Impact of Escalating Loading Dose Regimens of Ticagrelor in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention: Results of a Prospective Randomized Pharmacokinetic and Pharmacodynamic Investigation

Strategies to optimize initial P2Y12 inhibitor therapy in STEMI patients

INTRODUCTION

Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor is the standard of care for patients who undergo percutaneous coronary intervention (PCI) for ST elevation myocardial infarction (STEMI). Though this regimen reduces rates of ischemic events in patients with STEMI, the optimal strategy for P2Y12 administration in STEMI patients is still evolving.

PURPOSE

The purpose of this review is to summarize current evidence on optimal use of ticagrelor and prasugrel in the acute phase of STEMI.

SUMMARY

Due to high platelet activity in the acute setting of STEMI and PCI, adequate and rapid platelet inhibition is important. Strategies of increased ticagrelor/prasugrel loading dose or earlier administration in STEMI have not been successful in closing this platelet inhibition gap. Potential strategies for improving ticagrelor/prasugrel use early in STEMI include bridging with intravenous antiplatelet agents or crushed or chewed administration.

CONCLUSION

Oral ticagrelor/prasugrel given before or immediately after STEMI PCI is usually sufficient to prevent thrombotic complications. When faster platelet inhibition is desired, or oral administration is compromised by inability to swallow tablets, crushing/chewing ticagrelor/prasugrel tablets is an alternative to intravenous P2Y12 inhibitor therapy.

Progress in the clinical effects and adverse reactions of ticagrelor

BACKGROUND

Ticagrelor is a novel receptor antagonist that selectively binds to the P2Y12 receptor, thereby inhibiting adenosine diphosphate (ADP)-mediated platelet aggregation. Compared to clopidogrel, ticagrelor has the advantages of a fast onset, potent effects, and a reversible platelet inhibition function, which make this drug clinically suitable for treating acute coronary syndrome (ACS), especially acute ST-segment elevation myocardial infarction (STEMI).

OBJECTIVE

This review was performed to determine the basic characteristics, clinical effects, and adverse reactions of ticagrelor.

METHODS

Relevant trials and reports were obtained from the MEDLINE, Embase, and Cochrane Library databases.

RESULTS

Ticagrelor is rapidly absorbed by the body after oral administration, exhibits inherent activity without requiring metabolic activation, and binds reversibly to the P2Y12 receptor. Ticagrelor has been recommended in ACS treatment guidelines worldwide due to its advantageous pharmacological properties and significant clinical benefits. Ticagrelor inhibits platelet aggregation, inhibits inflammatory response, enhances adenosine function, and has cardioprotective effects. However, ticagrelor also causes adverse reactions such as bleeding tendency, dyspnea, ventricular pause, gout, kidney damage, and thrombotic thrombocytopenic purpura in clinical treatment. Therefore, it is necessary to pay attention to risk assessments when using ticagrelor.

CONCLUSION

Ticagrelor is a promising drug for the effective treatment of ACS. When using ticagrelor, individualized treatment should be provided based on the specific conditions of the patients to avoid serious adverse events.

Negative Impact of ST-Segment Elevation Myocardial Infarction and Morphine Dose on Ticagrelor Uptake and Pharmacodynamics: A Population PK/PD Analysis of Pooled Individual Participant Data

BACKGROUND

Ticagrelor is widely used in patients with stable and acute coronary artery disease. Understanding the factors that influence its pharmacokinetics (PK) and pharmacodynamics (PD) could improve therapeutic outcomes. We therefore performed a pooled population PK/PD analysis using individual patient data from two studies. We focused on the impact of morphine administration and ST-segment elevation myocardial infarction (STEMI) on the risk of high platelet reactivity (HPR) and dyspnea.

METHODS

A parent-metabolite population PK/PD model was developed based on data from 63 STEMI, 50 non-STEMI, and 25 chronic coronary syndrome (CCS) patients. Simulations were then run to evaluate the risk of non-response and adverse events associated with the identified variability factors.

RESULTS

The final PK model consisted of first-order absorption with transit compartments, distribution with two compartments for ticagrelor and one compartment for AR-C124910XX (active metabolite of ticagrelor), and linear elimination for both drugs. The final PK/PD model was an indirect turnover model with production inhibition. Morphine dose and STEMI, independently, had a significant negative effect on the absorption rate (reduction of log([Formula: see text]) by 0.21×morphine dose (mg) and by 2.37 in STEMI patients, both p < 0.001), and the presence of STEMI significantly impacted both efficacy and potency (both p < 0.001). The simulations run with the validated model showed a high rate of non-response in patients with those covariates (RR 1.19 for morphine, 4.11 for STEMI and 5.73 for morphine and STEMI, all three p < 0.001). By increasing ticagrelor dosage, the negative morphine effect was reversible in patients without STEMI and just limited in patients with STEMI.

CONCLUSION

The developed population PK/PD model confirmed the negative impact of morphine administration and presence of STEMI on ticagrelor PK and antiplatelet effect. Increasing ticagrelor doses seems effective in morphine users without STEMI, whereas the STEMI effect is not entirely reversible.

Timing, Selection, Modulation, and Duration of P2Y12 Inhibitors for Patients With Acute Coronary Syndromes Undergoing PCI

Dual antiplatelet therapy with aspirin and the oral P2Y₁₂ inhibitor clopidogrel as the cornerstone of treatment for patients with an acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) was firstly established in 2001. Soon thereafter, the newer-generation P2Y₁₂ inhibitors prasugrel and ticagrelor became commercially available. The clinical management of ACS patients undergoing PCI has evolved significantly in the last 2 decades, with a shift toward more rapid invasive management, broader use of drug-eluting stents, and the increasing recognition that major bleeding due to antiplatelet therapy is detrimental. In this ever-changing scenario, numerous studies have addressed 4 main questions regarding P2Y₁₂ inhibition in ACS patients undergoing PCI: timing, selection, modulation, and duration. This paper reviews the latest evidence surrounding these topical questions, with a focus on efficacy and safety data, practice guidelines, and residual areas of uncertainty.

Analgesic drug use in patients with STEMI: Current perspectives and challenges

Therapy for patients with ST-elevation myocardial infarction (STEMI) has been a controversial topic since the introduction of thrombolytic agents in the 1980s. The use of morphine, fentanyl and lidocaine has increased substantially during this period. However, there is still limited evidence on their advantages and limitations. In this review, the clinical application, as well as future considerations of morphine, fentanyl and lidocaine in patients with ST segment elevation myocardial infarction were discussed.

Gut microbiota induces high platelet response in patients with ST segment elevation myocardial infarction after ticagrelor treatment

Background:

Ticagrelor is a first-line drug for the treatment of acute ST elevation myocardial infarction (STEMI). However, approximately 20% STEMI patients taking ticagrelor exhibited a delayed response and the mechanism was still unclear.

Methods:

To explore the mechanism of the poor response of ticagrelor in post-percutaneous coronary intervention (PCI) patients, we enrolled 65 high platelet reactivity (HPR) patients and 90 controls (normal platelet reactivity [NPR]). Pharmacokinetic assessment result showed that the plasma concentrations of ticagrelor and its metabolism production, AR-C124910XX, were lower in HPR patients than controls. Further single nucloetide polymorphism (SNP) analysis identified that there is no difference in ATP binding cassette subfamily B member 1 (ABCB1) gene expression between the NPR group and the HPR group. Metagenomic and metabolomic analyses of fecal samples showed that HPR patients had higher microbial richness and diversity. Transplantation of the gut microbiota from HPR donors to microbiota-depleted mice obviously decreased plasma concentration of ticagrelor.

Results:

Our findings highlight that gut microbiota dysbiosis may be an important mechanism for the ticagrelor of HPR in patients with STEMI and support that modify gut microbiota is a potential therapeutic option for STEMI.

Conclusions:

Our findings highlight that gut microbiota dysbiosis may be an important mechanism for the ticagrelor of HPR in patients with ST elevation myocardial infarction (STEMI) and support that modify gut microbiota is a potential therapeutic option for STEMI

Funding:

NSFC 82170297 and 82070300 from the National Natural Science Foundation of China.

Periprocedural Myocardial Injury in High-Risk Patients With NSTEMI Pretreated With Ticagrelor for Less or More Than 6 Hours Before PCI

We assessed the impact on periprocedural myocardial injury of a ticagrelor loading dose given <6 or >6 hours before percutaneous coronary intervention (PCI) in non-ST-elevation myocardial infarction (NSTEMI) patients at high risk. All consecutive patients pretreated with ticagrelor and undergoing PCI for a high-risk NSTEMI have been included in the present analysis. Propensity-score matching was performed to compare the outcomes between patients pretreated with ticagrelor for >6 hours or ≤6 hours. The primary outcome was the rate of periprocedural myocardial injury after PCI. We also recorded clinical outcomes, including major adverse cardiovascular events and major bleedings at 1 month. A total of 1216 patients with NSTEMI were deemed eligible for the study: 481 received a ticagrelor loading dose ≤6 hours (mean time, 4.3 ± 1.2 h) and 735 >6 hours (16.1 ± 8.4 hours) before PCI. Patients pretreated with ticagrelor for >6 hours presented more risk factors and comorbidities compared to others. In patients pretreated with ticagrelor for >6 hours, the rate of periprocedural myocardial injury was significantly lower compared to the other group, in the overall population (19.6% vs 37.8%; P < .0001) and in the matched cohort of 644 patients (18.9% vs 33.5%; P < .0001). The rate of major adverse cardiovascular events and major bleeding events did not differ between the two groups, in both unmatched and matched populations. The present study suggests that ticagrelor pretreatment reduces periprocedural myocardial injury in high-risk patients with NSTEMI undergoing PCI with expected time intervals >6 hours.

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.

Pharmacokinetics, pharmacodynamics, and tolerability of subcutaneous administration of a novel glycoprotein IIb/IIIa inhibitor, RUC-4, in patients with ST-segment elevation myocardial infarction

BACKGROUND

Pre-hospital platelet inhibition in patients with ST-segment elevation myocardial infarction (STEMI) may improve outcomes. RUC-4 is a novel, second-generation glycoprotein IIb/IIIa inhibitor designed for first-point-of-medical-contact treatment for STEMI by subcutaneous injection.

AIMS

The open-label, phase 2A, CEL-02 trial aimed to assess the pharmacodynamics (PD), pharmacokinetics (PK), and tolerability of RUC-4 in STEMI patients undergoing primary PCI (pPCI).

METHODS

A total of 27 STEMI patients received a weight-adjusted subcutaneous injection of RUC-4 before pPCI in escalating doses (0.075 mg/kg [n=8], 0.090 mg/kg [n=9], or 0.110 mg/kg [n=10]).

RESULTS

The primary PD endpoint of high-grade (≥77%) inhibition of the VerifyNow iso-TRAP assay at 15 minutes was met in 3/8, 7/8, and 7/8 patients in the three cohorts with a dose-response relationship (mean inhibition [min - max] of 77.5% [65.7%-90.6%], 87.5% [73.8%-93.1%], and 91.7% [76.4%-99.3%], respectively; ptrend=0.002). Fifty percent (50%) inhibition remained after 89.1 (38.0-129.7), 104.2 (17.6-190.8), and 112.4 (19.7-205.0) minutes. Injection site reactions or bruising were observed in 1 (4%) and 11 (41%) patients, respectively. Mild access-site haematomas occurred in 6 (22%), and severe access-site haematomas occurred in 2 patients (7%). No thrombocytopaenia was observed within 72 hours post dose.

CONCLUSIONS

In patients with STEMI, a single subcutaneous dose of RUC-4 at 0.075, 0.090, and 0.110 mg/kg showed dose-response high-grade inhibition of platelet function within 15 minutes.

Prehospital Evaluation, ED Management, Transfers, and Management of Inpatient STEMI

ST elevation myocardial infarction diagnoses have reduced in number over the past 10 years; however, associated morbidity and mortality remain high. Societal guidelines focus on early diagnosis and timely access to reperfusion, preferably percutaneous coronary intervention (PCI), with fibrinolytics reserved for those who cannot receive timely PCI. Proposed algorithms recommend emergency department bypass in stable patients with a clear diagnosis to reduced door-to-balloon time. Emergency providers should limit their evaluation, focusing on life-threatening comorbidities, unstable vitals, or contraindications to a catheterization laboratory. In-hospital patients prove diagnostically challenging because they may be unable to express symptoms, and reperfusion strategies can complicate other diagnoses.

Feasibility and safety of cangrelor in patients with suboptimal P2Y12 inhibition undergoing percutaneous coronary intervention: rationale of the Dutch Cangrelor Registry

BACKGROUND

Despite the advances of potent oral P2Y12 inhibitors, their onset of action is delayed, which might have a negative impact on clinical outcome in patients undergoing percutaneous coronary intervention (PCI). Trials conducted in the United States of America have identified cangrelor as a potent and rapid-acting intravenous P2Y12 inhibitor, which has the potential of reducing ischemic events in these patients without an increase in the bleeding. As cangrelor is rarely used in The Netherlands, we conducted a nationwide registry to provide an insight into the use of cangrelor in the management of patients with suboptimal platelet inhibition undergoing (primary) PCI (the Dutch Cangrelor Registry).

STUDY DESIGN

The Cangrelor Registry is a prospective, observational, multicenter, single-arm registry with cangrelor administered pre-PCI in: (1) P2Y12 naive patients with ad-hoc PCI, (2) patients with STEMI/NSTEMI with suboptimal P2Y12 inhibition including (3) stable resuscitated/defibrillated patients with out-of-hospital cardiac arrest (OHCA) due to acute ischemia and (4) STEMI/NSTEMI patients with a high thrombotic burden. Primary endpoint is 48 h Net Adverse Clinical Events (NACE), which is a composite endpoint of all-cause death, recurrent myocardial infarction (MI), target vessel revascularization (TVR), stroke, stent thrombosis (ST) and BARC 2-3-5 bleeding. The Dutch Cangrelor Registry will assess the feasibility and safety of cangrelor in patients with suboptimal P2Y12 inhibition undergoing (primary) PCI in the setting of acute coronary syndrome (ACS) and stable coronary artery disease (CAD) in the Netherlands.

Impact Of Chronic Kidney Disease On The Pharmacodynamic And Pharmacokinetic Effects Of Ticagrelor In Patients With Diabetes Mellitus And Coronary Artery Disease

AIMS

Patients with diabetes mellitus (DM) and chronic kidney disease (CKD) are at increased risk of atherothrombotic events. Ticagrelor reduces ischaemic events compared to clopidogrel, with the greatest risk reduction in patients with both DM and CKD. How CKD status affects the pharmacodynamic (PD) and pharmacokinetic (PK) profiles of different ticagrelor maintenance dose regimens in patients with DM is unknown.

METHODS AND RESULTS

In this randomized, cross-over study, patients with DM on treatment with dual antiplatelet therapy (aspirin and clopidogrel) were stratified according to CKD status and randomized to ticagrelor 90 mg bid or 60 mg bid. PK/PD assessments were performed at baseline, after 7-10 days of ticagrelor (peak and trough), and after 7-10 days of alternative ticagrelor regimen (peak and trough). PK assessments included plasma concentrations of ticagrelor and its major metabolite. PD assessments included VASP-PRI, VerifyNow P2Y12, and LTA.A total of 92 patients with DM (CKD, n = 44; non-CKD, n = 48) were randomized. Levels of platelet reactivity were lower with the 90 mg compared with the 60 mg ticagrelor dose, which was statistically significant in non-CKD but not in CKD patients for most PD measures. There were no significant differences in the primary endpoint (trough levels of VASP-PRI following ticagrelor 90 mg dosing) between cohorts (31 ± 20 vs 25 ± 14; p = 0.105). VerifyNow and LTA provided similar findings. PK assessments tracked PD profiles showing increased plasma concentrations of ticagrelor and its major metabolite in CKD compared to non-CKD patients.

CONCLUSION

In patients with DM, although ticagrelor maintenance dose regimens (60 mg and 90 mg) yield potent P2Y12 inhibition, levels of platelet reactivity tended to be higher and subject to broader variability in non-CKD compared with CKD patients.

CLINICAL TRIAL REGISTRATION

http://www.clinicaltrials.gov Unique Identifier: NCT02539160.

Pharmacodynamic Effects of Pre-Hospital Administered Crushed Prasugrel in Patients With ST-Segment Elevation Myocardial Infarction

OBJECTIVES

This study sought to compare the pharmacodynamic effects of pre-hospitally administered P2Y₁₂ inhibitor prasugrel in crushed versus integral tablet formulation in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI).

BACKGROUND

Early dual antiplatelet therapy is recommended in STEMI patients. Yet, onset of oral P2Y₁₂ inhibitor effect is delayed and varies according to formulation administered.

METHODS

The COMPARE CRUSH (Comparison of Pre-hospital Crushed Versus Uncrushed Prasugrel Tablets in Patients With STEMI Undergoing Primary Percutaneous Coronary Interventions) trial randomized patients with suspected STEMI to crushed or integral prasugrel 60-mg loading dose in the ambulance. Pharmacodynamic measurements were performed at 4 time points: before antiplatelet treatment, at the beginning and end of pPCI, and 4 h after study treatment onset. The primary endpoint was high platelet reactivity at the end of pPCI. The secondary endpoint was impact of platelet reactivity status on markers of coronary reperfusion.

RESULTS

A total of 441 patients were included. In patients with crushed prasugrel, the occurrence of high platelet reactivity at the end of pPCI was reduced by almost one-half (crushed 34.7% vs. uncrushed 61.6%; odds ratio [OR] = 0.33; 95% confidence interval [CI] = 0.22 to 0.50; p < 0.01). Platelet reactivity <150 P2Y₁₂ reactivity units at the beginning of coronary angiography correlated with improved Thrombolysis In Myocardial Infarction flow grade 3 in the infarct artery pre-pPCI (OR: 1.78; 95% CI: 1.08 to 2.94; p = 0.02) but not ST-segment resolution (OR: 0.80; 95% CI: 0.48 to 1.34; p = 0.40).

CONCLUSIONS

Oral administration of crushed compared with integral prasugrel significantly improves platelet inhibition during the acute phase in STEMI patients undergoing pPCI. However, a considerable number of patients still exhibit inadequate platelet inhibition at the end of pPCI, suggesting the need for alternative agents to bridge the gap in platelet inhibition.

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.

Effects of morphine on P2Y12 platelet inhibitors in patients with acute myocardial infarction: A meta-analysis

OBJECTIVE

To explore the effects of morphine on P2Y₁₂ platelet inhibitors in patients with acute myocardial infarction (AMI).

METHODS

PubMed, Embase, Cochrane Library, and Web of Science were used to retrieve literature through 11th May 2019. Standardized weighted mean difference (SMD) and relative risk (RR) with 95% confidence intervals (CI), P-value, and I² value were used to assess the strength of the association in this meta-analysis. Outcomes included platelet reactivity, high residual platelet reactivity (HRPR), ticagrelor maximum concentration (Cmax), ticagrelor area under curve (AUC), death rate, reinfarction rate, stroke, stent thrombosis, thrombolysis in myocardial infarction (TIMI) hemorrhage, dyspnea, emesis, contrast-induced nephropathy, and pulmonary edema.

RESULTS

A total of 13 articles were included in this study, containing 5688 patients (morphine group: n = 2014, control group: n = 3674). Results illustrated that the morphine group had a higher platelet reactivity (SMD: 0.834, 95%CI: 0.483-1.186, P < 0.001) and HRPR rate (RR: 1.994, 95%CI: 1.536-2.588, P < 0.001) than the control group, while the Cmax of ticagrelor (WMD: -481.838, 95%CI: -841.242-122.434, P = 0.009) was lower than that of the control group. The death rate of the morphine group was lower than that in the control group (RR: 0.561, 95%CI: 0.337-0.933, P = 0.026). The morphine group had a higher emesis rate than the control group (RR: 4.486, 95%CI: 2.263-8.891, P < 0.001).

CONCLUSION

Morphine effectively suppresses the inhibition effect of P2Y₁₂ platelet inhibitors in patients with AMI.

Effect of Prehospital Crushed Prasugrel Tablets in Patients With ST-Segment–Elevation Myocardial Infarction Planned for Primary Percutaneous Coronary Intervention

Background:

Early treatment with a potent oral platelet P2Y 12 inhibitor is recommended in patients presenting with ST-segment–elevation myocardial infarction scheduled to undergo primary percutaneous coronary intervention (pPCI). The impact on coronary reperfusion of crushed P2Y 12 inhibitor tablets, which lead to more prompt and potent platelet inhibition, is unknown.

Methods:

We conducted a randomized controlled, multicenter trial in the Netherlands, enrolling patients with ST-segment–elevation myocardial infarction scheduled to undergo pPCI. Patients were randomly allocated to receive in the ambulance, before transfer, a 60-mg loading dose of prasugrel either as crushed or integral tablets. The independent primary end points were thrombolysis in myocardial infarction (TIMI) 3 flow in the infarct-related artery at initial coronary angiography, and complete (≥70%) ST-segment resolution 1 hour after pPCI. The safety end points were TIMI major and Bleeding Academic Research Consortium ≥3 bleedings. Secondary end points included platelet reactivity and ischemic outcomes.

Results:

A total of 727 patients were assigned to either crushed or integral tablets of prasugrel loading dose. The median time from study treatment to wire-crossing during pPCI was 57 (47–70) minutes. The primary end point TIMI 3 flow in the infarct-related artery before pPCI occurred in 31.0% in the crushed group versus 32.7% in the integral group (odds ratio, 0.92 [95% CI, 0.65–1.30], P =0.64). Complete ST-segment resolution 1 hour after pPCI was present in 59.9% in the crushed group versus 57.3% in the integral group (odds ratio, 1.11 [95% CI, 0.78–1.58], P =0.55). Platelet reactivity at the beginning of pPCI, measured as P2Y 12 reactivity unit, differed significantly between groups (crushed, 192 [132–245] versus integral, 227 [184–254], P ≤0.01). TIMI major and Bleeding Academic Research Consortium ≥3 bleeding occurred in 0% in the crushed group versus 0.8% in the integral group, and in 0.3% in the crushed group versus 1.1% in the integral group, respectively. There were no differences observed between groups regarding ischemic events at 30 days.

Conclusions:

Prehospital administration of crushed prasugrel tablets does not improve TIMI 3 flow in the infarct-related artery before pPCI or complete ST-segment resolution 1 h after pPCI in patients presenting with ST-segment–elevation myocardial infarction scheduled for pPCI.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03296540.

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.

Impact of opioids on P2Y12 receptor inhibition in patients with ST-elevation myocardial infarction who are pre-treated with crushed ticagrelor: Opioids aNd crushed Ticagrelor In Myocardial infarction Evaluation (ON-TIME 3) trial

Aims

Platelet inhibition induced by P2Y₁₂ receptor antagonists in patients with ST-elevation myocardial infarction (STEMI) can be affected by concomitant use of opioids. The aim of this trial was to examine the effect of intravenous (iv) acetaminophen compared with iv fentanyl on P2Y₁₂ receptor inhibition in patients with STEMI.

Methods and results

The Opioids aNd crushed Ticagrelor In Myocardial infarction Evaluation (ON-TIME 3) trial randomized 195 STEMI patients who were scheduled to undergo primary percutaneous coronary intervention (PCI) and were pre-treated with crushed ticagrelor to iv acetaminophen (N = 98) or iv fentanyl (N = 97) in the ambulance. The primary endpoint, consisting of the level of platelet reactivity units (PRU) measured immediately after primary PCI, was not significantly different between the study arms [median PRU 104 (IQR 37–215) vs. 175 (63–228), P = 0.18]. However, systemic levels of ticagrelor were significantly higher in the acetaminophen arm at the start of primary PCI [151 ng/mL (32–509) vs. 60 ng/mL (13–206), P = 0.007], immediately after primary PCI [326 ng/mL (94–791) vs. 115 ng/mL (38–326), P = 0.002], and at 1 h after primary PCI [488 ng/mL (281–974) vs. 372 ng/mL (95–635), P = 0.002]. Acetaminophen resulted in the same extent of pain relief when compared with fentanyl [reduction of 3 points on 10-step-pain scale before primary PCI (IQR 1–5)] in both study arms (P = 0.67) and immediately after PCI [reduction of 5 points (3–7); P = 0.96].

Conclusion

The iv acetaminophen in comparison with iv fentanyl was not associated with significantly lower platelet reactivity in STEMI patients but resulted in significantly higher ticagrelor plasma levels and was effective in pain relief.

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.

Rationale and design of the RIGHT trial: A multicenter, randomized, double-blind, placebo-controlled trial of anticoagulation prolongation versus no anticoagulation after primary percutaneous coronary intervention for ST-segment elevation myocardial infarction

BACKGROUND

Current guidelines recommend anticoagulation therapy during primary percutaneous coronary intervention (pPCI) for ST-segment elevation myocardial infarction (STEMI). However, whether anticoagulation should be continued after pPCI has not been well investigated.

METHODS/DESIGN

The RIGHT trial is a prospective, multicenter, randomized, double-blind, placebo-controlled trial in STEMI patients treated with pPCI evaluating the prolongation of anticoagulation after the procedure. Patients are randomized in a 1:1 fashion to receive either prolonged anticoagulant or matching placebo (no anticoagulation) for at least 48 hours after the procedure. When randomized to anticoagulation prolongation, the patient is assigned to intravenous unfractionated heparin (UFH) or subcutaneous enoxaparin or intravenous bivalirudin (same drug and same regimen at each center). The primary efficacy endpoint is the composite of all-cause death, non-fatal myocardial infarction, non-fatal stroke, stent thrombosis (definite) or urgent revascularization (any vessel) at 30 days. The primary safety endpoint is major bleeding (BARC 3-5) at 30 days. Based on a superiority design and assuming a 35% relative risk reduction (from 7% to 4.5%), 2856 patients will be enrolled, accounting for a 5% drop-out rate (α = 0.05 and power = 80%).

CONCLUSION

The RIGHT trial tests the hypothesis that post-procedural anticoagulation is superior to no anticoagulation in reducing ischemic events in STEMI patients undergoing pPCI.

Prolonged enoxaparin therapy compared with standard-of-care antithrombotic therapy in opiate-treated patients undergoing primary percutaneous coronary intervention

A novel enoxaparin regimen consisting of intra-arterial bolus (0.75 mg/kg) followed by intravenous infusion (0.75 mg/kg/6 hours) has been developed as a possible solution to the delayed absorption of oral P2Y₁₂ inhibitors in opiate-treated ST-elevation myocardial infarction (STEMI) patients undergoing primary angioplasty. We aimed to study the feasibility of this regimen as an alternative to standard-of-care treatment (SOC) with unfractionated heparin ± glycoprotein IIb/IIIa antagonist (GPI). One hundred opiate-treated patients presenting with STEMI and accepted for primary angioplasty were randomized (1:1) to either enoxaparin or SOC. Fifty patients were allocated enoxaparin (median age 61, 40% females) and 49 allocated SOC (median age 62, 22% females). One developed stroke before angiography and was withdrawn. One SOC patient had a gastrointestinal bleed resulting in 1 g drop in hemoglobin and early cessation of GPI infusion. Two enoxaparin patients had transient minor bleeding: one transient gingival bleed and one episode of coffee ground vomit with no hemoglobin drop or hemodynamic instability. Two SOC and no enoxaparin group patients had acute stent thrombosis. These preliminary data support further study of this novel 6-hour enoxaparin regimen in opiate-treated PPCI patients.

COMPARison of pre-hospital CRUSHed vs. uncrushed Prasugrel tablets in patients with STEMI undergoing primary percutaneous coronary interventions: Rationale and design of the COMPARE CRUSH trial

BACKGROUND

Dual antiplatelet therapy constitutes the cornerstone of medical treatment in patients with ST elevation myocardial infarction (STEMI). However, oral antiplatelet agents, such as prasugrel or ticagrelor, are characterized by slow gastrointestinal drug absorption in the acute phase of STEMI, leading to decreased bioavailability and therefore delayed onset of platelet inhibition. Evidence suggests that administration of crushed tablets of the P2Y₁₂ inhibitor prasugrel improves drug absorption and achieves earlier antiplatelet effects in STEMI patients undergoing primary percutaneous coronary intervention (PCI). However, the clinical implications of these pharmacokinetic and pharmacodynamic findings are unknown.

HYPOTHESIS

The present study is designed to test the hypothesis that patients presenting with STEMI planned for primary PCI will have improved markers of optimal reperfusion and clinical outcomes by prehospital administration of crushed tablets of prasugrel loading dose.

STUDY DESIGN

COMPARE CRUSH (NCT03296540) is a randomized trial in a regionally organized ambulance care setting evaluating the efficacy and safety of pre-hospital loading dose with prasugrel crushed tablets versus integral tablets in approximately 674 patients presenting with STEMI planned for primary PCI. The independent primary endpoints are percentage of patients reaching thrombolysis in myocardial infarction (TIMI) flow grade 3 in the infarct-related artery at initial angiography, or achieving ≥70% ST-segment elevation resolution at 1 hour post-PCI. Secondary clinical endpoints are death, myocardial infarction, revascularization, and stent thrombosis followed up to 1 year. Moreover, the primary safety endpoint is bleeding events assessed at 48 hours.

CONCLUSIONS

The COMPARE CRUSH trial will assess whether prehospital administration of loading dose prasugrel in form of crushed tablets - which is expected to provide faster platelet inhibition compared to standard treatment with integral tablets - results in improved reperfusion and clinical outcomes. RCT# NCT03296540.

Impact of Preadmission Morphine on Reinfarction in Patients With ST-Elevation Myocardial Infarction Treated With Percutaneous Coronary Intervention: A Meta-Analysis

Opiates are the traditional analgesics used in patients with ST-elevation myocardial infarction (STEMI). Pharmacodynamic studies indicate that opiates delay the absorption of orally administered P2Y₁₂ inhibitors and the onset of platelet inhibition. Whether these negative effects on platelet inhibition have an impact on clinical outcomes is unclear. A systematic review and meta-analysis was performed searching PubMed, MEDLINE, and Cochrane Central Register of Controlled Trials to identify studies comparing morphine and no-morphine treatment in STEMI patients undergoing primary percutaneous coronary intervention. The primary end point was the occurrence of in-hospital myocardial infarction, and secondary end points were in-hospital stroke and death. Four observational studies were identified, including 3,220 patients with STEMI. Morphine-treated patients had a higher unadjusted rate of reinfarction compared with patients not receiving morphine (1.5% vs. 0.67%, odds ratio (OR) 2.41; 95% confidence interval (CI), 1.11-5.21; P = 0.03). Unadjusted mortality rate was lower in morphine-treated patients (1.7% vs. 4.2%, OR 0.43, 95% CI, 0.23-0.81; P = 0.009). Exclusion of the study with baseline differences between groups showed more frequent reinfarction in the morphine group, but this was no longer statistically significant (1.3% vs. 0.5%, OR 2.02; 95% CI, 0.39-10.43; P = 0.40). There was no difference in stroke according to morphine treatment. Patients pretreated with morphine appear to have a higher rate of reinfarction than patients not receiving morphine. This may be attributable to opiate-related delay in P2Y₁₂ inhibitor absorption and resultant delay in onset of platelet inhibition. These concerning findings indicate the need for prospective, randomized trials to assess the impact of opiates on clinical outcomes in STEMI.

Platelet Inhibition With Cangrelor and Crushed Ticagrelor in Patients With ST-Segment-Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

BACKGROUND

The platelet inhibitory effects induced by oral P2Y₁₂ receptor antagonists are delayed in patients with ST-segment-elevation myocardial infarction undergoing primary percutaneous coronary intervention (P-PCI). In turn, this leads to a gap in platelet inhibition, exposing patients to an increased risk of early thrombotic complications and underscoring the need to define strategies associated with more effective platelet inhibition in the peri-primary percutaneous coronary intervention period. Cangrelor is an intravenous P2Y₁₂ inhibitor with prompt and potent antiplatelet effects. However, to date, there are limited data on the effects of cangrelor used in combination with ticagrelor in patients undergoing primary percutaneous coronary intervention. Moreover, questions have emerged on the potential for drug-drug interactions during the transition from cangrelor to oral P2Y₁₂ inhibitors.

METHODS

This was a prospective, randomized, double-blind, placebo-controlled pharmacodynamic study conducted in patients undergoing primary percutaneous coronary intervention (n=50) who were randomized to treatment with either cangrelor or matching placebo (bolus followed by 2-hour infusion). All patients received ticagrelor 180-mg loading dose administered as crushed tablets at the time of cangrelor/placebo bolus administration. Pharmacodynamic analyses were performed at 8 time points. Pharmacodynamic effects were measured as P2Y₁₂ reaction units by VerifyNow and platelet reactivity index by vasodilator-stimulated phosphoprotein.

RESULTS

Compared with placebo, cangrelor was associated with reduced P2Y₁₂ reaction units as early as 5 minutes after bolus, which persisted during the entire duration of drug infusion, including at 30 minutes (63 [32-93] versus 214 [183-245]; mean difference, 152 [95% CI, 108-195]; P<0·001; primary end point). Parallel findings were shown with platelet reactivity index. Accordingly, high on-treatment platelet reactivity rates were reduced with cangrelor. After discontinuation of cangrelor/placebo infusion, there were no differences in levels of platelet reactivity between groups, ruling out a drug-drug interaction when cangrelor and ticagrelor are concomitantly administered.

CONCLUSIONS

In patients undergoing primary percutaneous coronary intervention, cangrelor is an effective strategy to bridge the gap in platelet inhibition associated with the use of oral P2Y₁₂ inhibition induced by ticagrelor. Ticagrelor can be administered as a crushed formulation concomitantly with cangrelor without any apparent drug-drug interaction. The clinical implications of these pharmacodynamic findings warrant investigation in an adequately powered clinical trial.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov . Unique identifier: NCT03247738.

Drug-Drug Interactions in Acute Coronary Syndrome Patients: Systematic Review

Drug-drug interaction (DDI) is defined as a clinically significant change in the exposure and/or response to a drug caused by co-administration of another drug which may result in a precipitation of an adverse event or alteration of its therapeutic effects. The aim of this systematic review was to provide an overview of DDIs that were actually observed or evaluated in acute coronary syndrome (ACS) patients with particular focus on DDIs with clinical relevance. Electronic searches of the literature were conducted in the following databases: MEDLINE, EBSCO, Scopus, Google Scholar and SCIndeks. A total of 117 articles were included in the review. This review showed that ACS patients can be exposed to a variety of DDIs with diverse outcomes which include decreased efficacy of antiplatelet drugs, thrombolytics or anticoagulants, increased risk of bleeding, rhabdomyolysis, hepatotoxicity, adverse effects on cardiovascular system (e.g. QT interval prolongation, arrhythmias, excessive bradycardia, severe hypotension), serotonin syndrome and drug-induced fever. Majority of the DDIs involved antiplatelet drugs (e.g. aspirin, clopidogrel and ticagrelor). Evidence of some of the reported DDIs is inconclusive as some of the studies have shown conflicting results. There is a need for additional post-marketing and population-based studies to evaluate the true effects of disease states and other factors on the clinical outcomes of DDIs. Clinicians should be attentive to the potential for DDIs and their associated harm in order to minimize or, if possible, avoid medication-related adverse events in ACS patients.

Management of Out-of-Hospital Cardiac Arrest Complicating Acute Coronary Syndromes

PURPOSE OF THE REVIEW

Out-of-hospital cardiac arrest (OHCA) complicating acute coronary syndromes (ACS) continues to carry a high rate of morbidity and mortality despite significant advances in EMS and interventional cardiology services. In this review, we discuss an evidence-based approach to the initial care and management of patients with OHCA complicating ACS from the pre-hospital response and initial resuscitation strategy, to advanced therapies such as coronary angiography, targeted-temperature management, neuro-prognostication, and care of the post-arrest patient.

RECENT FINDINGS

Early recognition of cardiac arrest and prompt initiation of bystander CPR are the most important factors associated with improved survival. A comprehensive and coordinated approach to in-hospital management, including PCI, targeted temperature management, critical care, and hemodynamic support represents a significant critical link in the chain of survival. OHCA complicated by ACS continues to be one of the most challenging disease states facing healthcare practitioners and maintains a high mortality rate despite substantial advancements in healthcare delivery. A comprehensive approach to in-hospital management and further exploration of novel interventions, including ECMO, may yield opportunities to optimize care and improve outcomes for cardiac arrest patients.

Effects of Methylnaltrexone on Ticagrelor-Induced Antiplatelet Effects in Coronary Artery Disease Patients Treated With Morphine

OBJECTIVES

The aim of this study was to assess if intravenous methylnaltrexone can counteract the effects of morphine on the pharmacokinetic (PK) and pharmacodynamic (PD) profiles of ticagrelor.

BACKGROUND

Morphine delays the onset of action of oral P2Y₁₂ receptor inhibitors, including ticagrelor, by inhibiting gastric emptying and leading to delayed drug absorption. Methylnaltrexone is a peripheral opioid receptor antagonist that has the potential to prevent opioid-induced peripherally mediated side effects (e.g., gastric emptying inhibition) without affecting analgesia.

METHODS

In this prospective, randomized, double-blind, placebo-controlled, crossover study, aspirin-treated patients with stable coronary artery disease (n = 30) were randomized to receive methylnaltrexone (0.3 mg/kg intravenous) or matching placebo. After methylnaltrexone or placebo administration, all patients received morphine (5 mg intravenous). This was followed 15 min later by a 180-mg loading dose of ticagrelor. Patients crossed over to the alternative study treatment after 7 ± 2 days of washout. PK and PD assessments were performed at 12 time points (6 pre- and 6 post-crossover). PK analysis included measurement of plasma levels of ticagrelor and its major active metabolite (AR-C124910XX). PD assessments included VerifyNow P2Y₁₂, light transmittance aggregometry, and vasodilator-stimulated phosphoprotein.

RESULTS

Only marginal changes in plasma levels of ticagrelor (and its major active metabolite) were observed with ticagrelor: maximum plasma concentration and area under the plasma concentration versus time curve from time 0 to the last measurable concentration were 38% and 30% higher, respectively, in patients receiving methylnaltrexone compared with those receiving placebo, but no differences in time to maximum plasma concentration were observed. There were no differences in P2Y₁₂ reaction units by VerifyNow P2Y₁₂ between groups at each time point, including 2 h (the primary endpoint; p = 0.261). Similarly, there were no differences in PD markers assessed by light transmittance aggregometry and vasodilator-stimulated phosphoprotein.

CONCLUSIONS

In patients with coronary artery disease receiving morphine, intravenous administration of the peripheral opioid receptor antagonist methylnaltrexone leads to only marginal changes in plasma levels of ticagrelor and its major metabolite, without affecting levels of platelet reactivity. (Effect of Methylnaltrexone on the PK/PD Profiles of Ticagrelor in Patients Treated With Morphine; NCT02403830).

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.

Morphine in acute coronary syndrome: systematic review and meta-analysis

OBJECTIVE

Morphine is frequently used in acute coronary syndrome (ACS) due to its analgesic effect, it being recommended in the main cardiology guidelines in Europe and the USA. However, controversy exists regarding its routine use due to potential safety concerns. We conducted a systematic review of randomised-controlled trials (RCTs) and observational studies to synthesise the available evidence.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

CENTRAL, MEDLINE, EMBASE and trial registries.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

We included RCTs and observational studies evaluating the impact of morphine in cardiovascular outcomes or platelet reactivity measures.

DATA EXTRACTION AND SYNTHESIS

Data were screened, extracted and appraised by two independent reviewers. The data were pooled results using a random-effects model. Outcomes included in-hospital mortality, major adverse cardiovascular events (MACE), platelet reactivity (using VerifyNow) and bleeding, reported as relative risk (RR) with 95% CI. We assessed the confidence in the evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework. We followed the Meta-analysis Of Observational Studies in Epidemiology and Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

Five RCTs and 12 observational studies were included, enrolling 69 993 participants. Pooled results showed an increased risk of in-hospital mortality (RR 1.45 [95% CI 1.10 to 1.91], low GRADE confidence), MACE (RR 1.21, 95% CI 1.02 to 1.45) and an increased platelet reactivity at 1 and 2 hours (59.37 platelet reactivity units [PRU], 95% CI 36.04 to 82.71; 68.28 PRU, 95% CI 37.01 to 99.55, high GRADE confidence) associated with morphine. We found no significant difference in the risk of bleeding. We found no differences in subgroup analyses based on study design and ACS subtype.

CONCLUSIONS

Morphine was associated with an increased risk of in-hospital mortality and MACE but the high risk of bias leads to low result confidence. There is high confidence that morphine decreases the antiplatelet effect of P2Y12 inhibitors.

PROSPERO REGISTRATION NUMBER

CRD42016036357.

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.

Effect of morphine use on oral P2Y12 platelet inhibitors in acute myocardial infarction: Meta-analysis

BACKGROUND

Morphine is the recommended analgesic in acute myocardial infarction (AMI). This recommendation has come under scrutiny because of possible slow uptake of oral antiplatelet agents.

OBJECTIVE

We performed a meta-analysis of all available studies in AMI patients treated with prasugrel or ticagrelor (P2Y12 inhibitors) that reported use of morphine prior to loading the antiplatelet agents to critically assess the safety of co-administration of morphine and the newer P2Y12 inhibitors.

METHODS

Several sources were searched from inception to December 2017 with inclusion of eight studies, largely observational. Mean difference (MD) was calculated for continuous variables, and standardized mean difference (SMD) for platelet function was assessed by the various platelet assays, 2 h after the loading dose of oral P2Y12 inhibitors.

RESULTS

Higher platelet activity was noted among morphine group [SMD = 0.8, 95% confidence interval (CI) = 0.4-1.1, p < 0.01]. Morphine use caused higher odds of "high residual platelet reactivity" at 2 h (odds = 3.3, 95 %CI = 2.2-5.1, p < 0.01). Ticagrelor reached a lower plasma concentration in morphine group (MD = -481.8 ng/ml, 95% CI = -841.2 to -122.4 ng/ml, p < 0.01) with a higher vomiting rate (odds = 5.3, 95% CI = 2.5-11.1, p < 0.01). However, the composite of in-hospital mortality, stroke, and re-infarction was not significantly different between the groups (p = 0.83).

CONCLUSION

Co-administration of morphine with P2Y12 inhibitors possibly decreases their efficacy in platelet inhibition. However, this did not translate into higher adverse outcomes because of low event rates, inadequate for analysis. A large randomized study is needed to evaluate the narcotic-P2Y12 interaction.

Intravenous antiplatelet therapies (glycoprotein IIb/IIIa receptor inhibitors and cangrelor) in percutaneous coronary intervention: from pharmacology to indications for clinical use

Oral antiplatelet drugs are crucially important for patients with acute coronary syndrome or stable coronary artery disease undergoing percutaneous coronary intervention (PCI). In recent decades, several clinical trials have focused on reducing periprocedural ischemic events in patients undergoing PCI by means of more rapid platelet inhibition with the use of intravenous antiplatelet drugs. Glycoprotein IIb/IIIa receptor inhibitors (GPIs) block the final common pathway of platelet aggregation and enable potent inhibition in the peri-PCI period. In recent years, however, the use of GPIs has decreased due to bleeding concerns and the availability of more potent oral P2Y12 inhibitors. Cangrelor is an intravenous P2Y12 receptor antagonist. In a large-scale regulatory trial, cangrelor administration during PCI allowed for rapid, potent and rapidly reversible inhibition of platelet aggregation, with an anti-ischemic benefit and no increase in major bleeding. This article aims to provide an overview of general pharmacology, supporting evidence and current status of intravenous antiplatelet therapies (GPIs and cangrelor), with a focus on contemporary indications for their clinical use.

Metabolism of ticagrelor in patients with acute coronary syndromes

Ticagrelor is a state-of-the-art antiplatelet agent used for the treatment of patients with acute coronary syndromes (ACS). Unlike remaining oral P2Y12 receptor inhibitors ticagrelor does not require metabolic activation to exert its antiplatelet action. Still, ticagrelor is extensively metabolized by hepatic CYP3A enzymes, and AR-C124910XX is its only active metabolite. A post hoc analysis of patient-level (n = 117) pharmacokinetic data pooled from two prospective studies was performed to identify clinical characteristics affecting the degree of AR-C124910XX formation during the first six hours after 180 mg ticagrelor loading dose in the setting of ACS. Both linear and multiple regression analyses indicated that ACS patients presenting with ST-elevation myocardial infarction or suffering from diabetes mellitus are more likely to have decreased rate of ticagrelor metabolism during the acute phase of ACS. Administration of morphine during ACS was found to negatively influence transformation of ticagrelor into AR-C124910XX when assessed with linear regression analysis, but not with multiple regression analysis. On the other hand, smoking appears to increase the degree of ticagrelor transformation in ACS patients. Mechanisms underlying our findings and their clinical significance warrant further research.

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

Delayed onset of action of oral P2Y ₁₂ inhibitors in ST-elevation myocardial infarction (STEMI) patients may increase the risk of acute stent thrombosis. Available parenteral anti-thrombotic strategies, to deal with this issue, are limited by added cost and increased risk of bleeding. We investigated the pharmacodynamic effects of a novel regimen of enoxaparin in STEMI patients undergoing primary percutaneous coronary intervention (PPCI). Twenty patients were recruited to receive 0.75 mg/kg bolus of enoxaparin (pre-PPCI) followed by infusion of enoxaparin 0.75 mg/kg/6 h. At four time points (pre-anti-coagulation, end of PPCI, 2–3 hours into infusion and at the end of infusion), anti-Xa levels were determined using chromogenic assays, fibrin clots were assessed by turbidimetric analysis and platelet P2Y ₁₂ inhibition was determined by VerifyNow P2Y12 assay. Clinical outcomes were determined 14 hours after enoxaparin initiation. Nineteen of 20 patients completed the enoxaparin regimen; one patient, who developed no-reflow phenomenon, was switched to tirofiban after the enoxaparin bolus. All received ticagrelor 180 mg before angiography. Mean (± standard error of the mean) anti-Xa levels were sustained during enoxaparin infusion (1.17 ± 0.06 IU/mL at the end of PPCI and 1.003 ± 0.06 IU/mL at 6 hours), resulting in prolonged fibrin clot lag time and increased lysis potential. Onset of platelet P2Y ₁₂ inhibition was delayed in opiate-treated patients. No patients had thrombotic or bleeding complications. In conclusion, enoxaparin 0.75 mg/kg bolus followed by 0.75 mg/kg/6 h provides sustained anti-Xa levels in PPCI patients. This may protect from acute stent thrombosis in opiate-treated PPCI patients who frequently have delayed onset of oral P2Y ₁₂ inhibition.

A Case of Atrioventricular Block Potentially Associated with Right Coronary Artery Lesion and Ticagrelor Therapy Mediated by the Increasing Adenosine Plasma Concentration

Purpose

To report a case of atrioventricular block (AVB) which might be associated with the right coronary artery lesion and the novel oral antithrombotic drug ticagrelor mediated by the increasing adenosine plasma concentration (APC).

Case Report

A 65-year-old man was given loading dose of ticagrelor (180 mg) before coronary angiography with total thrombotic occlusion of right coronary artery and one stent was implanted. On second day after successful percutaneous coronary intervention, ECG monitoring showed second-degree (Mobitz type I) AVB with prolonged PR interval (299 ms). Hypothesis was drawn that elevated APC levels caused by ticagrelor would be the reason for AVB after excluding combination drugs or underlying disease. APC might be an indicator of this side effect caused by the P2Y12 receptor inhibitors. On fourth day after shifting to clopidogrel, the ECG showed normal sinus rhythm and PR interval depressed to 190 ms and APC dropped from 1.62 umol/L to 0.92 umol/L. The bradycardia and AVB did not occur in the three-month follow-up.

Conclusion

It was important to take the ticagrelor induced bradycardia into account particularly with the myocardial infarction of right coronary artery, treated with atrioventricular block drugs after initiating ticagrelor. Also, we should shift ticagrelor to clopidogrel if AVB occurred.

No Benefit of Ticagrelor Pretreatment Compared With Treatment During Percutaneous Coronary Intervention in Patients With ST-Segment–Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

Background—

The effects of ticagrelor pretreatment in patients with ST-segment–elevation myocardial infarction undergoing primary percutaneous coronary intervention (PCI) is debated. This study investigated the effects of ticagrelor pretreatment on clinical outcomes in this patient group.

Methods and Results—

Patients with ST-segment–elevation myocardial infarction undergoing primary PCI were included from October 2010 to October 2014 in Sweden. Screening was done using the SWEDEHEART register (Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies). A total of 7433 patients were included for analysis with 5438 patients receiving ticagrelor pretreatment and 1995 patients with ticagrelor given only in the catheterization laboratory. The primary end point of the study was 30-day event rates of a composite of all-cause mortality, myocardial infarction (MI), and stent thrombosis. Secondary end points were mortality, MI, or stent thrombosis alone and major in-hospital bleeding. Crude event rates showed no difference in 30-day composite end point (6.2% versus 6.5%; P=0 .69), mortality (4.5% versus 4.7%; P=0 .86), MI (1.6% versus 1.7%; P=0 .72), or stent thrombosis (0.5% versus 0.4%; P=0 .80) with ticagrelor pretreatment. Three different statistical models were used to correct for baseline differences. No difference in the composite end point, mortality, MI, or stent thrombosis was seen between the 2 groups after statistical adjustment. No increase in in-hospital major bleeding rate was observed with ticagrelor pretreatment.

Conclusions—

Ticagrelor pretreatment versus ticagrelor given in the catheterization laboratory in patients with ST-segment–elevation myocardial infarction undergoing primary PCI did not improve the composite end point of all-cause mortality or MI or stent thrombosis or its individual components at 30 days.

Ticagrelor - toward more efficient platelet inhibition and beyond

Novel antiplatelet drugs, including ticagrelor, are being successively introduced into the therapy of atherothrombotic conditions due to their superiority over a standard combination of clopidogrel with acetylsalicylic acid in patients with acute coronary syndromes (ACS). A P2Y12 receptor antagonist, ticagrelor, is unique among antiplatelet drugs, because ticagrelor inhibits the platelet P2Y12 receptor in a reversible manner, and because it demonstrates a wide palette of advantageous pleiotropic effects associated with the increased concentration of adenosine. The pleiotropic effects of ticagrelor comprise cardioprotection, restoration of the myocardium after an ischemic event, promotion of the release of anticoagulative factors and, eventually, anti-inflammatory effects. Beyond the advantageous effects, the increased concentration of adenosine is responsible for some of ticagrelor's adverse effects, including dyspnea and bradycardia. Large-scale clinical trials demonstrated that both standard 12-month therapy and long-term use of ticagrelor reduce the risk of cardiovascular events in patients with ACS, but at the expense of a higher risk of major bleeding. Further trials focused on the use of ticagrelor in conditions other than ACS, including ischemic stroke, peripheral artery disease and status after coronary artery bypass grafting. The results of these trials suggest comparable efficacy and safety of ticagrelor and clopidogrel in extra-coronary indications, but firm conclusions are anticipated from currently ongoing studies. Here, we summarize current evidence on the superiority of ticagrelor over other P2Y12 antagonists in ACS, discuss the mechanism underlying the drug-drug interactions and pleiotropic effects of ticagrelor, and present future perspectives of non-coronary indications for ticagrelor.

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

It was the study objective to evaluate whether chewing a 180 mg loading dose of ticagrelor versus an equal dose of traditional oral administration, enhances inhibition of platelet aggregation 1 hour (h) after administering a ticagrelor loading dose in non-ST elevation myocardial infarction (NSTEMI) patients. Dual anti-platelet therapy represents standard care for treating NSTEMI patients. Ticagrelor is a direct acting P2Y12 inhibitor and, unlike clopidogrel and prasugrel, does not require metabolic activation. Fifty NSTEMI patients were randomised to receive either a chewing loading dose of 180 mg ticagrelor or an equal standard oral dose of ticagrelor. Platelet reactivity was evaluated by VerifyNow at baseline, 1 and 4 h post-loading dose. Results are reported in P2Y12 reaction units. Patients then continued to receive standard 90 mg oral ticagrelor twice daily. Baseline characteristics did not differ between the two groups. P2Y12 reaction units in the chewing group compared with the standard group at 0, 1 and 4 h after ticagrelor loading dose were: 245 vs 239 (p=0.59), 45 vs 130 (p=0.001) and 39 vs 60 (p=0.12), respectively, corresponding to a relative inhibition of platelet aggregation of 83 % vs only 47 % at 1 h (p< 0.001), and 84 % vs 77 % (p=0.59) at 4 h. Major adverse cardiac and cardiovascular events at 30 days were low (2 %), occurring in only one patient in the standard group. In conclusion, chewing a 180 mg ticagrelor loading dose is feasible and facilitates both faster and improved early inhibition of platelet aggregation in NSTEMI patients, compared with a standard oral-loading dose.

Supplementary Material to this article is available online at www.thrombosis-online.com.

P2Y12 Receptor Antagonists and Morphine: A Dangerous Liaison?

P2Y12 receptor antagonists, concurrently administered with aspirin in what has come to be commonly called dual antiplatelet therapy, are a mainstay of treatment for patients with acute coronary syndromes. Morphine, on the contrary, is a commonly used drug in the acute phase of acute coronary syndromes to relieve pain-with the added potential benefit of attenuating acutely raised sympathetic tone. In current guidelines, though, morphine is recommended with decreasing strength of recommendation. One reason is that it raises concern regarding the potentially significant interaction with antiplatelet agents, leading to impaired inhibition of platelet activation. In any case, it is still considered a mandatory part of the inventory of available medications in prehospital acute myocardial infarction management. The goal of the present review is to present published evidence on morphine and its potential interactions with P2Y12 receptor antagonists, as well as on the central issue of whether such interactions may underlie clinically significant effects on patient outcomes.

Pharmacodynamics and pharmacokinetics of ticagrelor vs. clopidogrel in patients with acute coronary syndromes and chronic kidney disease

BACKGROUND

Pivotal clinical trials found that ticagrelor reduced ischaemic complications to a greater extent than clopidogrel, and also that the benefit gradually increased with the reduction in creatinine clearance. However, the underlying mechanisms remains poorly explored.

METHODS

This was a single-centre, prospective, randomized clinical trial involving 60 hospitalized Adenosine Diphosphate (ADP) P2Y12 receptor inhibitor-naïve patients with chronic kidney disease (CKD) (estimated glomerular filtration rate <60 ml min^-1 1.73 m^-2 ) and non-ST-elevation acute coronary syndromes (NSTE-ACS). Eligible patients were randomly assigned in a 1:1 ratio to receive ticagrelor (180 mg loading dose, then followed by 90 mg twice daily) or clopidogrel (600 mg loading dose, then followed by 75 mg once daily). The primary endpoint was the P2Y12 reactive unit (PRU) value assessed by VerifyNow at 30 days. The plasma concentrations of ticagrelor and clopidogrel and their active metabolites were measured in the first 10 patients in each group at baseline, and at 1 h, 2 h, 4 h, 8 h, 12 h and 24 h after the loading dose.

RESULTS

Baseline characteristics were well matched between the two groups. Our results indicated a markedly lower PRU in patients treated with ticagrelor vs. clopidogrel at 30 days (32.6 ± 11.29 vs. 203.7 ± 17.92; P < 0.001) as well as at 2 h, 8 h and 24 h after the loading dose (P < 0.001). Ticagrelor and its active metabolite AR-C124910XX showed a similar time to reach maximum concentration (C_max ) of 8 h, with the maximum concentration (C_max ) of 355 (242.50-522.00) ng ml^-1 and 63.20 (50.80-85.15) ng ml^-1 , respectively. Both clopidogrel and its active metabolite approached the C_max at 2 h, with a similar C_max of 8.67 (6.64-27.75) ng ml^-1 vs. 8.53 (6.94-15.93) ng ml^-1 .

CONCLUSION

Ticagrelor showed much more potent platelet inhibition in comparison with clopidogrel in patients with CKD and NSTE-ACS.

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).

Comparison of Ticagrelor Pharmacokinetics and Pharmacodynamics in STEMI and NSTEMI Patients (PINPOINT): protocol for a prospective, observational, single-centre study

INTRODUCTION

The most common classification of acute myocardial infarction (AMI) is based on electrocardiographic findings and distinguishes ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI). Both types of AMI differ concerning their epidemiology, clinical approach and early outcomes. Ticagrelor is a P2Y12 receptor inhibitor, constituting the first-line treatment for STEMI and NSTEMI. According to available data, STEMI may be associated with lower plasma concentration of ticagrelor in the first hours of AMI, but currently there are no studies directly comparing ticagrelor pharmacokinetics or antiplatelet effect in patients with STEMI versus NSTEMI.

METHODS AND ANALYSIS

The PINPOINT study is a phase IV, single-centre, investigator-initiated, prospective, observational study designed to compare the pharmacokinetics and pharmacodynamics of ticagrelor in patients with STEMI and NSTEMI assigned to the invasive strategy of treatment. Based on an internal pilot study, the trial is expected to include at least 23 patients with each AMI type. All subjects will receive a 180 mg loading dose of ticagrelor. The primary end point of the study is the area under the plasma concentration-time curve (AUC_(0-6)) for ticagrelor during the first 6 hours after the loading dose. Secondary end points include various pharmacokinetic features of ticagrelor and its active metabolite (AR-C124910XX), and evaluation of platelet reactivity by the vasodilator-stimulated phosphoprotein assay and multiple electrode aggregometry. Blood samples for the pharmacokinetic and pharmacodynamic assessment will be obtained at pretreatment, 30 min, 1, 2, 3, 4, 6 and 12 hours post-ticagrelor loading dose.

ETHICS AND DISSEMINATION

The study received approval from the Local Ethics Committee (Komisja Bioetyczna Uniwersytetu Mikołaja Kopernika w Toruniu przy Collegium Medicum im. Ludwika Rydygiera w Bydgoszczy; approval reference number KB 617/2015). The study results will be disseminated through conference presentations and peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT02602444; Pre-results.

Comparison of Platelet Reactivity in Black Versus White Patients With Acute Coronary Syndromes After Treatment With Ticagrelor

Ticagrelor, a potent platelet inhibitor, has primarily been studied in white patients. Platelet reactivity among black patients with acute coronary syndrome (ACS) on ticagrelor, however, is unknown. Our objective was to compare platelet reactivity in black versus white patients with ACS treated with ticagrelor. We conducted a prospective, pharmacodynamic study of 29 black patients with ACS treated with ticagrelor. Platelet reactivity was assessed at 1, 4, and 8 hours after a loading dose of ticagrelor 180 mg and at 30 days on a maintenance dose of ticagrelor 90 mg twice daily. Assays included light transmission aggregometry, VerifyNow P2Y12, and vasodilator-stimulated phosphoprotein. We provided comparison with a historical white cohort. Platelet reactivity among blacks with ACS on ticagrelor was similar to that in whites, except that blacks had lower values at 4 hours, 8 hours, and on maintenance therapy for light transmission aggregometry with 20 μmol/L adenosine diphosphate. Among blacks, high-on-treatment platelet reactivity for all 3 assays was uncommon at 1 hour and nonexistent at 4 hours, 8 hours, and while on maintenance therapy. Blacks preloaded with clopidogrel (n = 17) had significantly lower results of VerifyNow (64 ± 65 vs 198 ± 86, p <0.001) and vasodilator-stimulated phosphoprotein (12.8 ± 21.6 vs 58.9 ± 19.9, p <0.001) at 1 hour compared with those with no clopidogrel preload. In conclusion, among patients with ACS receiving ticagrelor, levels of platelet reactivity in blacks are similar to that in whites. This suggests that the cardiovascular benefits of ticagrelor observed in the platelet inhibition and patient outcomes (PLATO) trial are likely to be observed in blacks and whites.