Chewing versus Swallowing Ticagrelor to Accelerate Platelet Inhibition in Acute Coronary Syndrome - the CHEERS study

Evaluating the pharmacokinetic and pharmacodynamic impact of different modes of ticagrelor administration

INTRODUCTION

Alternative administration modes for oral P2Y12 inhibitors, particularly ticagrelor, have emerged as a potential alternative to overcome the limitations associated with the delayed onset of action of these drugs in patients who are unable to swallow or with impaired absorption.

AREAS COVERED

This comprehensive literature review aims to provide an overview of the current state of knowledge on the pharmacokinetics and administration modes of ticagrelor, including factors that may affect its action. It also compares the pharmacokinetics of ticagrelor with that of other drugs with similar uses to provide a comprehensive understanding of the potential advantages and limitations of different modalities of P2Y12 administration. For this purpose, Embase, Medline, Web of Science Core Collection, Cochrane Central Register of Controlled Trials, Google Scholar, and ClinicalTrials.gov were searched from database inception to July 2023.

EXPERT OPINION

Among the different alternatives, crushed formulations, especially for ticagrelor, have emerged as the most promising option, showing early and robust platelet inhibition. However, important questions remain unanswered, such as the comparative clinical benefits of crushed ticagrelor versus standard administration, the cost-effectiveness of alternative modes compared to intravenous P2Y12 inhibitors such as cangrelor, and the important limitations associated with the concomitant use of opioids, who have been proven to impair even the action of crushed ticagrelor.

Post-ST-Segment-Elevation Myocardial Infarction Platelet Reactivity Is Associated With the Extent of Microvascular Obstruction and Infarct Size as Determined by Cardiac Magnetic Resonance Imaging

Background Despite optimized medical management and techniques of primary percutaneous coronary intervention, a substantial proportion of patients with ST-segment-elevation myocardial infarction (STEMI) display significant microvascular damage. Thrombotic microvascular obstruction (MVO) has been implicated in the pathogenesis of microvascular and subsequent myocardial damage attributed to distal embolization and microvascular platelet plugging. However, there are only scarce data regarding the effect of platelet reactivity on MVO. Methods and Results We prospectively evaluated 105 patients in 2 distinct periods (2012-2013 and 2016-2018) who presented with first ST-segment-elevation myocardial infarction and underwent primary percutaneous coronary intervention. All patients were treated with dual antiplatelet therapy (DAPT). Blood samples were analyzed for platelet reactivity, and cardiac magnetic resonance imaging scans were evaluated for late gadolinium enhancement and MVO. DAPT suboptimal response was defined as hyporesponsiveness to either aspirin or P2Y12 receptor inhibitor agents and demonstrated in 31 patients (29.5%) of the current cohort. Suboptimal platelet response to DAPT was associated with a significantly greater extent of MVO when expressed as a percentage of the left ventricular mass, left ventricular scar, and the number of myocardial left ventricular segments showing MVO (P<0.01 for each). Adjusted multivariable logistic regression model revealed that suboptimal response to DAPT is significantly associated with both greater late gadolinium enhancement (P<0.01) and MVO extent (odds ratio, 3.7 [95% CI, 1.3-10.5]; P=0.01). Patients with a greater extent of MVO were more likely to sustain major adverse cardiovascular events at a 1-year follow-up (37% versus 11%; P<0.01). Conclusions In patients undergoing primary percutaneous coronary intervention for ST-segment-elevation myocardial infarction, platelet reactivity in response to DAPT is a key predictor of the extent of both myocardial and microvascular damage.

Morphine Use in ST-Elevation Myocardial Infarction With Downstream P2Y12 Receptor Blockers-Insight From Observational Study

BACKGROUND AND AIMS

Morphine use for patients presenting with NSTE-ACS is associated with excess mortality. However, the role of morphine in STE-ACS is ill characterized. We have recently confirmed direct prothrombotic effect of morphine using murine models. We sought to explore whether morphine use in STE-ACS patients, used to be scheduled for downstream P₂Y₁₂ blockers, is negatively associated with procedural and clinical outcomes.

METHODS

A single-center, observational retrospective analysis enrolling 130 non-randomized stable patients sustaining STE-ACS as their first manifestation of coronary disease, who presented between December 2010 and June 2013. All were managed by early invasive approach. Of study patients, 55 were treated by morphine, and 75 were not. All were administered downstream P₂Y₁₂ blockers according to an already abandoned local policy. Outcomes evaluated included TIMI grade flow, thrombus burden, ST-segment resolution, myocardial function by echocardiography, and cardiovascular death.

RESULTS

Morphine administration was associated with a significantly higher incidence of impaired final TIMI grade flow (TIMI < 3, 40% vs 4%, P < .05), lower incidence of ST-segment resolution >70% (40.7% vs 76.5%, P < .05), and a higher incidence of moderate or severe systolic dysfunction (48.1% vs 29.1%, P < .05) compared with morphine naive patients. Interestingly, the overall mortality rate was higher in the morphine-treated group (18% vs 5.3%, P < .05).

CONCLUSIONS AND RELEVANCE

Morphine administration combined with the downstream P₂Y₁₂ blockers practice signify a group with a higher occurrence of impaired myocardial reperfusion and cardiovascular death despite established on-time primary angioplasty.

Temporal trends in prognosis of patients with acute coronary syndrome complicated by ventricular tachyarrhythmia

OBJECTIVES

To evaluate clinical characteristics and prognosis of patients presented with acute coronary syndrome (ACS) that developed ventricular tachyarrhythmia VTA and to analyse it according to the period of presentation.

BACKGROUND

VTA is an infrequent yet serious complication of ACS. There is limited data regarding the incidence and prognostic implications of VTA in the last decade as compared with the previous decade.

METHODS

We evaluated clinical characteristics, major adverse cardiovascular events, short and long- term mortality of patients hospitalised with ACS who were enrolled in the Acute Coronary Syndrome Israeli Survey (ACSIS) during the years 2000-2016. Patients were classified into three groups: no VTA, early VTA (≤48 hours of onset) and late VTA (>48 hours of onset). Data were analysed according to the period of presentation: early vs late period (years 2000-2006 and 2008-2016 accordingly).

RESULTS

The study population comprised 15,200 patients. VTA occurred in 487 (3.2%) patients. Early VTA presented in 373/487 (77%) patients and late VTA in 114/487 (23%) patients. VTA's, occurring in ACS patients were associated with increased risk of in-hospital, 30-days, 1-year and 5-year mortality rates during both early and late periods compared with no VTA. Moreover, late VTA was associated with the highest mortality rate with up to 65% in 5-year follow up (P < .001). Nevertheless, late VTA was associated with a lower mortality rate in the late period compared with the early period.

CONCLUSIONS

Any VTA following ACS was associated with high short- and long-term mortality rate. However, over the late period, there has been a significant improvement in survival rates, especially in patients with late VTA. This may be attributed to early and invasive reperfusion therapy, implantable cardioverter-defibrillator implantation and better medical treatment.

Crushed/chewed administration of potent P2Y12 inhibitors in ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention: Systematic review and meta-analysis

Crushed or chewed potent P2Y₁₂ inhibitors are commonly used in the hope of bridging the gap of platelet inhibition in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI). The study aimed to investigate the efficacy and safety of this alternative oral administration strategy by performing a meta-analysis of available randomized clinical trials (RCTs). PubMed, Embase, the Cochrane Library and Web of Science medical literature databases were searched for RCTs comparing crushed/chewed vs. integral administration of loading dose potent P2Y₁₂ inhibitors in patients with STEMI undergoing pPCI with no language restrictions from inception to January 20th, 2021. The primary efficacy endpoints of high on treatment platelet reactivity (HPR) and P2Y₁₂ reaction units (PRU) at 1 hour together with safety and additional clinical endpoints were evaluated by pooled odds ratio (OR) or mean differences (MD) with 95% confidence intervals (95% CI). A total of 973 patents in six RCTs were eligible for analysis, while 876 patients present baseline and procedural characteristics. HPR and PRU at 1 hour were significantly reduced in the group receiving crushed/chewed P2Y₁₂ inhibitors compared with integral tablets (OR 0.28, 95% CI 0.16 to 0.49, P < .0001; MD -60.62, 95% CI -97.06 to -24.19, P = .001, respectively). Safety endpoints of major bleeding (OR 0.54, 95% CI 0.11 to 2.73, P = .46) and any bleeding (OR 0.84, 95% CI 0.43 to 1.64, P = .61), as well as additional clinical endpoints of cardiovascular death, myocardial infarction, and stroke were not affected by the oral administration strategy. In STEMI patients undergoing pPCI, crushed or chewed administration of potent P2Y₁₂ inhibitors are associated with enhanced early platelet inhibition and appear to be safe. The clinical profile transformed from this pharmacodynamic benefit need to be determined by further researches.

Tackling the gap in platelet inhibition with oral antiplatelet agents in high-risk patients undergoing percutaneous coronary intervention

Introduction: Oral P2Y₁₂ inhibitors represent the mainstay therapy for the prevention of thrombotic complications in patients presenting with an acute coronary syndrome and/or undergoing percutaneous coronary intervention (PCI). However, the onset of antiplatelet action of the oral P2Y₁₂ inhibitors is affected by their need to be absorbed in the gastrointestinal (GI) tract before becoming systemically available.Areas covered: Following oral intake of P2Y₁₂ inhibitors, the timeframe required for GI absorption leads to a window of inadequate antiplatelet protection during which patients are at increased thrombotic risk. The onset of action of the oral P2Y₁₂ inhibitors is even further delayed in high-risk patients, underscoring the need to define strategies to bridge the gap in platelet inhibitory effects following their intake.Expert opinion: Multiple mechanisms may impair GI absorption leading to a delay in the onset of action of oral P2Y₁₂ inhibitors. Several strategies have been tested to overcome the gap in platelet inhibition in high-risk patients undergoing PCI. These include administration of crushed or chewed tablets to improve the dissolution rate and use of opioid receptor antagonists or metoclopramide to counteract impairment of gastric motility induced by opioids. However, intravenous antiplatelet therapies represent the most effective strategy to bridge such gap in platelet inhibition.

Antithrombotic Therapy in Acute Coronary Syndromes: Current Evidence and Ongoing Issues Regarding Early and Late Management

A few decades ago, the understanding of the pathophysiological processes involved in the coronary artery thrombus formation has placed anticoagulant and antiplatelet agents at the core of the management of acute coronary syndrome (ACS). Increasingly potent antithrombotic agents have since been evaluated, in various association, timing, or dosage, in numerous randomized controlled trials to interrupt the initial thrombus formation, prevent ischemic complications, and ultimately improve survival. Primary percutaneous coronary intervention, initial parenteral anticoagulation, and dual antiplatelet therapy with potent P2Y₁₂ inhibitors have become the hallmark of ACS management revolutionizing its prognosis. Despite these many improvements, much more remains to be done to optimize the onset of action of the various antithrombotic therapies, for further treating and preventing thrombotic events without exposing the patients to an unbearable hemorrhagic risk. The availability of various potent P2Y₁₂ inhibitors has opened the door for individualized therapeutic strategies based on the clinical setting as well as the ischemic and bleeding risk of the patients, while the added value of aspirin has been recently challenged. The strategy of dual-pathway inhibition with P2Y₁₂ inhibitors and low-dose non-vitamin K antagonist oral anticoagulant has brought promising results for the early and late management of patients presenting with ACS with and without indication for oral anticoagulation. In this updated review, we aimed at describing the evidence supporting the current gold standard of antithrombotic management of ACS. More importantly, we provide an overview of some of the ongoing issues and promising therapeutic strategies of this ever-evolving topic.

Bridging the gap: Current and future insights for improving suboptimal platelet inhibition in STEMI

Antiplatelet therapy is one of the cornerstones in the acute treatment of patients with ST-elevation myocardial infarction (STEMI) who undergo primary percutaneous coronary intervention (PCI). However, hemodynamic changes and delayed intestinal absorption of P2Y₁₂ inhibitors leads to a delay in the onset of antiplatelet effects resulting in a gap of platelet inhibition. Several strategies have been proposed to bridge this gap, such as pre-hospital administration of antiplatelet therapy, higher loading doses of P2Y₁₂ inhibitors, crushing or chewing tablets, subcutaneous or intravenous administration of platelet inhibitors, or use of pain relievers alternative to opioids that do not delay intestinal absorption of oral platelet inhibitors. These strategies may improve platelet inhibition with the goal of optimizing clinical outcomes in the acute phase of STEMI. In this review we present current and future insights for bridging the gap in platelet inhibition in STEMI patients undergoing primary PCI.

Ticagrelor Pharmacokinetics and Pharmacodynamics in Chinese Patients with STEMI and NSTEMI Without Opioid Administration

INTRODUCTION

The pharmacodynamics (PD) and pharmacokinetics (PK) study of ticagrelor loading dose (LD) in Chinese patients with acute coronary syndrome (ACS) without opioid administration has never been investigated. Therefore, the aim of this study was to evaluate the antiplatelet effects and the PK parameters of ticagrelor in Chinese patients with ACS without opioid administration.

METHODS

A sample size of 30 eligible patients with ACS were enrolled in this study. Blood samples were obtained predose and 1, 2, 4, 8, and 12 h after 180 mg LD of ticagrelor. P2Y₁₂ reactivity units (PRU) and plasma concentrations of ticagrelor and its two metabolites were measured.

RESULTS

In total, 15 patients were admitted to ST segment elevation myocardial infarction (STEMI) and non-ST segment elevation myocardial infarction (NSTEMI) groups, respectively. For patients with NSTEMI, PRU declined significantly during the first 4 h and maintained a relatively stable antiplatelet effect from 4 to 12 h after LD. A similar trend was found in the STEMI group without significant differences of PRU in each designed time compared with patients with NSTEMI (P > 0.05). T_max of metabolite AR-C124910XX was 4 h after LD for both groups. There were no significant differences for drug concentration, C_max, or AUC of ticagrelor and AR-C124910XX between patients with STEMI and NSTEMI (P > 0.05).

CONCLUSIONS

For Chinese patients with ACS, at least 4 h was needed to achieve an adequate antiplatelet effect for ticagrelor LD. There were no differences in PK or PD between Chinese patients with STEMI and NSTEMI.

CLINICAL TRIAL REGISTRATION

ChiCTR1800014764.

Facilitation Through Aggrastat or Cangrelor Bolus and Infusion Over PrasugreL: a MUlticenter Randomized Open-label Trial in PatientS with ST-elevation Myocardial InFarction Referred for PrimAry PercutaneouS InTERvention (FABOLUS FASTER) Trial: Design and Rationale : The FABOLUS FASTER Trial

Antithrombotic therapy is a critical component of the management of ST-elevation myocardial infarction (STEMI) patients treated with primary percutaneous coronary intervention (PCI). Rapid and profound inhibition of platelet reactivity has been shown to mitigate the ischemic risks and improve myocardial salvage. High residual platelet reactivity (HRPR) has been reported up to 4 or 6 h after loading dose of prasugrel or ticagrelor; therefore, multiple alternative strategies, including crushed or chewed oral tables or intravenous agents, have been investigated to provide a more rapid and sustained inhibition of platelet function and bridge the initial treatment gap. The FABOLUS FASTER is the first investigator-initiated, multicentre, open-label, prospective, randomized study to directly compare the pharmacodynamics effects of cangrelor, tirofiban, chewed or integer prasugrel. This study will add new insights in the management of antiplatelet therapy in patients with STEMI undergoing primary PCI and might be hypothesis-generating for future clinical trials in this field. The trial is registered on clinicaltrials.gov NCT02978040, and EudraCT 2017-001065-24.

P2Y12 inhibitors for the treatment of acute coronary syndrome patients undergoing percutaneous coronary intervention: current understanding and outcomes

Introduction: Inhibition of P2Y₁₂ platelet receptors consists a crucial target of pharmacologic treatment in acute coronary syndrome patients. Several controversial issues however still remain and these are analyzed.Areas covered: The significance of early and strong platelet inhibition in the early phase of STEMI and the role of pretreatment are discussed. Concerns regarding morphine administration are raised. The role of crushing integral tablets to expedite the onset of action of oral P2Y₁₂ inhibitors is emphasized. New data on the intravenous cangrelor are reported. Antiplatelet therapies as adjunct to thrombolysis, as well as the role of de-escalation antiplatelet therapy are analyzed.Expert opinion: Pharmacodynamic studies convincingly demonstrate a gap in the onset of antiplatelet action in STEMI cases, even when prasugrel or ticagrelor loading dose is used. The clinical benefit, however, of the early platelet inhibition and pretreatment is not entirely clear. Morphine delays the onset of action of oral agents, while this is expedited by crushing the integral tablets. Cangrelor devoids of these deficiencies by achieving fast and strong platelet inhibition in all clinical scenarios. Concomitant administration of novel antiplatelet agents with thrombolysis and de-escalation of antiplatelet treatment necessitate further study to reach definite conclusion.

A paper microfluidics-based fluorescent lateral flow immunoassay for point-of-care diagnostics of non-communicable diseases

In the emergency diagnosis of patients, acute myocardial infarction (AMI) is always time-consuming to diagnose, and the process requires multiple laboratory procedures, expensive equipment and skilled workers. Herein, we developed an easy-to-use, low-cost and portable fluorescent lateral flow immunoassay based on paper microfluidics for the point-of-care diagnostics of non-communicable diseases. The fluorescent lateral flow immunoassay can produce results in less than 10 minutes, and the limit of detection (LOD) is 0.019 ng ml^-1. The slope was linear from 0 to 100 ng ml^-1; the equation is y = 0.0342e^2.1181x and R² = 0.9618, which are distinctive features that ensure maximum amplification of the signal and recording of quantitative values by an analyser. The detection sensitivity showed an exceptional increase to 0.01 ng ml^-1. Compared with conventional bioassay readers, our analyser shows some advantages to easily, clearly and effectively read data. The present point-of-care test for cardiac troponin I decreases the turnaround time and has a high coefficient of variation even at lower concentrations of troponin. So, the development of lateral flow assay-based point-of-care assays with higher analytical performance for real world samples can decrease the rule-out time for AMI in emergency departments and other fields.

Effect of Chewing vs Swallowing Ticagrelor on Platelet Inhibition in Patients With ST-Segment Elevation Myocardial Infarction: A Randomized Clinical Trial

Importance

Dual anti-platelet therapy represents standard care for treating patients with ST-segment elevation myocardial infarction (STEMI). Ticagrelor is a direct-acting P2Y12 inhibitor and, unlike clopidogrel and prasugrel, does not require metabolic activation.

Objective

To evaluate whether chewing a loading dose (LD) of ticagrelor, 180 mg, vs traditional oral administration of an equal dose enhances platelet inhibition at 30 minutes and 1 hour after LD administration in patients with STEMI.

Design, Setting, and Participants

A randomized clinical trial was conducted in adults aged 30 to 87 years from May to October 2016 in a large tertiary care center. Analyses were intention-to-treat.

Interventions

Fifty patients with STEMI were randomized to either chewing an LD of ticagrelor, 180 mg, or standard oral administration of an equal dose.

Main Outcomes and Measures

P2Y12 reaction units were evaluated using VerifyNow (Accumentrics) at baseline, 30 minutes, 1 hour, and 4 hours after LD.

Results

Baseline characteristics were similar in both groups. The mean (SD) of P2Y12 reaction units in the chewing group compared with the standard group at baseline, 30 minutes, 1 hour, and 4 hours after ticagrelor LD were 224 (33) vs 219 (44) (95% CI, -16.77 to 27.73; P = .26), 168 (78) vs 230 (69) (95% CI, -103.77 to -19.75; P = .003), 106 (90) vs 181 (89) (95% CI, -125.15 to -26.29; P = .005), and 43 (41) vs 51 (61) (95% CI, -36.34 to 21.14; P = .30), respectively. Platelet reactivity in the chewing group was significantly reduced by 24% at 30 minutes after LD (95% CI, 19.75 to 103.77; P = .001). The relative inhibition of platelet aggregation in the chewing vs the standard group were 51% vs 10% (95% CI, 13.69 to 67.67; P = .005) at 1 hour and 81% vs 76% (95% CI, -12.32 to 16.79; P = .24) at 4 hours, respectively. Major adverse cardiac and cardiovascular event rate at 30 days was low (4%) and occurred in 1 patient in each group (95% CI, 0.06 to 16.93; P > .99).

Conclusions and Relevance

Chewing an LD of ticagrelor, 180 mg, in patients with STEMI is feasible and facilitates better early platelet inhibition compared with a standard oral LD. Larger studies are warranted to see if our preliminary findings translate into clinical outcomes.

Trial Registration

clinicaltrials.gov Identifier: NCT02725099.

Efficacy and safety of alternative oral administrations of P2Y12-receptor inhibitors: Systematic review and meta-analysis

BACKGROUND

Early administration of P2Y12-receptor inhibitors is recommended in all patients with acute coronary syndrome undergoing invasive management, with the aim to achieve the fastest and most effective platelet inhibition. Several trials investigated alternative methods of P2Y12-receptor inhibitor administration (mainly chewed or crushed) aimed at ensuring faster and higher platelet inhibition. Thus, we decided to perform a systematic review and meta-analysis analyzing efficacy and safety of alternative P2Y12-receptor inhibitor administration strategies.

METHODS

Systematic research was performed on Pubmed, Cochrane Library, Biomed Central, and Web of Science databases. We included randomized or observational trials testing at least one P2Y12-receptor inhibitor alternative administration. The primary outcome of the study was the value of the platelet reactivity unit (PRU) at 1 h after drug administration, assessed by VerifyNow P2Y12 test (Accumetrics, Inc., San Diego, CA). Secondary outcomes were adverse bleeding events (safety outcome).

RESULTS AND DISCUSSION

Fourteen studies were selected for qualitative analysis. Five studies, all focused on ticagrelor, were selected for quantitative efficacy analyses. These five studies compared the administration of crushed/chewed ticagrelor 180 mg loading dose (LD) with the standard whole tablets LD. The pooled mean difference between the two administrations was -59.24 PRU (95% CI from -30.61 to -87.87 PRU) in favor of the crushed/chewed administration, corresponding to a 25% mean relative PRU reduction between alternative and standard P2Y12-receptor inhibitor administrations at 1 h after drug intake. A similar relationship was found in other studies on alternative administration of clopidogrel and prasugrel, not included in the quantitative analysis.

Determinants of high platelet reactivity in patients with acute coronary syndromes treated with ticagrelor

High platelet reactivity (HPR) is a risk factor for stent thrombosis, a potentially lethal complication of percutaneous coronary intervention. HPR is also associated with increased risk of myocardial infarction and death in invasively-treated patients with acute coronary syndrome (ACS). HPR occurs even in ACS patients treated with ticagrelor, a state-of-the-art antiplatelet agent, especially during the first hours of treatment. Patient-level pharmacodynamic data obtained from 102 ACS subjects enrolled in two prospective, pharmacodynamic trials were analysed in order to identify clinical features related with increased odds of on-ticagrelor HPR during the first two hours after ticagrelor loading dose in ACS patients. Presence of ST-segment elevation myocardial infarction (versus non-ST-segment elevation ACS) and morphine co-administration were the strongest predictors of HPR at 1 and 2 hours after ticagrelor loading dose according to linear regression analyses, multiple backward stepwise logistic regression analyses and generalized estimating equation model. By pinpointing simple to recognize clinical features, the results of this study facilitate identification of ACS patients who have the highest odds of HPR during the initial phase of treatment with ticagrelor, and who could potentially benefit from alternative treatment strategies.

Pharmacokinetic Profiles of Ticagrelor Orodispersible Tablets in Healthy Western and Japanese Subjects

Background and Objectives

Ticagrelor is an antiplatelet agent for patients with acute coronary syndrome or a history of myocardial infarction. Two studies compared pharmacokinetic profiles of orodispersible (OD) ticagrelor tablets versus immediate-release (IR) tablets in Western and Japanese subjects.

Methods

Both studies were open-label, randomized, crossover, single-center trials. Thirty-six healthy subjects (94% white, 6% other race; Western study NCT02400333) and 42 Japanese healthy subjects (Japanese study NCT02436577) received a single 90-mg ticagrelor dose as an OD tablet [with/without water, and via a nasogastric tube (Western study only)], and an IR tablet; washout between treatments was ≥7 days. Assessments included ticagrelor and AR-C124910XX (active metabolite) plasma concentrations for pharmacokinetic analyses, and safety evaluations.

Results

In the Western study, the 90% confidence intervals (CIs) of the geometric mean ratios (GMRs) for ticagrelor and AR-C124910XX maximum plasma concentration (C_max) and area under the plasma concentration–time curve (AUC) were within the acceptance interval (80%–125%) for OD tablets (with/without water, via a nasogastric tube) versus the IR tablet; except for an ~15% lowering of ticagrelor C_max (90% CI: 76.77%–93.78%) for the OD tablet taken with water. In the Japanese study, 90% CIs of the GMRs for AUC and C_max of both ticagrelor and AR-C124910XX were all within the acceptance intervals for the OD (with/without water) versus IR tablet. No new safety issues were identified.

Conclusions

Ticagrelor administered as an OD tablet to Western (without water, and via a nasogastric tube) and Japanese (with/without water) subjects was bioequivalent to the IR tablet.

Electronic supplementary material

The online version of this article (doi:10.1007/s40261-017-0554-8) contains supplementary material, which is available to authorized users.

Comparison of bioavailability and antiplatelet action of ticagrelor in patients with ST-elevation myocardial infarction and non-ST-elevation myocardial infarction: A prospective, observational, single-centre study

BACKGROUND

Data from available studies suggest that the presence of ST-elevation myocardial infarction (STEMI) may be associated with delayed and attenuated ticagrelor bioavailability and effect compared with non-ST-elevation myocardial infarction (NSTEMI).

METHODS

In a single-center, prospective, observational trial 73 patients with myocardial infarction (STEMI n = 49, NSTEMI n = 24) underwent a pharmacokinetic and pharmacodynamic assessment after a 180 mg ticagrelor loading dose (LD). Ticagrelor and its active metabolite (AR-C124910XX) plasma concentrations were determined with liquid chromatography tandem mass spectrometry, and their antiplatelet effect was measured with the VASP assay and multiple electrode aggregometry.

RESULTS

During the first six hours after ticagrelor LD, STEMI patients had 38% and 34% lower plasma concentration of ticagrelor and AR-C124910XX, respectively, than NSTEMI (ticagrelor AUC(0-6): 2491 [344-5587] vs. 3991 [1406-9284] ng*h/mL; p = 0.038; AR-C124910XX AUC(0-6): 473 [0-924] vs. 712 [346-1616] ng*h/mL; p = 0.027). STEMI patients also required more time to achieve maximal concentration of ticagrelor (tmax: 4.0 [3.0-12.0] vs. 2.5 [2.0-6.0] h; p = 0.012). Impaired bioavailability of ticagrelor and AR-C124910XX seen in STEMI subjects was associated with diminished platelet inhibition in this group, which was most pronounced during the initial hours of treatment.

CONCLUSIONS

Plasma concentrations of ticagrelor and AR-C124910XX during the first hours after ticagrelor LD were one third lower in STEMI than in NSTEMI patients. This reduced and delayed ticagrelor bioavailability was associated with weaker antiplatelet effect in STEMI.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02602444 (November 09, 2015).