduce the risk of recurrent cardiovascular events. Clopidogrel and ticagrelor are the most commonly used antiplatelet agents in DAPT regimens. However, the safety profiles of these drugs in ACS patients at HBR remain a subject of ongoing debate. AIM: To investigate any difference between the safety of clopidogrel and ticagrelor used as a part of DAPT regimen in ACS patients at HBR. METHODS: A systematic search on PubMed, Cochrane Library, and Google Scholar was conducted to identify experimental and observational studies published up to the knowledge cutoff date in September 2023. Studies comparing the safety of clopidogrel and ticagrelor in ACS patients at HBR were included for analysis. The primary outcomes assessed were major bleeding events, stroke, and myocardial infarction (MI), while secondary outcomes included all-cause mortality, major adverse cardiac and cerebrovascular events (MACCE), and net adverse clinical and cerebral events (NACCE). RESULTS: We included a total of 8 observational studies in our meta-analysis. The pooled analysis revealed a statistically significant increase in the risk of MI (pooled RR = 1.43; 95% CI 1.12-1.83; P = 0.005) in the patients using clopidogrel. There were no statistically significant differences in major bleeding events (pooled RR = 0.94; 95% CI 0.82-1.09; P = 0.44), stroke (pooled RR = 1.36; 95% CI 0.86-2.14; P = 0.18), all-cause mortality (pooled RR = 1.17; 95% CI 0.97-1.41; P = 0.10), MACCE (pooled RR = 1.07; 95% CI 0.76-1.50; P = 0.69) and NACCE (pooled RR = 0.95; 95% CI 0.66-1.37; P = 0.78) between the two groups. Subgroup analyses based on region were performed. CONCLUSION: Both drugs are generally safe for treating ACS patients with HBR at baseline, although a higher risk of MI was observed with the use of clopidogrel. Nevertheless, drug choice should factor in regional variations, patient-specific characteristics, cost, accessibility, and potential drug interactions.

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.

Ticagrelor downregulates the expression of proatherogenic and proinflammatory miR125-b compared to clopidogrel: A randomized, controlled trial.

BACKGROUND: Platelet P2Y12 antagonist ticagrelor reduces cardiovascular mortality after acute myocardial infarction (AMI) compared to clopidogrel, but the underlying mechanism is unknown. Because activated platelets release proatherogenic and proinflammatory microRNAs, including miR-125a, miR-125b and miR-223, we hypothesized that the expression of these miRNAs is lower on ticagrelor, compared to clopidogrel. OBJECTIVES: We compared miR-125a, miR-125b and miR-223 expression in plasma of patients after AMI treated with ticagrelor or clopidogrel. METHODS: After percutaneous coronary intervention on acetylsalicylic acid and clopidogrel, 60 patients with first AMI were randomized to switch to ticagrelor or to continue with clopidogrel. Plasma expression of miR-223, miR-125a-5p, miR-125b was measured using quantitative polymerase chain reaction at baseline and after 72 h and 6 months of treatment with ticagrelor or clopidogrel in patients and one in 30 healthy volunteers. Multiple electrode aggregometry using ADP test was used to determine platelet reactivity in response to P2Y12 inhibitors. RESULTS: Expression of miR-125b was higher in patients with AMI 72 h and 6 months, compared to healthy volunteers (p = 0.001), whereas expression of miR-125a-5p and miR-223 were comparable. In patients randomized to ticagrelor, expression of miR-125b decreased at 72 h (p = 0.007) and increased back to baseline at 6 months (p = 0.005). Expression of miR-125a-5p and miR-223 was not affected by the switch from clopidogrel to ticagrelor. CONCLUSIONS: Ticagrelor treatment leads to lower plasma expression of miR-125b after AMI, compared to clopidogrel. Higher expression of miR-125b might explain recurrent thrombotic events and worse clinical outcomes in patients treated with clopidogrel, compared to ticagrelor.

Impact of rise and fall phases of shear on platelet activation and aggregation using microfluidics.

Blood flow disorders are often the result of the non-physiological narrowing of blood arteries caused by atherosclerosis and thrombus. The blood then proceeds through rising-peak-decreasing phases as it passes through the narrow area. Although abnormally high shear is known to activate platelets, the shear process that platelets undergo in small arteries is complex. Thus, understanding how each shear phase affects platelet activation can be used to improve antiplatelet therapy and decrease the risk of side effects like bleeding. Blood samples were sheared (68.8 ms,5200 s-1) in vitro by the microfluidic technique, and platelet activation levels (P-selectin and integrin αIIbß3) and von Willebrand factor (vWF) binding to platelets were analyzed by flow cytometry. Post-stenosis platelet aggregation was dynamically detected using microfluidic technology. We studied TXA2, P2Y12-ADP, and integrin αIIbß3-fibrinogen receptor pathways by adding antiplatelet drugs, such as acetylsalicylic acid (ASA, an active ingredient of aspirin that inhibits platelet metabolism), ticagrelor (hinders platelet activation), and tirofiban (blocks integrin αIIbß3 receptor) in vitro, respectively, to determine platelet activation function mediated by transient non-physiological high shear rates. We demonstrated that platelets can be activated under transient pathological high shear rates. The shear rise and fall phases influenced shear-induced platelet activation by regulating the binding of vWF to platelets. The degree of platelet activation and aggregation increased with multiple shear rise and fall phases. ASA did not inhibit shear-mediated platelet activation, but ticagrelor and tirofiban effectively inhibited shear-mediated platelet activation. Our data demonstrated that the shear rise and fall phases play an important role in shear-mediated platelet activation and promote platelet activation and aggregation in a vWF-dependent manner. Blocking integrin αIIbß3 receptor and hindering P2Y12-ADP were beneficial to reducing shear-mediated platelet activation.

Ticagrelor with or without aspirin following percutaneous coronary intervention in high-risk patients with concomitant peripheral artery disease: A subgroup analysis of the TWILIGHT randomized clinical trial.

BACKGROUND: The optimal antiplatelet regimen after percutaneous coronary intervention (PCI) in patients with peripheral artery disease (PAD) is still debated. This analysis aimed to compare the effect of ticagrelor monotherapy versus ticagrelor plus aspirin in patients with PAD undergoing PCI. METHODS: In the TWILIGHT trial, patients at high ischemic or bleeding risk that underwent PCI were randomized after 3 months of dual antiplatelet therapy (DAPT) to aspirin or matching placebo in addition to open-label ticagrelor for 12 additional months. In this post-hoc analysis, patient cohorts were examined according to the presence or absence of PAD. The primary endpoint was Bleeding Academic Research Consortium (BARC) 2, 3, or 5 bleeding. The key secondary endpoint was a composite of all-cause death, myocardial infarction (MI), or stroke. Endpoints were assessed at 12 months after randomization. RESULTS: Among 7,119 patients, 489 (7%) had PAD and were older, more likely to have comorbidities, and multivessel disease. PAD patients had more bleeding or ischemic complications than no-PAD patients. Ticagrelor monotherapy compared to ticagrelor plus aspirin was associated with less BARC 2, 3, or 5 bleeding in PAD (4.6% vs 8.7%; HR 0.52; 95%CI 0.25-1.07) and no-PAD patients (4.0% vs 7.0%; HR 0.56; 95%CI 0.45-0.69; interaction P-value .830) and a similar risk of death, MI, or stroke in these 2 groups (interaction P-value .446). CONCLUSIONS: Despite their higher ischemic and bleeding risk, patients with PAD undergoing PCI derived a consistent benefit from ticagrelor monotherapy after 3 months of DAPT in terms of bleeding reduction without any relevant increase in ischemic events. CLINICAL TRIAL REGISTRY INFORMATION:: https://www. CLINICALTRIALS: gov/study/NCT02270242.

Impact of very low dose rivaroxaban in addition to dual antiplatelet therapy on endogenous fibrinolysis in acute coronary syndrome: The VaLiDate-R study.

BACKGROUND: Impaired endogenous fibrinolysis is adverse cardiovascular risk factor in acute coronary syndrome (ACS) patients. Addition of very low dose rivaroxaban (VLDR) to dual antiplatelet therapy (DAPT) reduces cardiovascular events but increases bleeding. OBJECTIVE: We aimed to assess whether addition of VLDR to DAPT can enhance endogenous fibrinolysis. METHODS: In a prospective, open-label trial, we assessed endogenous fibrinolysis in whole blood, in 549 patients with ACS using the Global Thrombosis Test (GTT) and Thromboelastography (TEG). Patients (n = 180) who demonstrated impaired endogenous fibrinolysis (lysis time [LT] >2000s with the GTT) were randomised 1:1:1 to (i) clopidogrel 75 mg daily; (ii) clopidogrel 75 mg daily plus rivaroxaban 2.5 mg twice daily; or (iii) ticagrelor 90 mg twice daily, for 30 days, in addition to aspirin. Fibrinolytic status was assessed at 0, 2, 4 and 8 weeks. The primary outcome was the change in LT from admission to week 4. We also measured thrombotic occlusion time (OT) at high shear, and rivaroxaban level. RESULTS: There was no difference between the groups with respect to LT or clot lysis with TEG, and no change in these parameters compared to baseline during study drug allocation. In the rivaroxaban plus clopidogrel group, OT was prolonged compared to the other groups, although rivaroxaban levels were low, suggesting non-compliance. CONCLUSION: Addition of rivaroxaban 2.5 mg twice daily to DAPT does not affect endogenous fibrinolysis of thrombus formed at either high or low shear. Further studies are needed to determine whether higher doses of rivaroxaban can favourably modulate fibrinolysis. CONDENSED ABSTRACT: Impaired endogenous fibrinolysis is a strong risk factor in ACS. We aimed to assess whether adding very low dose rivaroxaban (VLDR) to DAPT can enhance fibrinolysis. Fibrin and clot lysis were assessed in whole blood. ACS patients with impaired fibrinolysis were randomised 1:1:1 to clopidogrel 75 mg daily; clopidogrel 75 mg plus VLDR; or ticagrelor 90 mg twice daily, in addition to aspirin. At 30-days, there was no difference in lysis time between the groups, nor change from baseline. VLDR does not improve fibrinolysis at high or low shear. Further studies are needed to determine whether alternative antithrombotic regimens can enhance endogenous fibrinolysis.

One-month DAPT with ticagrelor and aspirin for patients undergoing coronary artery bypass grafting: rationale and design of the randomised, multicentre, double-blind, placebo-controlled ODIN trial.

The optimal antiplatelet strategy after coronary artery bypass graft (CABG) surgery in patients with chronic coronary syndromes (CCS) is unclear. Adding the P2Y12 inhibitor, ticagrelor, to low-dose aspirin for 1 year is associated with a reduction in graft failure, particularly saphenous vein grafts, at the expense of an increased risk of clinically important bleeding. As the risk of thrombotic graft failure and ischaemic events is highest early after CABG surgery, a better risk-to-benefit profile may be attained with short-term dual antiplatelet therapy followed by single antiplatelet therapy. The One Month Dual Antiplatelet Therapy With Ticagrelor in Coronary Artery Bypass Graft Patients (ODIN) trial is a prospective, randomised, double-blind, placebo-controlled, international, multicentre study of 700 subjects that will evaluate the effect of short-term dual antiplatelet therapy with ticagrelor plus low-dose aspirin after CABG in patients with CCS. Patients will be randomised 1:1 to ticagrelor 90 mg twice daily or matching placebo, in addition to aspirin 75-150 mg once daily for 1 month; after the first month, antiplatelet therapy will be continued with aspirin alone. The primary endpoint is a hierarchical composite of all-cause death, stroke, myocardial infarction, revascularisation and graft failure at 1 year. The key secondary endpoint is a hierarchical composite of all-cause death, stroke, myocardial infarction, Bleeding Academic Research Consortium (BARC) type 3 bleeding, revascularisation and graft failure at 1 year (net clinical benefit). ODIN will report whether the addition of ticagrelor to low-dose aspirin for 1 month after CABG reduces ischaemic events and provides a net clinical benefit in patients with CCS. (ClinicalTrials.gov: NCT05997693).

Recombinant human soluble domain of CD39L3 and ticagrelor: cardioprotective effects in experimental myocardial infarction.

BACKGROUND AND AIMS: The ecto-nucleoside triphosphate diphosphohydrolases of the CD39 family degrade ATP and ADP into AMP, which is converted into adenosine by the extracellular CD73/ecto-5-nucleotidase. This pathway has been explored in antithrombotic treatments but little in myocardial protection. We have investigated whether the administration of solCD39L3 (AZD3366) confers additional cardioprotection to that of ticagrelor alone in a pre-clinical model of myocardial infarction (MI). METHODS: Ticagrelor-treated pigs underwent balloon-induced MI (90 min) and, before reperfusion, received intravenously either vehicle, 1 mg/kg AZD3366 or 3 mg/kg AZD3366. All animals received ticagrelor twice daily for 42 days. A non-treated MI group was run as a control. Serial cardiac magnetic resonance (baseline, Day 3 and Day 42 post-MI), light transmittance aggregometry, bleeding time, and histological and molecular analyses were performed. RESULTS: Ticagrelor reduced oedema formation and infarct size at Day 3 post-MI vs. controls. A 3 mg/kg AZD3366 provided an additional 45% reduction in oedema and infarct size compared with ticagrelor and a 70% reduction vs. controls (P < .05). At Day 42, infarct size declined in all ticagrelor-administered pigs, particularly in 3 mg/kg AZD3366-treated pigs (P < .05). Left ventricular ejection fraction was diminished at Day 3 in placebo pigs and worsened at Day 42, whereas it remained unaltered in ticagrelor ± AZD3366-administered animals. Pigs administered with 3 mg/kg AZD3366 displayed higher left ventricular ejection fraction upon dobutamine stress at Day 3 and minimal dysfunctional segmental contraction at Day 42 (χ2P < .05 vs. all). Cardiac and systemic molecular readouts supported these benefits. Interestingly, AZD3366 abolished ADP-induced light transmittance aggregometry without affecting bleeding time. CONCLUSIONS: Infusion of AZD3366 on top of ticagrelor leads to enhanced cardioprotection compared with ticagrelor alone.