Stent Thrombosis With Ticagrelor Versus Clopidogrel in Patients With Acute Coronary Syndromes

Hyperacute in-Stent Thrombosis Causing Large Vessel Occlusion after Stent-Assisted Aneurysm Coiling Secondary to Complete Clopidogrel and Prasugrel Resistance: a Case Report

Dual antiplatelet therapy (DAPT) is standard treatment for endoluminal stent insertion, and complete resistance to DAPT is rare. A case of in-stent thrombosis occurring 3 hours after stent-assisted coiling of internal carotid artery aneurysm is presented despite compliance with DAPT. Platelet function tests (PFTs) revealed complete clopidogrel and prasugrel resistance.

Comparison of Clinical Outcomes Between Ticagrelor and Clopidogrel in East-Asian Patients with Acute Coronary Syndrome: Large Cohort Study

AIM

A high risk of bleeding is observed in East Asian patients with acute coronary syndrome (ACS). Therefore, the choice between two antiplatelet therapy drugs, ticagrelor and clopidogrel, remains controversial in this population with ACS. This study aimed to use a large cohort database to assess the clinical outcomes of ticagrelor and clopidogrel therapy, including major bleeding, recurrent ACS, and mortality, in this population.

METHODS

Between January 2009 and December 2019, 43,696 patients were diagnosed with ACS based on the medical history (International Classification of Diseases [ICD] code) of the Chang Gung Research Database. After excluding patients without percutaneous coronary intervention, with concurrent medical problems, and on non-standard dual antiplatelet therapy (DAPT) or a single antiplatelet agent, 18,046 patients were recruited for analysis. Ticagrelor- and clopidogrel-based DAPT were administered to 3666 patients and 14,380 patients, respectively. Baseline characteristics and clinical outcomes were compared between the two groups. A total of 4225 patients were defined as a high-bleeding-risk subgroup according to Academic Research Consortium for High Bleeding Risk (ARC-HBR) score (met one major or two minor criteria), of which 466 and 3759 patients received ticagrelor- and clopidogrel-based DAPT, respectively.

RESULTS

Before propensity score matching (PSM), younger age, higher prevalence of male sex, and higher body mass index were noted in the ticagrelor-based DAPT group in the whole cohort and high-bleeding-risk subgroup. After PSM, no difference in baseline characteristics and comorbidities between ticagrelor-based and clopidogrel-based DAPT groups in the whole cohort and high-bleeding-risk subgroup was noted. The Kaplan-Meier curves of recurrent ACS and major bleeding were significantly lower in the ticagrelor-based DAPT group than in the clopidogrel-based DAPT group, and that of cardiovascular (CV) and all-cause mortality showed no significant differences. After PSM, in the high-bleeding-risk subgroup, the Kaplan-Meier curve of recurrent ACS was significantly lower in the ticagrelor-based DAPT group than in the clopidogrel-based DAPT group, and that of major bleeding, CV, and all-cause mortality showed no significant differences.

CONCLUSION

In this large cohort study, patients receiving ticagrelor-based DAPT were at lower risk of recurrent ACS compared to those receiving clopidogrel-based DAPT, especially in the patients with myocardial infarction. Ticagrelor-based DAPT did not result in a higher risk of major bleeding in the whole ACS population and high-bleeding-risk subgroup. The rate of CV and all-cause mortality were similar between both the groups.

Biomarker-Based Prediction of Recurrent Ischemic Events in Patients With Acute Coronary Syndromes

BACKGROUND

In patients with acute coronary syndrome (ACS), there is residual and variable risk of recurrent ischemic events.

OBJECTIVES

This study aimed to develop biomarker-based prediction models for 1-year risk of cardiovascular (CV) death and myocardial infarction (MI) in patients with ACS undergoing percutaneous coronary intervention.

METHODS

We included 10,713 patients from the PLATO (A Comparison of Ticagrelor [AZD6140] and Clopidogrel in Patients With Acute Coronary Syndrome) trial in the development cohort and externally validated in 3,508 patients from the TRACER (Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome) trial. Variables contributing to risk of CV death/MI were assessed using Cox regression models, and a score was derived using subsets of variables approximating the full model.

RESULTS

There were 632 and 190 episodes of CV death/MI in the development and validation cohorts. The most important predictors of CV death/MI were the biomarkers, growth differentiation factor 15, and N-terminal pro-B-type natriuretic peptide, which had greater prognostic value than all candidate variables. The final model included 8 items: age (A), biomarkers (B) (growth differentiation factor 15 and N-terminal pro-B-type natriuretic peptide), and clinical variables (C) (extent of coronary artery disease, previous vascular disease, Killip class, ACS type, P2Y₁₂ inhibitor). The model, named ABC-ACS ischemia, was well calibrated and showed good discriminatory ability for 1-year risk of CV death/MI with C-indices of 0.71 and 0.72 in the development and validation cohorts, respectively. For CV death, the score performed better, with C-indices of 0.80 and 0.84 in the development and validation cohorts, respectively.

CONCLUSIONS

An 8-item score for the prediction of CV death/MI was developed and validated for patients with ACS undergoing percutaneous coronary intervention. The ABC-ACS ischemia score showed good calibration and discrimination and might be useful for risk prediction and decision support in patients with ACS. (A Comparison of Ticagrelor [AZD6140] and Clopidogrel in Patients With Acute Coronary Syndrome [PLATO]; NCT00391872; Trial to Assess the Effects of Vorapaxar [SCH 530348; MK-5348] in Preventing Heart Attack and Stroke in Participants With Acute Coronary Syndrome [TRACER]; NCT00527943).

Recent Advances in Stent Technology: Do They Reduce Cardiovascular Events?

PURPOSE OF REVIEW

Drug-eluting stents are used in nearly all cases of percutaneous coronary revascularization and have been shown to be superior to balloon angioplasty or bare metal stents. The designs of these stents are continually evolving to maximize efficacy and safety.

RECENT FINDINGS

This review outlines the important components of a drug-eluting stent and highlights the changes in stent design that have led to the optimization of clinical outcomes. Most stents used in contemporary times are thin strut, durable polymer drug-eluting stents (DES) that elute either everolimus or zotarolimus. Newer DES designs incorporating bioresorbable polymers or ultrathin struts have shown encouraging safety and efficacy profiles. DES are essential for the management of patients with obstructive coronary artery disease and are used in most coronary interventions. Changes in stent designs over the past 30 years reflect the ongoing need to address the limitations of earlier stents aimed to improve patient outcomes.

Abbreviated versus Standard Duration of DAPT after PCI: A Systematic Review and Network Meta-analysis

BACKGROUND

Dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) with drug-eluting stent (DES) is typically continued for 6-12 months depending on clinical presentation. Recent studies have evaluated the safety of shorter durations of DAPT across stable and unstable coronary syndrome but are limited by smaller patient pools and varying indications.

METHODS

The present study performed a systematic review and network meta-analysis comparing abbreviated (1-3 months) with standard (6-12 months) duration of DAPT. Both conventional and frequentist network meta-analyses with a random-effects model were conducted.

RESULTS

Seventeen randomized controlled trials, nine of which included 1-3 months of DAPT, were selected. The risks of any bleeding (RR 0.68, 95% CI 0.54-0.85), major bleeding (RR 0.66, 95% CI 0.50-0.86), and net adverse clinical events (NACE) (RR 0.87, 95% CI 0.76-0.99) were lower with abbreviated (1-3 months) than standard-term (6-12 months) DAPT. No significant differences in the risk of myocardial infarction (RR 1.02, 95% CI 0.87-1.18), definite or probable stent thrombosis (RR 1.11, 95% CI 0.83-1.50), and major adverse cardiac events (MACE) (RR 0.96, 95% CI 0.86-1.06) were observed. Network meta-analysis demonstrated lower risk of any bleeding, major bleeding, and NACE with shorter durations of DAPT compared with 12 months. Risks of definite or probable stent thrombosis, myocardial infarction, and MACE were not significantly different.

CONCLUSION

The results support the growing body of evidence that abbreviated duration (1-3 months) of DAPT may be considered to reduce the risk of bleeding without any differences in myocardial infarction, stent thrombosis, or MACE.

A Rare Case of Coronary Stent Thrombosis in the Modern Era

In patients with acute coronary syndrome or obstructive coronary artery disease, stents, especially drug-eluting stents (DESs), are used for percutaneous coronary interventions (PCI). DES prevents abrupt closure of the stented artery. Stent thrombosis is an uncommon but serious complication of PCI, especially with the recent advancement of stent technology. We present a case of a 75-year-old male who initially suffered a non-ST segment elevation myocardial infarction (NSTEMI) treated appropriately with PCI and subsequently developed stent thrombosis after 10 days of initial stent placement. He then underwent emergent repeat PCI with successful replacement of stents overlapping previous stents. The patient did well following the procedure. His clopidogrel was changed to a more potent antiplatelet ticagrelor. He remained stable throughout the hospital stay and was discharged home without any further complications following the next 90 days.

Safety and efficacy of immediate heparin reversal with protamine after complex percutaneous coronary intervention

Background

Compared to simple percutaneous coronary intervention (PCI), complex PCI is associated with higher bleeding and thrombotic risk. No previous study has evaluated the use of protamine after PCI with contemporary technologies. This study aimed to evaluate the safety and efficacy of manual compression with and without protamine after transfemoral complex PCI.

Methods

We retrospectively analyzed 160 patients (protamine group, n = 92; non-protamine group, n = 68) who underwent complex PCI via the femoral artery. The primary outcome was a composite of in-hospital death, myocardial infarction, stent thrombosis, stroke/systemic embolism, bleeding requiring blood transfusion, and vascular access complications.

Results

The primary outcome was significantly lower in the protamine group than in the non-protamine group (4.3% vs. 17.6%; p = 0.006). This was driven mainly by the lower incidences of hematoma in the protamine group (3.3% vs. 13.2%, p = 0.020). Furthermore, the protamine group had a significantly shorter hospital stay than the non-protamine group (4.8 ± 3.7 days vs. 8.4 ± 8.3 days, p = 0.001). While > 90% of the patients had acute coronary syndrome, there were no incidences of myocardial infarction or stent thrombosis in either group.

Conclusions

Among patients who underwent complex PCI via transfemoral access, immediate protamine administration was associated with a significantly lower rate of vascular access complications, especially hematoma, and shorter hospital stay than no protamine administration.

Current Perspectives on Antithrombotic Therapy for the Treatment of Acute Coronary Syndrome

Acute coronary syndrome (ACS) is one of the leading causes of death worldwide. Percutaneous coronary intervention (PCI) is the treatment of choice for ACS as this procedure reduces the morbidity and mortality rates of patients in clinical trials and daily practice. However, patients with a history of prior ACS who undergo PCI are still at high risk for recurrent major adverse cardiac events (MACE). Because the antithrombotic drugs reduce the rate of MACE and minimize stent-related complications such as target vessel failure or stent thrombosis, the utilization of these agents is the cornerstone treatment for secondary prevention of ACS patients after PCI. Unfortunately, using the antithrombotic agents may be associated with bleeding complications, including major or fatal bleeding. Therefore, premature discontinuation of antithrombotic regimens regarding the hemorrhagic events is sometimes inevitable and possibly leads to fatal complications such as stent thrombosis. To minimize the bleeding issues, shorten antithrombotic regimens have been proposed, which theoretically offers improved safety. Nevertheless, inappropriate withdrawal of antithrombotic drugs may increase the rate of ischemic events. On the other hand, an unnecessary prolonged antithrombotic regimen may cause avoidable bleeding. Balancing the risk of bleeding against the benefits of using antithrombotic drugs is therefore challenging especially for the patients who contain both bleeding and ischemic risks such as ACS patients who are concomitant using the anticoagulants. Currently, the treatment paradigms are shifting from the “one size fits all approach” toward the “tailored approach”. This means that the antithrombotic regimens can be adjustable individually. As a result, various clinical risk scoring systems have been established to help physicians with their decision-making. However, besides the development of these dedicated scoring tools, clinical judgment for balancing the safety versus the efficacy before deciding on the antithrombotic plan is still imperative.

Antiplatelet agents for chronic kidney disease

BACKGROUND

Antiplatelet agents are widely used to prevent cardiovascular events. The risks and benefits of antiplatelet agents may be different in people with chronic kidney disease (CKD) for whom occlusive atherosclerotic events are less prevalent, and bleeding hazards might be increased. This is an update of a review first published in 2013.

OBJECTIVES

To evaluate the benefits and harms of antiplatelet agents in people with any form of CKD, including those with CKD not receiving renal replacement therapy, patients receiving any form of dialysis, and kidney transplant recipients.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 13 July 2021 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We selected randomised controlled trials of any antiplatelet agents versus placebo or no treatment, or direct head-to-head antiplatelet agent studies in people with CKD. Studies were included if they enrolled participants with CKD, or included people in broader at-risk populations in which data for subgroups with CKD could be disaggregated.

DATA COLLECTION AND ANALYSIS

Four authors independently extracted data from primary study reports and any available supplementary information for study population, interventions, outcomes, and risks of bias. Risk ratios (RR) and 95% confidence intervals (CI) were calculated from numbers of events and numbers of participants at risk which were extracted from each included study. The reported RRs were extracted where crude event rates were not provided. Data were pooled using the random-effects model. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We included 113 studies, enrolling 51,959 participants; 90 studies (40,597 CKD participants) compared an antiplatelet agent with placebo or no treatment, and 29 studies (11,805 CKD participants) directly compared one antiplatelet agent with another. Fifty-six new studies were added to this 2021 update. Seven studies originally excluded from the 2013 review were included, although they had a follow-up lower than two months. Random sequence generation and allocation concealment were at low risk of bias in 16 and 22 studies, respectively. Sixty-four studies reported low-risk methods for blinding of participants and investigators; outcome assessment was blinded in 41 studies. Forty-one studies were at low risk of attrition bias, 50 studies were at low risk of selective reporting bias, and 57 studies were at low risk of other potential sources of bias. Compared to placebo or no treatment, antiplatelet agents probably reduces myocardial infarction (18 studies, 15,289 participants: RR 0.88, 95% CI 0.79 to 0.99, I² = 0%; moderate certainty). Antiplatelet agents has uncertain effects on fatal or nonfatal stroke (12 studies, 10.382 participants: RR 1.01, 95% CI 0.64 to 1.59, I² = 37%; very low certainty) and may have little or no effect on death from any cause (35 studies, 18,241 participants: RR 0.94, 95 % CI 0.84 to 1.06, I² = 14%; low certainty). Antiplatelet therapy probably increases major bleeding in people with CKD and those treated with haemodialysis (HD) (29 studies, 16,194 participants: RR 1.35, 95% CI 1.10 to 1.65, I² = 12%; moderate certainty). In addition, antiplatelet therapy may increase minor bleeding in people with CKD and those treated with HD (21 studies, 13,218 participants: RR 1.55, 95% CI 1.27 to 1.90, I² = 58%; low certainty). Antiplatelet treatment may reduce early dialysis vascular access thrombosis (8 studies, 1525 participants) RR 0.52, 95% CI 0.38 to 0.70; low certainty). Antiplatelet agents may reduce doubling of serum creatinine in CKD (3 studies, 217 participants: RR 0.39, 95% CI 0.17 to 0.86, I² = 8%; low certainty). The treatment effects of antiplatelet agents on stroke, cardiovascular death, kidney failure, kidney transplant graft loss, transplant rejection, creatinine clearance, proteinuria, dialysis access failure, loss of primary unassisted patency, failure to attain suitability for dialysis, need of intervention and cardiovascular hospitalisation were uncertain. Limited data were available for direct head-to-head comparisons of antiplatelet drugs, including prasugrel, ticagrelor, different doses of clopidogrel, abciximab, defibrotide, sarpogrelate and beraprost.

AUTHORS' CONCLUSIONS

Antiplatelet agents probably reduced myocardial infarction and increased major bleeding, but do not appear to reduce all-cause and cardiovascular death among people with CKD and those treated with dialysis. The treatment effects of antiplatelet agents compared with each other are uncertain.

Double Whammy: Subacute Stent Thrombosis While Being Adherent to Dual Antiplatelet Therapy Including Ticagrelor, Followed by Multiple Coronary Artery Aneurysms in a COVID-19 Patient

Coronavirus disease 2019 (COVID-19), although predominantly a respiratory illness, can have important cardiovascular implications, which include the development of myocardial injury/myocarditis, acute coronary syndromes, arrhythmias, pericarditis, and the occurrence of arterial and venous thrombosis. We describe a rare case of a middle-aged COVID-19 patient who developed sub-acute stent thrombosis after implantation of second-generation drug-eluting stents (DES) despite being adherent to dual antiplatelet therapy including ticagrelor and who subsequently developed multiple coronary artery aneurysms within a few weeks of the DES implantation.

Clopidogrel Versus Ticagrelor for Antiplatelet Therapy in Transcarotid Artery Revascularization (TCAR) in the Society for Vascular Surgery Vascular Quality Initiative

OBJECTIVE

Transcarotid artery revascularization (TCAR) with dynamic flow reversal is a hybrid technique for operative management of carotid artery stenosis. Dual antiplatelet therapy is recommended for patients undergoing TCAR; however, nonresponders to these medications may be predisposed to perioperative thromboembolic complications. Prevalent in up to 44-66% of patients taking clopidogrel, high on-treatment platelet reactivity (HTPR) may thus be responsible for a portion of adverse cerebrovascular events in TCAR. A previous single-institution study has demonstrated the use of ticagrelor as a viable alternative to clopidogrel for antiplatelet therapy in patients undergoing TCAR; however, large-scale comparisons between clopidogrel and ticagrelor are needed to confirm the safety of ticagrelor outside of highly selected patients and providers.

METHODS

Data from patients enrolled in the Society for Vascular Surgery Vascular Quality Initiative undergoing TCAR with a perioperative antiplatelet therapy regimen including either clopidogrel or ticagrelor from January 2015 to March 2021 were analyzed and compared. Multivariable logistic regression and propensity score matching were used to evaluate the primary 30-day outcomes of stroke, major bleeding event, and combined stroke/myocardial infarction (MI)/death rate while adjusting for baseline characteristics of the patients.

RESULTS

A total of 11973 patients underwent TCAR with a dual antiplatelet therapy regimen that included clopidogrel versus 426 patients with ticagrelor. Compared to clopidogrel, patients on ticagrelor were significantly more likely to have coronary artery disease (51% vs 66% [P = <.001]), particularly unstable angina or MI within 6 months (3% vs 9% [P = <.001]), and more likely to have insulin-dependent diabetes mellitus (14% vs 19% [P = <.001]). The unadjusted 30-day rates of stroke, major bleeding, and combined stroke/MI/death were not statistically significant among both groups (1.3% vs 0.5% [P = .14], 2.4% vs 1.4% [P = .18], and 1.9% vs 1.6% [P = .71], respectively). After multivariable adjustment and propensity matching, these remained statistically insignificant.

CONCLUSIONS

Despite a substantially higher medical risk in patients undergoing TCAR with ticagrelor, 30-day rates of stroke, major bleeding events, and combined stroke/MI/death were similar between patients on ticagrelor and clopidogrel as part of adjunctive antiplatelet therapy. Randomized prospective trials, and studies with larger sample sizes and longer follow-up will be needed to better examine the outcome differences in TCAR between these two medications.

Effects of clopidogrel, prasugrel and ticagrelor on prevention of stent thrombosis in patients underwent percutaneous coronary intervention: A network meta-analysis

Background

Clopidogrel, prasugrel and ticagrelor, acting on platelet P2Y12 receptor, are commonly used for prevention of stent thrombosis (ST) among patients who underwent percutaneous coronary intervention (PCI). This study aimed to compare the effects of these drugs by a systematic review and network meta‐analysis.

Hypothesis

Efficacies of clopidogrel, prasugrel and ticagrelor on preventing ST are not the same.

Methods

PubMed, Embase and Cochrane Library were searched for randomized controlled trials (RCTs) that investigated the effect of clopidogrel, prasugrel, or ticagrelor on prevention of ST in patients who underwent PCI. The efficacies between groups were compared by a Bayesian network meta‐analysis, by which the pooled odds ratios (ORs) and 95% confidence intervals (CIs) was calculated.

Results

Fourteen studies and 46 983 participants were included in this study. The pooled results illustrated that clopidogrel, prasugrel and ticagrelor were effective on prevention of ST. Patients treated with prasugrel (OR = 0.30, 95% CI = 0.052 ~ 0.73, P < 0.05) and ticagrelor (OR = 0.25, 95% CI = 0.035 ~ 0.65, P < 0.05) had lower incidence of ST compared to those treated with clopidogrel. Patients treated with ticagrelor showed similar frequency with those in prasugrel group (OR = 0.86, 95% CI = 0.22 ~ 2.3, P > 0.05). No significant heterogeneity was observed across included studies.

Conclusions

Our findings suggest that prasugrel and ticagrelor are more effective than clopidogrel on prevention of ST among patients underwent PCI. Simultaneously, there is no significant difference in the prevention of ST between prasugrel and ticagrelor.

Early stent thrombosis confirmed in a cancer patient receiving regorafenib, despite triple antithrombotic therapy: a case report

Background

While developments in oncology have lengthened survival in patients with cancer, such patients often develop cardiovascular diseases. Thus, percutaneous coronary intervention (PCI) is frequently undertaken in them. Although stent thrombosis remains a fatal complication in stent-based PCI, worldwide consensus panels tend to recommend shorter duration of dual-antiplatelet therapy. This is based on its clinical efficacy that has resulted from technological innovation. However, there is insufficient discussion on the risk of stent thrombosis in cancer patients with coronary artery disease, especially in those undergoing chemotherapeutic regimens that have a risk for thrombosis, such as regimens with the anti-vascular endothelial growth factor. Presented here is a case of early stent thrombosis that occurred in a cancer patient on regorafenib, despite the administration of triple antithrombotic therapy.

Case presentation

A 66-year-old Japanese male patient received regorafenib for metastatic colorectal carcinoma and apixaban for deep vein thrombosis. Coronary angiography revealed severe stenosis in the proximal left anterior descending artery. A sirolimus-eluting stent was implanted, without malapposition and under-expansion, under intravascular ultrasound guidance while administering a triple antithrombotic therapy (aspirin: 100 mg/day, prasugrel: 3.75 mg/day, and apixaban: 5 mg/day). However, he was admitted to the hospital for exacerbation of heart failure 1 month after PCI. Coronary angiography revealed contrastive defects in the previous stent. Optical frequency domain imaging confirmed stent thrombosis. PCI was successfully performed with perfusion balloon long-inflation. Antithrombotic therapy was enhanced (aspirin: 100 mg/day, ticagrelor: 120 mg/day, and apixaban: 10 mg/day) and regorafenib was discontinued permanently. While ischemic events did not occur thereafter, the patient died due to metastatic carcinoma progression.

Conclusions

This case suggests that anti-vascular endothelial growth factor might contribute to early stent thrombosis, despite triple antithrombotic therapy. Further discussion is needed on the surveillance and management of cancer patients with coronary artery disease receiving chemotherapy, which carries a risk of thrombosis.

On-Ticagrelor Platelet Reactivity and Clinical Outcome in Patients Undergoing Percutaneous Coronary Intervention for Acute Coronary Syndrome

BACKGROUND

 A strong association between on-thienopyridine platelet reactivity (PR) and the risk of both thrombotic and bleeding events in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI) has been demonstrated. However, no study has analyzed the relationship between on-ticagrelor PR and clinical outcome in this clinical setting.

OBJECTIVES

 We aimed to investigate the relationship between on-ticagrelor PR, assessed by the vasodilator-stimulated phosphoprotein (VASP) index, and clinical outcome in patients with ACS undergoing PCI.

METHODS

 We performed a prospective, multicenter, observational study of patients undergoing PCI for ACS. PR was measured using the VASP index following ticagrelor loading dose. The primary study endpoint was the rate of Bleeding Academic Research Consortium (BARC) type ≥2 at 1 year. The key secondary endpoint was the rate of major adverse cardiovascular events (MACE) defined as the composite of cardiovascular death, myocardial infarction, stroke, and urgent revascularization.

RESULTS

 We included 570 ACS patients, among whom 33.9% had ST-elevation myocardial infarction. BARC type ≥2 bleeding occurred in 10.9% and MACE in 13.8%. PR was not associated with BARC ≥2 or with MACE (p = 0.12 and p = 0.56, respectively). No relationship between PR and outcomes was observed, neither when PR was analyzed quantitatively nor when it was analyzed qualitatively (low on-treatment PR [LTPR] vs. no LTPR).

CONCLUSION

 On-ticagrelor PR measured by the VASP was not associated with bleeding or thrombotic events in ACS patients undergoing PCI. PR measured by the VASP should not be used as a surrogate endpoint in studies on ticagrelor.

Efficacy and safety of low dose ticagrelor in patients with acute coronary syndrome: a systematic review and meta-analysis

Our aim was to examine clinical trials, provide guidance to practitioners and estimate the efficacy and safety of two agents by comparing low dose ticagrelor with standard dose clopidogrel in patients with acute coronary syndrome. We systematically looked through Pubmed, Embase, the Cochrane Library, Wanfang data and CNKI for trials comparing low dose ticagrelor with standard dose clopidogrel for the treatment of patients with ACS since the database was created. The primary endpoint for efficacy was the rate of major adverse cardiac events (MACEs). The primary endpoint for safety was the rate of major bleeding events. We also evaluated platelet function between low dose ticagrelor and standard dose clopidogrel in ACS patients. From 6744 articles, 16 studies including 1629 patients met the inclusion criteria. In contrast with standard dose clopidogrel, low dose ticagrelor significantly reduced MACEs (OR 0.39, 95% CI 0.26, 0.58) and the difference was statistically significant (p<0.01). No difference was noted for major bleeding events (OR 1.16, 95% CI 0.43, 3.08) between the two agents (p=0.77). In addition, low dose ticagrelor showed lower platelet aggregation rate than clopidogrel (standardised mean difference (SMD) -0.68, 95% CI -0.83 to 0.53) (p<0.01). Platelet reaction units for low dose ticagrelor were much lower than those for standard dose clopidogrel (SMD -2.46, 95% CI -2.85 to -2.07) (p<0.01). In comparison with standard dose clopidogrel, low dose ticagrelor significantly lowered the incidence of MACEs, improved left ventricular ejection fraction, decreased left ventricular end diastolic dimension and did not expand the risk of major bleeding events or minor or minimal bleeding events in ACS patients with a considerable safety and efficacy profile. In addition, low dose ticagrelor was associated with dramatically lower platelet aggregation compared with standard dose clopidogrel.

Outcomes and strategy of tailored antiplatelet therapy with ticagrelor in patients undergoing transcarotid artery revascularization

OBJECTIVE

Antiplatelet drug resistance is associated with periprocedural ischemic complications in patients undergoing intravascular stent implantation. Nonresponders are subject to increased risk of stent thrombosis and in-stent stenosis, and high on-treatment platelet reactivity (HTPR) is present in up to 44% of patients taking clopidogrel, a widely used component of dual antiplatelet therapy (DAPT). Evidence points to ticagrelor as a viable alternative to overcome HTPR on clopidogrel. Studies have shown fewer thromboembolic events with ticagrelor therapy; however, results on bleeding risk are mixed, and its safety and efficacy in hybrid operative techniques have yet to be established. Transcarotid artery revascularization (TCAR) is a hybrid procedure to treat severe carotid stenosis. The objective of this study was to establish the safety and efficacy of ticagrelor as part of DAPT in patients undergoing TCAR and to develop a protocol to ensure adequate antithrombotic protection throughout the operative course.

METHODS

Data were collected retrospectively for patients undergoing TCAR on DAPT of aspirin and ticagrelor for symptomatic (≥50%) or asymptomatic (≥80%) carotid stenosis. Preoperative platelet reactivity was determined using Thromboelastography with Platelet Mapping (Haemonetics Corporation, Braintree, Mass), with adequate platelet reactivity defined as maximal amplitude produced by adenosine diphosphate <50 mm. The primary safety end point was 30-day major bleeding event rate. Primary efficacy end points were 30-day incidence of ipsilateral cerebrovascular ischemic event (stroke or transient ischemic attack), myocardial infarction, and death. Secondary end points were postoperative length of hospital stay, procedure time, and clamp/flow reversal time.

RESULTS

Sixty-seven TCAR procedures with patients receiving periprocedural DAPT of ticagrelor and aspirin were performed during the study period. Patients had an average age of 79 years, and 28 (42%) were symptomatic. The mean procedure time was 45.8 ± 9.2 minutes, with a mean clamp/flow reversal time of 4.8 ± 1.5 minutes, and mean postoperative length of hospital stay of 3.1 ± 2.2 days for inpatients and 1.3 ± 0.8 days for outpatients. Technical success was achieved in all cases, with no 30-day major bleeding events and no occurrence of ipsilateral cerebrovascular ischemic event, myocardial infarction, or death.

CONCLUSIONS

Initial experience with ticagrelor as part of DAPT in patients undergoing TCAR demonstrated its safety and efficacy in both symptomatic and asymptomatic disease. No bleeding events or thromboembolic complications occurred. Furthermore, a protocol to administer ticagrelor to assay for HTPR on ticagrelor and consequent medication and patient management is proposed. Ticagrelor may represent a safe and effective alternative to overcome clopidogrel nonresponsiveness in DAPT regimens for TCAR.

Ticagrelor versus clopidogrel in patients undergoing implantation of paclitaxel-eluting stent in the femoropopliteal district: A randomized pilot study using frequency-domain optical coherence tomography

OBJECTIVES

Aim of this study was to evaluate different response in platelet reactivity and vessel healing using high-resolution frequency-domain optical coherence tomography (FD-OCT) in patients with femoropopliteal artery disease treated with ZILVER PTX drug eluting stents (DES), and randomly assigned to clopidogrel or ticagrelor for 12 months.

BACKGROUND

The optimal antithrombotic regimen for long-term management of patients with peripheral artery disease (PAD) after revascularization is poorly defined and often extrapolated from trials performed on patients undergoing percutaneous coronary intervention.

METHODS

In this single center randomized trial 40 patients with femoropopliteal artery disease treated with ZILVER PTX DES stents, were randomized to Ticagrelor (T) + Aspirin for 3 months, subsequently continuing Ticagrelor alone for another 9 months or Clopidogrel (C) + Aspirin for 3 months, subsequently continuing Clopidogrel alone for 9 months. Platelet reactivity via the P2Y12 pathway was evaluated at baseline and at 3 months follow-up, angiographic and FD-OCT follow-up along the entire stented segment was performed at 12 months.

RESULTS

No significant difference between T and C group was found concerning net percentage volume obstruction (29.7% ± 17.6% vs. 31.2% ± 10.7%; p = 0.78). FD-OCT at 12 months showed a high percentage of uncovered stent struts in both groups: 24.2% ± 32.8% in the T group vs 15.3% ± 15.8% in the C group (p = 0.4). Mean values of platelet reactivity units (PRU) at 3 month follow-up were 81 ± 72 in the T group and 200 ± 61 in the C group (p < 0.001).

CONCLUSIONS

Significantly higher platelet reactivity remains in patients treated with clopidogrel as compared to ticagrelor 3 months after PTA and stent implantation. Ticagrelor does not reduce neointimal proliferation in patients treated with DES in the femoropopliteal district as compared with clopidogrel. A large amount of uncovered stent struts at 12-month follow-up was found in these patients regardless of the antiplatelet treatment assumed.

Prescription Patterns of Clopidogrel, Prasugrel, and Ticagrelor After Percutaneous Coronary Intervention With Stent Implantation (from the NCDR PINNACLE Registry)

The use of prasugrel and ticagrelor as part of dual antiplatelet therapy is increasing in patients after percutaneous coronary intervention (PCI). Accordingly, we aimed to evaluate their prescription patterns in the National Cardiovascular Data Registry (NCDR) Practice Innovation and Clinical Excellence (PINNACLE) registry. We analyzed patients enrolled in NCDR PINNACLE registry from January 2013 to March 2015 who underwent PCI with drug-eluting stent and were prescribed dual antiplatelet therapy. All patients received aspirin. The primary study outcome was a 3-level variable denoting the second antiplatelet agent prescribed: (1) clopidogrel, (2) prasugrel, or (3) ticagrelor. Baseline characteristics were compared among the 3 groups. Odds ratios and 95% credible intervals were calculated from a nested hierarchical Bayesian logistic regression models to identify independent predictors of prescription of antiplatelet medications, incorporating practice and provider as random effects. Our study cohort consisted of 26,710 patients during our study period January 2013 to March 2015. Seventy nine percent of patients were prescribed clopidogrel, 12% prasugrel, and 11% ticagrelor. Patients aged ≥75 years, women, history of tobacco use, Peripheral Arterial Disease (PAD), hypertension, diabetes, previous vascular complication, heart failure, and stroke/transient ischemic attack were more likely to be on clopidogrel than prasugrel or ticagrelor. The relative percentages of ticagrelor and prasugrel were higher in patients with history of myocardial infarction, compared with those without myocardial infarction. In summary, our study highlights the prescription patterns associated with prescription of antiplatelet agents after PCI. We found that both ticagrelor and prasugrel were mostly prescribed per the current practice guidelines, thus reflecting appropriate guideline adherence by practices in NCDR PINNACLE registry.

Platelet reactivity inhibition following ticagrelor loading dose in patients undergoing percutaneous coronary intervention for acute coronary syndrome

BACKGROUND

Ticagrelor induces more potent platelet reactivity (PR) inhibition with reduced interindividual variability compared to clopidogrel. Although on-clopidogrel PR was shown to correlate with ischemia and bleeding events, no study has investigated the relationship between on-ticagrelor PR and outcome.

OBJECTIVES

We aimed to evaluate the relationship between on-ticagrelor PR, assessed by the vasodilator-stimulated phosphoprotein index (VASP), and thrombotic and bleeding events in patients with acute coronary syndrome (ACS) treated by percutaneous coronary intervention (PCI).

METHODS

We performed a prospective, multicenter observational study on patients treated with PCI for ACS. The VASP index was used to assess PR after ticagrelor loading dose (LD). The primary endpoint was the link between major adverse cardiovascular events (MACE) and PR.

RESULTS

Among the 530 patients with ACS included, 183 (34.5%) were admitted for ST elevation myocardial infarction. We observed high potency and limited interindividual variability after the ticagrelor LD (VASP 19.1% ± 16.6%). At 1 month, 21 (3.8%) MACE and 29 (5.5%) bleedings ≥ 2 according to the Bleedings Academic Research Consortium (BARC) scale were recorded. Neither MACE nor bleeding was associated with PR (P = .34 and P = .78, respectively). However, there was a strong association between PR and the occurrence of definite acute stent thrombosis (P = .03). Platelet reactivity was the only factor associated with acute definite stent thrombosis.

CONCLUSION

In patients receiving a ticagrelor LD while undergoing PCI for ACS, PR using the VASP did not predict MACE or bleeding, but it was significantly associated with the occurrence of definite acute stent thrombosis.

Differential Effects of Ticagrelor With or Without Aspirin on Platelet Reactivity and Coagulation Activation: A Randomized Trial in Healthy Volunteers

Dual antiplatelet therapy (DAPT) is standard in acute coronary heart disease but confers a bleeding risk. To compare the effects of ticagrelor‐monotherapy with ticagrelor‐based DAPT on hemostatic system activation, we conducted a randomized controlled trial in 44 volunteers using a loading‐dose regimen and measured platelet‐aggregometry triggered by adenosine diphosphate (multiple electrode aggregometry (MEA)‐ADP) and arachidonic acid (MEA‐AA), the vasodilator‐stimulated phosphoprotein (VASP), prothrombin fragment 1.2 (f1.2), and d‐Dimer. Ticagrelor‐based DAPT and ticagrelor‐monotherapy significantly decreased MEA‐ADP (Δmean: −51.4 (−56.9; −45.8) and −46.2 (−51.7; −40.7)) and VASP (Δmean: −70.3 (−76.2; −64.4) and −69.6 (−75.5; −63.7)) at 2 hours and over 24 hours. MEA‐AA was reduced significantly by both treatments (Δmean: −72.9 (−80.6; −65.3) and −25.7 (−33.3; −18.0)) at 2 hours, and stronger by ticagrelor‐based DAPT over 24 hours. Both treatments decreased f1.2 (geometric mean ratio (GMR): 0.92 (0.84; 1.01) and 0.88 (0.80; 0.96)) and d‐Dimer (GMR: 0.89 (0.86; 0.92) and 0.91 (0.88; 0.94)) at 2 hours and d‐Dimer over 24 hours. Ticagrelor‐monotherapy and ticagrelor‐based DAPT comparably affect hemostatic system activation.

Rationale, design and baseline characteristics of the effect of ticagrelor on health outcomes in diabetes mellitus patients Intervention study

In the setting of prior myocardial infarction, the oral antiplatelet ticagrelor added to aspirin reduced the risk of recurrent ischemic events, especially, in those with diabetes mellitus. Patients with stable coronary disease and diabetes are also at elevated risk and might benefit from dual antiplatelet therapy. The Effect of Ticagrelor on Health Outcomes in diabEtes Mellitus patients Intervention Study (THEMIS, NCT01991795) is a Phase 3b randomized, double‐blinded, placebo‐controlled trial of ticagrelor vs placebo, on top of low dose aspirin. Patients ≥50 years with type 2 diabetes receiving anti‐diabetic medications for at least 6 months with stable coronary artery disease as determined by a history of previous percutaneous coronary intervention, bypass grafting, or angiographic stenosis of ≥50% of at least one coronary artery were enrolled. Patients with known prior myocardial infarction (MI) or stroke were excluded. The primary efficacy endpoint is a composite of cardiovascular death, myocardial infarction, or stroke. The primary safety endpoint is Thrombolysis in Myocardial Infarction major bleeding. A total of 19 220 patients worldwide have been randomized and at least 1385 adjudicated primary efficacy endpoint events are expected to be available for analysis, with an expected average follow‐up of 40 months (maximum 58 months). Most of the exposure is on a 60 mg twice daily dose, as the dose was lowered from 90 mg twice daily partway into the study. The results may revise the boundaries of efficacy for dual antiplatelet therapy and whether it has a role outside acute coronary syndromes, prior myocardial infarction, or percutaneous coronary intervention.

The effect of ticagrelor based dual antiplatelet therapy on development of late left ventricular thrombus after acute anterior ST elevation myocardial infarction

AIM

The aim of this study is to investigate the impact of ticagrelor as compared to clopidogrel based dual antiplatelet therapy (DAPT) during post-discharge management on the incidence of left ventricular (LV) thrombus in patients with first acute anterior ST elevation myocardial infarction (STEMI).

METHOD

641 patients who met the inclusion criteria were divided into two groups based on the receipt of either ticagrelor or clopidogrel based DAPT.

RESULT

Left ventricular thrombus was detected in 73 (11.4%) patients at the first month echocardiographic examination. Ticagrelor based DAPT was associated with significantly less incidence of LV thrombus when compared to clopidogrel [20 (7.4%) vs 53 (14.0%) OR: 0.50 (0.29-0.86)]. Penalized maximum likelihood estimation (PMLE) logistic regression analyses were performed to fourteen candidate variables for identifying the independent predictors of LV thrombus, ticagrelor (compared with clopidogrel) [OR: 0.53 (0.28-0.96), p = 0.039], body mass index (BMI) [OR: 0.58 (0.44-0.77), p < 0.001], KILLIP class (I vs II-IV) [OR: 0.35 (0.14-0.83), p = 0.017], age [OR: 1.22 (1.08-1.40), p < 0.001], poor postprocedural myocardial blush grade (MBG) [OR: 3.35 (1.32-8.15), p = 0.012] and LVEF predischarge [OR: 0.79 (0.72-0.86), p < 0.001] were found to be associated with LV thrombus.

CONCLUSION

Our study demonstrated that the incidence of LV trombus was significantly lower with ticagrelor than clopidogrel-based DAPT during postdischarge treatment for anterior STEMI patients.

Oral Antiplatelet Therapy for Secondary Prevention of Acute Coronary Syndrome

Patients surviving an acute coronary syndrome (ACS) remain at increased risk of ischemic events long term. This paper reviews current evidence and guidelines for oral antiplatelet therapy for secondary prevention following ACS, with respect to decreased risk of ischemic events versus bleeding risk according to individual patient characteristics and risk factors. Specifically, data are reviewed from clinical studies of clopidogrel, prasugrel, ticagrelor and vorapaxar, as well as the results of systematic reviews and meta-analyses looking at the benefits and risks of oral antiplatelet therapy, and the relative merits of shorter versus longer duration of dual antiplatelet therapy, in different patient groups.

Characteristics and outcomes of patients requiring bailout use of glycoprotein IIb/IIIa inhibitors for thrombotic complications of percutaneous coronary intervention: An analysis from the CHAMPION PHOENIX trial

AIMS

To describe the characteristics and outcomes of patients receiving bailout glycoprotein IIb/IIIa inhibitors (GPI) for thrombotic complications of percutaneous coronary intervention (PCI) in a large, contemporary trial.

METHODS AND RESULTS

In the CHAMPION PHOENIX trial, the use of GPI was restricted to bailout for thrombotic complications. We describe the characteristics and outcomes of patients requiring bailout GPI compared to patients not receiving GPIs, with adjustment through propensity-score. A multivariable model was constructed to identify independent correlates associated with bailout GPI use. A total of 380 out of 10,942 patients received GPI (3.5%); GPI patients were younger, more frequently male, more likely to present with ST segment elevation myocardial infarction and less frequently treated with cangrelor. At 48 h, GPI patients experienced higher rates of the primary composite outcome of death, myocardial infarction, ischemia-driven revascularization, or stent thrombosis (ST) (19.2% vs 4.8%; adjusted OR: 5.65(4.08, 7.82), p < 0.0001) and a higher rate of GUSTO severe or moderate bleeding (2.6% vs 0.4% adjusted OR: 4.90 (1.98, 12.18), p = 0.0006) compared with non GPI patients. Independent correlates of GPI use were STEMI, use of unfractionated heparin, drug-eluting stents and longer procedure duration.

CONCLUSIONS

In a large contemporary trial, patients receiving bailout GPI for thrombotic complications of PCI experienced very high risks of both ischemic and bleeding complications, suggesting that prevention of periprocedural complications rather than bailout GPI may be preferable.

CLINICAL TRIAL REGISTRATION

http://www.clinicaltrials.gov identifier: NCT01156571.

Cardiovascular Pharmacogenomics: Does It Matter If You're Black or White?

Race and ancestry have long been associated with differential risk and outcomes to disease as well as responses to medications. These differences in drug response are multifactorial with some portion associated with genomic variation. The field of pharmacogenomics aims to predict drug response in patients prior to medication administration and to uncover the biological underpinnings of drug response. The field of human genetics has long recognized that genetic variation differs in frequency between ancestral populations, with some single nucleotide polymorphisms found solely in one population. Thus far, most pharmacogenomic studies have focused on individuals of European and East Asian ancestry, resulting in a substantial disparity in the clinical utility of genetic prediction for drug response in US minority populations. In this review, we discuss the genetic factors that underlie variability to drug response and known pharmacogenomic associations and how these differ between populations, with an emphasis on the current knowledge in cardiovascular pharmacogenomics.

Promoting vascular healing using nanofibrous ticagrelor-eluting stents

Objective

The current treatment of atherosclerotic coronary heart disease with limus-eluting stents can lead to incomplete endothelialization and substantial impairment of arterial healing relative to treatment with bare-metal stents. The sustained and local delivery of ticagrelor, a reversibly binding P2Y12 receptor inhibitor, using hybrid biodegradable nanofibers/stents, was developed to reduce neointimal formation and endothelial dysfunction.

Methods

In this investigation, a solution of ticagrelor, poly(D,L)-lactide-co-glycolide, and hexafluoro isopropanol was electrospun to fabricate ticagrelor-eluting nanofibrous drug-eluting stents. The in vitro and in vivo ticagrelor concentrations were measured using a high-performance liquid chromatography assay. The effectiveness of ticagrelor-eluting stents was examined relative to that of sirolimus-eluting stents.

Results

Adequate ticagrelor levels were detected for four weeks in vitro. Less HES5-positive labeling was found near the ticagrelor-eluting stented vessels (0.33±0.12) than close to the sirolimus-eluting stented vessels (0.57±0.15) (p<0.05). Four weeks after deployment, the ticagrelor-eluting stent also exhibited an up-regulated local expression of SOD1 in the stenting area (p<0.001). The ticagrelor-eluting stent substantially preserved endothelial function and re-endothelialization, minimized inflammatory responses, and inhibited neointimal hyperplasia.

Conclusion

Ticagrelor-eluting stents may provide an alternative route for treating patients at a high risk of bleeding to preserve endothelial recovery and to reduce smooth muscle proliferation.

Choosing between ticagrelor and clopidogrel following percutaneous coronary intervention: A systematic review and Meta-Analysis (2007-2017)

BACKGROUND

Limitations have been observed with the use of clopidogrel following percutaneous coronary intervention (PCI) indicating the urgent need of a more potent anti-platelet agent. We aimed to compare the efficacy and safety of ticagrelor versus clopidogrel following PCI.

METHODS

Online databases were searched for relevant studies (published between the years 2007 and 2017) comparing ticagrelor versus clopidogrel following coronary stenting. Primary outcomes assessed efficacy whereas secondary outcomes assessed safety. Odds ratios (OR) with 95% confidence intervals (CIs) based on a random effect model were calculated and the analysis was carried out by the RevMan 5.3 software.

RESULTS

A total number of 25,632 patients with acute coronary syndrome (ACS) [12,992 patients with ST segment elevation myocardial infarction (STEMI) and 14,215 patients with non-ST segment elevation myocardial infarction (NSTEMI)] were included in this analysis, of whom 23,714 patients were revascularized by PCI. Results of this analysis did not show any significant difference in all-cause mortality, major adverse cardiac events (MACEs), myocardial infarction, stroke and stent thrombosis observed between ticagrelor and clopidogrel with (OR: 0.83, 95% CI: 0.67-1.03; P = .09), (OR: 0.64, 95% CI: 0.41-1.01; P = .06), (OR: 0.77, 95% CI: 0.57-1.03; P = .08), (OR: 0.85, 95% CI: 0.57-1.26; P = .42) and (OR: 0.70, 95% CI: 0.47-1.05; P =.09).However, ticagrelor was associated with a significantly higher minor and major bleeding with (OR: 1.57, 95% CI: 1.30-1.89; P = .00001) and (OR: 1.52, 95% CI: 1.01-2.29; P = 0.04) respectively. Dyspnea was also significantly higher in the ticagrelor group (OR: 2.64, 95% CI: 1.87-3.72; P = .00001).

CONCLUSION

Ticagrelor and clopidogrel were comparable in terms of efficacy in these patients with ACS. However, the safety outcomes of ticagrelor should further be investigated.

The impact of CYP2C19*2, CYP4F2*3, and clinical factors on platelet aggregation, CYP4F2 enzyme activity, and 20-hydroxyeicosatetraenoic acid concentration in patients treated with dual antiplatelet therapy

: The aim of the current study was to evaluate the impact of CYP2C192 (rs4244285), CYP4F23 (rs2108622), and nongenetic factors on platelet aggregation and to investigate the mechanism of CYP4F2's effect on platelet aggregation in the patients treated with dual antiplatelet therapy. A total of 146 patients were included in this study. Ticagrelor or clopidogrel were administered in a loading dose of 180 mg and 600 mg, respectively, in combination with aspirin (300 mg). Blood samples for analysis were taken the next morning after antiplatelet therapy induction. Clopidogrel users with the CYP2C1912 variant had higher platelet aggregation values (median 43, range 30-54%) compared with 11 wild-type carriers (median 33, range 15-77%; P = 0.009). Carriers of the CYP4F213 variant had higher platelet aggregation values than carriers of the 33 variant (median 34, range 8-70% vs. median 24.5, range 10-47%, P = 0.016, respectively). Higher CYP4F2 concentrations were detected in clopidogrel users than in ticagrelor users (median 3.6, range 1.6-22.0 ng/ml vs. median 2.3, range 1.6-27.2 ng/ml, P = 0.056, respectively) and in carriers of the CYP4F213 variant compared with carriers of the 11 variant (median 4.3, range 1.6-27.2 ng/ml vs. median 2.4, range 1.6-22.0 ng/ml, P = 0.009, respectively). No correlation between plasma 20-hydroxyeicosatetraenoic acid and CYP4F2 enzyme concentrations were detected (r = -0.045, P = 0.587). Our results proved that CYP2C192 might significantly affect antiplatelet function of clopidogrel. Plasma CYP4F2 concentrations were significantly lower in ticagrelor users than in clopidogrel users.

Chemokine CC-motif ligand 2 participates in platelet function and arterial thrombosis by regulating PKCα-P38MAPK-HSP27 pathway

BACKGROUND

Studies indicate that chemokine CC-motif ligand 2 (CCL2) is involved in inflammation and atherosclerosis. However, the roles and mechanisms of CCL2 on platelet function and arterial thrombosis are unknown.

METHODS

The expressions of CCL2 or CCR2 in the plasma, platelets and coronary thrombus of ST-elevated myocardial infarction (STEMI) patients were examined by ELISA, Western blot, immunohistochemistry and immunofluorescence. The roles of CCL2 on platelet aggregation, activation and secretion were examined by light transmission aggregometry, flow cytometry and ELISA.

RESULTS

The expressions of CCL2 or CCR2 in the plasma or platelets of STEMI patients with platelet high response were higher than those with platelet normal response; In vitro, exogenous recombinant human CCL2 markedly increased platelet aggregation, activation and granule secretion, which were abolished by CCL2 neutralizing antibody or CCR2 inhibiter. CCL2 increased the phosphorylation levels of PKCα (Thr638), P38MAPK (Thr180/Tyr182) and HSP27 (S78/S82) in human platelets, which were abrogated by PKCα inhibitor (RO 318220) or P38MAPK inhibitor (SB 203580). RO 318220 or SB 203580 diminished CCL2-induced platelet function. In CCL2^-/- mice, platelet aggregation and secretion were attenuated; the phosphorylation of PKCα, P38MAPK and HSP27 were decreased. In a carotid arterial thrombus mouse model, CCL2^-/- mice displayed a significantly extended carotid artery occlusion time compared with wild type.

CONCLUSIONS

CCL2 played important roles in regulating platelet function and arterial thrombosis through the PKCα-P38MAPK-HSP27 pathway, which might provide theoretical basis for searching new antiplatelet drugs and the treatment for cardiovascular diseases.

Impact of Timing on the Functional Recovery Achieved With Platelet Supplementation After Treatment With Ticagrelor

BACKGROUND

American College of Cardiology/American Heart Association guidelines advise waiting 5 to 7 days before operating on P2Y₁₂ inhibitor-treated acute coronary syndrome patients, to allow dissipation of its antiplatelet effects. Platelet transfusion is often used to restore hemostasis during operations, but its effectiveness and optimal timing are unclear. We investigated the degree of functional gains obtained from platelet supplementation after loading and maintenance of dual antiplatelet therapy with ticagrelor and the influence of timing on this strategy.

METHODS AND RESULTS

After baseline platelet testing (Multiplate Analyzer and VerifyNow), cardiovascular disease patients (n=20; 56.9±7.9 years; 65% men; 75% diabetic) received dual antiplatelet therapy as a single loading dose (ticagrelor 180 mg plus aspirin 325 mg) and as daily/maintenance treatment for 5 to 7 days (maintenance therapy: ticagrelor 90 mg BID plus aspirin 81 mg QD). At 4, 6, 24, and 48 hours from (last) dosing, patients' blood samples were supplemented with concentrated platelets from healthy donors in vitro, raising platelet counts by 0% (unsupplemented control), 25%, 50%, and 75%, and the function retested. Reactivity in supplemented samples was compared with respective 0% sample and with the pretreatment baseline. Results under loading dose and maintenance therapy regimens were nearly identical. Platelet reactivity was higher (P<0.05) in nearly all supplemented samples versus respective controls. Aggregations with supplementation were 59% to 79% of baseline at 24 hours and equal to baseline at 48 hours.

CONCLUSIONS

Platelet reactivity of ticagrelor-treated patients can be restored using concentrated platelets after a loading dose/maintenance therapy in a time-dependent manner under in vitro testing. Although statistically significant improvements are evident 6 hours after (last) dosing, ≥24 hours maybe needed for clinically meaningful restoration in platelet function.

CLINICAL TRIAL REGISTRATION

URL: https://clinicaltrials.gov. Unique identifier: NCT02201394.

Consensus Document ANMCO/ANCE/ARCA/GICR-IACPR/GISE/SICOA: Long-term Antiplatelet Therapy in Patients with Coronary Artery Disease

Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 receptor inhibitor is the cornerstone of pharmacologic management of patients with acute coronary syndrome (ACS) and/or those receiving coronary stents. Long-term (>1 year) DAPT may further reduce the risk of stent thrombosis after a percutaneous coronary intervention (PCI) and may decrease the occurrence of non-stent-related ischaemic events in patients with ACS. Nevertheless, compared with aspirin alone, extended use of aspirin plus a P2Y12 receptor inhibitor may increase the risk of bleeding events that have been strongly linked to adverse outcomes including recurrent ischaemia, repeat hospitalisation and death. In the past years, multiple randomised trials have been published comparing the duration of DAPT after PCI and in ACS patients, investigating either a shorter or prolonged DAPT regimen. Although the current European Society of Cardiology guidelines provide a backup to individualised treatment, it appears to be difficult to identify the ideal patient profile which could safely reduce or prolong the DAPT duration in daily clinical practice. The aim of this consensus document is to review contemporary literature on optimal DAPT duration, and to guide clinicians in tailoring antiplatelet strategies in patients undergoing PCI or presenting with ACS.

Ticagrelor in Peripheral Artery Disease Endovascular Revascularization (TI-PAD): Challenges in clinical trial execution

There is limited evidence to guide clinical decision-making for antiplatelet therapy in peripheral artery disease (PAD) in the setting of lower extremity endovascular treatment. The Ticagrelor in Peripheral Artery Disease Endovascular Revascularization Study (TI-PAD) evaluated the role of ticagrelor versus aspirin as monotherapy in the management of patients following lower extremity endovascular revascularization. The trial failed to recruit the targeted number of patients, likely due to aspects of the design including the lack of option for dual antiplatelet therapy, and inability to identify suitable patients at study sites. In response, the protocol underwent amendments, but these changes did not adequately stimulate recruitment, and thus TI-PAD was prematurely terminated. This article describes the rationale for TI-PAD and challenges in trial design, subject recruitment and trial operations to better inform the conduct of future trials in PAD revascularization. ClinicalTrials.gov Identifier: NCT02227368.

Early clinical outcomes as a function of use of newer oral P2Y12 inhibitors versus clopidogrel in the EUROMAX trial

Objective

To ascertain whether different oral P2Y₁₂ inhibitors might affect rates of acute stent thrombosis and 30-day outcomes after primary percutaneous coronary intervention (pPCI).

Methods

The European Ambulance Acute Coronary Syndrome Angiography (EUROMAX) randomised trial compared prehospital bivalirudin with heparin with optional glycoprotein IIb/IIIa inhibitor treatment in patients with ST-segment elevation myocardial infarction triaged to pPCI. Choice of P2Y₁₂ inhibitor was at the investigator’s discretion. In a prespecified analysis, we compared event rates with clopidogrel and newer oral P2Y₁₂ inhibitors (prasugrel, ticagrelor). Rates of the primary outcome (acute stent thrombosis) were examined as a function of the P2Y₁₂ inhibitor used for loading and 30-day outcomes (including major adverse cardiac events) as a function of the P2Y₁₂ inhibitor used for maintenance therapy. Logistic regression was used to adjust for differences in baseline characteristics.

Results

Prasugrel or ticagrelor was given as the loading P2Y₁₂ inhibitor in 49% of 2198 patients and as a maintenance therapy in 59%. No differences were observed in rates of acute stent thrombosis for clopidogrel versus newer P2Y₁₂ inhibitors (adjusted OR 0.50, 95% CI 0.13 to 1.85). After adjustment, no difference was observed in 30-day outcomes according to maintenance therapy except for protocol major (p=0.029) or minor (p=0.025) bleeding and Thrombolysis In Myocardial Infarction minor bleeding (p=0.002), which were less frequent in patients on clopidogrel. Consistent results were observed in the bivalirudin and heparin arms.

Conclusions

The choice of prasugrel or ticagrelor over clopidogrel was not associated with differences in acute stent thrombosis or 30-day ischaemic outcomes after pPCI.

Trial registration number

NCT01087723.

Review of aspirin and clopidogrel resistance in peripheral arterial disease

OBJECTIVE

Aspirin resistance (AR) and clopidogrel resistance (CR) are terms used to describe a reduction in the medication's efficacy in inhibiting platelet aggregation despite regular dosing. This review gives context to the clinical role and implications of antiplatelet resistance in peripheral arterial disease (PAD).

METHODS

A review of English-language literature on AR and CR in PAD involving human subjects using PubMed and MEDLINE databases was performed in April 2017. A total of 2075 patients in 22 relevant studies were identified. To give this issue context, a review of the larger, more established literature on antiplatelet resistance in coronary disease was undertaken, identifying significant research associating resistance to major adverse cardiovascular events (MACEs).

RESULTS

Studies in the coronary arterial disease literature have strongly associated antiplatelet resistance with increased MACE. Prevalence of AR or CR in coronary disease appears to be >55% for each in some studies. Meta-analyses of >50 studies revealed that AR and CR are significantly associated with MACE (relative risk of 2.09 and 2.8, respectively). This adds further weight to the literature reporting antiplatelet resistance as an independent predictor of and a threefold risk factor for major adverse cardiovascular events. The prevalence of resistance in PAD in this review was comparable to that in the coronary disease literature, with AR and CR prevalence up to 60% and 65%, respectively. There is evidence that the adverse effects of antiplatelet resistance are significant in PAD. In fact, research directly studying stent thrombosis populations with either coronary arterial disease or PAD revealed more significantly impaired platelet responsiveness to clopidogrel and aspirin in PAD compared with similar individuals with coronary disease. AR in PAD was found in studies to be a significant risk factor for iliofemoral stent reocclusion (P = .0093) and stroke in patients with symptomatic carotid disease (P = .018). CR was found to be a significant, independent risk factor in predicting ischemic outcomes in several recent PAD studies (P < .0001). Loss-of-function carriers of enzyme CYP2C19, important in clopidogrel metabolism, have a 30% greater risk of ischemic events (P < .001). Importantly, less antiplatelet drug resistance may be encountered with newer antiplatelet agents, including ticagrelor and prasugrel, because of reduced enzymatic polymorphisms.

CONCLUSIONS

The limited research addressing AR and CR in PAD suggests that further research is required to clarify the role of platelet assays and potential for individualized antiplatelet therapy.

Cangrelor compared with clopidogrel in patients with prior myocardial infarction - Insights from the CHAMPION trials

BACKGROUND

Patients who have had a prior myocardial infarction (MI) are at increased risk for adverse outcomes after subsequent percutaneous coronary intervention (PCI).

OBJECTIVE

The objective of this study is to examine the efficacy and safety of cangrelor, a potent intravenous P2Y₁₂ inhibitor, in patients with prior MI.

METHODS

Pooled data from the CHAMPION trials were examined. Prior MI was defined as a history of MI, excluding MI events at baseline. The primary endpoint was a composite of death, MI, ischemia-driven revascularization, or stent thrombosis at 48-h post-randomization. The primary safety endpoint was GUSTO-defined severe bleeding at 48h.

RESULTS

Out of 24,691 patients, 5699 (23%) had a prior MI. The primary endpoint was higher in patients with vs. without prior MI (4.9% vs. 4.0%, p=0.002). The primary endpoint was 4.2% with cangrelor vs. 5.7% with clopidogrel (absolute risk reduction=1.5%; OR 0.72 [95%CI 0.57-0.92]) in patients with prior MI and 3.7% with cangrelor vs. 4.3% with clopidogrel (absolute risk reduction=0.6%; OR 0.85 [95%CI 0.74-0.99]) in patients without prior MI (P-interaction=0.25). The rate of GUSTO-defined severe bleeding was 0.1% with cangrelor vs. 0.1% with clopidogrel (OR 1.39 [95%CI 0.31-6.24]) in patients with prior MI, and 0.2% with cangrelor vs. 0.2% with clopidogrel (OR 1.18 [95%CI 0.65-2.14]) in patients without prior MI (P-interaction=0.84).

CONCLUSION

In the CHAMPION trials, patients with prior MI had higher rates of ischemic outcomes within 48h after PCI. Cangrelor reduced ischemic events with no significant increase in GUSTO-defined severe bleeding in patients with or without prior MI.

Antiplatelet Therapy After Implantation of Bioresorbable Vascular Scaffolds: A Review of the Published Data, Practical Recommendations, and Future Directions

The introduction of bioresorbable vascular scaffolds (BVS) for clinical use has raised a number of questions on whether current dual-antiplatelet therapy (DAPT) recommendations after drug-eluting stent (DES) implantation, mostly deriving from data on second-generation DES, are also applicable to this completely different technology. This article aims to review the technical shortcomings of BVS-the most extensively studied fully bioresorbable coronary stent-and its contemporary rates of scaffold thrombosis, with a focus on recommendations for DAPT duration.

Ticagrelor mitigates ischaemia-reperfusion induced vascular endothelial dysfunction in healthy young males - a randomized, single-blinded study

AIMS

Animal data suggest that ticagrelor but not clopidogrel protects against tissue injury. It is unclear if this effect of ticagrelor is also detectable in humans. We studied the effect of ticagrelor and clopidogrel at standard clinical doses on endothelial dysfunction in an experimental model of forearm vascular ischaemia-reperfusion (IR) injury.

METHODS

In a randomized, single-blinded trial, 24 subjects underwent forearm blood flow (FBF) measurements in response to the endothelium-dependent vasodilator acetylcholine (ACh) and to glyceryltrinitrate (GTN; endothelium-independent) before and after a 20 min forearm ischaemia. FBF reactivity was assessed after an oral loading dose of ticagrelor or clopidogrel and after 14 days of regular intake of maintenance doses of the study medicines. In addition, the effect on platelet inhibition was evaluated using multiple electrode aggregometry.

RESULTS

ACh-induced vasodilation was impaired during reperfusion and not completely normalized by acute or chronic treatment with ticagrelor or clopidogrel (post- vs. pre-ischaemia). However, ticagrelor mitigated endothelial dysfunction compared to clopidogrel after loading (FBF ACh_AUC ratio post- vs. pre-ischaemia: 0.83 [0.70; 0.96] vs. 0.64 [0.56; 0.72]; P = 0.024) and after chronic administration (FBF ACh_AUC ratio: 0.86 [0.71; 1.00] vs. 0.66 [0.55; 0.77]; P = 0.027). As expected, GTN-induced vasodilation was not affected by ischaemia. Ticagrelor or clopidogrel treatment inhibited platelet activation to a similar degree.

CONCLUSION

Our data indicate that ticagrelor treatment exerts a greater vascular salutary effect than clopidogrel during reperfusion after an acute vascular occlusion. IR-induced vascular injury cannot be prevented completely by administration of these antiplatelet agents at standard clinical doses.

Clinically significant bleeding with low-dose rivaroxaban versus aspirin, in addition to P2Y12 inhibition, in acute coronary syndromes (GEMINI-ACS-1): a double-blind, multicentre, randomised trial

BACKGROUND

Dual antiplatelet therapy (DAPT), aspirin plus a P2Y12 inhibitor, is the standard antithrombotic treatment following acute coronary syndromes. The factor Xa inhibitor rivaroxaban reduced mortality and ischaemic events when added to DAPT, but caused increased bleeding. The safety of a dual pathway antithrombotic therapy approach combining low-dose rivaroxaban (in place of aspirin) with a P2Y12 inhibitor has not been assesssed in acute coronary syndromes. We aimed to assess rivaroxaban 2·5 mg twice daily versus aspirin 100 mg daily, in addition to clopidogrel or ticagrelor (chosen at investigator discretion before randomisation), for patients with acute coronary syndromes started within 10 days after presentation and continued for 6-12 months.

METHODS

In this double-blind, multicentre, randomised trial (GEMINI-ACS-1) done at 371 clinical centres in 21 countries, eligible patients were older than 18 years with unstable angina, non-ST segment elevation myocardial infarction (NSTEMI) or ST segment elevation myocardial infarction (STEMI), with positive cardiac biomarkers and either ischaemic electrocardiographic changes or an atherosclerotic culprit lesion identified during angiography. Participants were randomly assigned (1:1) within 10 days after admission for the index acute coronary syndromes event to either aspirin or rivaroxaban based on a computer-generated randomisation schedule. Randomisation was balanced by using randomly permuted blocks with size of four and was stratified based on the background P2Y12 inhibitor (clopidogrel or ticagrelor) intended to be used at the time of randomisation. Investigators and patients were masked to treatment assignment. Patients received a minimum of 180 days of double-blind treatment with rivaroxaban 2·5 mg twice daily or aspirin 100 mg daily. The choice of clopidogrel or ticagrelor during trial conduct was not randomised and was based on investigator preference. The primary endpoint was thrombolysis in myocardial infarction (TIMI) clinically significant bleeding not related to coronary artery bypass grafting (CABG; major, minor, or requiring medical attention) up to day 390. Primary analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT02293395.

FINDINGS

Between April 22, 2015, and Oct 14, 2016, 3037 patients with acute coronary syndromes were randomly assigned; 1518 to receive aspirin and 1519 to receive rivaroxaban. 1704 patients (56%) were in the ticagrelor and 1333 (44%) in the clopidogrel strata. Median duration of treatment was 291 days (IQR 239-354). TIMI non-CABG clinically significant bleeding was similar with rivaroxaban versus aspirin therapy (total 154 patients [5%]; 80 participants [5%] of 1519 vs 74 participants [5%] of 1518; HR 1·09 [95% CI 0·80-1·50]; p=0·5840).

INTERPRETATION

A dual pathway antithrombotic therapy approach combining low-dose rivaroxaban with a P2Y12 inhibitor for the treatment of patients with acute coronary syndromes had similar risk of clinically significant bleeding as aspirin and a P2Y12 inhibitor. A larger, adequately powered trial would be required to definitively assess the efficacy and safety of this approach.

FUNDING

Janssen Research & Development and Bayer AG.

Administration of Ticagrelor and Double-Dose Clopidogrel Based on Platelet Reactivity Determined by VerifyNow-P2Y12 for Chinese Subjects After Elective PCI

Previous studies have identified high on treatment platelet reactivity (HTPR) as a potent factor predicting ischemic events for patients with coronary heart disease. We assessed the efficacy and safety of ticagrelor (90 mg twice-daily) and double-dose of clopidogrel (150 mg once-daily) among Chinese patients for elective percutaneous coronary intervention. We enrolled 40 patients with HTPR from among 317 patients with non-ST-segment elevation acute coronary syndromes after a successful elective percutaneous coronary intervention (PCI). Platelet reactivity was measured by VerifyNow P2Y12 assay. Platelet reactivity was significantly lower for both groups when compared with baseline platelet reactivity after medication adjustment (all P < 0.001). The mean platelet reactivity units (PRU) was significantly lower for the ticagrelor group compared with that of the clopidogrel group over time (all P < 0.001). The differences in the rate of sustained HTPR at different time points between the two groups were significant (2 hours: 0% versus 60%; 8 hours: 5.6% versus 50%; 24 hours: 5.9% versus 43.8%, all P < 0.05). Genetic variation of CYP2C19*2 had no impact on PRU means or rate of HTPR in the ticagrelor group (P > 0.05). During the 30-day follow-up, no MACE occurred in any patient, and the overall risk of bleeding showed no difference between the two groups (35% versus 21%, P = 0.48). Our results suggest that ticagrelor may achieve a more rapid and greater platelet inhibition than double-dose clopidogrel. Further studies are still needed to assess the differences in efficacy and safety between ticagrelor and double-dose clopidogrel administration for Chinese patients post elective PCI.