High On-treatment Platelet Reactivity Research Articles

Progress Analysis of Personalized Antiplatelet Therapy in Patients with Coronary Heart Disease Undergoing Interventional Therapy

Coronary atherosclerosis (or coronary heart disease [CHD]) is a common cardiovascular disease that seriously damages human health. Percutaneous coronary stent implantation represents the primary treatment option for severe CHD in clinical practice; meanwhile, dual antiplatelet therapy (DAPT) is widely used to reduce the risk of postoperative thrombosis. Although the mechanisms of action of the two most commonly used antiplatelet drugs, aspirin and clopidogrel, remain unclear, clinical studies have shown that some patients are susceptible to stent thrombosis—antiplatelet resistance (high on-treatment platelet reactivity [HTPR])—despite using these drugs. Therefore, screening for HTPR and formulating personalized antiplatelet therapies is necessary. Ticagrelor, indobufen, and rivaroxaban are the most common and safe antiplatelet drugs used in clinical practice, with broad application prospects. This review summarizes the mechanisms of action of existing antiplatelet drugs, reasons for personalized treatment, screening of antiplatelet reactions, and development of novel antiplatelet drugs.

Remnant cholesterol is associated with platelet reactivity for patients with coronary artery disease underwent percutaneous coronary intervention

Abstract Background In recent years, remnant cholesterol has received increasing attention and has been shown to be associated with thrombotic and bleeding events in coronary clinical research, but the mechanisms are not fully understood. Aim To investigate the relationship between the remnant cholesterol (RC) and the platelet reactivity in patients with coronary artery disease undergoing percutaneous coronary intervention (PCI) who were receiving the dual antiplatelet therapy (DAPT). Methods: A total of 10,724 consecutive PCI patients in China from January 2013 to December 2013 were enrolled, among whom 6212 patients had the results of thromborlastogram (TEG) with DAPT for analysis. Low on-treatment platelet reactivity (LTPR) and high on-treatment platelet reactivity (HTPR) were defined as adenosine diphosphate-induced platelet maximum amplitude of TEG<31mm and >47mm, respectively. Results: A total of 6,212 PCI patients (mean age, 58.24±10.27 years;male, 77.5%) were finally enrolled for analysis. There were 2362 (38.02%) patients in LTPR group, and 1900 (30.59%) patients in HTPR group. For LTPR,when the RC is used as a continuous variable, the multivariate logistic regression showed that RC concentration was independently and negatively associated with LTPR (OR: 0.769, 95%CI 0.610-0.968, p=0.025). For quartiles of RC, the quartile 3 of RC was also associated with LTPR, compared with the lowest quartile (Q1) (OR: 0.854, 95%CI 0.732-0.996, p=0.044). For HTPR, when the RC is used as a continuous variable, the multivariate logistic regression showed that RC concentration was independently and positively associated with HTPR (OR: 1.492, 95%CI 1.162-1.916, p=0.002). For quartiles of RC, compared with the lowest quartile (Q1), the higher quartile of RC (Q2, Q3, Q4) was also associated with HTPR (ORQ2: 1.211, 95%CI 1.024-1.431, p=0.025; ORQ3: 1.380, 95%CI 1.165-1.634, p＜0.001; ORQ4: 1.391, 95%CI 1.143-1.692, p=0.001). Conclusions: In this large sample real-world study, we firstly reported that the lower RC concentration was an independent risk factor for LTPR, representing a higher risk of bleeding, whereas the higher RC concentration was an independent risk factor for HTPR, representing a higher risk of ischemic. These results suggest that higher or lower RC may increase the potential risk of bleeding or ischemia in patients with PCI, which provides new perspectives on individualized lipid-lowering and antithrombotic treatment strategies for patients with coronary artery disease.

The first in-human study to evaluate the antiplatelet properties of the clopidogrel conjugate DT-678 in acute coronary syndrome patients and healthy volunteers.

DT-678 is a novel antiplatelet prodrug, capable of releasing the antiplatelet active metabolite of clopidogrel (AM) upon exposure to glutathione. In this study, we investigated factors responsible for clopidogrel high on-treatment platelet reactivity (HTPR) in acute coronary syndrome (ACS) patients and evaluated the capacity of DT-678 to overcome HTPR. A total of 300 consecutive ACS patients naive to P2Y12 receptor inhibitors were recruited and genotyped for CYP2C19 alleles. Blood samples were drawn before and after administration of 600-mg clopidogrel. Platelet reactivity index (PRI) and plasma AM concentrations were determined and grouped according to their CYP2C19 genotypes. DT-678 was applied ex vivo to whole blood samples to examine its inhibitory effects. To further examine the antiplatelet effectiveness of DT-678 in vivo, 20 healthy human subjects were recruited in a Phase I clinical trial, and each received a single dose of either 3-mg DT-678 or 75-mg clopidogrel. The pharmacokinetics and pharmacodynamics in different CYP2C19 genotype groups were compared. Statistical analyses revealed that CYP2C19 genotype, body mass index, hyperuricaemia, and baseline PRI were significantly associated with a higher risk of clopidogrel HTPR in ACS patients. The addition of DT-678 ex vivo decreased baseline PRI regardless of CYP2C19 genotypes, overcoming clopidogrel HTPR. This observation was further confirmed in healthy volunteers receiving 3mg of DT-678. These results suggest that DT-678 effectively overcomes clopidogrel HTPR resulting from genetic and/or clinical factors in Chinese ACS patients, demonstrating its potential to improve antiplatelet therapy.

Perioperative platelet reactivityover time inpatients undergoing vascular surgery: An observational pilot study.

Despite Antiplatelet therapy (APT), cardiovascular patients undergoing revascularisation remain at high risk for thrombotic events. Individual response to APT varies substantially, resulting in insufficient protection from thrombotic events due to high on-treatment platelet reactivity (HTPR) in ≤40% of patients. Individual variation in platelet response impairs APT guidance on a single patient level. Unfortunately, little is known about individual platelet response to APT over time, timing for accurate residual platelet reactivity measurement, or the optimal test to monitor residual platelet reactivity. To investigate residual platelet reactivity variability over time in individual patients undergoing carotid endarterectomy (CEA) treated with clopidogrel. Platelet reactivity was determined in patients undergoing CEA in a prospective, single-centre, observational study using the VerifyNow (change in turbidity from ADP-induced binding to fibrinogen-coated beads), the VASP assay (quantification of phosphorylation of vasodilator-stimulated phosphoprotein), and a flow-cytometry-based assay (PACT) at four perioperative time points. Genotyping identified slow (CYP2C19*2 and CYP2C19*3) and fast (CYP2C19*17) metabolisers. Between December 2017 and November 2019, 50 patients undergoing CEA were included. Platelet reactivity measured with the VerifyNow (p = < .001) and VASP (p = .029) changed over time, while the PACT did not. The VerifyNow identified patients changing HTRP status after surgery. The VASP identified patients changing HTPR status after eight weeks (p = .018). CYP2C19 genotyping identified 13 slow metabolisers. In patients undergoing CEA, perioperative platelet reactivity measurements fluctuate over time with little agreement between platelet reactivity assays. Consequently, HTPR status of individual patients measured with the VerifyNow and VASP assay changed over time. Therefore, generally used perioperative platelet reactivity measurements seem unreliable for adjusting perioperative APT strategy.

Unraveling the transcriptomic landscape of platelets: RPs vs. MPs in CCS patients

Abstract Funding Acknowledgements Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Else Kröner Fresenius Stiftung Background Reticulated platelets (RPs), characterized by youth, hyper-reactivity, and RNA abundance, signify pro-thrombotic potential and serve as predictors for inadequate antiplatelet therapy response post-myocardial infarction. Their pivotal role in chronic coronary syndrome (CCS) and high on-treatment platelet reactivity highlights their significance as promising biomarkers for adverse cardiovascular events in diverse pathological settings. Purpose We aimed to compare for the first time the transcriptomic profiles of RPs and MPs in CCS patients. Methods Using fluorescent activated cell sorting (FACS), RPs and MPs were isolated based on RNA content from peripheral blood of 19 CCS patients. RNA assessment involved the Tapestation 4200 platform (Agilent), and totalRNA libraries were sequenced on a NextSeq 500 Illumina platform. RNA sequencing analysis, with a cut-off of p &amp;lt;0.005 and a log2fc &amp;gt;1, and alternative splicing event detection using MAJIQ, were performed. Circular RNA (circRNA) analysis employed CIRCexplorer. Results Total RNA-sequencing identified 1589 differentially expressed genes, with 1100 transcripts upregulated in RPs and 489 enriched in MPs (Figure 1 A, B and D). Notably, collagen receptor GP6 (log2FC 1.12, p=6.89x10-41), thrombin receptor PAR4 (F2RL3, log2FC 1.1, p=3.54*10-21) and Von Willebrand Factor (log2FC 1.2, p=1.26*10-38) transcripts were significantly enriched in RPs. Gene Ontology identified a higher enrichment of relevant biological categories in RPs compared to MPs, such as "platelet activation", "platelet degranulation" and "blood coagulation" (Figure 1C). These findings are consistent with our previously established discovery and support the hypothesis that RPs in cardiovascular disease are hyper-reactive and pro-thrombotic due to their different RNA content compared to other platelets. Several splicing events were detected as differentially regulated: there is an upregulation of an alternative splicing on the collagen receptor transcript GP6 in RPs (Figure 1E); by the transcript of the G-protein GNAQ, one alternative splicing event was found upregulated in RPs, whilst two others were upregulated in MPs. Moreover, we found an enrichment of the total level of circular RNAs in MPs as compared to RPs (Figure 1F). Several previously undescribed circular RNAs were discovered to be enriched in RPs, as shown in Figure 1F. Conclusion This groundbreaking transcriptomic profiling of RPs and MPs in CCS patients elucidates the biological basis for RPs' hyperreactivity, emphasizing the differential enrichment of platelet activation transcripts. The pronounced upregulation of prothrombotic signaling in RPs provides insight into their hyperactivity and correlation with cardiovascular events. These findings illuminate a novel therapeutic niche in CCS patients, although further investigations are essential to comprehend the detrimental role of RPs in coronary artery disease.

Association of Age- and Body Mass Index-Stratified High On-Treatment Platelet Reactivity With Coronary Intervention Outcomes in East Asian Patients.

Although age and body mass index (BMI) significantly affect platelet reactivity units and clinical outcomes after percutaneous coronary intervention, there are limited data on the relationship between high on-treatment platelet reactivity (HPR) and clinical outcomes on age and BMI differences. Thus, we investigated the association of HPR with clinical outcomes according to age and BMI. The study analyzed 11 714 patients who underwent platelet function tests after percutaneous coronary intervention. The primary end point was the occurrence of major adverse cardiac and cerebrovascular events (MACCEs), whereas the secondary end point was major bleeding. HPR was defined as platelet reactivity units ≥252. Patients were categorized by age (<67 years of age or ≥67 years of age) and BMI (≤22.6 kg/m2 or >22.6 kg/m2). Patients <67 years of age with HPR had increases in both MACCEs (adjusted hazard ratio [HR], 1.436 [95% CI, 1.106-1.867]; P=0.007) and major bleeding (adjusted HR, 1.584 [95% CI, 1.095-2.290]; P=0.015) compared with the those with non-HPR, respectively. In patients ≥67 years of age with HPR, there were no differences in MACCEs, but there was a decrease in major bleeding (adjusted HR, 0.721 [95% CI, 0.542-0.959]; P=0.024). Meanwhile, patients with HPR with BMI >22.6 kg/m2 had increases in MACCEs (adjusted HR, 1.387 [95% CI, 1.140-1.688]; P=0.001). No differences were shown in major bleeding. HPR was linked to an increase in MACCEs or a decrease in major bleeding in patients after percutaneous coronary intervention, depending on age and BMI. This study is the first to observe that clinical outcomes in patients with HPR after percutaneous coronary intervention may vary based on age and BMI. Because the study is observational, the results should be viewed as hypothesis generating and emphasize the need for randomized clinical trials.

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.

Immediate Platelet Inhibition Strategy for Comatose Out-of-Hospital Cardiac Arrest Survivors Undergoing Percutaneous Coronary Intervention and Mild Therapeutic Hypothermia.

Background: Comatose survivors of out-of-hospital cardiac arrest (OHCA) undergoing percutaneous coronary intervention (PCI) and target temperature management (TTM) are at increased risk of stent thrombosis (ST), partly due to delayed platelet inhibition even with more potent P2Y12 agents. We hypothesized that periprocedural cangrelor would induce immediate platelet inhibition, bridging the "P2Y12 inhibition gap". Methods: In our pilot study, we randomized 30 comatose OHCA patients undergoing PCI and TTM (32-34 °C) into cangrelor and control groups. Both groups received unfractioned heparin, acetylsalicylic acid, and ticagrelor via enteral tube. The cangrelor group also received an intravenous bolus of cangrelor followed by a 4 h infusion. Platelet inhibition was measured using VerifyNow® and Multiplate® ADP at baseline and 1, 3, 5, and 8 h post PCI. Results: Patient characteristics did not differ between groups. VerifyNow® showed significantly decreased platelet reactivity with cangrelor at 1 h (30 vs. 221 PRU; p < 0.001) and 3 h (24 vs. 180 PRU; p < 0.001), with differences at 5 and 8 h. Similarly, the proportion of patients with high on-treatment platelet reactivity (HPR) in the cangrelor group was significantly lower at 1 h (0% vs. 67%; p < 0.001) and 3 h (0% vs. 47%; p = 0.007). Multiplate® ADP was also decreased at 1 h (14 vs. 48 U; p < 0.001) and 3 h (11 vs. 42 U; p = 0.001), with no difference at 5 and 8 h. The occurrence of bleeding events was similar in both groups. Conclusions: Cangrelor safely induced immediate and profound platelet inhibition. We observed no significant drug-drug interaction with ticagrelor.

Impact of Platelet Hyperreactivity and Diabetes Mellitus on Ischemic Stroke Recurrence: A Single-Center Cohort Clinical Study.

Ischemic stroke recurrence (ISR) is prevented by inhibiting platelet function. To investigate the impact of high on-treatment platelet reactivity (HTPR) assessed by thromboelastography (TEG) and its risk factors on ISR in individuals who have experienced acute ischemic stroke (AIS) receiving dual anti-platelet therapy (DAPT). At the end of follow-up, a total of 264 patients who met the criteria were enrolled in this cohort study. The primary endpoint event was a recurrence of ischemic stroke within 90 days of onset. The ISR rate was 7.2% (19/264). The recurrence rate in the HTPR group was 15.1% (8/53), which was significantly higher than the 5.2% (11/211) in the non-HTPR group (p = 0.013), and the type 2 diabetes mellitus (T2DM) group (12.5%, 10/80) was also significantly higher compared to the non-T2DM group (4.9%, 9/184) (p = 0.028). T2DM was an isolated risk factor for HTPR (adjusted OR = 3.06, 95% CI 1.57-5.98, P = 0.001). Kaplan-Meier plots showed that the cumulative risk (CR) of ISR was statistically different in the HTPR and T2DM groups compared to the non-HTPR group (log-rank P = 0.009) and the non-T2DM group (log-rank P = 0.026), respectively. The HTPR and T2DM groups had greater hazard ratios (HR) of ISR than the non-HTPR (adjusted HR = 2.78, 95% CI 1.06-7.32, P = 0.038) and non-T2DM (adjusted HR = 2.64, 95% CI 1.01-6.92, P = 0.049) groups. Both HTPR and T2DM are linked to ISR. Platelet Inhibition Rate (PIR) of TEG can early identify patients who are at high risk for having another ischemic stroke in patients undergoing DAPT, and this study may offer more evidence in favor of clinically personalized treatment and secondary prevention tactics.

Gut microbiota as predictors of the occurrence of high on-treatment platelet reactivity in acute ischemic stroke patients.

In this study, we aimed to investigate the association between gut microbiota and high on-treatment platelet reactivity (HTPR) in patients with acute ischemic stroke (AIS). We enrolled a total of 48 AIS patients, including 19 HTPR patients and 29 non-high on-treatment platelet reactivity (NHTPR) patients, along with 10 healthy controls. Clinical and laboratory data, as well as stool samples, were collected from all participants. The composition and function of gut microbiota were assessed using 16S rRNA sequencing. Differences in the gut microbiota between the two groups were analyzed, and a diagnostic model based on the gut microbiota was established using random forest model. HTPR patients exhibited a decreased microbial richness compared to NHTPR patients. Additionally, the relative abundance of unidentified_Clostridia and Ralstonia was lower in HTPR patients. Significant differences in biological functions, such as toxoplasmosis, were observed between the two groups. The combination of Ralstonia, unidentified-Clostridia, Mailhella, Anaerofustis, and Aggregatibacter showed excellent predictive ability for HTPR occurrence (AUC=0.896). When comparing AIS patients with healthy controls, alterations in the microbiota structure were observed in AIS patients, with imbalances in short-chain fatty acid-producing bacteria and pathogenic bacteria. Significant differences in biological functions, such as oxidative phosphorylation, were noted between the two groups. The combination of Alloprevotella, Terrisporobacter, Streptococcus, Proteus, and unidentified_Bacteria exhibited strong predictive power for AIS occurrence (AUC=0.994). This study is the first to uncover the microbial characteristics of HTPR in AIS patients and demonstrate the predictive potential of specific bacterial combinations for HTPR occurrence.

Elevated High-Sensitivity C-Reactive Protein Level Enhances the Impact of Lipoprotein(a) on Platelet Reactivity in PCI Patients Treated with Clopidogrel.

Recently, the effect of Lipoprotein(a) [Lp(a)] on thrombogenesis has aroused great interest, while inflammation has been reported to modify the Lp(a)-associated risks through an unidentified mechanism. This study aimed to evaluate the association between platelet reactivity with Lp(a) and high-sensitivity C-reactive protein (hs-CRP) levels in percutaneous intervention (PCI) patients treated with clopidogrel. Data were collected from 10,724 consecutive PCI patients throughout the year 2013 in Fuwai Hospital. High on-treatment platelet reactivity (HTPR) and low on-treatment platelet reactivity (LTPR) were defined as thrombelastography (TEG) maximum amplitude of adenosine diphosphate-induced platelet (MAADP) > 47 mm and < 31 mm, respectively. 6615 patients with TEG results were finally enrolled. The mean age was 58.24 ± 10.28 years and 5131 (77.6%) were male. Multivariable logistic regression showed that taking Lp(a) < 30 mg/dL and hs-CRP < 2 mg/L as the reference, isolated Lp(a) elevation [Lp(a) ≥ 30 mg/dL and hs-CRP < 2 mg/L] was not significantly associated with HTPR (P = 0.153) or LTPR (P = 0.312). However, the joint elevation of Lp(a) and hs-CRP [Lp(a) ≥ 30 mg/dL and hs-CRP ≥ 2 mg/L] exhibited enhanced association with both HTPR (OR:1.976, 95% CI 1.677-2.329) and LTPR (OR:0.533, 95% CI 0.454-0.627). The isolated elevation of Lp(a) level was not an independent indicator for platelet reactivity, yet the concomitant elevation of Lp(a) and hs-CRP levels was significantly associated with increased platelet reactivity. Whether intensified antiplatelet therapy or anti-inflammatory strategies could mitigate the risks in patients presenting combined Lp(a) and hs-CRP elevation requires future investigation.

The polygenic implication of clopidogrel responsiveness: Insights from platelet reactivity analysis and next-generation sequencing.

Clopidogrel is widely used worldwide as an antiplatelet therapy in patients with acute coronary disease. Genetic factors influence interindividual variability in response. Some studies have explored the polygenic contributions in the drug response, generating pharmacogenomic risk scores (PgxPRS). Importantly, these factors are less explored in underrepresented populations, such as Latin-American countries. Identifying patients at risk of high-on-treatment platelet reactivity (HTPR) is highly valuable in translational medicine. In this study we used a custom next-generation sequencing (NGS) panel composed of 91 single nucleotide polymorphisms (SNPs) and 28 genes related to clopidogrel metabolism, to analyze 70 patients with platelet reactivity values, assessed through closure time (CT). Our results demonstrated the association of SNPs with HTPR and non-HTPR, revealing the strongest associations with rs2286823 (OR: 5,0; 95% CI: 1,02-24,48; p: 0,03), rs2032582 (OR: 4,41; 95% CI: 1,20-16,12; p: 0,019), and rs1045642 (OR: 3,38; 95% CI: 0,96-11,9; p: 0,05). Bivariate regression analysis demonstrated the significant association of several SNPs with the CT value, a "surrogate" biomarker of clopidogrel response. Exploratory results from the LASSO regression model showed a high discriminatory capacity between HTPR and non-HTPR patients (AUC: 0,955), and the generated PgxPRS demonstrated a significant negative association between the risk score, CT value, and the condition of HTPR and non-HTPR. To our knowledge, our study addresses for the first time the analysis of the polygenic contribution in platelet reactivity using NGS and establishes PgxPRS derived from the LASSO model. Our results demonstrate the polygenic implication of clopidogrel response and offer insights applicable to the translational medicine of antiplatelet therapy in an understudied population.

A novel machine learning model to predict high on-treatment platelet reactivity on clopidogrel in Asianpatients after percutaneous coronary intervention.

Various genetic and nongenetic variables influence the high on-treatment platelet reactivity (HTPR) in patients taking clopidogrel. This study aimed to develop a novel machine learning (ML) model to predict HTPR in Chinese patients after percutaneous coronary intervention (PCI). This cohort study collected information on 507 patients taking clopidogrel. Data were randomly divided into a training set (90%) and a testing set (10%). Nine candidate Machine learning (ML) models and multiple logistic regression (LR) analysis were developed on the training set. Their performance was assessed according to the area under the receiver operating characteristic curve, precision, recall, F1 score, and accuracy on the test set. Model interpretations were generated using importance scores by transforming model variables into scaled features and representing in radar plots. Finally, we established a prediction platform for the prediction of HTPR. A total of 461 patients (HTPR rate: 19.52%) were enrolled in building the prediction model for HTPR. The XGBoost model had an optimized performance, with an AUC of 0.82, a precision of 0.80, a recall of 0.44, an F1 score of 0.57, and an accuracy of 0.87, which was superior to those of LR. Furthermore, the XGBoost method identified 7 main predictive variables. To facilitate the application of the model, we established an XGBoost prediction platform consisting of 7 variables and all variables for the HTPR prediction. A ML-based approach, such as XGBoost, showed optimum performance and might help predict HTPR on clopidogrel after PCI and guide clinical decision-making. Further validated studies will strengthen this finding.

An assessment of platelet response to ticagrelor in post-percutaneous coronary intervention patients using light transmission platelet aggregometry (LTA)

Background: Low on-treatment platelet reactivity (LTPR) or High on-treatment platelet reactivity (HTPR) with P2Y12 inhibitors is associated with bleeding (LTPR) or ischemic events (HTPR) in patients on dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI). Objective: Mapping of Indonesian patients’ platelet response secondary to ticagrelor and thus identifying either LTPR or HTPR. Method: During May – June 2019, 20 post-PCI patients on aspirin–ticagrelor combination were included. Light transmission aggregometry (LTA) for monitoring platelet function was used. Ticagrelor’s LTA &lt;40% is LTPR while &gt;70% is HTPR. Result: Patients were mostly male (18 patients) and aged between 40-73 years old with a history of diabetes and/or hypertension and smoking. About eight patients (40%) were LTPR and one (5%) patient was HTPR. Conclusion: A personalised DAPT strategy for preventing bleeding events, a de-escalation, might be valuable for Indonesian patients.

Effect of lipid-lowering therapy on platelet reactivity in patients treated with and without antiplatelet therapy.

Circulating lipoproteins may interact with platelets, increasing platelet sensitivity to aggregating agonists and their tendency towards activation and thrombus formation. In particular, patients with hypercholesterolemia exhibit a higher degree of platelet reactivity compared to normolipidemic. Moreover, accruing evidence report that lipid-lowering therapies can reduce thrombus formation, particularly in the absence of concomitant antiplatelet therapy. However, the underlying biological mechanism(s) explaining these clinical observations are not completely understood. Baseline platelet reactivity and high on-treatment platelet reactivity while on antiplatelet therapy (e.g., aspirin and clopidogrel) are associated with poor clinical outcomes. Therefore, strategies to reduce baseline platelet reactivity or improve the pharmacodynamic profile of antiplatelet therapies are an unmet clinical need. The potential use of lipid-lowering therapies for optimizing platelet reactivity provides several advantages as there is strong evidence that reducing circulating lipoproteins can improve clinical outcomes, and they may avoid the need for potent antiplatelet therapies that, although more effective, are associated with increased bleeding risk. This review will provide a systematic overview of the effects of lipid-lowering therapy on platelet reactivity in patients treated with and without antiplatelet therapy. We will focus on the potential biological mechanism(s) of action and the effect of statins, ezetimibe, proprotein convertase subtilisin/kexin 9 inhibitors, omega-3 fatty acids, and recombinant high-density lipoprotein on platelet reactivity. Ultimately, we will assess the current gaps in the literature and future perspective in the field.

Dual antiplatelet therapy is associated with high α-tubulin acetylation in circulating platelets from coronary artery disease patients

Platelet inhibition is the main treatment strategy to prevent atherothrombotic complications after acute coronary syndrome or percutaneous coronary intervention. Despite dual antiplatelet therapy (DAPT) combining aspirin and a P2Y12 receptor inhibitor, high on-treatment platelet reactivity (HPR) persists in some patients due to poor response to treatment and is associated with ischemic risk. Tubulin acetylation has been pointed out as a hallmark of stable microtubules responsible for the discoid shape of resting platelets. However, the impact of antiplatelet treatments on this post-translational modification has never been studied. This study investigated whether tubulin acetylation differs according to antiplatelet therapy and on-treatment platelet reactivity. Platelets were isolated from arterial blood samples of 240 patients admitted for coronary angiography, and levels of α-tubulin acetylation on lysine 40 (α-tubulin K40 acetylation) were assessed by western blot. We show that platelet α-tubulin K40 acetylation was significantly increased in DAPT-treated patients. In addition, the proportion of patients with high levels of α-tubulin K40 acetylation was drastically reduced among DAPT-treated patients with HPR. Multivariate logistic regression confirmed that DAPT resulting in adequate platelet inhibition was strongly associated with elevated α-tubulin K40 acetylation. In conclusion, our study highlights the role of elevated platelet α-tubulin K40 acetylation as a marker of platelet inhibition in response to DAPT. Clinical trial registration: https://clinicaltrials.gov - NCT03034148.

Guided Anti-P2Y12 Therapy in Patients Undergoing PCI: Three Systematic Reviews with Meta-analyses of Randomized Controlled Trials with Homogeneous Design.

The value of guided therapy (GT) with anti-P2Y12 drugs in percutaneous coronary intervention (PCI) is unclear. Meta-analyses lumped together randomized controlled trials (RCTs) with heterogeneous designs, comparing either genotype-GT or platelet function test (PFT)-GT with unguided therapy. Some meta-analysis also included RCTs that did not explore GT, but included the effects of switching patients with high on-treatment platelet reactivity (HTPR) to alternative therapies (HTPR-Therapy). We performed three distinct systematic reviews/meta-analyses, each exploring only RCTs with homogeneous design. MEDLINE, Embase, and Central databases were searched for RCTs testing genotype-GT, PFT-GT, or HTPR-Therapy in PCI-treated patients, through October 1, 2022. Two reviewers extracted the data. Risk ratios (RRs) (95% confidence intervals) were calculated. Primary outcomes were major bleedings (MBs) and major adverse cardiovascular events (MACE). In seven genotype-GT RCTs, RRs were: MB, 1.06 (0.73-1.54; p = 0.76); MACE, 0.65 (0.47-0.91; p = 0.01), but significant risk reduction was observed in RCTs performed in China (0.30, 0.16-0.54; p < 0.0001) and not elsewhere (0.75, 0.48-1.18; p = 0.21). In six PFT-GT RCTs, RRs were: MB, 0.91 (0.64-1.28, p = 0.58); MACE, 0.82 (0.56-1.19; p = 0.30): 0.62 (0.42-0.93; p = 0.02) in China, 1.08 (0.82-1.41; p = 0.53) elsewhere. In eight HTPR-Therapy RCTs, RRs were: MB, 0.71 (0.41-1.23; p = 0.22); MACE, 0.57 (0.44-0.75; p < 0.0001): 0.56 (0.43-0.74, p < 0.0001) in China, 0.58 (0.27-1.23, p = 0.16) elsewhere. No GT strategy affected MB. Overall, genotype-GT but not PFT-GT reduced MACE. However, genotype-GT and PFT-GT reduced MACE in China, but not elsewhere. PFT-GT performed poorly compared to HTPR-Therapy, likely due to inaccurate identification of HTPR patients by PFT.

Plasma protein signatures for high on-treatment platelet reactivity to aspirin and clopidogrel in peripheral artery disease

BackgroundA significant proportion of patients with peripheral artery disease (PAD) displays a poor response to aspirin and/or the platelet P2Y12 receptor antagonist clopidogrel. This phenomenon is reflected by high on-treatment platelet reactivity (HTPR) in platelet function assays in vitro and is associated with an increased risk of adverse cardiovascular events. ObjectiveThis study aimed to elucidate specific plasma protein signatures associated with HTPR to aspirin and clopidogrel in PAD patients. Methods and resultsBased on targeted plasma proteomics, 184 proteins from two cardiovascular Olink panels were measured in 105 PAD patients. VerifyNow ASPI- and P2Y12-test values were transformed to a continuous variable representing HTPR as a spectrum instead of cut-off level-defined HTPR. Using the Boruta random forest algorithm, the importance of 3 plasma proteins for HTPR in the aspirin, six in clopidogrel and 10 in the pooled group (clopidogrel or aspirin) was confirmed. Network analysis demonstrated clusters with CD84, SLAMF7, IL1RN and THBD for clopidogrel and with F2R, SELPLG, HAVCR1, THBD, PECAM1, TNFRSF10B, MERTK and ADM for the pooled group. F2R, TNFRSF10B and ADM were higher expressed in Fontaine III patients compared to Fontaine II, suggesting their relation with PAD severity. ConclusionsA plasma protein signature, including eight targets involved in proatherogenic dysfunction of blood cell-vasculature interaction, coagulation and cell death, is associated with HTPR (aspirin and/or clopidogrel) in PAD. This may serve as important systems-based determinants of poor platelet responsiveness to aspirin and/or clopidogrel in PAD and other cardiovascular diseases and may contribute to identify novel treatment strategies.

Variability of response on prophylactic prasugrel for endovascular treatment of intracranial aneurysms: Clinical implications.

Prophylactic prasugrel for endovascular treatment of intracranial aneurysms has been introduced and increased, but HTPR (high on-treatment platelet reactivity) or LTPR (low on-treatment platelet reactivity) of prasugrel is not uncommon in clinical circumstances. To investigate the predisposing factors of HTPR and LTPR on prasugrel premedication in the neurointerventional field and to determine its clinical implications. Between February 2016 and December 2020, 191 patients treated with coil embolization using prophylactic prasugrel in 234 intracranial aneurysms were the final candidates for this study. Patient and aneurysm characteristics, clinical status, and laboratory study values were carefully reviewed retrospectively. We performed risk factor analyses for HTPR and LTPR on prasugrel. Ultimately, 20 patients (10.5%) had HTPR, and 74 patients (38.7%) were categorized as having LTPR. In multivariable analyses, the factors related to HTPR were BMI (adjusted OR 1.21, 95% CI 1.04-1.41, p = 0.01), history of antithrombotics (adjusted OR 3.79, 95% CI 1.39-10.34, p = 0.01), and hematocrit (adjusted OR 0.91, 95% CI 0.84-0.99, p = 0.03). Low BMI was the only risk factor for LTPR (adjusted OR 0.84, 95% CI 0.76-0.94, p = 0.001). In the neurointerventional field, high BMI and prior use of antithrombotic agents were related to HTPR, and low BMI was associated with LTPR on prophylactic prasugrel. High hematocrit levels decreased the risk of HTPR. When preparing endovascular treatment for intracranial aneurysms, attention to patients with these clinical features is required to address the possibility of ischemic or bleeding complications.

Randomized, Double-Blind, Active Comparator Pharmacodynamic Study of Platelet Inhibition with Crushed and Integral Formulations of Clopidogrel and Ticagrelor in Acute Coronary Syndrome.

Crushed formulations of specific antiplatelet agents produce earlier and stronger platelet inhibition. We studied the platelet inhibitory effect of crushed clopidogrel in patients with acute coronary syndrome (ACS) and its relative efficacy compared with integral clopidogrel, crushed and integral ticagrelor. We aimed to compare the platelet inhibitory effect of crushed and integral formulations of clopidogrel and ticagrelor in patients with acute coronary syndrome (ACS). Overall, 142 patients with suspected ACS were randomly assigned to receive crushed or integral formulations of clopidogrel or ticagrelor. Platelet inhibition at baseline and 1 and 8h was assessed using the VerifyNow assay. High on-treatment platelet reactivity (HTPR) ≥ 235 P2Y12reaction units (PRUs) 1h after the medication loading dose was also determined. The PRU and percentage inhibition median (interquartile range) at 1h for the different formulations were as follows: crushed clopidogrel: 196.50 (155.50, 246.50), 9.36 (- 1.79, 25.10); integral clopidogrel: 189.50 (159.00, 214.00), 2.32 (- 2.67, 19.89); crushed ticagrelor: 59.00 (10.00, 96.00), 75.53 (49.12, 95.18); and integral ticagrelor: 126.50 (50.00, 168.00), 40.56 (25.59, 78.69). There was no significant difference in PRU or percentage platelet inhibition between the crushed and integral formulations of clopidogrel (p=0.990, p=0.479); both formulations of ticagrelor were superior to the clopidogrel formulations (p<0.05). On paired comparison, crushed ticagrelor showed robust early inhibition of platelets compared with the integral formulation (p=0.03). Crushed clopidogrel exhibited the maximal HTPR of 34.3%, but was < 3% for both formulations of ticagrelor. The platelet inhibitory effect of crushed clopidogrel is not superior to integral preparation in patients with ACS. Crushed ticagrelor produced maximal platelet inhibition acutely. HTPR rates in ACS are similar and very low with both formulations of ticagrelor, and maximal with crushed clopidogrel. Clinical Trials Registry of India identifier number CTRI/2020/06/025647.