Platelet-fibrin clot strength and platelet reactivity predicting cardiovascular events after percutaneous coronary interventions.

BACKGROUND AND AIMS: Platelet-fibrin clot strength (PFCS) is linked to major adverse cardiovascular event (MACE) risk. However, the association between PFCS and platelet reactivity and their prognostic implication remains uncertain in patients undergoing percutaneous coronary intervention (PCI). METHODS: In PCI-treated patients (n = 2512) from registry data from January 2010 to November 2018 in South Korea, PFCS using thromboelastography and platelet reactivity using VerifyNow were measured. High PFCS (PFCSHigh) was defined as thromboelastography maximal amplitude ≥ 68 mm, and high platelet reactivity (HPR) was defined as >208 P2Y12 reaction units. Patients were stratified into four groups according to maximal amplitude and P2Y12 reaction unit levels: (i) normal platelet reactivity (NPR)-PFCSNormal (31.8%), (ii) HPR-PFCSNormal (29.0%), (iii) NPR-PFCSHigh (18.1%), and (iv) HPR-PFCSHigh (21.1%). Major adverse cardiovascular event (all-cause death, myocardial infarction, or stroke) and major bleeding were followed up to 4 years. RESULTS: High platelet reactivity and PFCSHigh showed an additive effect for clinical outcomes (log-rank test, P < .001). Individuals with NPR-PFCSNormal, NPR-PFCSHigh, HPR-PFCSNormal, and HPR-PFCSHigh demonstrated MACE incidences of 7.5%, 12.6%, 13.4%, and 19.3%, respectively. The HPR-PFCSHigh group showed significantly higher risks of MACE compared with the NPR-PFCSNormal group [adjusted hazard ratio (HRadj) 1.89; 95% confidence interval (CI) 1.23-2.91; P = .004] and the HPR-PFCSNormal group (HRadj 1.60; 95% CI 1.12-2.27; P = .009). Similar results were observed for all-cause death. Compared with HPR-PFCSNormal phenotype, NPR-PFCSNormal phenotype was associated with a higher risk of major bleeding (HRadj 3.12; 95% CI 1.30-7.69; P = .010). CONCLUSIONS: In PCI patients, PFCS and platelet reactivity demonstrated important relationships in predicting clinical prognosis. Their combined assessment may enhance post-PCI risk stratification for personalized antithrombotic therapy.

Impact of proton pump inhibitor use on clinical outcomes in East Asian patients receiving clopidogrel following drug-eluting stent implantation.

BACKGROUND: Concomitant use of clopidogrel and proton pump inhibitor (PPI) is common, but PPI may reduce the antiplatelet effects of clopidogrel in patients undergoing percutaneous coronary intervention (PCI). We evaluated the impact of PPI use on clinical outcomes in post-PCI patients, by incorporating P2Y12 reaction unit (PRU) and CYP2C19 genotyping results. METHODS: From a multicenter registry of patients who underwent PCI with drug-eluting stent implantation and received clopidogrel-based dual antiplatelet therapy (DAPT), patients who were prescribed a PPI at the time of PCI (PPI users) were compared to those who were not (non-users). The primary outcome included all-cause death, myocardial infarction, stent thrombosis, or cerebrovascular accident at 12 months. Major bleeding (Bleeding Academic Research Consortium [BARC] types 3-5) and gastrointestinal (GI) bleeding (BARC types 3-5) were important secondary outcomes. The adjusted outcomes were compared using a 1:1 propensity-score (PS) matching and competing risk analysis. RESULTS: Of 13,160 patients, 2,235 (17.0%) were prescribed PPI, with an average age of 65.4 years. PPI users had higher on-treatment PRU levels than non-users. After PS matching, the primary outcome occurred in 51 patients who were PPI users (cumulative incidence, 4.7%) and 41 patients who were non-users (cumulative incidence, 3.7%; log-rank p = 0.27). In carriers of both CYP2C19 loss-of-function alleles, PPI use was linked to an increased risk of the primary outcome (hazard ratio, 3.22; 95% confidence interval, 1.18-8.78). The incidence of major bleeding and GI bleeding (BARC types 3-5) was comparable between PPI users and non-users in the PS-matched cohort. CONCLUSIONS: In post-PCI patients receiving clopidogrel-based DAPT, PPI use was not linked to an increased risk of adverse cardiac and cerebrovascular events, but there was a small but significant increase in on-treatment PRU. Future research using a more individualized approach would further elucidate these interactions and guide evidence-based clinical practices.

Gestational diabetes mellitus is associated with in vivo platelet activation and platelet hyperreactivity.

BACKGROUND: Gestational diabetes mellitus is associated with obstetrical and long-term cardiovascular complications. Although platelet hyperresponsiveness in type-2 diabetes mellitus has been well characterized and has been shown to play a crucial role in cardiovascular complications, this aspect has been little studied in gestational diabetes mellitus. OBJECTIVE: We aimed to evaluate platelet reactivity, in vivo platelet activation, and endothelial function in gestational diabetes mellitus in comparison with normal pregnancy. STUDY DESIGN: This was a prospective, case-control study of 23 women with gestational diabetes mellitus and 23 healthy pregnant women who were studied at 26 to 28 and 34 to 36 weeks of gestation and at 8 weeks postpartum. Platelet reactivity and in vivo platelet activation, including light transmission aggregometry, PFA-100, platelet activation antigen expression, platelet adhesion under flow, platelet nitric oxide and reactive oxygen species production, and endothelial dysfunction markers, were assessed. RESULTS: The study of platelet function showed a condition of platelet hyperreactivity in cases with gestational diabetes mellitus when compared with healthy pregnant women at enrollment, which was further enhanced at the end of pregnancy and tended to decrease 2 months after delivery, although it still remained higher in gestational diabetes mellitus. In vivo platelet activation was also evident in gestational diabetes mellitus, especially at the end of pregnancy, in part persisting up to 8 weeks after delivery. Finally, women with gestational diabetes mellitus showed defective platelet nitric oxide production and endothelial dysfunction when compared with healthy pregnancies. CONCLUSION: Our data showed that gestational diabetes mellitus generates a condition of platelet hyperreactivity that in part persists up to 2 months after delivery. Impaired platelet sensitivity to nitric oxide and reduced platelet and endothelial nitric oxide production may contribute to the platelet hyperreactivity condition. Platelet hyperreactivity may play a role in the long-term cardiovascular complications of gestational diabetes mellitus women.

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

BACKGROUND: In the Asian population, the presence of the CYP2C19 loss-of-function (LOF) allele is a known genetic variation. This allele is associated with a reduced capacity to metabolize clopidogrel into its active forms through the CYP2C19 enzyme, resulting in diminished platelet inhibition and an elevated risk of recurrent cardiovascular events. Regulatory authorities have recommended an alternative P2Y12 inhibitor, ticagrelor, for individuals carrying the LOF allele. Consequently, this study seeks to assess the impact of the CYP2C19 genotype on the Platelet reactivity index (PRI) using a rapid genetic testing approach in Asian patients with chronic coronary syndromes (CCS) who undergo percutaneous coronary intervention (PCI). METHODS: This prospective study employed a parallel design, single-center design, and randomized approach. Genotyping for the CYP2C19*2 and *3 polymorphisms was conducted using the Nested Allele-Specific Multiplex PCR (NASM-PCR) technique. Patients meeting the inclusion criteria underwent genotyping for CYP2C19 polymorphisms. Following PCI, patients were randomly assigned to receive either ticagrelor or clopidogrel. PRI assessments were performed four hours after loading dose administration. The trial was registered with ClinicalTrials.gov under the identifier NCT05516784. RESULTS: Among the 94 patients recruited for the study, 40 (42.55%) were identified as carriers of the LOF allele for CYP2C19*2 and *3 (*1/*2, *2/*2, *1/*3). Out of the 84 patients evaluated for PRI (44 receiving clopidogrel and 40 receiving ticagrelor), 21 (47.7%) of the clopidogrel group and 39 (97.5%) of the ticagrelor group exhibited a favorable response to antiplatelet therapy (PRI < 50). Patients treated with ticagrelor demonstrated superior antiplatelet responses compared to those receiving clopidogrel, regardless of LOF carrier status (P = 0.005 and < 0.001 for non-LOF and LOF carriers, respectively). CONCLUSION: NASM-PCR as a rapid genetic test holds promise for personalizing antiplatelet therapy in Asian CCS patients.

Remote intensive management to improve antiplatelet adherence in acute myocardial infarction: a secondary analysis of the randomized controlled IMMACULATE trial.

This study aim to investigate if remote intensive coaching for the first 6 months post-AMI will improve adherence to the twice-a-day antiplatelet medication, ticagrelor. Between July 8, 2015, to March 29, 2019, AMI patients were randomly assigned to remote intensive management (RIM) or standard care (SC). RIM participants underwent 6 months of weekly then two-weekly consultations to review medication side effects and medication adherence coaching by a centralized nurse practitioner team, whereas SC participants received usual cardiologist face-to-face consultations. Adherence to ticagrelor were determined using pill counting and serial platelet reactivity measurements for 12 months. A total of 149 (49.5%) of participants were randomized to RIM and 152 (50.5%) to SC. Adherence to ticagrelor was similar between RIM and SC group at 1 month (94.4 ± 0.7% vs. 93.6±14.7%, p = 0.537), 6 months (91.0±14.6% vs. 90.6±14.8%, p = 0.832) and 12 months (87.4±17.0% vs. 89.8±12.5%, p = 0.688). There was also no significant difference in platelet reactivity between the RIM and SC groups at 1 month (251AU*min [212-328] vs. 267AU*min [208-351], p = 0.399), 6 months (239AU*min [165-308] vs. 235AU*min [171-346], p = 0.610) and 12 months (249AU*min [177-432] vs. 259AU*min [182-360], p = 0.678). Sensitivity analysis did not demonstrate any association of ticagrelor adherence with bleeding events and major adverse cardiovascular events. RIM, comprising 6 months of intensive coaching by nurse practitioners, did not improve adherence to the twice-a-day medication ticagrelor compared with SC among patients with AMI. A gradual decline in ticagrelor adherence over 12 months was observed despite 6 months of intensive coaching.

Inflammation modifies the platelet reactivity among thrombocytopenia patients undergoing percutaneous coronary intervention.

Percutaneous coronary intervention (PCI) patients combined with thrombocytopenia (TP) are usually considered to be at low ischemic risk, receiving less proper antiplatelet therapy. However, recent studies reported a paradoxical phenomenon that PCI patients with TP were prone to experience thrombotic events, while the mechanisms and future treatment remain unclear. We aim to investigate whether inflammation modifies platelet reactivity among these patients. Consecutive 10 724 patients undergoing PCI in Fuwai Hospital were enrolled throughout 2013. High-sensitivity C-reactive protein (hsCRP) ≥2 mg/L was considered inflammatory status. TP was defined as platelet count <150×109/L. High on-treatment platelet reactivity (HTPR) was defined as adenosine diphosphate-induced platelet maximum amplitude of thromboelastogram >47mm. Among 6617 patients finally included, 879 (13.3%) presented with TP. Multivariate logistic regression demonstrated that patients with TP were associated with a lower risk of HTPR (odds ratio [OR] 0.64, 95% confidence interval [CI] 0.53-0.76) than those without TP in the overall cohort. In further analysis, among hsCRP <2 mg/L group, patients with TP exhibited a decreased risk of HTPR (OR 0.53, 95% CI 0.41-0.68); however, in hsCRP ≥2mg/L group, TP patients had a similar risk of HTPR as those without TP (OR 0.83, 95% CI 0.63-1.08). Additionally, these results remain consistent across subgroups, including patients presenting with acute coronary syndrome and chronic coronary syndrome. Inflammation modified the platelet reactivity of PCI patients with TP, providing new insights into the mechanisms of the increased thrombotic risk. Future management for this special population should pay more attention to inflammation status and timely adjustment of antiplatelet therapy in TP patients with inflammation.

What is the context? Recent studies reported a paradoxical phenomenon that percutaneous coronary intervention (PCI) patients with thrombocytopenia (TP) were prone to experience thrombotic events. The potential mechanisms underlying the increased thrombotic risk and how to manage antiplatelet therapy in PCI patients with TP remain unclear.Growing attention has been paid to immunothrombosis. Inflammation is closely associated with high-on treatment platelet reactivity (HTPR) and thrombotic risk.HTPR is an independent risk factor of thrombosis and can provide information for guiding antiplatelet therapy.What is new? This prospective cohort study enrolled 10 724 patients undergoing PCI in Fuwai Hospital (National Center for Cardiovascular Diseases, Beijing, China), with HTPR risk being the study endpoint of interest.We first reported that inflammation significantly modified the platelet reactivity of PCI patients with TP.When hsCRP level <2 mg/L, PCI patients with TP had a decreased risk of HTPR. However, when hsCRP ≥2 mg/L, TP patients had similar HTPR risk as those without TP.HsCRP levels could modify the relationship between TP and HTPR risks both in patients with acute coronary syndrome and chronic coronary syndrome.What is the impact? These results provide insights into potential mechanisms of the increased thrombotic risk in PCI patients with TP. Specifically, inflammation might be involved in the thrombotic risk of PCI patients with TP by modifying the platelet reactivity.As for future management, personalized antiplatelet therapy should be administrated to TP patients with inflammation status.

The rapid change of shear rate gradient is beneficial to platelet activation.

Fluid shear plays a key role in hemostasis and thrombosis, and the purpose of this study was to investigate the effect of shear gradient change rate (SGCR) on platelet reactivity and von Willebrand factor (vWF) activity and its mechanism. In this study, we developed a set of microfluidic chips capable of generating different shear gradients and simulated the shear rate distribution in the flow field by COMSOL Multiphysics software. Molecular markers of platelet activation (P-selectin, activated GPIIb/IIIa, phosphatidylserine exposure, and monocyte-platelet aggregate formation) were analyzed by flow cytometry. Platelet aggregation induced by shear gradient was studied by a microfluidic experimental platform, and plasma vWF ristocetin cofactor (vWF: RCO) activity was investigated by flow cytometry. The expression of p-Akt was studied by Western blotting. The results showed that the faster the SGCR, the higher the expression of platelet p-Akt, and the stronger the platelet reactivity and vWF activity. This indicates that fluid shear stress can activate platelets and vWF in a shear gradient-dependent manner through the PI3K/AKT signal pathway, and the faster the SGCR, the more significant the activation effect.

What is the context? Recent studies have shown that fluid shear stress plays a key role in platelet activation and thrombosis. However, its mechanism and effect have not been fully elucidated.The development of microfluidic chip technology enables people to study platelet function in a precisely controlled flow field environment.Previous studies have shown that the PI3K-AKT signal pathway may be a mechanically sensitive signal transduction pathway.What is new?In this study, we designed a microfluidic model with different narrow geometry, and controlled the injection pump to perfuse fluid at the same flow rate, so that the platelets flowing through the model experienced the flow field environment of different shear gradients.We studied the activities of platelets and von Willebrand factor in different flow fields and explored their signal transduction pathways.What is the impact? Our results suggest that vascular stenosis does increase platelet activity and the risk of thrombosis. However, its ability to activate platelets is not only related to the peak shear rate and shear time, but also closely related to the decreasing rate of shear gradient. Even if the peak shear rate at the stenosis is the same, the faster the shear rate decreases, the higher the reactivity of platelets and von Willebrand factor, which may be mediated by the PI3K-AKT signal pathway. This study not only helps clinicians to judge the risk of thrombosis in patients with atherosclerosis or percutaneous coronary intervention, but also helps us to better understand the mechanism of shear-induced platelet activation.

Integrating platelet reactivity in the age, creatinine and ejection fraction score to predict clinical outcomes following percutaneous coronary intervention in patients with chronic coronary syndrome: the PR-ACEF score.

To evaluate if integrating platelet reactivity (PR) evaluation in the original age, creatinine and ejection fraction (ACEF) score could improve the diagnostic accuracy of the model in patients with stable coronary artery disease (CAD). We enrolled patients treated with percutaneous coronary intervention between 2010 and 2011. High PR was included in the model (PR-ACEF). Co-primary end points were a composite of death/myocardial infarction (MI) and major adverse cardiovascular events (MACE). Overall, 471 patients were enrolled. Compared to the ACEF score, the PR-ACEF showed an improved diagnostic accuracy for death/MI (AUC 0.610 vs 0.670, p < 0.001) and MACE (AUC 0.572 vs 0.634, p < 0.001). These findings were confirmed using internal validation with bootstrap resampling. At 5 years, the PR-ACEF value > 1.75 was independently associated with death/MI [HR 3.51, 95% CI (1.97-6.23)] and MACE [HR 2.77, 95% CI (1.69-4.53)]. The PR-ACEF score was effective in improving the diagnostic performance of the ACEF score at the long-term follow-up.

Role of Cyp2c19 Genotype-Guided Antiplatelet Therapy After Percutaneous Coronary Intervention.

PURPOSE OF REVIEW: Identification of a reliable discriminatory test to accurately stratify patient responses to antiplatelet therapy following coronary revascularization has become increasingly desirable to optimize therapeutic efficacy and safety. RECENT FINDINGS: The expansion of platelet function testing to include genotype assessment has been an evolutionary journey, initially fraught with confounding results. However, more recent and rigorous data analysis suggests that genotype testing- guided, tailored antiplatelet therapy may hold promise in optimizing treatment of patients after coronary intervention. Current evidence increasingly supports the use of genotype guided CYP2C19 testing to better match the post coronary intervention patient with the most efficacious and least risky antiplatelet inhibitor. The risk stratification of poor, intermediate, and good metabolizers of these drugs with such testing promises to yield clinical dividends in terms of morbidity, mortality and cost control, in this growing patient population.

Prognostic Implication of Platelet Reactivity According to Left Ventricular Systolic Dysfunction Status in Patients Treated With Drug-Eluting Stent Implantation: Analysis of the PTRG-DES Consortium.

BACKGROUND: Coronary artery disease patients undergoing percutaneous coronary intervention (PCI) often exhibit reduced left ventricular ejection fraction (LVEF). However, the impact of LV dysfunction status in conjunction with platelet reactivity on clinical outcomes has not been previously investigated. METHODS: From the multicenter PTRG-DES (Platelet function and genoType-Related long-term prognosis in DES-treated patients) consortium, the patients were classified as preserved-EF (PEF: LVEF ≥ 50%) and reduced-EF (REF: LVEF< 5 0%) group by echocardiography. Platelet reactivity was measured using VerifyNow P2Y12 assay and high platelet reactivity (HPR) was defined as PRU ≥ 252. The major adverse cardiac and cerebrovascular events (MACCEs) were a composite of death, myocardial infarction, stent thrombosis and stroke at 5 years after PCI. Major bleeding was defined as Bleeding Academic Research Consortium bleeding types 3-5. RESULTS: A total of 13,160 patients from PTRG-DES, 9,319 (79.6%) patients with the results of both PRU and LVEF were analyzed. The incidence of MACCE and major bleeding was higher in REF group as compared with PEF group (MACCEs: hazard ratio [HR] 2.17, P < 0.001, 95% confidence interval [CI] 1.85-2.55; major bleeding: HR 1.78, P < 0.001, 95% CI 1.39-2.78). The highest rate of MACCEs was found in patients with REF and HPR, and the difference between the groups was statistically significant (HR 3.14 in REF(+)/HPR(+) vs. PEF(+)/HPR(-) group, P < 0.01, 95% CI 2.51-3.91). The frequency of major bleeding was not associated with the HPR in either group. CONCLUSION: LV dysfunction was associated with an increased incidence of MACCEs and major bleeding in patients who underwent PCI. The HPR status further exhibited significant increase of MACCEs in patients with LV dysfunction in a large, real-world registry. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04734028.

Implication of diabetic status on platelet reactivity and clinical outcomes after drug-eluting stent implantation: results from the PTRG-DES consortium.

BACKGROUND: Diabetes mellitus (DM) is associated with thrombogenicity, clinically manifested with atherothrombotic events after percutaneous cutaneous intervention (PCI). This study aimed to investigate association between DM status and platelet reactivity, and their prognostic implication in PCI-treated patients. METHODS: The Platelet function and genoType-Related long-term Prognosis-Platelet Function Test (PTRG-PFT) cohort was established to determine the linkage of platelet function test (PFT) with long-term prognosis during dual antiplatelet therapy including clopidogrel in patients treated with drug-eluting stent (DES). We assessed platelet reactivity using VerifyNow and 'high platelet reactivity (HPR)' was defined as ≥ 252 P2Y12 reaction unit (PRU). Major adverse cardiac and cerebrovascular event (MACCE) was a composite of all-cause death, myocardial infarction, stent thrombosis or stroke. RESULTS: Between July 2003 and Aug 2018, DES-treated patients with available PFT were enrolled (n = 11,714). Diabetic patients demonstrated significant higher levels of platelet reactivity (DM vs. non-DM: 225.7 ± 77.5 vs. 213.6 ± 79.1 PRU, P < 0.001) and greater prevalence of HPR compared to non-diabetic patients (38.1% vs. 32.0%, P < 0.001). PRU level and prevalence of HPR were significantly associated with insulin requirement and HbA1c level, as well as diabetic status. DM status and HPR phenotype had a similar prognostic implication, which showed the synergistic clinical impact on MACCE. Association between PRU level and MACCE occurrence seemed higher in diabetic vs. non-diabetic patients. In non-DM patients, HPR phenotype did not significantly increase the risk of MACCE (adjusted hazard ratio [HRadj]: 1.073; 95% confidence interval [CI]: 0.869-1.325; P = 0.511), whereas HPR was an independent determinant for MACCE occurrence among diabetic patients (HRadj: 1.507; 95% CI: 1.193-1.902; P < 0.001). CONCLUSION: The levels of on-clopidogrel platelet reactivity are determined by diabetic status and the severity of DM. In addition, HPR phenotype significantly increases the risk of MACCE only in diabetic patients. CLINICAL TRIAL REGISTRATION: URL: https://www. CLINICALTRIALS: gov . Unique identifier: NCT04734028.

Inadequate response to antiplatelet therapy in patients with peripheral artery disease: a prospective cohort study.

BACKGROUND: Patients with peripheral artery disease (PAD) are treated with preventive strategies to improve the cardiovascular risk. The incidence of cardiovascular events and mortality however remains high in PAD populations. We therefore aimed to better characterize PAD patients suffering from cardiovascular events and mortality in order to tailor preventive treatment. METHODS: Between 2018 and 2020, 246 PAD outpatients (17 newly diagnosed, 229 with known PAD) were prospectively enrolled in this observational cohort study. Patient data and blood samples were collected after inclusion, and the primary composite endpoint (myocardial infarction, elective coronary revascularization, ischemic stroke, acute limb ischemia, mortality) was evaluated after one year. Secondary outcomes included platelet reactivity, measured using the VerifyNow assay, and medication adherence, assessed using the Morisky Medication Adherence Scale-8 (MMAS-8). Logistic regression models were used to identify associations between characteristics and the occurrence of events. RESULTS: The cohort comprised 207 patients with claudication and 39 with chronic limb threatening ischemia. Twenty-six (10.6%) patients suffered from an event during follow-up. Prior myocardial infarction (OR 3.3 [1.4-7.7]), prior ischemic stroke (OR 4.5 [1.8-10.9]), higher levels of creatinine (OR 5.2 [2.2-12.6]), lower levels of high-density lipoprotein (OR 4.2 [1.5-10.6]) and lower haemoglobin levels (OR 3.1 [1.3-7.1]) were associated with events. Patients with events had more often high on-treatment platelet reactivity (HTPR) on aspirin (OR 5.9 [1.4-25.1]) or clopidogrel (OR 4.3 [1-19.3]). High adherence to medication was associated with the occurrence of events (OR 4.1 [1-18]). CONCLUSIONS: Patients suffering from cardiovascular events and mortality were characterized by prior cardiovascular events as compared to patients who did not experience any events. Antiplatelet therapy was not optimally protective despite high medication adherence, and HTPR was independently associated with the occurrence of events. More research is needed on alternative treatment strategies such as dual antiplatelet therapy or combinations with anticoagulant drugs. TRIAL REGISTRATION: The Medical Ethics Committee (METC) of the MUMC+ approved the study (NL63235.068.17) and the study was registered in the Netherlands Trial Register ( NTR7250 ).

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.

On-treatment platelet reactivity through the thromboxane A2 or P2Y12 platelet receptor pathways is not affected by pelacarsen.

BACKGROUND: Pelacarsen decreases plasma levels of lipoprotein(a) [Lp(a)] and oxidized phospholipids (OxPL). It was previously reported that pelacarsen does not affect the platelet count. We now report the effect of pelacarsen on on-treatment platelet reactivity. METHODS: Subjects with established cardiovascular disease and screening Lp(a) levels ≥60 mg per deciliter (~ ≥150 nmol/L) were randomized to receive pelacarsen (20, 40, or 60 mg every 4 weeks; 20 mg every 2 weeks; or 20 mg every week), or placebo for 6-12 months. Aspirin Reaction Units (ARU) and P2Y12 Reaction Units (PRU) were measured at baseline and the primary analysis timepoint (PAT) at 6 months. RESULTS: Of the 286 subjects randomized, 275 had either an ARU or PRU test, 159 (57.8%) were on aspirin alone and 94 (34.2%) subjects were on dual anti-platelet therapy. As expected, the baseline ARU and PRU were suppressed in subjects on aspirin or on dual anti-platelet therapy, respectively. There were no significant differences in baseline ARU in the aspirin groups or in PRU in the dual anti-platelet groups. At the PAT there were no statistically significant differences in ARU in subjects on aspirin or PRU in subjects on dual anti-platelet therapy among any of the pelacarsen groups compared to the pooled placebo group (p > 0.05 for all comparisons). CONCLUSION: Pelacarsen does not modify on-treatment platelet reactivity through the thromboxane A2 or P2Y12 platelet receptor pathways.

Altered platelet reactivity, coagulation, endothelial and inflammatory markers early after smoking cessation verified with cotinine plasma concentration.

BACKGROUND/INTRODUCTION: Cigarette smoking is a potent modifiable risk factor for coronary artery disease (CAD). However, little is known about alterations to prothrombotic state and platelet reactivity early after smoking cessation following percutaneous coronary interventions (PCI). PURPOSE: We investigated alterations to platelet reactivity, coagulation and markers of platelet, endothelial, inflammatory and coagulation activation in clopidogrel-treated patients with CAD after PCI before and after smoking cessation. METHODS: Smoking patients aged 18 years or older at least 30 days after PCI were recruited and encouraged to quit the habit. At baseline and at 30 days, we measured platelet reactivity with VerifyNow system, thrombomodulin, P-selectin, platelet factor 4 (CXCL4/PF4), citrullinated histone H3 (H3cit) and cotinine level. RESULTS: Among 117 patients, 84 patients (72%) at a median age of 60.5 years (40 [interquartile range 30-47] pack-years) completed a 30-day follow-up. At day 30, 30 (35.7%) patients stopped smoking with cotinine level < 50 ng/ml. Baseline characteristics were similar in both groups. In smoking quitters a change in platelet reactivity was larger (Δ platelet reactivity units (PRU) 19 [2, 43] vs. -6 [-32, 37], p = 0.018), along with a change in P-selectin concentration (-11.82 [-23.62, 1.34] vs. 7.19 [-14.24, 17.19] ng/ml, p = 0.005). Positive correlations was noticed between cotinine and both P-selectin ( r = 0.23, p = 0.045) and CXCL4 (r = 0.27, p = 0.02). CONCLUSION: After smoking cessation in CAD patients following PCI an increase in platelet reactivity and a decrease in P-selectin levels were observed. The risk of thrombotic complications post PCI might be paradoxically enhanced among patients who stopped smoking.

Time from blood draw to multiple electrode aggregometry and association with platelet reactivity.

Results from multiple electrode aggregometry (MEA) may vary according to pre-analytic factors. This study aimed to analyze the association of time from blood draw to MEA in patients undergoing percutaneous coronary intervention (PCI). In this observational single-center cohort study, platelet aggregation (aggregation units, U) was quantified by MEA (Multiplate Analyzer) after stimulation with adenosine diphosphate (ADP; final concentration [Fc] 6.4 µM), thrombin receptor activating peptide (TRAP; Fc 32 µM), or arachidonic acid (AA; Fc 0.5 mM) in patients treated with ASA and clopidogrel following PCI. High on-clopidogrel platelet reactivity (HPR) was defined as ADP-induced platelet aggregation ≥ 46 U. The manufacturer recommends performing the analysis within 30-180 min after blood draw. Patients were grouped according to the time from blood draw to MEA: 30-180 min, < 30 min, or > 180 min. Platelet function of 273 patients with coronary artery disease undergoing PCI with dual antiplatelet therapy was analyzed. The median age was 72 years (interquartile range, IQR 62-79) and 179 (66%) were male. Median ADP-, TRAP-, and AA-induced aggregation was 25 (IQR 18-36) U, 79 (IQR 63-96) U, and 12 (IQR 7-18) U, respectively. For those analyzed within 30-180 min from blood draw, no significant correlation of time from blood draw to MEA was observed 1) ADP (r = - 0.04, p = 0.51); 2) TRAP (r = - 0.06, p = 0.32); 3) AA (r = - 0.03, p = 0.67). In patients undergoing percutaneous coronary intervention and treated with dual antiplatelet therapy, the time from blood draw to multiple electrode aggregometry does not correlate with ADP- induced aggregation when the measurement occurred within the recommended time interval of 30-180 min after blood draw.

Clinical impact of high platelet reactivity in patients with atrial fibrillation and concomitant percutaneous coronary intervention on dual or triple antithrombotic therapy.

High platelet reactivity (HPR) on clopidogrel is an established thrombotic risk factor after percutaneous coronary intervention (PCI). The introduction of more potent antiplatelet drugs has partially surpassed this issue. However, in the setting of concomitant atrial fibrillation (AF) and PCI clopidogrel is still the most adopted P2Y12 inhibitor. In the present study all consecutive patients with history of AF discharged from our cardiology ward with dual (DAT) or triple (TAT) antithrombotic therapy after a PCI from April 2018 to March 2021 were enrolled in an observational registry. For all subjects, blood serum samples were collected and tested for platelet reactivity by arachidonic acid and ADP (VerifyNow system) and genotyping of the CYP2C19*2 loss-of-function polymorphism. We recorded at 3 and 12-months follow-up: (1) major adverse cardiac and cerebrovascular events (MACCE), (2) major hemorrhagic or clinically relevant non-major bleeding and (3) all-cause mortality. A total of 147 patients were included (91, 62% on TAT). In 93.4% of patients, clopidogrel was chosen as P2Y12 inhibitor. P2Y12 dependent HPR resulted an independent predictor of MACCE both at 3 and 12 months (HR 2.93, 95% C.I. 1.03 to 7.56, p = 0.027 and HR 1.67, 95% C.I. 1.20 to 2.34, p = 0.003, respectively). At 3-months follow-up the presence of CYP2C19*2 polymorphism was independently associated with MACCE (HR 5.21, 95% C.I. 1.03 to 26.28, p = 0.045). In conclusion, in a real-world unselected population on TAT or DAT, the entity of platelet inhibition on P2Y12 inhibitor is a potent predictor of thrombotic risk, suggesting the clinical utility of this laboratory evaluation for a tailored antithrombotic therapy in this high-risk clinical scenario. The present analysis was performed in patients with AF undergoing PCI on dual or triple antithrombotic therapy. At 1 year follow-up MACCE incidence was consistent, and it was not different in different antithrombotic pattern groups. P2Y12 dependent HPR was a potent independent predictor of MACCE both at 3- and 12-months follow-up. In the first 3 months after stenting the carriage of CYP2C19*2 allele was similarly associated with MACCE. Abbreviation: DAT, dual antithrombotic therapy; HPR, high platelet reactivity; MACCE, major adverse cardiac and cerebrovascular events; PRU, P2Y12 reactive unit; TAT, triple antithrombotic therapy. Created with BioRender.com.

Effects of exercise on platelet reactivity after myocardial infarction: a randomized clinical trial.

Exercise training (ET) can lower platelet reactivity in patients with cardiovascular risk factors. However, the effects of ET on platelet reactivity in higher-risk patients is unknown. The aim of this study was to evaluate the effects of ET on platelet reactivity in patients with recent myocardial infarction (MI). Ninety patients were randomly assigned 1 month post-MI to the intervention (patients submitted to a supervised ET program) or control group. All patients were on dual antiplatelet therapy (DAPT). Platelet reactivity by VerifyNow-P2Y12 (measured by P2Y12 reaction units - PRUs) test was determined at baseline and at the end of 14 ± 2 weeks of follow-up at rest (primary endpoint), and multiplate electrode aggregometry (MEA) adenosine diphosphate (ADP) and aspirin (ASPI) tests were performed immediately before and after the maximal cardiopulmonary exercise test (CPET) at the same time points (secondary endpoints). Sixty-five patients (mean age 58.9 ± 10 years; 73.8% men; 60% ST elevation MI) completed follow-up (control group, n = 31; intervention group, n = 34). At the end of the follow-up, the mean platelet reactivity was 172.8 ± 68.9 PRUs and 166.9 ± 65.1 PRUs for the control and intervention groups, respectively (p = .72). Platelet reactivity was significantly increased after the CPET compared to rest at the beginning and at the end of the 14-week follow-up (among the intervention groups) by the MEA-ADP and MEA-ASPI tests (p < .01 for all analyses). In post-MI patients on DAPT, 14 weeks of supervised ET did not reduce platelet reactivity. Moreover, platelet reactivity was increased after high-intensity exercise (ClinicalTrials.gov: NCT02958657; https://clinicaltrials.gov/ct2/show/NCT02958657).

What is the context? Platelet reactivity is reduced after exercise training in healthy individuals and patients with cardiovascular risk factors, but the effect in higher-risk patients is unknown.High-intensity exercise in untrained individuals increases platelet reactivity. The effect of dual antiplatelet therapy in inhibiting exercise-induced hyperreactivity is poorly understood.What's new?Exercise training did not reduce platelet reactivity in post-myocardial infarction patients.High-intensity exercise increased platelet reactivity in post-myocardial infarction patients on dual antiplatelet therapy.Exercise training did not attenuate the exercise-induced increase in platelet reactivity.What's the impact?The study suggests that strenuous exercise, if indicated, should be applied carefully to patients with high risk of recurrent ischemic events, even if on optimal medical therapy and after being trained.

Impact of intravascular ultrasound parameters and platelet reactivity on primary patency after drug-coated balloon angioplasty for femoropopliteal artery disease.

Although the superiority of DCBs to uncoated balloon angioplasty for the treatment of femoropopliteal (FP) lesions has been demonstrated, the association of clinical factors, including anatomical features evaluated by intravascular ultrasound (IVUS) and platelet reactivity, with the loss of patency has not been systematically studied. The current prospective, observational study enrolled 160 consecutive patients (male 67.5%, mean age 74.7 ± 9.7 years) with 213 FP lesions treated with DCBs under IVUS evaluation. The platelet reactivity was measured in P2Y12 reaction units for all of the patients at the DCB treatment. The primary end point was primary patency at 12 months, while the secondary end points were freedom from target lesion revascularization (TLR), all-cause death, major target limb amputation and bleeding events at 12 months. Mean lesion length was 11.9 ± 9.4 cm and 34 (16.0%) were chronic total occlusions (CTOs). Thirty-four (16.0%) were severely calcified lesions. Primary patency by Kaplan-Meier estimate was 79.2% at 12 months, while the 12-month freedom from TLR, all-cause death and bleeding events were observed in 89.1%, 93.4% and 97.4%, respectively. There were no major target limb amputations through 12 months. Multivariate analysis showed that subintimal angioplasty for CTO lesions was a sole risk factor for loss of 12-month primary patency, while other IVUS parameters and platelet reactivity were not.

High On-Treatment Platelet Reactivity: Aspirin versus Clopidogrel.

BACKGROUND: Antithrombotic regimen in patients on oral anticoagulation (OAC) post-percutaneous coronary intervention (PCI) is challenging. At least, one antiplatelet agent in combination with OAC is recommended after PCI for 6-12 months. Clopidogrel is used most frequently in this setting. However, data comparing P2Y12 inhibition with clopidogrel versus cyclooxygenase inhibition by acetylsalicylic acid (ASA, aspirin) is missing. It is well known that the antiplatelet effects of ASA and clopidogrel are frequently impaired (high on-treatment platelet reactivity [HTPR]). In this pilot investigation, we compared the antiplatelet effects of clopidogrel versus ASA. METHODS: In this retrospective single-center database analysis, we investigated platelet reactivity by light transmission aggregometry in patients under different antiplatelet regimes. Results were presented as maximum of aggregation (MoA). HTPR to ASA and to clopidogrel were assessed. RESULTS: 755 patients were enrolled. 677 were on ASA, 521 were on clopidogrel, and 198 had OAC. Overall mean age was 73 ± 13.4 years, and 458 (60.7%) were male. HTPR to ASA occurred in 94/677 patients (13.9%), and mean arachidonic acid-induced MoA was 14.15 ± 19.04%. HTPR to clopidogrel occurred in 241/521 patients (46.3%), and mean adenosine diphosphate-induced MoA was 50.06 ± 20.42%. HTPR to clopidogrel was significantly more frequent than HTPR to ASA; single antiplatelet therapy (SAPT)-mono ASA: 27/199 (13.6%) versus mono clopidogrel: 6/18 (33.3%); p = 0.037; SAPT with OAC-OAC with ASA: 8/35 (22.9%) versus OAC with clopidogrel: 27/60 (45%); p = 0.046. Same difference in HTPR contingency could be shown in subgroups of dual antiplatelet therapy and ASA + clopidogrel + OAC therapy. CONCLUSION: Impaired pharmacodynamic response to clopidogrel was more frequent as HTPR to ASA. Hence, ASA should be tested in combination with OAC post-PCI.