Prehospital initiation of tirofiban in patients with ST-elevation myocardial infarction undergoing primary angioplasty (On-TIME 2): a multicentre, double-blind, randomised controlled trial

Chinese expert consensus on the diagnosis and treatment of coronary microvascular diseases (2023 Edition)

Since the four working groups of the Chinese Society of Cardiology issued first expert consensus on coronary microvascular diseases (CMVD) in 2017, international consensus documents on CMVD have increased rapidly. Although some of these documents made preliminary recommendations for the diagnosis and treatment of CMVD, they did not provide classification of recommendations and levels of evidence. In order to summarize recent progress in the field of CMVD, standardize the methods and procedures of diagnosis and treatment, and identify the scientific questions for future research, the four working groups of the Chinese Society of Cardiology updated the 2017 version of the Chinese expert consensus on CMVD and adopted a series of measures to ensure the quality of this document. The current consensus has raised a new classification of CMVD, summarized new epidemiological findings for different types of CMVD, analyzed key pathological and molecular mechanisms, evaluated classical and novel diagnostic technologies, recommended diagnostic pathways and criteria, and therapeutic strategies and medications, for patients with CMVD. In view of the current progress and knowledge gaps of CMVD, future directions were proposed. It is hoped that this expert consensus will further expedite the research progress of CMVD in both basic and clinical scenarios.

Tirofiban-induced thrombocytopenia

Tirofiban is a small non-peptide ligand-mimetic Glycoprotein (GP) IIb/IIIa inhibitor which can reversibly bind to the arginine-glycine-aspartic acid (RGD) recognition site of GP IIb/IIIa to prevent platelet aggregation. It reduces the incidence of thrombotic cardiovascular events in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS). Although generally considered safe, tirofiban has been reported to be associated with thrombocytopenia in several case reports and clinical trials. The pathogenesis for this adverse reaction is not entirely understood, is thought to be due to immune-mediated reaction. This side effect caused by tirofiban is especially concerning given how frequently it is used in the practice of contemporary cardiovascular care. The present review provides an overview of the pathophysiology, clinical presentation, management, and risk factors associated with tirofiban-induced thrombocytopenia.

Adverse Drug Effect Profiles of Gp2b/3a Inhibitors: A Comparative Review of the Last Two Decades

ST-Elevation Myocardial Infarction and non-ST Elevation Myocardial Infarction belong to the acute coronary syndrome group of diseases. These conditions are characterized by the complete or partial blockage of one or several coronary arteries, resulting in myocardial injury or necrosis. Various medications are used in their treatment, with the most recent addition being Glycoprotein IIb/IIIa inhibitors. They work by hindering the activity of glycoprotein IIb/IIIa receptors, which, in turn, prevents the clumping of platelets. Some of the GpIIb/IIIa inhibitors available in this category include abciximab, tirofiban, eptifibatide, roxifiban, and orbofiban. With this comprehensive literature review, we aimed to explore the potential adverse effects of these medications and compare the three in terms of their side effects profile. We searched through PubMed and Google Scholar and pinpointed 13 articles aligned with our inclusion criteria: six articles utilized eptifibatide, four were related to abciximab, and three used tirofiban. In 85% of the cases, a severe drop in platelet count, reaching as low as 1000/μL, was reported. Additionally, several other side effects were noted: one case documented multiple bruising spots appearing around the patient's body, two cases reported diffuse alveolar hemorrhage, and one case described a cardiac tamponade resulting from hemorrhagic pericarditis. Our study highlights the crucial significance of keeping a watchful eye on and comprehending the potential drawbacks linked to these medications in cardiovascular treatment. The necessity of researching these medications and their side effects is also evident, as this will significantly enhance the quality of treatment provided.

Comparison of the effects of the GPIIb-IIIa antagonist Zalunfiban and the P2Y12 antagonist Selatogrel on Platelet Aggregation

Understanding the pharmacodynamic effects of platelet inhibitors is standard for developing more effective antithrombotic therapies. An example is the antithrombotic treatment of acute coronary syndrome (ACS), in particular ST-elevated myocardial infarction (STEMI) patients who are in need for rapid acting strong antithrombotic therapy despite the use of aspirin and oral P2Y12-inhibitors. In this study, we evaluated two injectable platelet inhibitors under clinical development (the P2Y12 antagonist selatogrel and the GPIIb-IIIa antagonist zalunfiban) that may be amenable to pre-hospital treatment of STEMI patients. Platelet reactivity was assessed at inhibitor concentrations that represent clinically relevant levels of platelet inhibition (IC20-50%, 1/2Cmax, and Cmax). Light transmission aggregometry (LTA), was used to evaluate the initial rate of aggregation (primary slope, PS) and maximal aggregation (MA). Both adenosine diphosphate (ADP) and thrombin receptor agonist peptide (TRAP) were used as agonists. Zalunfiban demonstrated similar inhibition of platelet aggregation when blood was collected in PPACK or TSC, whereas selatogrel demonstrated greater inhibition in PPACK. In this study, using PPACK anticoagulant, selatogrel and zalunfiban affected PS in response to ADP equivalently at all drug concentrations tested. In contrast, zalunfiban had significantly greater potency at its Cmax concentration compared to selatogrel using TRAP as agonist. Upon evaluation of MA responses at lower doses, selatogrel had greater inhibition of MA in response to ADP than zalunfiban; however, at concentrations that represent Cmax, the drugs were equivalent. Zalunfiban also had greater inhibition of MA in response to TRAP at the Cmax dose. These data suggest that zalunfiban may provide greater protection in reducing thrombus formation than selatogrel, especially since thrombin is an early, key primary agonist in the pathophysiology of thrombotic events.

Beneficial Effects of IABP in Anterior Myocardial Infarction Complicated by Cardiogenic Shock

Background and Objectives. Recent guidelines have downgraded the routine use of the intra-aortic balloon pump (IABP) in patients with cardiogenic shock (CS) due to ST-elevation myocardial infarction (STEMI). Despite this, its use in clinical practice remains high. The aim of this study was to evaluate the prognostic impact of the IABP in patients with STEMI complicated by CS undergoing primary PCI (pPCI), focusing on patients with anterior MI in whom a major benefit has been previously hypothesized. Materials and Methods. We enrolled 2958 consecutive patients undergoing pPCI for STEMI in our department from 2005 to 2018. Propensity score matching and mortality analysis were performed. Results. CS occurred in 246 patients (8.3%); among these patients, 145 (60%) had anterior AMI. In the propensity-matched analysis, the use of the IABP was associated with a lower 30-day mortality (39.3% vs. 60.9%, p = 0.032) in the subgroup of patients with anterior STEMI. Conversely, in the whole group of CS patients and in the subgroup of patients with non-anterior STEMI, IABP use did not have a significant impact on mortality. Conclusions. The use of the IABP in cases of STEMI complicated by CS was found to improve survival in patients with anterior infarction. Prospective studies are needed before abandoning or markedly limiting the use of the IABP in this clinical setting.

Safety and efficacy of tirofiban in the management of stroke: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

About 30 % of stroke patients have experienced unsuccessful reperfusion following endovascular therapy. Mechanical thrombectomy instruments may contribute to this by stimulating platelet aggregation. Tirofiban is a selective and rapidly activated antagonist of the platelets nonpeptide glycoprotein IIb/IIIa receptors that can reversibly suppress platelet aggregation. But, data from the medical literature are conflicting regarding its safety and efficacy for stroke patients. Hence, this study was designed to assess the safety and efficacy of tirofiban in stroke patients.

METHODS

Five major databases (PubMed, Scopus, Web of Science, Embase, and Cochrane library) were searched till December 2022. The Cochrane tool was used for risk of bias assessment, and the RevMan 5.4 was utilized for data analysis.

RESULTS

Seven RCTs with 2088 stroke patients were included. Tirofiban significantly increased the number of patients with mRS 0 score after 90 days than control; RR= 1.39, 95 %CI [1.15, 1.69]; p = 0.0006. Additionally, it reduced the NIHSS score after seven days; MD= -0.60, 95 %CI [-1.14, -0.06]; p = 0.03. However, tirofiban increased the incidence of intracranial haemorrhage (ICH); RR= 1.22, 95 %CI [1.03, 1.44]; p = 0.02. Other assessed outcomes showed insignificant results.

CONCLUSIONS

Tirofiban was associated with a higher mRS 0 score after three months and a lower NIHSS score after seven days. However, it is associated with higher ICH. Multicentric trials are required to provide more convincing proof of its utility.

What do we know about platelets in myocardial ischemia-reperfusion injury and why is it important?

Myocardial ischemia-reperfusion injury (MIRI), the joint result of ischemic injury and reperfusion injury, is associated with poor outcomes in patients with acute myocardial infarction undergoing primary percutaneous coronary intervention. Accumulating evidence demonstrates that activated platelets directly contribute to the pathogenesis of MIRI through participating in the formation of microthrombi, interaction with leukocytes, secretion of active substances, constriction of microvasculature, and activation of spinal afferent nerves. The molecular mechanisms underlying the above detrimental effects of activated platelets include the homotypic and heterotypic interactions through surface receptors, transduction of intracellular signals, and secretion of active substances. Revealing the roles of platelet activation in MIRI and the associated mechanisms would provide potential targets/strategies for the clinical evaluation and treatment of MIRI. Further studies are needed to characterize the temporal (ischemia phase vs. reperfusion phase) and spatial (systemic vs. local) distributions of platelet activation in MIRI by multi-omics strategies. To improve the likelihood of translating novel cardioprotective interventions into clinical practice, basic researches maximally replicating the complexity of clinical scenarios would be necessary.

Coronary No-Reflow after Primary Percutaneous Coronary Intervention-Current Knowledge on Pathophysiology, Diagnosis, Clinical Impact and Therapy

Coronary no-reflow (CNR) is a frequent phenomenon that develops in patients with ST-segment elevation myocardial infarction (STEMI) following reperfusion therapy. CNR is highly dynamic, develops gradually (over hours) and persists for days to weeks after reperfusion. Microvascular obstruction (MVO) developing as a consequence of myocardial ischemia, distal embolization and reperfusion-related injury is the main pathophysiological mechanism of CNR. The frequency of CNR or MVO after primary PCI differs widely depending on the sensitivity of the tools used for diagnosis and timing of examination. Coronary angiography is readily available and most convenient to diagnose CNR but it is highly conservative and underestimates the true frequency of CNR. Cardiac magnetic resonance (CMR) imaging is the most sensitive method to diagnose MVO and CNR that provides information on the presence, localization and extent of MVO. CMR imaging detects intramyocardial hemorrhage and accurately estimates the infarct size. MVO and CNR markedly negate the benefits of reperfusion therapy and contribute to poor clinical outcomes including adverse remodeling of left ventricle, worsening or new congestive heart failure and reduced survival. Despite extensive research and the use of therapies that target almost all known pathophysiological mechanisms of CNR, no therapy has been found that prevents or reverses CNR and provides consistent clinical benefit in patients with STEMI undergoing reperfusion. Currently, the prevention or alleviation of MVO and CNR remain unmet goals in the therapy of STEMI that continue to be under intense research.

Prepercutaneous coronary intervention Zalunfiban dose-response relationship to target vessel blood flow at initial angiogram in st-elevation myocardial infarction - A post hoc analysis of the cel-02 phase IIa study

BACKGROUND

Zalunfiban (RUC-4) is a novel, subcutaneously administered glycoprotein IIb/IIIa inhibitor (GPI) designed for prehospital treatment to initiate reperfusion in the infarct-related artery (IRA) before primary percutaneous coronary intervention in patients with ST-elevation myocardial infarction (STEMI). Since GPIs have been reported to rapidly reperfuse IRAs, we assessed whether there was a dose-dependent relationship between zalunfiban treatment and angiographic reperfusion indices and thrombus grade of the IRA at initial angiogram in patients with STEMI.

METHODS

This was a post hoc analysis from the open-label Phase IIa study that investigated the pharmacodynamics, pharmacokinetics, and tolerability of three doses of zalunfiban - 0.075, 0.090 and 0.110 mg/kg - in STEMI patients. This analysis explored dose-dependent associations between zalunfiban and three angiographic indices of the IRA, namely coronary and myocardial blood flow and thrombus burden. Zalunfiban was administered in the cardiac catheterization laboratory prior to vascular access, ∼10 to 15 minutes before the initial angiogram. All angiographic data were analyzed by a blinded, independent, core laboratory.

RESULTS

Twentyfour out of 27 STEMI patients were evaluable for angiographic analysis (0.075 mg/kg [n=7], 0.090 mg/kg [n=9], and 0.110 mg/kg [n=8]). TIMI flow grade 2 or 3 was seen in 1/7 patients receiving zalunfiban at 0.075 mg/kg, in 6/9 patients receiving 0.090 mg/kg, and in 7/8 patients receiving 0.110 mg/kg (ptrend = 0.004). A similar trend was observed based on TIMI flow grade 3. Myocardial perfusion was also related to zalunfiban dose (ptrend = 0.005) as reflected by more frequent TIMI myocardial perfusion grade 3. Consistent with the dose-dependent trends in greater coronary and myocardial perfusion, TIMI thrombus ≥4 grade was inversely related to zalunfiban dose (ptrend = 0.02).

CONCLUSION

This post hoc analysis found that higher doses of zalunfiban administered in the cardiac catheterization lab prior to vascular access were associated with greater coronary and myocardial perfusion, and lower thrombus burden at initial angiogram in patients with STEMI undergoing primary percutaneous coronary intervention.

Association between intravenous tirofiban and intracranial hemorrhage in acute large vessel occlusion stroke: insight from the RESCUE BT randomized placebo-controlled trial

BACKGROUND

The aim of this study is to investigate the association between intravenous tirofiban and symptomatic intracranial hemorrhage (SICH) in patients with acute ischemic stroke (AIS) secondary to large vessel occlusion (LVO) receiving endovascular thrombectomy (EVT) within 24 h of time last known well (LKW).

METHODS

Patients with AIS-LVO who were randomly assigned to receive intravenous tirofiban or placebo before EVT within 24 h of time LKW and had follow-up brain non-contrast computed tomography within 24 h after stopping tirofiban treatment were derived from "RESCUE BT": a multicenter, randomized, placebo-controlled, double-blind trial. All eligible patients were divided into SICH and NO-SICH groups. Subgroup analyses were performed to explore for heterogeneity.

RESULTS

Of 945 patients included in this cohort, there were 76 (8.0%) in the SICH group and 869 (92.0%) in the NO-SICH group. The incidence of SICH was not higher in patients receiving intravenous tirofiban compared with placebo (adjusted risk ratio (RR), 1.51; 95% confidence interval (CI), 0.97-2.36; P = 0.07). Subgroup analyses showed that age greater than 67-year-old (adjusted RR, 2.18; 95% CI 1.18-4.00), NIHSS greater than 16 (adjusted RR, 1.88; 95% CI 1.06-3.34), and cardioembolism (adjusted RR, 3.73; 95% CI 1.66-8.35) were associated with increased SICH risk.

CONCLUSIONS

In patients with acute large vessel occlusion stroke, intravenous tirofiban before EVT within 24 h of time from last known well is not associated with increased risk of SICH. Patients who are older, have more severe neurological deficits, or with cardioembolism are at higher risk of SICH with intravenous tirofiban.

TRIAL REGISTRATION NUMBER

URL: http://www.chictr.org.cn ; Unique identifier: ChiCTR-INR-17014167.

Prehospital treatment with zalunfiban (RUC-4) in patients with ST- elevation myocardial infarction undergoing primary percutaneous coronary intervention: Rationale and design of the CELEBRATE trial

BACKGROUND

Early and complete restoration of target vessel patency in ST-elevation myocardial infarction (STEMI) is associated with improved outcomes. Oral P2Y₁₂ inhibitors have failed to demonstrate either improved patency or reduced mortality when administered in the prehospital setting. Thus, there is a need for antiplatelet agents that achieve prompt and potent platelet inhibition, and that restore patency in the prehospital setting. Zalunfiban, a novel subcutaneously administered glycoprotein IIb/IIIa inhibitor designed for prehospital administration, has shown to achieve rapid, high-grade platelet inhibition that exceeds that of P2Y₁₂ inhibitors. Whether prehospital administration of zalunfiban can improve clinical outcome is unknown.

HYPOTHESIS

The present study is designed to assess the hypothesis that a single, prehospital injection of zalunfiban given in the ambulance, in addition to standard-of-care in patients with STEMI with intent to undergo primary percutaneous coronary intervention (PCI) will improve clinical outcome compared to standard-of-care with placebo.

STUDY DESIGN

The ongoing CELEBRATE trial (NCT04825743) is a phase 3, randomized, double-blinded, placebo-controlled, international trial. Patients with STEMI intended to undergo primary PCI will receive treatment with a single subcutaneous injection containing either zalunfiban dose 1 (0.110 mg/kg), zalunfiban dose 2 (0.130 mg/kg) or placebo, and the study drug will be administered in the ambulance before transportation to the hospital. A target of 2499 patients will be randomly assigned to one of the treatment groups in a 1:1:1 ratio, ie, to have approximately 833 evaluable patients per group. The primary efficacy outcome is a ranked 7-point scale on clinical outcomes. The primary safety outcome is severe or life-threatening bleeding according to the Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO) criteria.

SUMMARY

The CELEBRATE trial will assess whether a single prehospital subcutaneous injection of zalunfiban in addition to standard-of-care in patients with STEMI with intent to undergo primary PCI will result in improved clinical outcome.

Antiplatelet Therapy in Coronary Artery Disease: Now and Then

Cardiovascular disease, particularly coronary artery disease (CAD), remains the leading cause of mortality and morbidity in industrialized countries. Platelet activation and aggregation at the site of endothelial injury play a key role in the processes ultimately resulting in thrombus formation with vessel occlusion and subsequent end-organ damage. Consequently, antiplatelet therapy has become a mainstay in the pharmacological treatment of CAD. Several drug classes have been developed over the last decades and a broad armamentarium of antiplatelet agents is currently available. This review portrays the evolution of antiplatelet therapy, and provides an overview on previous and current antiplatelet drugs and strategies.

Spontaneous Reperfusion in Patients with Transient ST-Elevation Myocardial Infarction-Prevalence, Importance and Approaches to Management

Patients with transient ST-elevation myocardial infarction (STEMI) or spontaneous resolution (SpR) of the ST-segment elevation on electrocardiogram could potentially represent a unique group of patients posing a therapeutic management dilemma. In this review, we discuss the potential mechanisms underlying SpR, its relation to clinical outcomes and the proposed management options for patients with transient STEMI with a focus on immediate versus early percutaneous coronary intervention. We performed a structured literature search of PubMed and Cochrane Library databases from inception to December 2020. Studies focused on SpR in patients with acute coronary syndrome were selected. Available data suggest that deferral of angiography and revascularization within 24-48 h in these patients is reasonable and associated with similar or perhaps better outcomes than immediate angiography. Further randomized trials are needed to elucidate the best pharmacological and invasive strategies for this cohort.

Parenteral Antiplatelet Drugs in ST-Elevation Myocardial Infarction: Current Status and Future Directions

Oral inhibitors of the platelet P2Y₁₂ receptor are indispensable in the treatment of ST-elevation myocardial infarction (STEMI), improving outcomes and even reducing mortality in some studies. However, these drugs are limited by delayed absorption and suboptimal platelet inhibition at the time of primary percutaneous coronary intervention. Despite efforts to achieve faster and more sustained platelet inhibition, strategies such as prehospital administration, higher loading doses, and crushed formulations have not led to improved coronary reperfusion. Parenteral glycoprotein IIb/IIIa inhibitors act sooner and are more potent than oral P2Y₁₂ inhibitors, but their use has been limited by the increased risk of major bleeding and thrombocytopenia. Hence, there is a clinical need to refine drugs that deliver rapid, effective, yet safe platelet inhibition in the setting of STEMI. Novel parenteral antiplatelet drugs, such as cangrelor, selatogrel, and zalunfiban, have been recently developed to achieve rapid, potent antiplatelet effects while preserving hemostasis. We provide a description of currently available parenteral antiplatelet agents and of those in clinical development for prehospital administration in STEMI patients.

Association of Intravenous Tirofiban with Functional Outcomes in Acute Ischemic Stroke Patients with Acute Basilar Artery Occlusion Receiving Endovascular Thrombectomy

INTRODUCTION

The aim of this study was to test the hypothesis that intravenous tirofiban improves functional outcomes without promoting the risk of intracranial hemorrhage (ICH) in stroke secondary to basilar artery occlusion (BAO) receiving endovascular thrombectomy.

METHODS

Patients with acute BAO stroke who were treated with endovascular thrombectomy and had tirofiban treatment information were derived from "BASILAR": a nationwide, prospective registry. All eligible patients were divided into tirofiban and no-tirofiban groups according to whether tirofiban was used intravenously. The primary endpoint was the 90-day severity of disability as assessed by the modified Rankin scale score. Safety outcomes were the frequency of ICH and mortality.

RESULTS

Of 645 patients included in this cohort, 363 were in the tirofiban group and 282 were in the no-tirofiban group. Thrombectomy with intravenous tirofiban reduced the 90-day disability level over the range of the modified Rankin scale (adjusted common odds ratio, 2.08; 95% confidence interval (CI), 1.45-2.97; p < 0.001). The 90-day mortality of patients in the tirofiban group was lower than that in the no-tirofiban group (41.6% vs. 52.1%; adjusted hazard ratio, 0.60; 95% CI, 0.47-0.77; p < 0.001). The frequency of any ICH (6.7% vs. 13.7%; p = 0.004) and symptomatic ICH (4.8% vs. 10.1%; p = 0.01) in the tirofiban group was significantly lower than that in the no-tirofiban group.

CONCLUSIONS

In patients with acute BAO stroke who underwent endovascular treatment, intravenous tirofiban might be associated with favorable outcome, reduced mortality, and a decreased frequency of ICH.

Intracoronary bolus of glycoprotein IIb/IIIa inhibitor as bridging or adjunctive strategy to oral P2Y12 inhibitor load in the modern setting of ST-elevation myocardial infarction

BACKGROUND

In the acute management of ST-elevation myocardial infarction (STEMI), glycoprotein IIb/IIIa inhibitors (GPIs) bolus not followed by intravenous infusion is potentially advantageous given their fast onset and offset of action, but clinical evidence in a contemporary setting is limited.

METHODS

We collected data from consecutive STEMI patients admitted to the cardiac catheterization laboratory of the IRCCS A. Gemelli University Polyclinic Foundation from October 2017 to September 2019.

RESULTS

Out of 423 consecutive STEMI patients, 297 met the inclusion and exclusion criteria and were included in the study. Of them, 107/297 (36%) received an intracoronary GPI bolus-only during primary percutaneous coronary intervention (PPCI) not followed by intravenous infusion and 190/297 (64%) received standard antithrombotic therapy. Of the 107 GPI-treated, 22/107 (21%) had P2Y<inf>12</inf> inhibitor pretreatment (adjunctive strategy) and 85/107 (79%) did not (bridging strategy). During hospital staying, there was no difference in the primary safety endpoint of TIMI major+minor bleeding (P=0.283), TIMI major (P=0.267) or TIMI minor (P=0.685) bleeding between groups. No stroke event occurred in the GPI group. Despite patients receiving GPI having a significantly higher intraprocedural ischemic burden, no significant differences were found in the efficacy outcomes between groups. Consistent findings were observed for patients receiving GPIs bolus before (bridging strategy) or after (adjunctive strategy) P2Y<inf>12</inf> inhibitors, compared to those receiving standard therapy. Multivariate logistic regression analyses did not find any independent predictors significantly associated to the primary and secondary composite endpoints.

CONCLUSIONS

In a contemporary real-world population of STEMI patients undergoing PPCI, the use of intracoronary GPIs bolus-only in selected patients at high ischemic risk is safe and could represent a useful antithrombotic strategy both in those pretreated and in those naïve to P2Y<inf>12</inf> inhibitors.

Current and Future Insights for Optimizing Antithrombotic Therapy to Reduce the Burden of Cardiovascular Ischemic Events in Patients with Acute Coronary Syndrome

The pharmacological treatment strategies for acute coronary syndrome (ACS) in recent years are constantly evolving to develop more potent antithrombotic agents, as reflected by the introduction of more novel P2Y₁₂ receptor inhibitors and anticoagulants to reduce the ischemic risk among ACS patients. Despite the substantial improvements in the current antithrombotic regimen, a noticeable number of ACS patients continue to experience ischemic events. Providing effective ischemic risk reduction while balancing bleeding risk remains a clinical challenge. This updated review discusses the currently approved and widely used antithrombotic agents and explores newer antithrombotic treatment strategies under development for the initial phase of ACS.

Effect of Intravenous Tirofiban vs Placebo Before Endovascular Thrombectomy on Functional Outcomes in Large Vessel Occlusion Stroke: The RESCUE BT Randomized Clinical Trial

IMPORTANCE

Tirofiban is a highly selective nonpeptide antagonist of glycoprotein IIb/IIIa receptor, which reversibly inhibits platelet aggregation. It remains uncertain whether intravenous tirofiban is effective to improve functional outcomes for patients with large vessel occlusion ischemic stroke undergoing endovascular thrombectomy.

OBJECTIVE

To assess the efficacy and adverse events of intravenous tirofiban before endovascular thrombectomy for acute ischemic stroke secondary to large vessel occlusion.

DESIGN, SETTING, AND PARTICIPANTS

This investigator-initiated, randomized, double-blind, placebo-controlled trial was implemented at 55 hospitals in China, enrolling 948 patients with stroke and proximal intracranial large vessel occlusion presenting within 24 hours of time last known well. Recruitment took place between October 10, 2018, and October 31, 2021, with final follow-up on January 15, 2022.

INTERVENTIONS

Participants received intravenous tirofiban (n = 463) or placebo (n = 485) prior to endovascular thrombectomy.

MAIN OUTCOMES AND MEASURES

The primary outcome was disability level at 90 days as measured by overall distribution of the modified Rankin Scale scores from 0 (no symptoms) to 6 (death). The primary safety outcome was the incidence of symptomatic intracranial hemorrhage within 48 hours.

RESULTS

Among 948 patients randomized (mean age, 67 years; 391 [41.2%] women), 948 (100%) completed the trial. The median (IQR) 90-day modified Rankin Scale score in the tirofiban group vs placebo group was 3 (1-4) vs 3 (1-4). The adjusted common odds ratio for a lower level of disability with tirofiban vs placebo was 1.08 (95% CI, 0.86-1.36). Incidence of symptomatic intracranial hemorrhage was 9.7% in the tirofiban group vs 6.4% in the placebo group (difference, 3.3% [95% CI, -0.2% to 6.8%]).

CONCLUSIONS AND RELEVANCE

Among patients with large vessel occlusion acute ischemic stroke undergoing endovascular thrombectomy, treatment with intravenous tirofiban, compared with placebo, before endovascular therapy resulted in no significant difference in disability severity at 90 days. The findings do not support use of intravenous tirofiban before endovascular thrombectomy for acute ischemic stroke.

TRIAL REGISTRATION

Chinese Clinical Trial Registry Identifier: ChiCTR-IOR-17014167.

Effects of early myocardial reperfusion and perfusion on myocardial necrosis/dysfunction and inflammation in patients with ST-segment and non-ST-segment elevation acute coronary syndrome: results from the PLATelet inhibition and patients Outcomes (PLATO) trial

Aims

Restoration of myocardial blood flow and perfusion during percutaneous coronary intervention (PCI) measured using Thrombolysis in Myocardial Infarction (TIMI) flow grade (TFG) and perfusion grade (TMPG) is associated with improved outcomes in acute coronary syndrome (ACS). Associations between TFG/TMPG and changes in biomarkers reflecting myocardial damage/dysfunction and inflammation is unknown.

Methods and results

Among 2606 patients included, TFG was evaluated in 2198 and TMPG in 1874 with ST-segment elevation myocardial infarction (STEMI) or non-ST-segment ACS (NSTE-ACS). Biomarkers reflecting myocardial necrosis [troponin T (TnT)], myocardial dysfunction [N-terminal prohormone brain natriuretic peptide (NT-proBNP)], inflammation [interleukin-6 (IL-6) and C-reactive protein (CRP)], and oxidative stress/ageing/inflammation [growth differentiation factor-15 (GDF-15)] were measured at baseline, discharge, and 1- and 6-month post-randomization. Associations between TFG/TMPG and changes in biomarker levels were evaluated using the Mann–Whitney–Wilcoxon signed test. In total, 1423 (54.6%) patients had STEMI and 1183 (45.4%) NSTE-ACS. Complete reperfusion after PCI with TFG = 3 was achieved in 1110 (85.3%) with STEMI and in 793 (88.5%) with NSTE-ACS. Normal myocardial perfusion with TMPG = 3 was achieved in 475 (41.6%) with STEMI and in 396 (54.0%) with NSTE-ACS. Levels of TnT, NT-proBNP, IL-6, CRP, and GDF-15 were substantially lower at discharge in patients with complete vs. incomplete TFG and STEMI (P < 0.01). This pattern was not observed for patients with NSTE-ACS. Patients with normal vs. abnormal TMPG and NSTE-ACS had lower levels of NT-proBNP at discharge (P = 0.01).

Conclusions

Successful restoration of epicardial blood flow in STEMI was associated with less myocardial necrosis/dysfunction and inflammation. Attainment of normal myocardial perfusion was associated with less myocardial dysfunction in NSTE-ACS.

Antiplatelet Agents in Acute ST Elevation Myocardial Infarction

Platelet aggregation and thrombus formation represent the basic mechanism for clinical, electrocardiographic, and biomarker changes consistent with acute coronary syndrome. Various oral and intravenous formulations of platelet function inhibitors have been developed to help decrease platelet aggregation due to acute atherosclerotic plaque rupture. In this article, we review the various mechanisms, pharmacokinetics/pharmacodynamics, and the key clinical trials related to the platelet inhibitors that form the basis for current recommendations of their use in the ST elevation myocardial infarction guidelines by the American College of Cardiology/American Heart Association.

“No-Reflow” Phenomenon: A Contemporary Review

Primary percutaneous angioplasty (pPCI), represents the reperfusion strategy of choice for patients with STEMI according to current international guidelines of the European Society of Cardiology. Coronary no-reflow is characterized by angiographic evidence of slow or no anterograde epicardial flow, resulting in inadequate myocardial perfusion in the absence of evidence of mechanical vessel obstruction. No reflow (NR) is related to a functional and structural alteration of the coronary microcirculation and we can list four main pathophysiological mechanisms: distal atherothrombotic embolization, ischemic damage, reperfusion injury, and individual susceptibility to microvascular damage. This review will provide a contemporary overview of the pathogenesis, diagnosis, and treatment of NR.

Periprocedural Antithrombotic Treatment in Complex Percutaneous Coronary Intervention

ABSTRACT

In recent years, the management of complex lesions in patients undergoing percutaneous coronary intervention (PCI) constitutes a field of high interest and concern for the interventional cardiology. As more and more studies demonstrate the increased hazard of ischemic events in this group of patients, it is of paramount importance for the physicians to choose the optimal periprocedural (pre-PCI, during-PCI and post-PCI) antithrombotic treatment strategies wisely. Evidence regarding the safety and efficacy of current anticoagulation recommendation, the possible beneficial role of the pretreatment with a potent P2Y12 inhibitor in the subgroup of patients with non-ST segment elevation myocardial infarction with complex lesions, and the impact of a more potent P2Y12 inhibitor in individuals with stable coronary artery disease undergoing complex PCI are needed. This will provide and serve as a guide to clinicians to deploy the maximum efficacy of the current choices of antithrombotic therapy, which will lead to an optimal balance between safety and efficacy in this demanding clinical scenario.

Primary Percutaneous Coronary Intervention with High-Bolus Dose Tirofiban: The FASTER (Favorite Approach to Safe and Effective Treatment for Early Reperfusion) Multicenter Registry

Objectives

To investigate the safety and clinical efficacy of tirofiban during primary percutaneous coronary interventions (pPCI).

Background

Gp IIb/IIIa inhibitors (GPI) use during pPCI has declined over years, mainly for the increased hemorrhagic risk associated to their use and for the availability of potent, fast-acting oral antiplatelet drugs. However, several pharmacodynamic studies showed suboptimal platelet inhibition with P2Y12-blockers, such as prasugrel or ticagrelor.

Methods

Patients with ST-segment elevation myocardial infarction (STEMI) undergoing pPCI were prospectively enrolled in a multicenter registry conducted in high-volume centers in Italy. All patients received intraprocedural tirofiban. The primary safety endpoint was the occurrence of in-hospital bleedings according to the Bleeding Academic Research Consortium definition. In-hospital major adverse coronary events (MACE, defined as death, reinfarction, stent thrombosis, and target vessel revascularization), final TIMI flow, myocardial blush grade, and ST-segment resolution were also evaluated.

Results

A total of 472 patients (mean age 61 ± 11 years, 83% males) were enrolled in 16 Italian centers from October 2015 to June 2018. Mean basal thrombus grade score was 3.47 ± 1.25. PCI was performed by transradial approach in 88% of patients. We observed a very low rate of 30 days BARC bleedings (2.1%) and MACE (0.8%). Complete (>70%) ST-segment resolution was observed in 67% of patients.

Conclusions

In the FASTER registry, the use of tirofiban during primary PCI, performed with a transradial approach in most cases, in patients with high thrombus burden was associated with high rates of complete ST-segment resolution and low rates of in-hospital bleeding and MACE.

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.

Pre-Hospital Antiplatelet Therapy for STEMI Patients Undergoing Primary Percutaneous Coronary Intervention: What We Know and What Lies Ahead

Early recanalization of the infarct-related artery to achieve myocardial reperfusion is the primary therapeutic goal in patients with ST-elevation myocardial infarction (STEMI). To decrease the duration of ischaemia, continuous efforts have been made to improve pre-hospital treatment and to target the early period after symptom onset. In this period the platelet content of the fresh coronary thrombus is maximal and the thrombi are dynamic, and thus more susceptible to powerful antiplatelet agents. There have been substantial advances in antiplatelet therapy in the last three decades with several classes of oral and intravenous antiplatelet agents with different therapeutic targets, pharmacokinetics, and pharmacodynamic properties. New parenteral drugs achieve immediate inhibition of platelet aggregation, and fast and easy methods of administration may create the opportunity to bridge the initial gap in platelet inhibition observed with oral P2Y12 inhibitors. Moreover, potential future management of STEMI could directly involve patients in the process of care with self-administered antiplatelet agents designed to achieve rapid reperfusion. However, the potential anti-ischaemic benefits of potent antiplatelet agents will need to be balanced against their risk of increased bleeding. This study presents a comprehensive and updated review of pre-hospital antiplatelet therapy among STEMI patients undergoing primary percutaneous intervention and explores new therapies under development.

Intralesional delivery of glycoprotein IIb/IIIa inhibitors in acute myocardial infarction: Review and recommendations

Plaque rupture leads to a cascade of events culminating in collagen disruption, tissue factor release, platelet activation and thrombus formation. Pro-inflammatory conditions, hyperglycemia and smoking predispose to high thrombus burden (HTB) which is an independent predictor of slow or no-reflow. In patients with acute myocardial infarction (AMI), glycoprotein IIb/IIIa inhibitors (GPI) reduce thrombus burden and improve myocardial perfusion. These agents are typically administered systemically via the intravenous route or locally via an intracoronary (IC) route. However, as higher local concentrations of GPI are associated with enhanced platelet inhibition, intralesional (IL) GPI administration may be particularly effective in cases of HTB. Modest-sized randomized trials comparing IL and IC GPI delivery have reported conflicting outcomes. Some trials have demonstrated improved coronary flow and myocardial perfusion with reduced major adverse cardiac events with IL compared with IC GPI administration, whereas others have shown no significant benefits. Furthermore, although no direct comparison has been made between IL delivery using an aspiration catheter, microcatheter or a dedicated balloon-based "weeping" infusion-catheter, improved outcomes have been most consistent following GPI administration at the site of the lesion and thrombus with the dedicated infusion catheter. This review provides an update on the role and outcomes of IL GPI administration in patients with AMI and HTB. Based on the evidence we offer an algorithm demonstrating when to consider IL administration in patients with AMI undergoing intervention. We conclude with a perspective on the management of patients with STEMI and COVID-19 in whom a prothrombotic state often results in HTB.

The effectiveness of alprostadil in treating coronary microcirculation dysfunction following ST-segment elevation myocardial infarction in a pig model

Though alprostadil has been reported to improve the impaired microcirculation of patients with pulmonary arterial hypertension, its effectiveness as a treatment for coronary microvasculature dysfunction (CMD) following ST-segment elevation myocardial infarction (STEMI) is unknown. A total of 18 miniature pigs with CMD following STEMI were randomized into three groups that received an intracoronary injection of 5 ml of normal saline, 2 mg of nicorandil or 10 µg of alprostadil immediately after measurement of the index of microcirculatory resistance (IMR) and then an intravenous drip containing 5 ml of normal saline, 2 mg of nicorandil or 10 µg of alprostadil once a day for 6 days. The IMR, cardiac function using ultrasound, infarct areas and heparanase levels in infarct areas were measured and compared between the three groups. The IMR decreased markedly 10 min after alprostadil or nicorandil intracoronary injection (both P<0.05) but not following saline injection (P>0.05). After 7 days, the IMR was substantially lower in the alprostadil and nicorandil groups compared with the saline group (both P<0.05) and the ejection fraction was considerably higher in the alprostadil and nicorandil groups compared with the saline group (both P<0.05). Differences in infarct areas and the relative heparanase expression levels among the 3 groups were similar to the differences in the ejection fraction. No significant differences in the above assessment indexes were identified in the alprostadil and nicorandil groups. Alprostadil infusion improved coronary microcirculation function, reduced the infarct area and limited left ventricular dilatation in a pig coronary microvasculature dysfunction model following STEMI.

Effect of GP IIb/IIIa inhibitor duration on the clinical prognosis of primary percutaneous coronary intervention in ST-segment elevation myocardial infarction with no-/slow-reflow phenomenon

BACKGROUND

In patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI) accompanied by the no-/slow-reflow phenomenon, the maintenance duration of GP IIb/IIIa inhibitor (GPI) is controversial. We compare the efficacy and safety of short- and long-term GPI infusion in STEMI patients with the no-/slow-reflow phenomenon.

METHODS

From June 2016 to December 2019, we continuously included patients with on-set STEMI who underwent pPCI, accompanied by the no-/slow-reflow, during interventional procedures at Guangdong Provincial People's Hospital and Zhuhai Golden Bay Hospital. The hemorrhage events, heart function, and major adverse cardiovascular events (MACE) were compared between < 24 h and ≥ 24 h GPI duration groups. The Kaplan-Meier curve was used to estimate the 1-year MACE-free survival at different GPI utility times.

RESULTS

In total, 127 patients were divided into two groups based on the duration of tirofiban use (less and more than 24 h). There was no significant difference between two groups in terms of baseline characteristics, plaque condition, and coronary physiological function. The two groups showed similar in-hospital MACE (1 [1.85%] vs. 4 [5.48%], p = 0.394) and 1-year MACE-free survival (log-rank test p = 0.9085). The 1-year MACE remained consistent between the two groups in all subgroups of different risk factors of no-/slow-reflow. There was no significant difference in heart function and in-hospital hemorrhage events (3.7% vs. 1.37%, p = 0.179).

CONCLUSION

In the real world, prolonging the duration of GPI may not significantly improve the clinical outcome in patients with STEMI with no-/slow-reflow.

Application of Auxiliary VerifyNow Point-of-Care Assays to Assess the Pharmacodynamics of RUC-4, a Novel αIIbβ3 Receptor Antagonist

Introduction  Prehospital therapy of ST-elevation myocardial infarction (STEMI) with αIIbβ3 antagonists improves clinical outcomes, but they are difficult to use in prehospital settings. RUC-4 is a novel αIIbβ3 antagonist being developed for prehospital therapy of STEMI that rapidly achieves high-grade platelet inhibition after subcutaneous administration. Standard light transmission aggregometry (LTA) is difficult to perform during STEMI, so we applied VerifyNow (VN) assays to assess the pharmacodynamics of RUC-4 relative to aspirin and ticagrelor.

Methods  Blood from healthy volunteers was anticoagulated with phenylalanyl-prolyl-arginyl chloromethyl ketone (PPACK) or sodium citrate, treated in vitro with RUC-4, aspirin, and/or ticagrelor, and tested with the VN ADP + PGE ₁ , iso-TRAP, and base channel (high concentration iso-TRAP + PAR-4 agonist) assays. The results were correlated with both ADP (20 µM)-induced LTA and flow cytometry measurement of receptor occupancy and data from individuals treated in vivo with RUC-4.

Results  RUC-4 inhibited all three VN assays, aspirin did not affect the assays, and ticagrelor markedly inhibited the ADP + PGE ₁ assay, slightly inhibited the iso-TRAP assay, and did not inhibit the base channel assay. RUC-4's antiplatelet effects were potentiated in citrate compared with PPACK. Cut-off values were determined to correlate the results of the VN iso-TRAP and base channel assays with 80% inhibition of LTA.

Conclusion  The VN assays can differentiate the early potent anti-αIIbβ3 effects of RUC-4 from delayed effects of P2Y12 antagonists in the presence of aspirin. These pharmacodynamic assays can help guide the clinical development of RUC-4 and potentially be used to monitor RUC-4's effects in clinical practice.

Acute Coronary Syndromes (ACS)-Unravelling Biology to Identify New Therapies-The Microcirculation as a Frontier for New Therapies in ACS

In acute coronary syndrome (ACS) patients, restoring epicardial culprit vessel patency and flow with percutaneous coronary intervention or coronary artery bypass grafting has been the mainstay of treatment for decades. However, there is an emerging understanding of the crucial role of coronary microcirculation in predicting infarct burden and subsequent left ventricular remodelling, and the prognostic significance of coronary microvascular obstruction (MVO) in mortality and morbidity. This review will elucidate the multifaceted and interconnected pathophysiological processes which underpin MVO in ACS, and the various diagnostic modalities as well as challenges, with a particular focus on the invasive but specific and reproducible index of microcirculatory resistance (IMR). Unfortunately, a multitude of purported therapeutic strategies to address this unmet need in cardiovascular care, outlined in this review, have so far been disappointing with conflicting results and a lack of hard clinical end-point benefit. There are however a number of exciting and novel future prospects in this field that will be evaluated over the coming years in large adequately powered clinical trials, and this review will briefly appraise these.

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.

Efficacy and safety of glycoprotein IIb/IIIa inhibitors in addition to P2Y12 inhibitors in ST-segment elevation myocardial infarction: A subanalysis of the POPular Genetics trial

BACKGROUND

Glycoprotein IIb/IIIa inhibitors (GPI) are still used in patients with ST-segment elevation myocardial infarction (STEMI) who undergo primary percutaneous coronary intervention (PCI), although discussion about its clinical benefit is ongoing.

METHODS

GPI use was analyzed in this subanalysis of the POPular Genetics trial, which randomized STEMI patients to CYP2C19 genotype-guided treatment (clopidogrel or ticagrelor) or standard treatment with ticagrelor/prasugrel. The composite thrombotic endpoint consisted of cardiovascular death, myocardial infarction (MI), definite stent thrombosis, and stroke at 30 days. The combined bleeding endpoint consisted of Platelet Inhibition and Patient Outcomes (PLATO) major and minor bleeding at 30 days. Univariable and multivariable analyses in addition to a propensity score-matched (PSM) analysis were conducted.

RESULTS

In total, 2378 patients, of whom 1033 received GPI and 1345 did not, were included. In multivariable analysis, GPI administration was associated with fewer thrombotic events (hazard ratio [HR] 0.22, 95% confidence interval [CI] 0.09-0.55) and MIs (HR 0.24, 95% CI 0.08-0.73). Furthermore, GPI administration was associated with an increase in bleedings (HR 2.02, 95% CI 1.27-3.19), driven by minor bleedings (HR 2.32, 95% CI 1.43-3.76), without a significant difference in major bleedings (HR 0.69, 95% CI 0.19-2.57). In the PSM analysis, no significant association was found.

CONCLUSION

In STEMI patients undergoing primary PCI, GPI administration was associated with a reduction in thrombotic events at a cost of an increase in (mostly minor) bleedings in multivariable analysis, while propensity score analysis did not show significant associations.

Pre-hospital heparin use for ST-elevation myocardial infarction is safe and improves angiographic outcomes

AIMS

This study aims to evaluate if pre-hospital heparin administration by paramedics is safe and improves clinical outcomes.

METHODS AND RESULTS

Using the multicentre Victorian Cardiac Outcomes Registry, linked with state-wide ambulance records, we identified consecutive patients undergoing primary percutaneous coronary intervention for STEMI between January 2014 and December 2018. Information on thrombolysis in myocardial infarction (TIMI) flow at angiography was available in a subset of cases. Patients receiving pre-hospital heparin were compared to those who did not receive heparin. Findings at coronary angiography and 30-day clinical outcomes were compared between groups. Propensity-score matching was performed for risk adjustment. We identified a total of 4720 patients. Of these, 1967 patients had TIMI flow data available. Propensity-score matching in the entire cohort yielded 1373 matched pairs. In the matched cohort, there was no observed difference in 30-day mortality (no-heparin 3.5% vs. heparin 3.0%, P = 0.25), MACCE (no-heparin 7% vs. heparin 6.2%, P = 0.44), and major bleeding (no-heparin 1.9% vs. heparin 1.4%, P = 0.64) between groups. Propensity-score analysis amongst those with TIMI data produced 552 matched pairs. The proportion of cases with TIMI 0 or 1 flow in the infarct-related artery (IRA) was lower among those receiving pre-hospital heparin (66% vs. 76%, P < 0.001) compared to those who did not.

CONCLUSION 

In this multicentre, propensity-score matched study, the use of pre-hospital heparin by paramedics was safe and is associated with fewer occluded IRAs in patients presenting with STEMI.

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.

NT-proBNP level before primary PCI and risk of poor myocardial reperfusion: Insight from the On-TIME II trial

BACKGROUND

N-terminal fragment of the brain natriuretic peptide prohormone (NT-proBNP), a marker for neurohumoral activation, has been associated with adverse outcome in patients with myocardial infarction. NT-proBNP levels may reflect extensive ischemia and microvascular damage, therefore we investigated the potential association between baseline NT-proBNP level and ST-resolution (STR), a marker of myocardial reperfusion, after primary percutaneous coronary intervention (pPCI).

METHODS

we performed a post-hoc analysis of the On-TIME II trial (which randomized ST-elevation myocardial infarction (STEMI) patients to pre-hospital tirofiban administration vs placebo). Patients with measured NT-proBNP before angiography were included. Multivariate logistic-regression analyses was performed to investigate the association between baseline NTproBNP level and STR one hour after pPCI.

RESULTS

Out of 984 STEMI patients, 918 (93.3%) had NT-proBNP values at baseline. Patients with STR <70% had higher NT-proBNP values compared to patients with complete STR (>70%) [Mean ±SD 375.2 ±1021.7 vs 1007.4 ±2842.3, Median (IQR) 111.7 (58.4-280.0) vs 168.0 (62.3-601.3), P <.001]. At multivariate logistic regression analysis, independent predictors associated with higher risk of poor myocardial reperfusion (STR <70%) were: NT-proBNP (OR 1.17, 95%CI 1.04-1.31, P = .009), diabetes mellitus (OR 1.87, 95%CI 1.14-3.07, P = .013), anterior infarct location (OR 2.74, 95% CI 2.00-3.77, P <.001), time to intervention (OR 1.06, 95%CI 1.01-1.11, P = .021), randomisation to placebo (OR 1.45, 95%CI 1.05-1.99, P = .022).

CONCLUSIONS

In STEMI patients, higher baseline NT-proBNP level was independently associate with higher risk of poor myocardial reperfusion, supporting the potential use of NT-proBNP as an early marker for risk stratification of myocardial reperfusion after pPCI in STEMI patients.

Efficacy and safety of abciximab versus tirofiban in addition to ticagrelor in STEMI patients undergoing primary percutaneous intervention

Platelet glycoprotein IIb/IIIa inhibitors (GPIs) have been part of the adjuvant treatment of acute coronary syndrome for years. However, real-life data regarding the efficacy and safety of GPIs under the current indications are lacking in the setting of potent platelet inhibition. The objectives were to assess the efficacy and safety of abciximab versus tirofiban in patients with ST-elevation acute myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI) and pretreated with ticagrelor, and to identify independent predictor factors of efficacy, bleeding and platelet drop. Three hundred sixty-two patients were divided by GPI administered. Clinical, laboratory, angiographic and outcome characteristics were compared. The primary objective was a composite efficacy endpoint (death from any cause, nonfatal myocardial infarction and nonfatal stroke) at 30 days. The secondary objectives were its individual components, safety (bleeding) and the impact on platelet count during hospital stay. The composite efficacy endpoint was similar in the abciximab and tirofiban groups (6.1% vs 7.3%; p = .632). There were also no differences in cardiovascular death (2.5% vs 2.4%; p = .958), nonfatal myocardial infarction (3% vs 4.3%; p = .521) and nonfatal stroke (0.5% vs 1.8%; p = .332). Tirofiban administration was associated with a higher incidence of bleeding (11.6% vs 22%; p = .008) with no differences in BARC ≥ 3b bleeding (3.6 vs 2.5%; p = .760). In STEMI patients undergoing PPCI with ticagrelor, abciximab and tirofiban had similar rates in the composite efficacy endpoint at 30 days. The 30-day bleeding rate was significantly higher in the tirofiban group. Tirofiban administration was an independent predictor of both bleeding and platelet count drop.

Modulators of Mortality Benefit From Peri-Angioplasty Adjunctive Tirofiban in Patients With ST-Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

BACKGROUND

Studies investigating the modulators of mortality benefit conferred by peri-angioplasty glycoprotein IIb/IIIa inhibitors in ST-elevation myocardial infarction (STEMI) are still lacking.Methods and Results:A prospective database (n=1,025) of consecutive cases undergoing primary percutaneous coronary intervention for STEMI was retrospectively analyzed. For patients in Killip class I, II or III, IV, the multivariate-adjusted hazard ratios of 30-day all-cause mortality associated with adjunctive tirofiban were 3.873 (95% CI 0.504-29.745; P=0.193), 0.550 (95% CI 0.188-1.609; P=0.275), and 0.264 (95% CI 0.099-0.704; P=0.008), respectively. The P value for a linear trend was 0.032. Patients who had a body mass index (BMI) within 22.9-25.0 kg/m²had a significant benefit from tirofiban (adjusted HR 0.344; 95% CI 0.145-0.814; P=0.015) compared to other BMI groups. The P value for a quadratic trend was 0.012. A novel Killip-BMI score (KBS = 2.5 × Killip category - | BMI - 24 |) was calculated to select the beneficial population. A KBS ≥2 was associated with significant mortality benefit, whereas a KBS <0 predicted increased 30-day mortality with tirofiban use.

CONCLUSIONS

Survival benefit from peri-angioplasty tirofiban therapy for STEMI was positively correlated with the Killip class. Tirofiban should be used cautiously in either underweight or overweight patients. The novel KBS used in this study can guide peri-angioplasty use of adjunctive tirofiban in patients with STEMI undergoing primary angioplasty.

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.

Sonothrombolysis in the ambulance for ST-elevation myocardial infarction: rationale and protocol

Background

Treatment of ST-elevation myocardial infarction (STEMI) has improved over the years. Current challenges in the management of STEMI are achievement of early reperfusion and the prevention of microvascular injury. Sonothrombolysis has emerged as a potential treatment for acute myocardial infarction, both for epicardial recanalisation as well as improving microvascular perfusion. This study aims to determine safety and feasibility of sonothrombolysis application in STEMI patients in the ambulance.

Methods

Ten patients with STEMI will be included and treated with sonothrombolysis in the ambulance during transfer to the PCI centre. Safety will be assessed by the occurrence of ventricular arrhythmias and shock during sonothrombolysis intervention. Feasibility will be assessed by the extent of protocol completion and myocardial visibility. Efficacy will be determined by angiographic patency rate, ST-elevation resolution, infarct size and left ventricular volumes, and function measured with cardiovascular magnetic resonance imaging, and contrast and strain echocardiography. A comparison will be made with matched controls using an existing STEMI database.

Discussion

Sonothrombolysis is a novel technique for the treatment of cardiovascular thromboembolic disease. The first clinical trials on its use for STEMI have demonstrated promising results. This study will be the first to examine the feasibility of in-ambulance sonothrombolysis for STEMI.

Trial registration

EU Clinical Trials Register (identifier: 2019-001883-31), registered 2020-02-25.

State of the Art: No-Reflow Phenomenon

Primary percutaneous coronary intervention is the preferred reperfusion strategy for the management of acute ST-segment elevation myocardial infarction. No reflow is characterized by the inadequate myocardial perfusion of a given segment without angiographic evidence of persistent mechanical obstruction of epicardial vessels. Both pharmacologic and device-based strategies have been tested to resolve coronary no reflow. This article provides an updated overview of the no-reflow phenomenon, discussing clinical evidence and ongoing investigations of existing and novel therapeutic strategies to counteract it.

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.

First Human Use of RUC-4: A Nonactivating Second-Generation Small-Molecule Platelet Glycoprotein IIb/IIIa (Integrin αIIbβ3) Inhibitor Designed for Subcutaneous Point-of-Care Treatment of ST-Segment-Elevation Myocardial Infarction

Background Despite reductions in door-to-balloon times for primary coronary intervention, mortality from ST-segment-elevation myocardial infarction has plateaued. Early pre-primary coronary intervention treatment of ST-segment-elevation myocardial infarction with glycoprotein IIb/IIIa inhibitors improves pre-primary coronary intervention coronary flow, limits infarct size, and improves survival. We report the first human use of a novel glycoprotein IIb/IIIa inhibitor designed for subcutaneous first point-of-care ST-segment-elevation myocardial infarction treatment. Methods and Results Healthy volunteers and patients with stable coronary artery disease receiving aspirin received escalating doses of RUC-4 or placebo in a sentinel-dose, randomized, blinded fashion. Inhibition of platelet aggregation (IPA) to ADP (20 μmol/L), RUC-4 blood levels, laboratory evaluations, and clinical assessments were made through 24 hours and at 7 days. Doses were increased until reaching the biologically effective dose (the dose producing ≥80% IPA within 15 minutes, with return toward baseline within 4 hours). In healthy volunteers, 15 minutes after subcutaneous injection, mean±SD IPA was 6.9%+7.1% after placebo and 71.8%±15.0% at 0.05 mg/kg (n=6) and 84.7%±16.7% at 0.075 mg/kg (n=6) after RUC-4. IPA diminished over 90 to 120 minutes. In patients with coronary artery disease, 15 minutes after subcutaneous injection of placebo or 0.04 mg/kg (n=2), 0.05 mg/kg (n=6), and 0.075 mg/kg (n=18) of RUC-4, IPA was 14.6%±11.7%, 53.6%±17.0%, 76.9%±10.6%, and 88.9%±12.7%, respectively. RUC-4 blood levels correlated with IPA. Aspirin did not affect IPA or RUC-4 blood levels. Platelet counts were stable and no serious adverse events, bleeding, or injection site reactions were observed. Conclusions RUC-4 provides rapid, high-grade, limited-duration platelet inhibition following subcutaneous administration that appears to be safe and well tolerated. Registration URL: https://www.clini​caltr​ials.gov; Unique identifier: NTC03844191.