Impact of Smoking on Platelet Reactivity and Clinical Outcomes After Percutaneous Coronary Intervention: Findings From the ADAPT-DES Study.

BACKGROUND: Smoking is a potent risk factor for coronary artery disease; however, prior studies describe increased platelet inhibition with clopidogrel among smokers, and some studies report improved outcomes among smokers, a finding described as the smoker's paradox. This study assessed the relationship between platelet reactivity and clinical outcomes after percutaneous coronary interventions among current smokers and nonsmokers. METHODS: ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) was a prospective, multicenter registry of patients treated with coronary drug-eluting stents. Platelet reactivity was assessed by the VerifyNow point-of-care assay; high on-treatment platelet reactivity (HPR) was defined as P2Y12 reaction units >208. A propensity-adjusted multivariable analysis was performed to determine the relationship between current smoking, platelet reactivity, and subsequent adverse events. RESULTS: Among 8582 patients, 22.6% were active smokers at the time of their percutaneous coronary intervention procedure. Current smokers were younger and had fewer comorbidities compared with nonsmokers. Current smokers had lower mean P2Y12 reaction units and lower rates of HPR compared with nonsmokers. Current smokers had similar rates of adverse events compared with nonsmokers. HPR was associated with higher rates of adverse events for both smokers and nonsmokers; however, there was evidence of interaction between smoking status and the effect of HPR. Smokers with HPR had significantly higher rates of stent thrombosis. Adverse event rates were highest among current smokers with HPR. CONCLUSIONS: Current smoking was associated with lower P2Y12 reaction units and lower rates of HPR on average; however, the combination of current smoking and HPR was associated with high rates of stent thrombosis. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00638794.

Reasons for the Failure of Platelet Function Testing to Adjust Antiplatelet Therapy: Pharmacodynamic Insights From the ARCTIC Study.

BACKGROUND: In the ARCTIC trial (Assessment by a Double Randomization of a Conventional Antiplatelet Strategy Versus a Monitoring-Guided Strategy for Drug-Eluting Stent Implantation and of Treatment Interruption Versus Continuation One Year After Stenting), treatment adjustment following platelet function testing failed to improve clinical outcomes. However, high-on-treatment platelet reactivity (HPR) is considered as a predictor of poor ischemic outcome. This prespecified substudy evaluated clinical outcomes according to the residual platelet reactivity status after antiplatelet therapy adjustment. METHODS: We analyzed the 1213 patients assigned to the monitoring arm of the ARCTIC trial in whom platelet reactivity was evaluated by the VerifyNow P2Y12 test before percutaneous coronary intervention and during the maintenance phase (at 14 days). HPR was defined as platelet reaction unit≥235U. The primary ischemic end point, a composite of death, myocardial infarction, stent thrombosis, stroke, or urgent revascularization and the safety end point of major bleeding were assessed according to the platelet reactivity status. RESULTS: Before percutaneous coronary intervention, 35.7% of patients displayed HPR (n=419). During the acute phase, between percutaneous coronary intervention and the 14-day platelet function testing, ischemic (adjusted hazard ratio, 0.94 [95% CI, 0.74-1.18]; P=0.58) and safety outcomes (hazard ratio, 1.28 [95% CI, 0.22-7.59]; P=0.78) were similar in HPR and non-HPR patients. During the maintenance phase, the proportion of HPR patients (n=186, 17.4%) decreased by 56%. At 1-year, there was no difference for the ischemic end point (5.9% versus 6.0%; adjusted hazard ratio, 0.79 [95% CI, 0.40-1.58]; P=0.51) and a nonsignificant higher rate of major bleedings (2.7% versus 1.0%, hazard ratio, 2.83 [95% CI, 0.96-8.41]; P=0.06) in HPR versus non-HPR patients. CONCLUSIONS: The proportion of HPR was halved after platelet function testing and treatment adjustment but without significant ischemic benefit at 1 year. HPR seems more as a modifiable risk marker than a risk factor of ischemic outcome. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00827411.

Arterial and venous thrombosis by high platelet count and high hematocrit: 108 521 individuals from the Copenhagen General Population Study.

BACKGROUND: It is unclear whether high platelet count or high hematocrit predict risk of thrombosis in individuals from the general population. OBJECTIVES: We tested the hypothesis that individuals from the general population with high platelet count or high hematocrit have high risk of arterial and venous thrombosis. METHODS: We prospectively followed 108 521 individuals from The Copenhagen General Population Study for a median of 8 years. Platelet count and blood hematocrit were measured at study entry. RESULTS AND CONCLUSION: Multivariable adjusted hazard ratios for individuals with platelet counts in the top 5 percentiles (>398 × 109 /L) vs in the 25th-75th percentiles (231-316 × 109 /L) were 1.77 (95% confidence interval [CI], 1.38-2.24) for arterial thrombosis in the brain (38 and 26 events/10 000 person-years) and 0.82 (95%, 0.61-1.11) for arterial thrombosis in the heart (23 and 28 events/10 000 person-years). For individuals with hematocrit values in the top 5 percentiles (women/men: >45/>48%) vs the 25th-75th percentiles (women/men: 38.1-42/41.1-45%), hazard ratios were 1.27 (95% CI, 0.91-1.75) for arterial thrombosis in the brain (40 and 26 events/10 000 person-years) and 1.46 (95% CI, 1.06-2.00) for arterial thrombosis in the heart (43 and 25 events/10 000 person-years). Neither high platelet count nor high hematocrit was associated with risk of venous thromboembolism. When excluding individuals with myeloproliferative neoplasia from the main analyses, results on risk of thrombosis were similar. In this prospective study, high platelet counts were associated with 1.8-fold risk of arterial thrombosis in the brain, whereas high hematocrit was associated with 1.5-fold risk of arterial thrombosis in the heart.

Acute myocardial infarction and transient elevated anticardiolipin antibody in a young adult with possible familial hypercholesterolemia: a case report : Anticardiolipin antibody and myocardial infarction.

BACKGROUND: Familial hypercholesterolemia (FH) can lead to premature coronary heart disease. Anticardiolipin antibody may be a contributor for thrombosis. Here, we report an adult with possible FH suffered from premature myocardial infarction that may be triggered by transient increased anticardiolipin antibody. CASE PRESENTATION: A 29-year-old male had presented with a history of 2-h chest pain and numbness of left upper arm before 5 days. The electrocardiogram (ECG) had demonstrated inferior wall myocardial infarction (MI). Five days later he was admitted to our hospital and diagnosed as acute MI and possible FH (premature coronary heart disease, low density lipoprotein cholesterol of 5.90 mmol/L) with increased anticardiolipin antibody (up to 120 RU/ml). Other auto-antibodies including ß2-glicoprotein antibodies IgM, IgA, IgG, lupus anticoagulant (LA), antinuclear antibodies, anti-myocardial antibody were normal. Coronary artery angiography (CAG) showed right coronary artery was total occlusion from the middle segment. Then he underwent percutaneous coronary intervention with a stent. Four days later, he was discharged with complete recovery. CAG showed intra-stent restenosis and anticardiolipin antibody level was normal and the patient had no any symptoms at 6-month follow-up. CONCLUSIONS: Transient elevated anticardiolipin antibody may be a trigger or biomarker of cardiac thrombotic events in younger atherosclerotic patients.

Updated Expert Consensus Statement on Platelet Function and Genetic Testing for Guiding P2Y12 Receptor Inhibitor Treatment in Percutaneous Coronary Intervention.

Dual-antiplatelet therapy (DAPT) with aspirin and a P2Y12 receptor inhibitor is the standard treatment for patients undergoing percutaneous coronary intervention. The availability of different P2Y12 receptor inhibitors (clopidogrel, prasugrel, ticagrelor) with varying levels of potency has enabled physicians to contemplate individualized treatment regimens, which may include escalation or de-escalation of P2Y12-inhibiting therapy. Indeed, individualized and alternative DAPT strategies may be chosen according to the clinical setting (stable coronary artery disease vs. acute coronary syndrome), the stage of the disease (early- vs. long-term treatment), and patient risk for ischemic and bleeding complications. A tailored DAPT approach may be potentially guided by platelet function testing (PFT) or genetic testing. Although the routine use of PFT or genetic testing in percutaneous coronary intervention-treated patients is not recommended, recent data have led to an update in guideline recommendations that allow considering selective use of PFT for DAPT de-escalation. However, guidelines do not expand on when to implement the selective use of such assays into decision making for personalized treatment approaches. Therefore, an international expert consensus group of key leaders from North America, Asia, and Europe with expertise in the field of antiplatelet treatment was convened. This document updates 2 prior consensus papers on this topic and summarizes the contemporary updated expert consensus recommendations for the selective use of PFT or genotyping in patients undergoing percutaneous coronary intervention.

Pharmacodynamic Effects of a 6-Hour Regimen of Enoxaparin in Patients Undergoing Primary Percutaneous Coronary Intervention (PENNY PCI Study).

Delayed onset of action of oral P2Y12 inhibitors in ST-elevation myocardial infarction (STEMI) patients may increase the risk of acute stent thrombosis. Available parenteral anti-thrombotic strategies, to deal with this issue, are limited by added cost and increased risk of bleeding. We investigated the pharmacodynamic effects of a novel regimen of enoxaparin in STEMI patients undergoing primary percutaneous coronary intervention (PPCI). Twenty patients were recruited to receive 0.75 mg/kg bolus of enoxaparin (pre-PPCI) followed by infusion of enoxaparin 0.75 mg/kg/6 h. At four time points (pre-anti-coagulation, end of PPCI, 2-3 hours into infusion and at the end of infusion), anti-Xa levels were determined using chromogenic assays, fibrin clots were assessed by turbidimetric analysis and platelet P2Y12 inhibition was determined by VerifyNow P2Y12 assay. Clinical outcomes were determined 14 hours after enoxaparin initiation. Nineteen of 20 patients completed the enoxaparin regimen; one patient, who developed no-reflow phenomenon, was switched to tirofiban after the enoxaparin bolus. All received ticagrelor 180 mg before angiography. Mean (± standard error of the mean) anti-Xa levels were sustained during enoxaparin infusion (1.17 ± 0.06 IU/mL at the end of PPCI and 1.003 ± 0.06 IU/mL at 6 hours), resulting in prolonged fibrin clot lag time and increased lysis potential. Onset of platelet P2Y12 inhibition was delayed in opiate-treated patients. No patients had thrombotic or bleeding complications. In conclusion, enoxaparin 0.75 mg/kg bolus followed by 0.75 mg/kg/6 h provides sustained anti-Xa levels in PPCI patients. This may protect from acute stent thrombosis in opiate-treated PPCI patients who frequently have delayed onset of oral P2Y12 inhibition.

Early P2Y12 Inhibitors Escalation in Primary PCI Patients: Insights from the RENOVAMI Registry.

BACKGROUND: Early escalation from clopidogrel to new generation P2Y12 inhibitors is common practice in patients with ST-elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (pPCI). Real-world data about this strategy, however, are limited. METHODS: From 2012 to 2015, 1,057 consecutive STEMI patients treated with pPCI in an Italian hub-and-spoke network were prospectively included in an observational registry (RENOVAMI, ClinicalTrials.gov Identifier: NCT01760382). We compared the prevalence, predictive factors and in-hospital outcomes of patients escalated to a new generation P2Y12 inhibitor within the first 24 hours from pPCI with those continuing on admission antiplatelet therapy. RESULTS: In the first 24 hours after pPCI, 165 patients (15.6%) were escalated from clopidogrel to a new generation P2Y12 inhibitor, while de-escalation to clopidogrel was occasional (19 patients, 1.8%) and switch between new generation P2Y12 inhibitors was rare (8 patients, 0.8%, all from ticagrelor to prasugrel). Drug eluting stent use (adjusted odds ratio [OR], 2.19, 95% confidence interval [CI], 1.55-3.08, p = 0.0002) and impaired renal function (adjusted OR, 0.19, 95% CI, 0.05-0.77, p = 0.02) were the only independent predictive factors for the decision to escalate. After adjustment for potential confounders, escalation did not predict in-hospital outcomes, whereas the overall use of new generation P2Y12 inhibitors was correlated with a better in-hospital survival (adjusted hazard ratio, 0.47, 95% CI, 0.25-0.91, p = 0.03). Moreover, escalation did not influence bleeding rates. CONCLUSIONS: In this prospective registry of STEMI patients treated with pPCI and contemporary antiplatelet therapy, early escalation to a new generation P2Y12 inhibitor appeared safe and did not significantly affect in-hospital bleeding rates.

Association of Monocyte Count on Admission with the Angiographic Thrombus Burden in Patients with ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention / Associação da Contagem de Monócitos na Internação com a Carga Trombótica Angiográfica em Pacientes com Infarto com Supradesnivelamento do Segmento ST Submetidos à Intervenção Coronária Percutânea Primária

Abstract Background: The intracoronary high-thrombus burden during the primary percutaneous coronary intervention in patients with ST-elevation myocardial infarction (STEMI) can lead to poor outcomes. Monocytes have been described to play an important role in thrombotic disorders. Objectives: This study aimed to investigate the relationship between admission monocyte count and angiographic intracoronary thrombus burden in patients receiving primary percutaneous coronary intervention (PPCI). Methods: A total of 273 patients with acute STEMI who underwent PPCI were enrolled. The patients were divided into two groups according to the thrombolysis in myocardial infarction (TIMI) thrombus grade: low-thrombus burden group with a grade of 0-2 and high-thrombus burden group with a grade of 3-4. The monocyte count and other laboratory parameters were measured on admission before PPCI. P-value < 0.05 was considered significant. Results: There were 95 patients (34.8%) in the high-thrombus burden group, and 178 patients (65.2%) in the low-thrombus burden group. Patients with high-thrombus burden had significantly higher admission monocyte count (0.61 ± 0.29×109/L vs. 0.53 ± 0.24×109/L, p = 0.021). In multivariate analysis, monocyte count was the independent predictor of angiographic high-thrombus burden (odds ratio 3.107, 95% confidence interval [CI] 1.199-7.052, p = 0.020). For the prediction of angiographic high-thrombus burden, admission monocyte count at a cut-off value of 0.48×109/L yielded 0.59 ROC-AUC (71.9% sensitivity, 46.9% specificity). Conclusions: Monocyte count on admission was an independent clinical predictor of high-thrombus burden in patients with STEMI undergoing PPCI. Our findings suggest that admission monocyte count may be available for early risk stratification of high-thrombus burden in acute STEMI patients and might allow the optimization of antithrombotic therapy to improve the outcomes of PPCI.

Resumo Fundamento: A carga trombótica intracoronária durante a intervenção coronária percutânea primária em pacientes com Infarto com Supradesnivelamento do Segmento ST (STEMI) pode levar a resultados negativos.Os monócitos foram descritos para desempenhar um papel importante nos distúrbios trombóticos. Objetivos: Este estudo investigou a relação entre a contagem de monócitos no momento da internação e a carga trombótica angiográfica intracoronária em pacientes submetidos à intervenção coronária percutânea primária (ICPP). Métodos: Um total de 273 pacientes com STEMI agudo submetidos à ICPP participaram. Os pacientes se dividiram em dois grupos de acordo com o grau trombótico na trombólise do infarto do miocárdio (TIMI): grupo baixa carga trombótica, com graus de 0-2, e grupo alta carga trombótica, com graus de 3-4. A contagem de monócitos e outros parâmetros laboratoriais foram medidos na internação antes da ICPP. Consideramos o valor de p < 0,05 significativo. Resultados: Havia 95 pacientes (34,8%) no grupo alta carga trombótica, e 178 pacientes (65,2%) no grupo baixa carga trombótica. Pacientes com alta carga trombótica apresentaram contagem de monócitos no momento da internação mais alta (0,61 ± 0,29×109/L vs. 0,53 ± 0,24×109/L, p = 0,021). Na análise multivariada, a contagem de monócitos foi o indicador independente da alta carga trombótica angiográfica (odds ratio 3,107, intervalo de confiança de 95% [IC] 1,199-7,052, p = 0,020). Para a previsão da alta carga trombótica angiográfica, a contagem de monócitos na internação tinha ponto de corte de 0,48×109/L, chegou a 0.59 ROC-AUC (71,9% sensibilidade, 46,9% especificidade). Conclusões: a contagem de monócitos na internação foi um indicador clínico independente da alta carga trombótica em pacientes com STEMI submetidos à ICPP. Nossos achados sugerem que a contagem de monócitos na internação pode estar disponível para a estratificação de risco precoce da alta carga trombótica em pacientes com STEMI agudo, e podem levar à otimização da terapia antitrombótica para melhorar os resultados da ICPP.

[Platelet inhibition in patients with coronary, cerebral and peripheral macroangiopathy : What, when and how long?] / Thrombozytenaggregationshemmer bei koronarer, zerebraler und peripherer Makroangiopathie : Was, wann, wie lange?

BACKGROUND: Inhibition of platelet aggregation can reduce the rate of vascular events in patients with coronary artery disease, carotid artery stenosis and symptomatic peripheral arterial disease. The choice of platelet inhibitors in monotherapy and combination therapy as well as the duration of dual platelet inhibition depend on the clinical situation and individual patient characteristics. GOAL: The present review summarizes the latest data from clinical trials and recommendations regarding platelet inhibition in coronary, cerebral and peripheral arterial disease. DATA: A large number of randomized trials on platelet inhibition in different clinical situations have been performed, allowing evidence-based recommendations on the choice of drugs and duration of treatment. Moreover, new guidelines of European professional societies on platelet inhibition in patients with coronary, cerebral and peripheral arterial disease have been recently published. CONCLUSION: Based on latest randomized trials and major society guidelines, a number of recommendations on platelet inhibition in stable coronary artery disease, after stent implantation, after acute coronary syndromes and in cerebral and peripheral arterial disease can be made.

Comparison of the effects of P2Y12 receptor antagonists on platelet function and clinical outcomes in patients undergoing Primary PCI: A substudy of the HEAT-PPCI trial.

AIMS: The HEAT-PPCI trial compared bivalirudin and unfractionated heparin in patients undergoing primary percutaneous coronary intervention (PPCI). The aim of this study was to report pre-specified, secondary analyses comparing the effects of P2Y12 inhibiting agents on platelet reactivity and clinical events. METHODS AND RESULTS: All patients received preprocedural oral antiplatelet therapy. During the early stages of the trial, the P2Y12 inhibitor of choice was prasugrel with some use of clopidogrel. Later, routine therapy switched to ticagrelor. For cases performed during working hours, multiple electrode aggregometry (MEA) was used to assess ADP-induced platelet aggregation at the end of the index procedure. The effect of P2Y12 inhibitors on the primary efficacy (major adverse cardiac events [MACE]) and safety (major bleeding) outcomes was assessed in all patients. Multiple logistic regression was used to adjust for differences in baseline characteristics. With MEA data from 469 patients, prasugrel therapy resulted in significantly greater suppression of ADP-induced platelet aggregation at 40 U (23, 78) (median; interquartile range [IQR]) when compared against ticagrelor 75 U (41, 100.75); p<0.001 or clopidogrel 79 U (56, 96); p<0.001. In the entire study population (N=1,803), prasugrel therapy was associated with significantly fewer MACE (26/497; 5.2%) in comparison to ticagrelor (83/1,123; 7.4%) or clopidogrel (18/183; 9.8%); odds ratio (OR) 0.64, confidence interval (CI): 0.41-0.99, p=0.045. For major bleeding, there were no significant differences among the three groups - clopidogrel (3/183; 1.6%), prasugrel (13/497; 2.6%) and ticagrelor (43/1,123; 3.8%); OR 0.73, CI: 0.39-1.35, p=0.31. Patients treated with clopidogrel had more high-risk features and clopidogrel use was more common as an alternative to prasugrel. After adjustment, there were no significant differences in the rates of MACE (OR 0.70, CI: 0.41-1.21, p=0.20) or major bleeding (OR 0.80, CI: 0.41-1.60, p=0.53). CONCLUSIONS: In HEAT-PPCI, patients who received prasugrel (rather than clopidogrel or ticagrelor) had significantly greater suppression of ADP-induced platelet aggregation at the end of the procedure. After adjustment for differences in baseline characteristics, there were no significant differences in ischaemic or bleeding outcomes among the antiplatelet therapies.

Observational Study of Platelet Reactivity in Patients Presenting With ST-Segment Elevation Myocardial Infarction Due to Coronary Stent Thrombosis Undergoing Primary Percutaneous Coronary Intervention: Results From the European PREvention of Stent Thrombosis by an Interdisciplinary Global European Effort Registry.

OBJECTIVES: High platelet reactivity (HPR) was studied in patients presenting with ST-segment elevation myocardial infarction (STEMI) due to stent thrombosis (ST) undergoing immediate percutaneous coronary intervention (PCI). BACKGROUND: HPR on P2Y12 inhibitors (HPR-ADP) is frequently observed in stable patients who have experienced ST. The HPR rates in patients presenting with ST for immediate PCI are unknown. METHODS: Consecutive patients presenting with definite ST were included in a multicenter ST registry. Platelet reactivity was measured before immediate PCI with the VerifyNow P2Y12 or Aspirin assay. RESULTS: Platelet reactivity was measured in 129 ST patients presenting with STEMI undergoing immediate PCI. HPR-ADP was observed in 76% of the patients, and HPR on aspirin (HPR-AA) was observed in 13% of the patients. HPR rates were similar in patients who were on maintenance P2Y12 inhibitor or aspirin since stent placement versus those without these medications. In addition, HPR-ADP was similar in patients loaded with a P2Y12 inhibitor shortly before immediate PCI versus those who were not. In contrast, HPR-AA trended to be lower in patients loaded with aspirin as compared with those not loaded. CONCLUSIONS: Approximately 3 out of 4 ST patients with STEMI undergoing immediate PCI had HPR-ADP, and 13% had HPR-AA. Whether patients were on maintenance antiplatelet therapy while developing ST or loaded with P2Y12 inhibitors shortly before undergoing immediate PCI had no influence on the HPR rates. This raises concerns that the majority of patients with ST have suboptimal platelet inhibition undergoing immediate PCI.

Myeloid-related protein-8/14 in acute coronary syndrome.

BACKGROUND: The alarmin family member myeloid-related protein (MRP)-14 (S100A9), which has been identified by platelet transcriptional profiling as an acute myocardial infarction gene, regulates vascular inflammation and thrombosis. Elevated plasma levels of MRP-8/14 (S100A8/A9) heterodimer predict first and recurrent cardiovascular events. The aim of this study was to elucidate pathophysiological roles of MRP-8/14 in acute coronary syndrome (ACS). METHODS AND RESULTS: In 38 consecutive ACS patients, the MRP-8/14 level in coronary artery blood obtained at thrombus aspiration was higher in 23 patients, in whom aspirated thrombus was confirmed, compared to the 15 patients, in whom it was absent [4.86 (1.95, 8.29) vs 2.94 (1.31, 4.44), P=0.017]. The MRP-8/14 level was correlated with myeloperoxidase (MPO) level (R2=0.52), but not with soluble P-selectin level (R2=0.0002) in the coronary artery blood. Immunohistochemistry of the aspirated thrombus exhibited that expression of MRP8/14 was co-localized with leukocytes positive for activated Mac-1. Finally, in cultured human umbilical vein endothelial cells, MRP-8/14 increased tissue factor expression. CONCLUSIONS: Our findings indicate that MRP-8/14 concentration increases in coronary artery blood in association with thrombus formation in ACS, co-localizes with leukocytes, and is associated with leukocyte activation. MRP-8/14 is positioned as a unique biomarker at the interface of inflammation and thrombosis in ACS.

Antithrombotic potency of ticagrelor versus clopidogrel in type-2 diabetic patients with cardiovascular disease.

Type-2 Diabetes Mellitus [T2DM] is associated with increased platelet reactivity and hypo-response to antiplatelet drugs. Ticagrelor, with its faster and more potent antiplatelet effects, was shown to reduce adverse events more than clopidogrel in the overall CAD patient population of PLATO trial, but the benefits did not reach statistical significance in the T2DM subgroup. To better understand these findings, we compared the antithrombotic effects of ticagrelor versus with clopidogrel in T2DM patients with cardiovascular disease. In a randomized, 2 treatment-sequence, crossover-design, T2DM patients (n=20, 57±8 years, 60 % male) received a loading-dose [LD] plus one week of daily-therapy [DT] of clopidogrel or ticagrelor. Treatment effects were assessed by measuring thrombus formation (Badimon Chamber) and platelet aggregation (Multiple Electrode Aggregometry (MEA) Analyzer and VerifyNow®) at 2- and 6-hour post-LD and on Day-7 of DT, in comparison with pre-treatment baseline. After 2 weeks of washout, patients switched to the second treatment under identical testing conditions. Ticagrelor significantly reduced thrombus formation versus baseline at 2- and 6-hour post-LD and Day-7 of DT (33 %, 40 % and 31 %, respectively, p<0.01 for all) whereas thrombus reductions with clopidogrel were much lower and significant only at 6-hour post-LD (16 %, 20 % and 17 %, respectively). Antithrombotic effect of ticagrelor at 6-hour was significantly stronger than clopidogrel (p<0.05). Platelet aggregation (MEA and VerifyNow®) was inhibited by both treatments but effects of ticagrelor were significantly stronger at each time-point. Ticagrelor exhibits a faster and more potent antithrombotic effect than clopidogrel in T2DM patients with cardiovascular disease, supporting its use in this population.

Individualized dual antiplatelet therapy based on platelet function testing in patients undergoing percutaneous coronary intervention: a meta-analysis of randomized controlled trials.

BACKGROUND: High on-treatment platelet reactivity (HPR) represents a strong risk factor for thrombotic events after PCI. We aim to evaluate the efficacy and safety of individualizing intensified dual antiplatelet therapy (DAPT) in PCI-treated patients with HPR based on platelet function testing (PFT). METHODS: Electronic databases were searched for randomized control trials that reported the clinical outcomes of using an intensified antiplatelet protocol with P2Y12 receptor inhibitor comparing with standard maintenance dose of clopidogrel on the basis of platelet function testing. Clinical endpoints were assessed. RESULTS: From 2005 to 2016, thirteen clinical studies comprising 7290 patients were included for analysis. Compared with standard antiplatelet therapy with clopidogrel, the intensified protocol based on platelet function testing was associated with a significant reduction in major adverse cardiovascular events (RR:0.55, 95% CI: 0.36-0.84, p = 0.005), cardiovascular death (RR:0.60, 95% CI: 0.38-0.96, p = 0.03), stent thrombosis (RR:0.58, 95% CI: 0.36-0.93, p = 0.02) and target vessel revascularization (RR:0.33, 95% CI: 0.14-0.76, p = 0.009). No significant difference was found in the rate of bleeding events between intensified and standard protocol. CONCLUSIONS: Compared with standard clopidogrel therapy, individualized intensified antiplatelet therapy on the basis of platelet reactivity testing reduces the incidence of cardiovascular events in patient undergoing PCI, without increasing the risk of bleeding.

Duration of dual antiplatelet therapy in acute coronary syndrome.

Despite a large volume of evidence supporting the use of dual antiplatelet therapy in patients with acute coronary syndrome, there remains major uncertainty regarding the optimal duration of therapy. Clinical trials have varied markedly in the duration of therapy, both across and within trials. Recent systematic reviews and meta-analyses suggest that shorter durations of dual antiplatelet therapy are superior because the avoidance of atherothrombotic events is counterbalanced by the greater risks of excess major bleeding with apparent increases in all-cause mortality with longer durations. These findings did not show significant heterogeneity according to whether patients had stable or unstable coronary heart disease. Moreover, the potential hazards and benefits may differ when applied to the general broad population of patients encountered in everyday clinical practice who have markedly higher bleeding and atherothrombotic event rates. Clinicians lack definitive information regarding the duration of therapy in patients with acute coronary syndrome and risk scores do not appear to be sufficiently robust to address these concerns. We believe that there is a pressing need to undertake a broad inclusive safety trial of shorter durations of therapy in real world populations of patients with acute coronary syndrome. The clinical evidence would further inform future research into strategies for personalised medicine.

Platelet Reactivity and Clinical Outcomes After Coronary Artery Implantation of Drug-Eluting Stents in Subjects With Peripheral Arterial Disease: Analysis From the ADAPT-DES Study (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents).

BACKGROUND: Patients with peripheral arterial disease (PAD) have high rates of adverse cardiovascular events after percutaneous coronary intervention and may additionally have heightened platelet reactivity. This study assessed the relationship between platelet reactivity and clinical outcomes after percutaneous coronary interventions among subjects with and without PAD. METHODS AND RESULTS: ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) was a prospective, multicenter registry of patients treated with coronary drug-eluting stents. Platelet reactivity was assessed by the VerifyNow point-of-care assay; high on-treatment platelet reactivity (HPR) was defined as P2Y12 reaction units >208. A propensity-adjusted multivariable analysis was performed to determine the relationship between PAD, platelet reactivity, and subsequent adverse events (definite or probable stent thrombosis, all-cause mortality, myocardial infarction, and clinically relevant bleeding). Among 8582 patients, 10.2% had a history of PAD. Patients with PAD were older and more likely to have comorbid conditions; however, mean P2Y12 reaction units and HPR were not significantly different between PAD and no PAD groups. Patients with PAD had higher 2-year rates of all-cause mortality, myocardial infarction, stent thrombosis, and clinically relevant bleeding. Associations between HPR and adverse events were similar in PAD and no PAD groups, without evidence of interaction; however, adverse event rates were highest among subjects with both PAD and HPR. In a propensity-adjusted multivariable model, both PAD and HPR were independent predictors of myocardial infarction at 2 years. CONCLUSIONS: A history of PAD was associated with ischemic and bleeding outcomes 2 years after successful coronary drug-eluting stent implantation; however, these associations did not seem to be directly mediated by heightened platelet reactivity. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00638794.

Advocating cardiovascular precision medicine with P2Y12 receptor inhibitors.

Antiplatelet therapy with P2Y12-receptor inhibitors has become the cornerstone of medical treatment in patients with acute coronary syndrome treated with percutaneous coronary intervention (PCI). With over 100 million prescriptions filled since its approval, clopidogrel is the most widely used P2Y12-receptor inhibitor. Dual antiplatelet therapy with clopidogrel plus aspirin has been associated with a lower rate of major cardiovascular events in patients after PCI than aspirin monotherapy. However, an alarmingly high number of clopidogrel-treated patients experience adverse thrombotic events. Insufficient P2Y12-inhibition or high on-treatment platelet reactivity to adenosine diphosphate has stimulated the increased use of more potent P2Y12 inhibitors: prasugrel (a third generation thienopyridine) and ticagrelor (a cyclopentyl-triazolo-pyrimidine). However, more potent platelet inhibition and low on-treatment platelet reactivity has resulted in increased major bleeding and higher costs. These limitations have suggested the need for an individualized antiplatelet approach in order to decrease thrombotic events and minimize bleeding. This model of personalized medicine integrates a patient's demographic and biological data (pharmacodynamic, genomic, epigenomic, transcriptomic, and metabolic information) to target therapy in order to maximize efficacy while minimizing bleeding and costs. This review discusses the role of diagnostic tools such as platelet function and pharmacogenomic testing to personalize antiplatelet therapy.

Venous and Arterial Thrombosis: Is There a Link?

An increasing body of evidence suggests the likelihood of a link between venous and arterial thrombosis. The two vascular complications share several risk factors, such as age, obesity, smoking, diabetes mellitus, blood hypertension, hypertriglyceridemia, and metabolic syndrome. Moreover, there are many examples of conditions accounting for both venous and arterial thrombosis, such as the antiphospholipid antibody syndrome, hyperhomocysteinemia, malignancies, infections, and the use of hormonal treatment. Finally, several recent studies have consistently shown that patients with venous thromboembolism are at a higher risk of arterial thrombotic complications than matched control individuals. We, therefore, speculate the two vascular complications are simultaneously triggered by biological stimuli responsible for activating coagulation and inflammatory pathways in both the arterial and the venous system. Future studies are needed to clarify the nature of this association, to assess its extent, and to evaluate its implications for clinical practice.

Quantified coronary frequency domain optical coherence tomography signal analysis for the evaluation of erythrocyte-rich thrombus: ex-vivo validation study.

Previous study has demonstrated that erythrocyte-rich thrombi contain more inflammatory cells and reflect high thrombus burden, leading to impaired myocardial reperfusion in myocardial infarction. The aim of this study is to investigate the utility of quantified frequency domain optical coherence tomography (FD-OCT) signal analysis in evaluating the erythrocyte-rich thrombus with ex-vivo materials. We evaluated 54 specimens of coronary artery thrombus obtained by thrombectomy catheter from 8 patients who underwent primary percutaneous coronary intervention. The thrombi were immersed in saline immediately after thrombectomy and FD-OCT image acquisition was performed ex-vivo. Quantitative analysis for all contiguous frames was performed by the dedicated automated software (OCT system software, Light Lab Inc.). For the maximum thrombus area, mean signal intensity (MSI) and normalized standard deviation of signal (NSD) was evaluated. All thrombi were stained using double staining of phosphotungstic acid-hematoxylin and eosin to enable automatic extraction of erythrocyte from fibrin. Computer-assisted analysis was performed using dedicated image processing software (WinROOF, Mitani Corp., Tokyo, Japan) for color identification of the erythrocyte area. Erythrocyte-rich thrombus, defined as % erythrocyte [(erythrocyte area/total thrombus area) × 100] ≥ 10%, showed significantly lower MSI [4.39 ± 0.24 vs. 4.74 ± 0.35, p = 0.002] than that of <10%. The cut-off point for prediction of erythrocyte-rich thrombus was defined as MSI ≤ 4.56, sensitivity: 87.5%, specificity: 82.9%, area under the curve: 0.836, respectively). The present ex-vivo study suggested the utility of quantified FD-OCT signal analysis on the detection of erythrocyte-rich thrombus.

Variation in Patient Profiles and Outcomes in US and Non-US Subgroups of the Cangrelor Versus Standard Therapy to Achieve Optimal Management of Platelet Inhibition (CHAMPION) PHOENIX Trial.

BACKGROUND: The Cangrelor Versus Standard Therapy to Achieve Optimal Management of Platelet Inhibition (CHAMPION) PHOENIX trial demonstrated superiority of cangrelor in reducing ischemic events at 48 hours in patients undergoing percutaneous coronary intervention compared with clopidogrel. METHODS AND RESULTS: We analyzed all patients included in the modified intention-to-treat analysis in US (n=4097; 37.4%) and non-US subgroups (n=6845; 62.6%). The US cohort was older, had a higher burden of cardiovascular risk factors, and had more frequently undergone prior cardiovascular procedures. US patients more frequently underwent percutaneous coronary intervention for stable angina (77.9% versus 46.2%). Almost all US patients (99.1%) received clopidogrel loading doses of 600 mg, whereas 40.5% of non-US patients received 300 mg. Bivalirudin was more frequently used in US patients (56.7% versus 2.9%). At 48 hours, rates of the primary composite end point were comparable in the US and non-US cohorts (5.5% versus 5.2%; P=0.53). Cangrelor reduced rates of the primary composite end point compared with clopidogrel in US (4.5% versus 6.4%; odds ratio 0.70 [95% confidence interval 0.53-0.92]) and in non-US patients (4.8% versus 5.6%; odds ratio 0.85 [95% confidence interval 0.69-1.05]; interaction P=0.26). Similarly, rates of the key secondary end point, stent thrombosis, were reduced by cangrelor in both regions. Rates of Global Use of Strategies to Open Occluded Arteries (GUSTO)-defined severe bleeding were low and not significantly increased by cangrelor in either region. CONCLUSIONS: Despite broad differences in clinical profiles and indications for percutaneous coronary intervention by region in a large global cardiovascular clinical trial, cangrelor consistently reduced rates of ischemic end points compared with clopidogrel without an excess in severe bleeding in both the US and non-US subgroups. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01156571.