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Cardiovascular disease is an important contributor to morbidity and mortality in people living with HIV. The immature platelet fraction (IPF) is increased in HIV-negative patients with cardiovascular disease and evidence suggests that an enlarged IPF is associated with adverse cardiovascular events. In this multi-center observational study, we aimed to investigate how the IPF in people living with HIV is influenced by antiretroviral therapy and cardiovascular disease. Subjects without cardiovascular disease that received antiretroviral therapy showed a smaller IPF accompanied by lower D-dimer and C-reactive protein (CRP) levels compared to therapy-naïve subjects (mean IPF: 2.9% vs. 3.9%, p =.016; median D-dimer: 252 µg/L vs. 623 µg/L, p <.001; median CRP: 0.2 mg/dL vs. 0.5 mg/dL, p =.004). No significant differences for the IPF, D-dimer or CRP were found between subjects on antiretroviral therapy with documented cardiovascular disease and therapy-naïve subjects. In conclusion, we observed a reduction in the IPF among subjects on therapy only in the absence of cardiovascular disease. In contrast, subjects receiving therapy that had documented cardiovascular disease showed an IPF comparable to therapy-naïve subjects. Future studies are needed to investigate if an enlarged IPF may serve as a biomarker in predicting adverse cardiovascular events in people living with HIV. [ABSTRACT FROM AUTHOR]

Objectives: The ISAR-REACT 4 (Intracoronary Stenting and Antithrombotic Regimen: Rapid Early Action for Coronary Treatment-4) platelet substudy aimed to determine the relevance of high on-clopidogrel treatment platelet reactivity (HPR) in non-ST-segment elevation myocardial infarction patients that received abciximab with unfractionated heparin (UFH) or bivalirudin during percutaneous coronary intervention (PCI).Background: In patients undergoing PCI, HPR has been linked to a higher risk for ischemic events. The influence of HPR on clinical outcomes may differ with regard to the adjunctive antithrombotic treatment administered. In ISAR-REACT 4, bivalirudin treatment showed similar efficacy profiles as compared to abciximab with UFH. The impact of HPR on clinical outcomes in abciximab with UFH versus bivalirudin treated non-ST-segment elevation myocardial infarction patients has never been investigated specifically.Methods: A total of 564 patients (274 in abciximab/UFH group vs. 290 in bivalirudin group) were enrolled in this study. Presence or absence of HPR following clopidogrel loading was determined by platelet function testing on a Multiplate analyzer (Verum Diagnostica, Munich, Germany). Per study group and stratified in HPR and no-HPR patients, the 30-day incidence of a combined efficacy endpoint (death, myocardial infarction, urgent target vessel revascularization) was determined.Results: For abciximab with UFH, the incidence of the efficacy endpoint was similar in HPR versus no-HPR patients (9.4% vs. 6.7%; odds ratio: 1.4; 95% confidence interval: 0.6 to 3.5; p = 0.43). For bivalirudin, the incidence of the efficacy endpoint was significantly higher in HPR versus no-HPR patients (22.0% vs. 5.0%; odds ratio: 5.4; 95% confidence interval: 2.4 to 12.1; p < 0.0001).Conclusions: For patients with a risk profile similar to the subjects enrolled in this platelet substudy, the impact of HPR on clinical outcomes may depend on the type of adjunctive antithrombotic therapy used during PCI. Further investigations are warranted to clarify whether assessment of platelet function may help tailoring antithrombotic therapy during PCI. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Mild therapeutic hypothermia (TH) is standard of care after cardiac arrest of any cause. However, its impact on on-treatment platelet reactivity and clinical outcome in patients with acute myocardial infarction (AMI) complicated by cardiogenic shock and undergoing PCI with P2Y12 receptor inhibitor treatment is less clear. METHODS AND RESULTS: For the ISAR-SHOCK registry, 145 patients with AMI, cardiogenic shock and primary PCI in two centers (Deutsches Herzzentrum München and Klinikum rechts der Isar, Technical University Munich) between January 2009-May 2012 were analysed. Of these, 64 (44%) patients received TH treatment. The median [IQR] ADP-induced platelet aggregation following thienopyridine loading dose administration (clopidogrel in 95 and prasugrel in 50 patients) did not differ between the two groups (419 [283-684] for TH vs. 355 [207-710] AU x min for non-TH patients, P=0.22). After 30days follow-up, no significant differences were observed between both groups for mortality (42 vs. 44 %, HR: 0.93, 95% CI [0.56-1.53], p=0.77), MI (6 vs. 6%, HR: 0.99 95% CI [0.27-3.7], p=0.99) and TIMI minor bleedings (17 vs. 17%, HR 0.99 95% CI [0.45-2.18], p=0.98). TIMI major bleedings were numerically higher in the TH vs. non-TH cohort (25 % vs. 12 %, HR: 2.1 95% CI [0.95-4.63], p=0.07). Three definite stent thrombosis (ST) were observed in this registry and all STs occurred in the TH group of patients (p=0.09). CONCLUSION: Results of this registry suggest that TH does not negatively impact on platelet reactivity in shock patients receiving either clopidogrel or prasugrel. The numerically higher rate of major bleedings and the clustering of STs in the TH cohort warrant further investigation. [ABSTRACT FROM AUTHOR]

Thromboembolic events are common in patients with essential thrombocythemia (ET). However, the pathophysiological mechanisms underlying the increased thrombotic risk remain to be determined. Here, we perform the first phenotypical characterization of platelet expression using single-cell mass cytometry in six ET patients and six age- and sex-matched healthy individuals. A large panel of 18 transmembrane regulators of platelet function and activation were analyzed, at baseline and after ex-vivo stimulation with thrombin receptor-activating peptide (TRAP). We detected a significant overexpression of the activation marker CD62P (p-Selectin) ( p  = .049) and the collagen receptor GPVI ( p  = .044) in non-stimulated ET platelets. In contrast, ET platelets had a lower expression of the integrin subunits of the fibrinogen receptor GPIIb/IIIa CD41 ( p  = .036) and CD61 ( p  = .044) and of the von Willebrand factor receptor CD42b ( p  = .044). Using the FlowSOM algorithm, we identified 2 subclusters of ET platelets with a prothrombotic expression profile, one of them (cluster 3) significantly overrepresented in ET (22.13% of the total platelets in ET, 2.94% in controls, p  = .035). Platelet counts were significantly increased in ET compared to controls ( p  = .0123). In ET, MPV inversely correlated with platelet count ( r =-0.96). These data highlight the prothrombotic phenotype of ET and postulate GPVI as a potential target to prevent thrombosis in these patients.

Background: The ISAR-REACT 5 trial compared the efficacy and safety of ticagrelor and prasugrel in patients with ACS managed invasively. The present study sought to investigate the impact of ticagrelor and prasugrel on the incidence and pattern of urgent revascularization in acute coronary syndromes (ACS) patients undergoing percutaneous coronary intervention (PCI)., Methods and Results: This post-hoc analysis of the ISAR-REACT 5 trial included all ACS patients who underwent PCI. The primary endpoint for this analysis was the incidence of urgent revascularization at 12-month follow-up. Secondary outcome was the pattern of urgent revascularization procedures (namely, urgent target vessel/non-target vessel revascularization - TVR/NTVR). Among 3,377 ACS patients who underwent PCI, 1,676 were assigned to ticagrelor and 1,701 to prasugrel before PCI. After 12 months, the incidence of urgent revascularization was higher among patients assigned to ticagrelor as compared to prasugrel (6.8% vs. 5.2%; hazard ratio [HR] = 1.32, 95% confidence interval [CI] 1.00-1.75; p = 0.051), mostly attributable to significantly more urgent NTVR in the ticagrelor group (3.8% vs. 2.4%; HR = 1.62 [1.09-2.41]; p = 0.017). The risk of urgent TVR did not differ between treatment groups (3.3% vs. 3.0%; HR = 1.13 [0.77-1.65]; p = 0.546)., Conclusions: In ACS patients treated with PCI, the cumulative rate of urgent revascularizations after 12 months is higher with ticagrelor compared to prasugrel, due to a significant increase in urgent revascularizations involving remote coronary vessels., (© 2024. The Author(s).)

Aims: Pulmonary vein isolation (PVI) represents the gold standard in the treatment of atrial fibrillation (AF) and the use of single-shot techniques, such as cryoballoon ablation (CBA) and pulsed field ablation (PFA) using a pentaspline catheter, has gained prominence. Recent studies hypothesize that PFA might be superior to CBA, although procedural efficacy and safety data are inconsistent. A meta-analysis was conducted to compare both energy sources for the treatment of AF., Methods and Results: A structured systematic database search and meta-analysis were performed on studies investigating outcomes, periprocedural complications, and/or procedural parameters of AF patients treated by either CBA or PFA. Eleven studies reporting data from 3805 patients were included. Pulmonary vein isolation by PFA was associated with a significantly lower recurrence of atrial fibrillation/atrial tachycardia [odds ratio (OR) = 0.73, 95% confidence interval (CI) = 0.54-0.98, I 2 = 20%] and fewer periprocedural complications (OR = 0.62, 95% CI = 0.40-0.96, I 2 = 6%) compared to CBA. The lower complication rate following PFA was mainly driven by fewer phrenic nerve injuries (OR = 0.19, 95% CI = 0.08-0.43, I 2 = 0%). However, there were more cases of cardiac tamponades after PFA (OR = 2.56, 95% CI = 1.01-6.49, I 2 = 0%). Additionally, using PFA for PVI was associated with shorter total procedure times [mean difference (MD) = -9.68, 95% CI = -14.92 to -4.43 min, I 2 = 92%] and lower radiation exposure (MD = -148.07, 95% CI = -276.50 to -19.64 µGy·mI 2 = 7%)., Conclusion: Our results suggest that PFA for PVI, compared to CBA, enables shorter procedure times with lower arrhythmia recurrence and a reduced risk of periprocedural complications. Randomized controlled trials need to confirm our findings., Competing Interests: Conflict of interest: R.W. received honoraria for lectures and advisory board activities and research funding from Boston Scientific. Otherwise, there are no conflicts of interest., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background:  The pro-thrombotic immature or reticulated platelets (RPs) are known to be elevated in high-risk patients and in different pathological settings. It has been shown that RPs correlate with an insufficient antiplatelet response to antiplatelet agents. RPs are emerging novel predictors of adverse cardiovascular events in cardiovascular disease. This study, using the totality of existing evidence, evaluated the prognostic role of RPs in patients with coronary artery disease., Methods:  We performed a systematic review and meta-analysis including trials of acute and chronic coronary syndrome reporting clinical outcomes according to RPs levels in the peripheral blood. We compared patients with elevated RPs (RPs high ) to patients without elevated RPs (RPs low ). Odds ratios (ORs) and 95% CIs were used as metric of choice for treatment effects with random-effects models. The primary endpoint was major adverse cardiovascular and cerebrovascular events (MACCE). Secondary endpoints were cardiovascular death, myocardial infarction, ischemic stroke, urgent coronary revascularization and bleedings., Results:  A total of 7 studies, including 2213 patients, were included. The risk for MACCE was significantly higher in RPs high compared to RPs low patients (OR 2.67 [1.87; 3.81], I2  = 43.8%). RPs high were associated with cardiovascular death (OR 2.09 [1.36; 3.22], I2  = 40.4%). No associations for RPs high were detected with the other singular components of MACCE: myocardial infarction (OR 1.73 [0.89; 3.38] I2  = 60.5%) and stroke (OR 1.72 [0.59; 4.96] I2  = 21%). The risk of bleeding did not differ between groups(OR 0.58 [0.15; 2.22] I2  = 86.1%)., Conclusion:  Elevated RPs are significantly associated with increased risk of cardiovascular events and cardiovascular death., Competing Interests: None declared., (Thieme. All rights reserved.)

Background and Aims:  Glycoprotein VI (GPVI) is the major platelet-specific collagen receptor. GPVI shedding with generation of soluble GPVI (sGPVI) is an endogenous feedback mechanism preventing platelet overstimulation. sGPVI has not been investigated in patients with chronic coronary syndrome (CCS) undergoing percutaneous coronary intervention (PCI), especially regarding its potential value as a predictor of ischemic and bleeding risk., Methods:  Baseline plasma sGPVI levels were available in 318 patients with CCS undergoing PCI. Platelet function was assessed by measuring both adenosine diphosphate (ADP) and collagen-induced platelet aggregation. Co-primary endpoints were a composite of death or myocardial injury at 48 hours after PCI, and Bleeding Academic Research Consortium (BARC) type 1 to 5 bleeding at 30 days., Results:  There was no significant correlation between sGPVI and platelet function at baseline or at 48 hours after PCI and loading with antiplatelet drugs. Baseline plasma sGPVI levels were not associated with the ischemic risk: the incidence of the ischemic endpoint was 25.0% in the lower, 22.9% in the middle, and 26.7% in the upper sGPVI tertile ( p  = 0.82). There was a significant nonlinear relationship between sGPVI and the risk of bleeding: the incidence of the bleeding endpoint was 11.8% in the lower, 12.6% in the middle, and 26.4% in the upper sGPVI tertile ( p  = 0.006)., Conclusion:  In patients with CCS undergoing PCI, plasma levels of sGPVI did not correlate with ADP- or collagen-induced platelet aggregation. Patients with higher baseline levels of sGPVI may carry an increased risk of bleeding at 30 days after PCI but no excess risk of ischemic events., Competing Interests: R.H.-R. reported grants from German Center for Cardiovascular Research, Deutsches Herzzentrum München, the Federal Ministry of Education and Research, and advanceCOR GmbH during the conduct of the study. I.B. reported personal fees from Sysmex Europe GmbH outside the submitted work. S.S. reported grants from Else Kröner-Fresenius-Stiftung (Else Kröner-Memorial grant) during the conduct of the study and DZHK (German Center for Cardiovascular Research) for the Intracoronary Stenting and Antithrombotic Regimen: Lesion Platelet Adhesion as Selective Target of Endovenous Revacept in Patients with Chronic Coronary Syndromes Undergoing Percutaneous Coronary Intervention trial and personal fees from Bayer Vital GmbH, Daiichi Sankyo, and Biopas Laboratories outside the submitted work. S.H. has received research grants and honoraria from Roche Diagnostics, Bristol Myers Squibb, Merck KGaA, Sysmex Inostics, and Volition SPRL outside the submitted work. M.G. is cofounder of advanceCor, the manufacturer of Revacept. H.S. reports honoraria from AstraZeneca, Bayer Vital, MSD Sharp & Dohme, Novartis, Servier, Sanofi-Aventis, Boehringer Ingelheim, Daiichi Sankyo, Amgen, Pfizer and consulting fees from AstraZeneca, Amgen, MSD Sharp & Dohme, not related to the current work. G.M. is the founder of advanceCOR GmbH, Martinsried, Germany. K.A. is employee of advanceCOR GmbH, Martinsried, Germany., (Thieme. All rights reserved.)

Immature platelets are newly formed platelets with an increased prothrombotic potential. This study evaluates whether immature platelets are associated with relevant complications in neurosurgical patients. Data were obtained in the frame of a prospectively conducted observational study exploring the association between immature platelets and major cardiovascular events after surgery. Immature platelet fraction (IPF) and H-IPF (highly fluorescent immature platelet fraction) were measured preoperatively and postoperatively at the neurosurgical ward (24-72 hours after surgery). Therapy-relevant complications after surgery were stratified using the Clavien-Dindo Grade (CDG >2) as primary outcome. Data were analyzed in 391 neurosurgical patients. While preoperatively there were no differences in IPF or H-IPF, patients with higher therapy-complication grades had higher values post-op compared to patients with lower grade complications (≤2 CDG). Cut-off values identified by receiver operating characteristic curve analysis revealed that there were significantly more patients with H-IPF ≥0.95% in the group with serious complications (CDG >2) [odds ratio OR (95% confidence interval CI) = 2.06 (1.09-3.9), p  = .025], whereas this association was not present for the IPF cutoff value. In a multivariate model, H-IPF≥0.95% was independently associated with serious complications after surgery [OR (95% CI) = 1.97 (1.03-3.78), p  = .041]. These findings suggest that H-IPF is associated with surgical complications and may improve risk stratification of neurosurgical patients (clinicaltrials.gov: NCT02097602, registration date: 27/03/2014).

Objective: The aim of this study was to assess the association between high on-aspirin treatment platelet reactivity (HAPR) and the subsequent risk of restenosis after percutaneous coronary intervention (PCI) with predominantly drug-eluting stents., Background: The association between HAPR and subsequent risk of restenosis after PCI is unclear., Methods: This study included 4839 patients undergoing PCI (02/2007-12/2011) in the setting of the Intracoronary Stenting and Antithrombotic Regimen-ASpirin and Platelet Inhibition (ISAR-ASPI) registry. Platelet function was assessed with impedance aggregometry using the multi-plate analyzer immediately before PCI and after intravenous administration of aspirin (500 mg). The primary outcome was clinical restenosis, defined as target lesion revascularization at 1 year. Secondary outcomes included binary angiographic restenosis and late lumen loss at 6- to 8-month angiography., Results: The upper quintile cut-off of platelet reactivity measurements (191 AU × min) was used to categorize patients into a group with HAPR (platelet reactivity > 191 AU × min; n = 952) and a group without HAPR (platelet reactivity ≤ 191 AU × min; n = 3887). The primary outcome occurred in 94 patients in the HAPR group and 405 patients without HAPR (cumulative incidence, 9.9% and 10.4%; HR = 0.96, 95% CI 0.77-1.19; P = 0.70). Follow-up angiography was performed in 73.2% of patients. There was no difference in binary restenosis (15.2% vs. 14.9%; P = 0.79) or late lumen loss (0.32 ± 0.57 vs. 0.32 ± 0.59 mm; P = 0.93) between patients with HAPR versus those without HAPR., Conclusions: This study did not find an association between HAPR, measured at the time of PCI, and clinical restenosis at 1 year after PCI., (© 2023. The Author(s).)

Aims: Variants of the junctional cadherin 5 associated (JCAD) locus associate with acute coronary syndromes. JCAD promotes experimental atherosclerosis through the large tumor suppressor kinase 2 (LATS2)/Hippo pathway. This study investigates the role of JCAD in arterial thrombosis., Methods and Results: JCAD knockout (Jcad-/-) mice underwent photochemically induced endothelial injury to trigger arterial thrombosis. Primary human aortic endothelial cells (HAECs) treated with JCAD small interfering RNA (siJCAD), LATS2 small interfering RNA (siLATS2) or control siRNA (siSCR) were employed for in vitro assays. Plasma JCAD was measured in patients with chronic coronary syndrome or ST-elevation myocardial infarction (STEMI). Jcad-/- mice displayed reduced thrombogenicity as reflected by delayed time to carotid occlusion. Mechanisms include reduced activation of the coagulation cascade [reduced tissue factor (TF) expression and activity] and increased fibrinolysis [higher thrombus embolization episodes and D-dimer levels, reduced vascular plasminogen activator inhibitor (PAI)-1 expression]. In vitro, JCAD silencing inhibited TF and PAI-1 expression in HAECs. JCAD-silenced HAECs (siJCAD) displayed increased levels of LATS2 kinase. Yet, double JCAD and LATS2 silencing did not restore the control phenotype. si-JCAD HAECs showed increased levels of phosphoinositide 3-kinases (PI3K)/ proteinkinase B (Akt) activation, known to downregulate procoagulant expression. The PI3K/Akt pathway inhibitor-wortmannin-prevented the effect of JCAD silencing on TF and PAI-1, indicating a causative role. Also, co-immunoprecipitation unveiled a direct interaction between JCAD and Akt. Confirming in vitro findings, PI3K/Akt and P-yes-associated protein levels were higher in Jcad-/- animals. Lastly, as compared with chronic coronary syndrome, STEMI patients showed higher plasma JCAD, which notably correlated positively with both TF and PAI-1 levels., Conclusions: JCAD promotes arterial thrombosis by modulating coagulation and fibrinolysis. Herein, reported translational data suggest JCAD as a potential therapeutic target for atherothrombosis., Competing Interests: Conflict of interest: L.L. and G.G.C. are coinventors on the International Patent WO/2020/226993 filed in April 2020. The patent relates to the use of antibodies which specifically bind IL-1α to reduce various sequelae of ischemia-reperfusion injury to the central nervous system. G.G.C. is a consultant to Sovida solutions limited. T.F.L. has no conflicts related to this manuscript. Outside the work he received unrestricted research and education grants from Abbott, Amgen, Boehringer Ingelheim, Daichi-Sankyo, Novartis, Roche Diagnostics, Sanofi, Servier and Vifor. L.L. reports speaker fees outside of this work from Daichi-Sankyo. G.L. reports Consulting fees and Payment or honoraria for lectures: Novo Nordisk, Novartis, Sanofi, AstraZeneca, Boehringer, Bayer. F.C. reports speaker fees from Amgen, Astra Zeneca, Servier, BMS, other from GlyCardial Diagnostics, outside the submitted work. The other authors report no conflict of interest., (© The Author(s) 2022. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background:  The relative efficacy and safety of ticagrelor and prasugrel based dual antiplatelet therapy strategies according to the platelet count (PC) in patients with acute coronary syndromes (ACS) have not been defined., Methods:  This is a posthoc analysis of the ISAR-REACT 5 trial, in which patients presenting with ACS were randomized to treatment with ticagrelor versus prasugrel. Patients were divided into quartiles according to PC. The primary endpoint was incidence of death, myocardial infarction, or stroke, and the safety endpoint was incidence of BARC (Bleeding Academic Research Consortium) type 3 to 5 bleeding at 12 months., Results:  A total of 3,943 patients with known PC (997 patients in quartile 1 (Q1), 1,003 in quartile 2 (Q2) [205 ± 10.3 × 10 9 /L], 961 patients in quartile 3 (Q3) [241 ± 11.7 × 10 9 /L], and 982 patients in quartile 4 (Q4) [317 ± 68.6 × 10 9 /L]). There was no significant interaction between treatment arm (ticagrelor vs. prasugrel) and PC group with respect to primary endpoint (Q1: 8.8 vs. 6.3%, hazard ratio [HR] =1.41, 95% confidence interval [CI]: 0.89-2.23; p  = 0.148; Q2: 9.9 vs. 5.8%, HR = 1.68, 95% CI: 1.06-2.66; p  = 0.027; Q3: 7.8 vs. 5.5%, HR = 1.43, 95% CI: 0.87-2.37; p  = 0.159; Q4: 10.1 vs. 10.1%, HR = 1.05, 95% CI: 0.71-1.57; p  = 0.799; p for interaction [ p int ] = 0.482) and with respect to bleeding endpoint (Q1: 5.8 vs. 4.2%, HR = 1.41, 95% CI: 0.76-2.63; p  = 0.279; Q2: 6.4 vs. 3.7%, HR = 1.62, 95% CI: 0.85-2.06; p  = 0.140; Q3: 4.4 vs. 3.0%, HR = 1.53, 95% CI: 0.73-3.18; p  = 0.258; Q4: 5.6 vs. 8.5%, HR = 0.67, 95% CI: 0.40-1.14; p  = 0.138, p int  = 0.102)., Conclusions:  In this analysis, incidences of ischemic and bleeding events at 12 months are comparable across quartiles of platelet count., Competing Interests: D.J.A. reports consulting fees or honoraria from Abbott, Amgen, AstraZeneca, Bayer, Biosensors, Boehringer Ingelheim, Bristol-Myers Squibb, Chiesi, Daiichi-Sankyo, Eli Lilly, Haemonetics, Janssen, Merck, PhaseBio, PLx Pharma, Pfizer, and Sanofi; and research grants to his institution from Amgen, AstraZeneca, Bayer, Biosensors, CeloNova, CSL Behring, Daiichi-Sankyo, Eisai, Eli Lilly, Gilead, Janssen, Matsutani Chemical Industry Co., Merck, Novartis, Osprey Medical, Renal Guard Solutions, and Scott R. MacKenzie Foundation. H.S. reports honoraria from AstraZeneca, Bayer Vital, MSD SHARP&DOHME, Novartis, Servier, Sanofi-Aventis, Boehringer Ingelheim, Daiichi Sankyo, Amgen, and Pfizer, and consulting fees from AstraZeneca, Amgen, and MSD SHARP&DOHME. S.K. reports consulting and lecture fees from Astra Zeneca, Bristol-Myers Squibb, and Translumina. T.K. is named inventor on a patent application for prevention of restenosis after angioplasty and stent implantation outside the submitted work and received lecture fees from Bayer AG, Pharmaceuticals; M.J. reports speaker fees from Biotronik, personal fees from OrbusNeich, grants and personal fees from Boston Scientific, grants and personal fees from Edwards, personal fees from AstraZeneca, personal fees from Recor, grants from Amgen, not related to the current work., (The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/).)

Objectives: To assess the efficacy and safety of ticagrelor versus prasugrel in patients with acute coronary syndrome (ACS) presenting during off- and on-hours., Background: The efficacy and safety of ticagrelor versus prasugrel in patients with ACS according to time of hospital presentation remain unknown., Methods: This post hoc analysis of the ISAR-REACT 5 trial included 1565 patients with ACS presenting off-hours and 2453 patients presenting on-hours, randomized to ticagrelor or prasugrel. The primary endpoint was a composite of death, myocardial infarction, or stroke; the safety endpoint was Bleeding Academic Research Consortium (BARC) type 3-5 bleeding, both at 12 months., Results: The primary endpoint occurred in 80 patients (10.4%) in the ticagrelor group and 57 patients (7.3%) in the prasugrel group in patients presenting off-hours (hazard ratio [HR] = 1.45; 95% confidence interval [CI] 1.03-2.03; P = 0.033), and 104 patients (8.5%) in the ticagrelor group and 80 patients (6.7%) in the prasugrel group in patients presenting on-hours (HR = 1.29 [0.97-1.73]; P = 0.085), without significant treatment arm-by-presentation time interaction (P int  = 0.62). BARC type 3 to 5 bleeding occurred in 35 patients (5.1%) in the ticagrelor group and 37 patients (5.3%) in the prasugrel group (P = 0.84) in patients presenting off-hours, and 60 patients (5.9%) in the ticagrelor group and 43 patients (4.6%) in the prasugrel group in patients presenting on-hours (P = 0.17)., Conclusions: In patients with ACS planned to undergo an invasive treatment strategy, time of presentation (off-hours vs. on-hours) does not interact significantly with the relative efficacy and safety of ticagrelor vs. prasugrel., Clinical Trial Registration: NCT01944800., (© 2022. The Author(s).)

Background: Immature or reticulated platelets are associated with impaired efficacy of antiplatelet drugs and adverse events in cardiovascular patients. Their role as a predictive biomarker in patients with acute coronary syndrome treated with potent P2Y 12 receptor inhibitors is not fully understood. We aimed to prospectively evaluate reticulated platelets as a predictor of the primary end point of the ISAR-REACT 5 trial consisting of death, myocardial infarction, or stroke at 1 year in patients with acute coronary syndrome randomized to prasugrel or ticagrelor., Methods: Immature platelet fraction (IPF) was assessed within 48 hours after randomization. Patients were divided based on the IPF median values: the IPF high group included patients with IPF>median and the IPF low group included patients with IPF≤median. Platelet aggregation was assessed using the Multiplate Analyzer and was correlated to IPF., Results: Five hundred seventy-seven patients were included in the study. IPF values in % (median [interquartile range]) within the first 48 hours did not differ between the two study groups: 3.6 (2.5-5.2)% in the prasugrel group and 3.6 (2.5-5.4)% in the ticagrelor group ( P =0.882). The incidence of the primary end point was significantly higher in the IPF high (IPF>3.6%) group compared with the IPF low (IPF ≤ 3.6%) group: 13.0% versus 7.2% (HR adj , 1.74 [1.02-3.00]; P =0.044), independently from the assigned drug ( P int =0.159). No significant association between IPF and BARC 3 to 5 bleeding was observed. ADP-induced platelet aggregation correlated significantly with IPF in patients treated with prasugrel ( r =0.22; P =0.005) while no correlation was detected in patients treated with ticagrelor ( r =0.09; P =0.257)., Conclusions: Independently from drug treatment, IPF was associated with the primary end point and therefore is a promising biomarker for the prediction of adverse cardiovascular events in patients with acute coronary syndrome treated with prasugrel or ticagrelor., Registration: https://www., Clinicaltrials: gov; Unique identifier: NCT01944800.

Background The efficacy and safety of ticagrelor versus prasugrel in patients with acute coronary syndrome and prior myocardial infarction (MI) remain unstudied. We aimed to assess the treatment effect of ticagrelor versus prasugrel according to prior MI status in patients with ACS. Methods and Results Patients with acute coronary syndrome planned for an invasive strategy and randomized to ticagrelor or prasugrel in the ISAR-REACT (Intracoronary Stenting and Antithrombotic Regimen: Rapid Early Action for Coronary Treatment) 5 trial were included. The primary end point was the composite of 1-year all-cause death, MI, or stroke; the secondary safety end point was the composite of 1-year Bleeding Academic Research Consortium type 3 to 5 bleeding. The study included 4015 patients (prior MI=631 patients; no prior MI=3384 patients). As compared with patients without prior MI, the primary end point occurred more frequently in patients with prior MI (12.6% versus 7.2%; hazard ratio [HR], 1.78 [95% CI, 1.38-2.29]); the secondary safety end point appears to differ little between patients with and without prior MI (5.8% versus 5.7%, respectively; HR, 1.02 [95% CI, 0.71-1.45]). With regard to the primary end point, ticagrelor versus prasugrel was associated with an HR of 1.62 (95% CI, 1.03-2.55) in patients with prior MI and an HR of 1.28 (95% CI, 0.99-1.65) in patients without prior MI ( P int =0.37). With regard to the secondary safety end point, ticagrelor versus prasugrel was associated with an HR of 1.28 (95% CI, 0.56-2.91) in patients with prior MI and an HR of 1.13 (95% CI, 0.82-1.55) in patients without prior MI ( P int =0.79). Conclusions Patients with acute coronary syndrome and prior MI are at higher risk for recurrent ischemic but not bleeding events. Prasugrel is superior to ticagrelor in reducing the risk of ischemic events without a tradeoff in bleeding regardless of prior MI status. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT01944800.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection induces a coagulopathy characterized by platelet activation and a hypercoagulable state with an increased incidence of cardiovascular events. The viral spike protein S has been reported to enhance thrombosis formation, stimulate platelets to release procoagulant factors, and promote the formation of platelet-leukocyte aggregates even in absence of the virus. Although SARS-CoV-2 vaccines induce spike protein overexpression to trigger SARS-CoV-2-specific immune protection, thrombocyte activity has not been investigated in this context. Here, we provide the first phenotypic platelet characterization of healthy human subjects undergoing BNT162b2 vaccination. Using mass cytometry, we analyzed the expression of constitutive transmembrane receptors, adhesion proteins, and platelet activation markers in 12 healthy donors before and at five different time points within 4 weeks after the first BNT162b2 administration. We measured platelet reactivity by stimulating thrombocyte activation with thrombin receptor-activating peptide. Activation marker expression (P-selectin, LAMP-3, LAMP-1, CD40L, and PAC-1) did not change after vaccination. All investigated constitutive transmembrane proteins showed similar expressions over time. Platelet reactivity was not altered after BNT162b2 administration. Activation marker expression was significantly lower compared with an independent cohort of mild symptomatic COVID-19 patients analyzed with the same platform. This study reveals that BNT162b2 administration does not alter platelet protein expression and reactivity., Competing Interests: The authors declare that they have no conflict of interest, except C.D.S. Christoph Spinner reports grants, personal fees, nonfinancial support, and other from AbbVie, grants, personal fees, nonfinancial support, and other from Apeiron, personal fees from Formycon, grants, personal fees, nonfinancial support, and other from Gilead Sciences, grants, personal fees and other from Eli Lilly, grants, personal fees, nonfinancial support, and other from Janssen-Cilag, grants, personal fees, nonfinancial support, and other from GSK/ViiV Healthcare, grants, personal fees, nonfinancial support, and other from MSD, outside the submitted work., (Thieme. All rights reserved.)

Background: The relative efficacy and safety of more potent P2Y 12 inhibitors in patients with acute coronary syndrome and high bleeding risk (HBR) undergoing percutaneous coronary intervention remains unclear. We aimed to study the treatment effect of ticagrelor and prasugrel in percutaneous coronary intervention patients presenting with acute coronary syndrome and HBR., Methods: This post hoc analysis of the ISAR-REACT 5 trial (Intracoronary Stenting and Antithrombotic Regimen: Rapid Early Action for Coronary Treatment 5) included patients with acute coronary syndrome undergoing percutaneous coronary intervention, randomized to ticagrelor or prasugrel, in whom HBR was defined as per Academic Research Consortium criteria. The primary (efficacy) end point was the composite of all-cause death, myocardial infarction, or stroke. The secondary (safety) end point was Bleeding Academic Research Consortium type 3 to 5 bleeding. Outcomes were assessed 12 months after randomization., Results: Out of the 3239 patients included in this analysis, 486 fulfilled the criteria for Academic Research Consortium-HBR definition (HBR group; ticagrelor, n=230 and prasugrel, n=256), while 2753 did not (non-HBR group; ticagrelor, n=1375 and prasugrel, n=1378). Compared with the non-HBR group, the HBR group had a higher risk for the primary (hazard ratio [HR]=3.57 [95% CI, 2.79-4.57]; P <0.001) and secondary end point (HR=2.94 [2.17-3.99]; P <0.001). In the HBR group, the primary (HR=1.09 [0.73-1.62]) and secondary (HR=1.18 [0.67-2.08]) end points were not significantly different between patients assigned to ticagrelor and prasugrel. In the non-HBR group, the primary end point (HR=1.62 [1.19-2.20]) occurred more frequently in patients assigned to ticagrelor as compared to patients assigned to prasugrel, without difference in safety (HR=1.08 [0.74-1.58]). There was no significant treatment allocation-by-HBR status interaction with respect to the primary ( P for interaction=0.12) or secondary ( P for interaction=0.80) end points., Conclusions: In patients with acute coronary syndrome undergoing percutaneous coronary intervention, HBR status increased both ischemic and bleeding risk without significant impact on the relative efficacy and safety of either ticagrelor or prasugrel. These results warrant confirmation in larger cohorts., Registration: URL: https://www., Clinicaltrials: gov; Unique identifier: NCT01944800.

Aims: To assess whether the efficacy and safety of ticagrelor vs. prasugrel in patients with acute coronary syndromes (ACSs) are influenced by pre-admission treatment with aspirin and/or clopidogrel., Methods and Results: Patients (n = 4018) were categorized into two groups: pre-admission aspirin and/or clopidogrel group (n = 1455) and no pre-admission aspirin or clopidogrel group (n = 2563). The primary endpoint was the composite of all-cause death, myocardial infarction, or stroke; the secondary safety endpoint was Bleeding Academic Research Consortium (BARC) type 3-5 bleeding, both at 1 year. Patients in the pre-admission aspirin and/or clopidogrel group had a higher risk of ischaemic events, but a similar risk of bleeding to patients in the no pre-admission aspirin or clopidogrel group (cumulative incidences 10.5% vs. 6.7%, and 5.7% vs. 5.7%, respectively). The primary endpoint occurred in 81/717 patients assigned to ticagrelor and 69/738 patients assigned to prasugrel in the pre-admission aspirin and/or clopidogrel group [11.5% vs. 9.5%; hazard ratio (HR) = 1.23; 95% confidence interval (CI) 0.89-1.69], and in 103/1295 patients assigned to ticagrelor and 68/1268 patients assigned to prasugrel in the no pre-admission aspirin or clopidogrel group [8.0% vs. 5.4%; HR = 1.50 (1.10-2.03); Pint = 0.38]. BARC type 3-5 bleeding events did not differ between ticagrelor and prasugrel in patients in the pre-admission aspirin and/or clopidogrel (6.2% vs. 4.5%) or no pre-admission aspirin or clopidogrel (5.3% vs. 5.1%) group (Pint = 0.54)., Conclusion: In patients with ACS, pre-admission therapy with aspirin and/or clopidogrel has no influence on the relative efficacy and safety of ticagrelor and prasugrel., (© The Author(s) 2022. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Introduction and Objectives: The efficacy and safety of ticagrelor vs prasugrel in patients with acute coronary syndromes (ACS) according to body mass index (BMI) remain unstudied. We assessed the efficacy and safety of ticagrelor vs prasugrel in patients with ACS according to BMI., Methods: Patients (n=3987) were grouped into 3 categories: normal weight (BMI <25kg/m 2 ; n=1084), overweight (BMI ≥ 25 to <30kg/m 2 ; n=1890), and obesity (BMI ≥ 30kg/m 2 ; n=1013). The primary efficacy endpoint was the 1 year incidence of all-cause death, myocardial infarction, or stroke. The secondary safety endpoint was the 1 year incidence of Bleeding Academic Research Consortium type 3 to 5 bleeding., Results: The primary endpoint occurred in 63 patients assigned to ticagrelor and 39 patients assigned to prasugrel in the normal weight group (11.7% vs 7.5%; HR, 1.62; 95%CI, 1.09-2.42; P=.018), 78 patients assigned to ticagrelor and 58 patients assigned to prasugrel in the overweight group (8.3% vs 6.2%; HR, 1.36; 95%CI, 0.97-1.91; P=.076), and 43 patients assigned to ticagrelor and 37 patients assigned to prasugrel in the obesity group (8.6% vs 7.3%; HR, 1.18; 95%CI, 0.76-1.84; P=.451). The 1-year incidence of bleeding events did not differ between ticagrelor and prasugrel in patients with normal weight (6.5% vs 6.6%; P=.990), overweight (5.6% vs 5.0%; P=.566) or obesity (4.4% vs 2.8%; P=.219). There was no significant treatment arm-by-BMI interaction regarding the primary endpoint (P int =.578) or secondary endpoint (P int =.596)., Conclusions: In patients with ACS, BMI did not significantly impact the treatment effect of ticagrelor vs prasugrel in terms of efficacy or safety., Clinical Trial Registration: NCT01944800., (Copyright © 2021 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.)

Mass cytometry (CyTOF) is a new technology that allows the investigation of protein expression at single cell level with high resolution. While several protocols are available to investigate leukocyte expression, platelet staining and analysis with CyTOF have been described only from whole blood. Moreover, available protocols do not allow sample storage but require fresh samples to be obtained, processed, and measured immediately. We provide a structured and reproducible method to stain platelets from platelet-rich plasma to study thrombocyte protein expression and reactivity using mass cytometry. With our method, it is possible to acquire a large number of events allowing deep bioinformatic investigation of platelet expression heterogeneity. Integrated in our protocol is also a previously established freezing protocol that allows the storage of stained samples and to delay their measurement. Finally, we provide a structured workflow using different platelet stimulators and a freely available bioinformatic pipeline to analyze platelet expression. Our protocol unlocks the potential of CyTOF analysis for studying platelet biology in health and disease.

Background: Whether the access site influences the comparative efficacy and safety of ticagrelor and prasugrel in patients with acute coronary syndrome (ACS) undergoing invasive treatment strategy remains unstudied., Methods: This post-hoc analysis included ACS patients undergoing invasive treatment via radial or femoral access and randomized to either ticagrelor or prasugrel in the ISAR-REACT 5 trial. The primary efficacy endpoint was the composite of death, myocardial infarction (MI) or stroke, safety endpoint was BARC 3 to 5 bleeding. Outcomes were assessed out to 12 months after randomization., Results: Out of 4018 patients, 3984 underwent invasive treatment via radial or femoral access. 1479 had coronary angiography via radial access (ticagrelor, N = 748; prasugrel, N = 731) and 2505 via femoral access (ticagrelor, N = 1245; prasugrel, N = 1260). There was no interaction between access route and assignment to either ticagrelor or prasugrel regarding the primary efficacy or safety endpoints (P for interaction≥0.616). In the radial group, the primary efficacy endpoint (7.6% versus 5.8%, HR: 1.32 [0.88-1.97], P = 0.151) and the safety endpoint (4.3% versus 3.0%, HR: 1.36, [0.73-1.31], P = 0.300) were not statistically different in patients receiving either ticagrelor or prasugrel. In the femoral group, the primary efficacy endpoint occurred more frequently in patients assigned to ticagrelor as compared to prasugrel (10.3% versus 7.3%, HR: 1.44 [1.10-1.88], P = 0.006) without significant difference in terms of safety endpoint (6.4% versus 5.8%, HR: 1.14, [0.81-1.60], P = 0.470)., Conclusions: In patients with ACS undergoing an invasive treatment strategy, the access route does not influence the comparative efficacy and safety of ticagrelor and prasugrel., Clinical Trial Registration: NCT01944800., (Copyright © 2021. Published by Elsevier Inc.)

Human platelets differ considerably with regard to their size, RNA content and thrombogenicity. Reticulated platelets (RPs) are young, hyper-reactive platelets that are newly released from the bone marrow. They are larger and contain more RNA compared to older platelets. In comparison to more mature platelets, they exhibit a significantly higher thrombogenicity and are known to be elevated in patients with an increased platelet turnover such as, diabetics and after acute myocardial infarction. Several studies have shown that RPs correlate with an insufficient antiplatelet response to aspirin and specific P2Y 12 receptor inhibitors. In addition, RPs are promising novel biomarkers for the prediction of adverse cardiovascular events in cardiovascular disease. However, the reason for RPs intrinsic hyper-reactivity and their association with ischemic events is not completely understood and the biology of RPs is still under investigation. We here present a structured review of preclinical and clinical findings concerning the role of RPs in cardiovascular disease.