Early glycoprotein IIb-IIIa inhibitors in primary angioplasty (EGYPT) cooperation: an individual patient data meta-analysis

Current and Future Roles of Glycoprotein IIb-IIIa Inhibitors in Primary Angioplasty for ST-Segment Elevation Myocardial Infarction

Acute myocardial infarction still represents the major cause of mortality in high-income countries. Therefore, considerable efforts have been focused on the treatment of myocardial infarctions in the acute and long-term phase, with special attention being paid to reperfusion strategies and adjunctive antithrombotic therapies. In fact, despite the successful mechanical recanalization of the epicardial conduit, a substantial percentage of patients still experience poor myocardial reperfusion or acute/subacute in-stent thrombosis. Due the delayed onset of action of currently available oral antiplatelet therapies, glycoprotein (GP) IIb-IIIa inhibitors could be expected to improve clinical outcomes, especially when administrated in the early phase of the infarction, due to the larger platelet composition of fresh thrombi, the dynamic nature of early thrombi, and the larger amount of viable myocardium existing in the early, as compared to a delayed, phase. Considerable evidence has accumulated regarding the benefits from GP IIb-IIIa inhibitors on mortality, especially among high-risk patients and when administered as an upstream strategy. Therefore, based on currently available data, GP IIb-IIIa inhibitors can be considered when the drug can be administered within the first 3 h of symptom onset and among high-risk patients (e.g., those with advanced Killip class or an anterior myocardial infarction). Even though it is not universally accepted, in our opinion, this strategy should be implemented in a pre-hospital setting (in an ambulance) or as soon as possible when arriving at the hospital (at the Emergency Room or Coronary Care Unit, irrespective of whether they are in spoke or hub hospitals). A new, second-generation GP IIb-IIIa inhibitor (zalunfiban) appears to be highly suitable as a pre-hospital pharmacological facilitation strategy at the time of first medical contact due to its favourable features, including its simple subcutaneous administration, rapid onset of action (15 min), and limited time of action (with a half-life of ~1 h), which is likely to minimize the risk of bleeding. The ongoing CELEBRATE trial, including 2499 STEMI patients, may potentially provide compelling data to support the upstream treatment of STEMI patients undergoing mechanical reperfusion. In fact, although the current therapeutic target of increased rates of timely reperfusion has been achieved, the future goal in myocardial infarction treatment should be to achieve the most rapid reperfusion prior to primary percutaneous coronary intervention, thus further minimizing myocardial damage, or, in some cases, even preventing it completely, and improving survival.

Prehospital tirofiban increases the rate of disrupted myocardial infarction in patients with ST-segment elevation myocardial infarction: insights from the On-TIME 2 trial

AIMS

In patients with ST-segment elevation myocardial infarction (STEMI), prehospital tirofiban significantly improved myocardial reperfusion. However, its impact on the rate of disrupted myocardial infarction (MI), particularly in the context of high-sensitivity cardiac troponin (hs-cTn) assays, is still unclear.

METHODS AND RESULTS

The On-TIME 2 (Ongoing Tirofiban In Myocardial infarction Evaluation 2) trial randomly assigned STEMI patients to prehospital tirofiban or placebo before transportation to a percutaneous coronary intervention (PCI) centre. In this post hoc analysis, we evaluated STEMI patients that underwent primary PCI and had measured hs-cTn levels. Troponin T levels were collected at 18-24 and 72-96 h after PCI. Disrupted MI was defined as peak hs-cTn T levels ≤ 10 times the upper limit of normal (≤140 ng/L). Out of 786 STEMI patients, 47 (6%) had a disrupted MI. Disrupted MI occurred in 31 of 386 patients (8.0%) in the tirofiban arm and in 16 of 400 patients (4.0%) in the placebo arm (P = 0.026). After multivariate adjustment, prehospital tirofiban remained independently associated with disrupted MI (odds ratio 2.03; 95% confidence interval 1.10-3.87; P = 0.027). None of the patients with disrupted MI died during the 1-year follow-up, compared with a mortality rate of 2.6% among those without disrupted MI.

CONCLUSION

Among STEMI patients undergoing primary PCI, the use of prehospital tirofiban was independently associated with a higher rate of disrupted MI. These results, highlighting a potential benefit, underscore the need for future research focusing on innovative pre-treatment approaches that may increase the rate of disrupted MI.

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.

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.

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.

The Effects of Percutaneous Coronary Intervention on the Flow in Acute Coronary Syndrome Patients-Geometry in Focus

Evaluation of the effect of three dimensional (3D) coronary plaque characteristics derived from two dimensional (2D) invasive angiography images (ICA) on coronary flow determined by TIMI frame count (TFC) in acute coronary syndrome (ACS) has not been thoroughly investigated. A total of 71 patients with STEMI, and 73 with NSTEMI were enrolled after primary angioplasty. Pre- and post-PCI TFCs were obtained. From 2D images, 3D reconstruction was performed of the culprit vessel, and multiple plaque parameters were measured. In STEMI, the average post-PCI frame count decreased significantly, resulting in better flow. With regards to 2/3D parameters, no differences were found between the STEMI and NSTEMI groups. The 3D parameters in the subgroup with an increase with at least three frames resulting in worsening post-PCI flow were compared to parameters of the patients with improved or significantly not change flow (delta frame count < 3), and greater minimal luminal diameter and area was found in the worsening (increased) frame group. In STEMI 2/3D, parameters showed no correlation with worsening flow, whereas in NSTEMI, greater minimal luminal diameter and area correlated with decreased flow. We can conclude that certain 2/3D parameters can predict slower flow in ACS, resulting in the use of GP IIb/IIIa receptor blocker.

Evaluate Short-Term Outcomes of abciximab in ST-Segment Elevation Myocardial Infarction Patients Undergoing Percutaneous Coronary Intervention: A Meta-Analysis of Randomized Clinical Trials

Objectives

This meta-analysis was to verify the short-time efficacy and safety of abciximab in patients with ST-segment elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI).

Background

Abciximab has long-term efficacy in patients with STEMI undergoing PCI, but the short-term efficacy is still controversial.

Methods

We conducted a systematic review and meta-analysis compared with or without abciximab in patients with STEMI undergoing PCI. The relevant randomized controlled trials were included by searching PubMed, EMBASE, Cochrane Library, and Web of Science databases and other sources. The relative risk (RR) and 95% confidence intervals (CI) of outcomes were calculated by the fixed-effects model.

Results

Ten randomized controlled trials with 5008 patients met inclusion criteria. There were no significant differences in risk of all-cause death at 30-day (RR 0.79, CI 0.55–1.12, P=0.18), major bleeding (1.37, 0.93–2.03, P=0.11), and transfusion (1.23, 0.94–1.61, P=0.13) between the two groups. However, there were significant differences in risk of all-cause death at 6 months (0.57, 0.36–0.90, P=0.02), recurrent myocardial infarction (0.55, 0.33–0.92, P=0.02), repeat revascularization (0.58, 0.43–0.78, P=0.0004), final TIMI flow <3 (0.77, 0.62–0.96, P=0.02), minor bleeding (1.29, 1.02–1.63, P=0.04), and thrombocytopenia (2.04, 1.40–2.97, P=0.0002).

Conclusions

The application of abciximab can lead to a lower risk of reinfarction, revascularization, and all-cause death at 6 months, but a higher risk of minor bleeding, and thrombocytopenia.

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.

The FAST-STEMI Network in Biella From 2013 to 2019: Impact of the Delocalization of the Hospital Facilities on Ischemia Time and In-hospital Outcomes

BACKGROUND

The optimization of the strategies for myocardial revascularization has improved the outcomes of patients with ST-segment elevation myocardial infarction. In Piedmont, the FAST-STEMI regional network was created for improving the management and transportation of ST-segment elevation (STEMI) patients to primary percutaneous coronary intervention facilities, reducing the time to reperfusion. Within this network, the Hospital of Biella was delocalized in December 2014 to a new suburban structure designed for an easier access, which might have shortened the duration of patients' transportation and ischemia, with potential positive prognostic effects. The aim of the present study was to define the impact of the decentralization of the hospital structure on the time to reperfusion and in-hospital outcomes among STEMI patients admitted to the Hospital of Biella.

METHODS

We included STEMI patients admitted to our urban hospital between 2013 and 2019 and included in the FAST-STEMI database. The primary endpoint was the duration of ischemia, defined as pain to balloon (PTB). The primary outcome endpoint (PE) was in-hospital mortality.

RESULTS

We included 276 consecutive patients with STEMI undergoing primary percutaneous coronary intervention between 2016 and 2019 in the new hospital facility, which were compared with 170 patients treated between 2013 and June 2014 in the prior structure. Patients' characteristics included a mean age of 67.5 ± 12.5 years, 72.1% males and 18.7% patients with diabetes. In the new facility, the median PTB was 188 minutes [interquartile range: 125-340 min], reduced as compared with the period 2013-2014 [215 (128.5-352 min), P = 0.002]. The median in-hospital stay was also shorter (P = 0.004), whereas a nonsignificant improvement was noted for ejection fraction (EF) at discharge (P = 0.14). A linear relationship was demonstrated between PTB and the EF (r = -0.183, P = 0.003) in patients treated between 2016 and 2019 while not affecting the length of hospitalization or in-hospital outcomes. In fact, in-hospital death occurred in 36 patients, 8% in the new structure versus 7.7% in 2013-2014 [hazard ratio (HR) (95% confidence interval [CI]) = 1.20 (0.59-2.42), P = 0.62]. The independent predictors of mortality were patients' age and EF at discharge (age ≥ 75 y: adjusted HR [95% CI] = 6.75 [1.51-30.1], P = 0.01; EF: adjusted HR [95% CI] = 0.91 [0.88-0.95], P < 0.001).

CONCLUSIONS

The present study shows that, among the STEMI patients treated in our center, the delocalization of the hospital facilities and the optimization of the FAST-STEMI network reduced the duration of ischemia, with positive effects on left ventricular function at discharge. However, this did not translate into a significant benefit in survival, which was instead conditioned by the aging of the population.

Preprocedural Ticagrelor Treatment was Associated with Improved Early Reperfusion and Reduced Short-term Heart Failure in East-Asian ST-segment Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention

Purpose

The purpose of this monocentric retrospective observational study is to investigate whether a loading dose of ticagrelor treatment before percutaneous coronary intervention (PCI) procedure improves the early reperfusion and short-term heart function in East-Asian ST segment elevation myocardial infarction (STEMI) patients.

Patients and Methods

The study included 326 STEMI patients undergoing primary PCI in Jiading Central Hospital. One hundred and forty patients received a loading dose of ticagrelor before entering the catheter laboratory. One hundred and eighty-six patients received a loading dose of ticagrelor in the catheter laboratory before the initiation of PCI. Reperfusion endpoints included the presence of self-patency in the culprit artery, the ST-segment elevation resolution over 50% within 24 h after PCI, and the presence of no-reflow in the culprit artery. Clinical endpoints included all-cause mortality, new-onset heart failure, reinfarction and stent thrombosis within 28 days after PCI. Secondary clinical endpoints included mechanical complications and bleeding events.

Results

In comparison with the in-lab treatment group, the preprocedural treatment group had a significant higher proportion of self-patency in the culprit artery (25.71% vs 16.67%, P=0.045) and early ST-segment elevation resolution (48.57% vs 27.96%, P<0.001). Preprocedural ticagrelor treatment was associated with a significant reduction of new-onset heart failure (9.29% vs 18.82%, p=0.016). Stent thrombosis risks were numerically reduced in the preprocedural treatment group (0.71% vs 1.61%, P=0.466). The rates of major cardiovascular adverse events, reinfarctions and mortality did not differ between the two groups. Bleeding events in the preprocedural treatment group was notn significantly higher than the in-lab treatment group (4.39% vs 1.39%, P=0.142).

Conclusion

Preprocedural administration of a loading dose of ticagrelor was associated with improved early reperfusion and reduced short-term heart failure in East-Asian STEMI patients undergoing primary PCI, but care should be taken for excess bleeding events.

Impact of the Polymorphism rs5751876 of the Purinergic Receptor ADORA2A on Periprocedural Myocardial Infarction in Patients Undergoing Percutaneous Coronary Intervention

Aim: Periprocedural myocardial infarction (PMI), a severe complication of Percutaneous Coronary Intervention (PCI) procedures, has a negative prognostic effect, both at short and long-term follow-up. So far, adenosine's role in preventing PMI has shown contrasting results. A genetic variant of ADORA2A receptor, 1976 C > T, has been suggested as a potential determinant of the interindividual response to adenosine, thus conditioning its potential benefits on PMI. In our study, we investigated whether the ADORA2A 1976 C > T polymorphism is associated with PMI occurrence in patients undergoing coronary stenting.

Methods: The study included consecutive patients undergoing PCI at the Azienda Ospedaliera-Universitaria “Maggiore della Carità,” Novara, Italy, between January 2010 and January 2016. Their genetic status was assessed using polymerase chain reaction (PCR) and restriction-fragment-length-polymorphism technique. Myonecrosis biomarkers were measured at intervals from 6 to 48 hours. PMI was defined as CKMB increased 3 times over the Upper Limit of Normal (ULN), or 50% of pre-PCI value; periprocedural myonecrosis was defined as troponin I increased 3 times over the ULN or by 50% of the baseline value.

Results: We included 1,104 patients undergoing PCI, 863 (78.2%) of whom carried the ADORA2A T-allele. No difference was found for the main demographic, clinical features, or biochemistry parameters. However, C-carriers had lower statin therapy use (p = 0.008) and lower HDL-cholesterol levels (p = 0.01). Homozygous C/C patients had more frequent multivessel disease (p = 0.03), longer lesions (p = 0.01) and Type C lesions (p = 0.01), thus requiring more complex procedures. After correction for baseline confounding factors at multivariate analysis, there was no difference in myocardial necrosis according to the ADORA2A genotype (p = 0.40). In contrast, PMI tended to increase in the homozygous C/C population (p = 0.06), but this trend was attenuated at multivariate analysis after correction for baseline confounding factors (C/C: OR[95%CI]= 1.52 [0.88–2.6], p = 0.14).

Conclusions: Our study showed that the polymorphism rs5751876 of the ADORA2A receptor is associated with a higher prevalence of complex coronary lesions and multivessel disease. However, it does not significantly influence the occurrence of periprocedural MI or myonecrosis.

Frequency of Thrombolysis in Myocardial Infarction III Flow in Patients With Primary Percutaneous Coronary Intervention: Not All Culprit Vessels Are Completely Occluded in ST Elevation Myocardial Infarction

Background

ST elevation myocardial infarction (STEMI) is classically characterized by total occlusion of the culprit coronary artery. However during primary percutaneous coronary intervention (PCI) thrombolysis in myocardial infarction (TIMI) 0 flow is not observed in all patients' culprit arteries in angiographic views. This study was conducted to find out the frequency of TIMI flow in acute STEMI patients in view of the above concept. The aim of this study was to evaluate the frequency of pre-procedural TIMI III flow in those patients who underwent primary PCI for acute STEMI in a public sector hospital in Karachi, Pakistan.

Methodology

This study is an audit of already saved data in the catheterization laboratory of the National Institute of Cardiovascular Diseases (NICVD), Karachi, that was collected prospectively from January 2016 to December 2018. These data were collected after taking consent from those patients who presented to hospital within 12 hours of symptoms and underwent primary PCI. Data were entered and analyzed on Statistical Package for the Social Sciences (SPSS) version 19 (IBM Corp., Armonk, NY, USA).

Results

A total of 8018 patients were included in this study who presented with STEMI and underwent primary PCI. Out of them 80.9% were males. Hypertension was the leading risk factor in 54.1% (4340) of patients. TIMI III flow was present in 11.4% of patients before primary PCI, while TIMI 0, I and II flow were present in 57.1%, 15.1%, and 16.3% of patients respectively (p<0.001). Fourteen percent of patients with TIMI III flow were of age group 51 to 60 years. Among those who had TIMI III flow, 11.2% were those with door to balloon time of <90 minutes. In 11% of cases, left anterior descending (LAD) artery had TIMI III flow as compared to other vessels (p<0.001). The length of the lesion was significantly smaller in patients who had TIMI III flow compared to those who had TIMI 0-II flow.

Conclusions

This study revealed that not all patients with acute STEMI had totally occluded culprit coronary artery but some of them had angiographic TIMI I-III flow in the infarct-related artery. Further studies are needed to find the reason for re-establishment of flow in the culprit vessel in STEMI patients before PCI.

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.

Novel Biomarkers, ST-Elevation Resolution, and Clinical Outcomes Following Primary Percutaneous Coronary Intervention

Background Despite restoration of epicardial flow following primary percutaneous coronary intervention (PPCI), microvascular reperfusion as reflected by ST-elevation resolution (ST-ER) resolution remains variable and its pathophysiology remains unclear. Methods and Results Using principal component analyses, we explored associations between 91 serum biomarkers drawn before PPCI clustered into 14 pathobiologic processes (including NT-proBNP [N-terminal pro-B-type natriuretic peptide] as an independent cluster), and (1) ST-ER resolution ≥50% versus <50%; and (2) 90-day composite of death, shock, and heart failure. Network analyses were performed to understand interbiomarker relationships between the ST-ER groups. Among the 1160 patients studied, 861 (74%) had ST-ER ≥50% at a median 40 (interquartile range, 23-70) minutes following PPCI, yet both groups had comparable post-PPCI TIMI (Thrombolysis in Myocardial Infarction) grade 3 flow (86.6% versus 82.9%; P=0.25). ST-ER ≥50% was associated with significantly lower pre-PPCI concentrations of platelet activation cluster (particularly P-selectin, von Willebrand factor, and platelet-derived growth factor A) and NT-proBNP, including after risk adjustment. Across both ST-ER groups, strong interbiomarker relationships were noted between pathways indicative of myocardial stretch, platelet activation, and inflammation, whereas with ST-ER <50% correlations between iron homeostasis and inflammation were observed. Of all 14 biomarker clusters, only NT-proBNP was significantly associated with the 90-day clinical composite. Conclusions Suboptimal ST-ER is common despite achieving post-PPCI TIMI grade 3 flow. The cluster of platelet activation proteins and NT-proBNP were strongly correlated with suboptimal ST-ER and NT-proBNP was independently associated with 90-day outcomes. This analysis provides insights into the pathophysiology of microvascular reperfusion in ST-segment-elevation myocardial infarction and suggests novel pre-PPCI risk targets potentially amenable to enhancing tissue-level reperfusion following PPCI.

Impact of preprocedural TIMI flow on clinical outcome in low-risk patients with ST-elevation myocardial infarction: Results from the ATLANTIC study

OBJECTIVES

This study sought to analyze the impact of the preprocedural thrombolysis in myocardial infarction (TIMI) flow on clinical outcome in patients with ST-elevation myocardial infarction (STEMI).

BACKGROUND

Previous studies have shown that the TIMI flow 0/1 prior to primary percutaneous coronary intervention (PCI) is associated with a poor clinical outcome. However, it is unclear whether the same is true in patients with ongoing STEMI of less than 6 hr duration, rapid reperfusion, and modern guideline-adherent therapy.

METHODS

The ATLANTIC study compared prehospital versus inhospital treatment with ticagrelor in patients with acute STEMI. For this analysis, patients were divided into three groups according to the preprocedural TIMI flow grade of the infarct vessel: TIMI 0/1, TIMI 2, and TIMI 3.

RESULTS

From a total of 1,680 patients, 1,113 had TIMI 0/1, 279 TIMI 2, and 288 TIMI 3 flow before primary PCI. At 30 days, the composite ischemic endpoint (5.5, 2.9, and 2.1%, p < .05) and all-cause death (3.0, 1.4, and 2.1%, p = .30) were highest in patients with TIMI flow 0/1. After adjustment, preprocedural TIMI flow <3 (versus 3) was not an independent predictor of major adverse ischemic events within 30 days (odds ratio 1.89, 95% confidence interval 0.74-4.85). However, definite stent thrombosis occurred only in patients with initial TIMI flow 0/1 (1.0%). Among these patients, those with prehospital administration of ticagrelor were less often affected (0.3% vs. 1.3%, p < .05).

CONCLUSION

In this post-hoc analysis, preprocedural TIMI flow was not independently associated with a higher rate of adverse ischemic events.

Antithrombotic therapy before, during and after emergency angioplasty for ST elevation myocardial infarction

The first three hours after symptom onset hold the maximum potential for myocardial reperfusion and salvage in ST-elevation myocardial infarction (STEMI) patients. During this period timely primary percutaneous coronary intervention (PPCI) or, when PPCI is not promptly feasible, pre-hospital administration of fibrinolyis or a glycoprotein IIb/IIIa-inhibitor (GPI) have been shown to restore coronary patency and reperfusion and even result in myocardial infarction (MI) abortion. On the other hand, oral antiplatelet therapy may not yet guarantee sufficient platelet inhibition. Patients presenting after this golden time have less, if any, benefit from an aggressive antithrombotic treatment prior to PPCI. Antithrombotic treatment during primary angioplasty should be tailored on the basis of the coronary thrombotic burden, vascular approach and the patient's risk of bleeding complications. A GPI-based approach may be favourable in patients presenting early with large MI and high thrombus burden, whereas a bivalirudin-based approach without GPI may be preferred in patients with higher bleeding risk. There are no data to support the use of GPI in bailout conditions. The powerful oral P2Y₁₂ inhibitors, prasugrel and ticagrelor, have been clearly shown to prevent stent thrombosis and recurrent ischaemic events after emergency percutaneous coronary intervention in STEMI patients. Open issues remaining are the treatment of patients with high bleeding risk, such as the elderly and those requiring anticoagulation, as well as the duration of dual antiplatelet therapy after STEMI.

Relationship between early administration of abciximab and TIMI flow in STEMI patients undergoing primary angioplasty: findings from a large regional STEMI network

AIMS

The aim of this study is to assess whether in S-T Elevation Myocardial Infarction (STEMI) a relationship between early administration of abciximab and Thrombolysis In Myocardial Infarction (TIMI) flow before and after primary percutaneous coronary intervention (PCI) in 960 consecutive patients exists.

METHODS

From 1 February 2001 onward, in the Province of Mantua it has been operating a 'Cardiology Network for the Acute Infarction Care' having its Hub in the Central Coronary ICU/Cath Lab of Mantua Hospital and being its Spokes centers represented by the emergency rooms and Central Coronary ICUs of the four territorial hospitals.

RESULTS

T1 (time from symptoms onset to first medical contact) and T2 (time from first medical contact to angioplasty) are shorter for patients rescued by first aid units rather than for those presented in emergency rooms as well as Ta (time from symptoms onset to abciximab administration). Furthermore, the patients that received abciximab before hospital arrival had less frequently a coronary occlusion [odds ratio = 0.74, 95% confidence interval (0.57-0.96), P = 0.013]. The patients with T1 less than 4 h are 753/960 (78.4%). For this type of patients, there was a significant Ta difference between the pre-PCI TIMI-flow classes (F = 4.467, df = 3, P = 0.04). Planned contrasts revealed that mean time of TIMI flow 0 (M = 104.2) is statistically different from mean time of TIMI flow 3 (M = 85.7), P = 0.013.

CONCLUSION

Our results suggest that the use of abciximab, free from pharmacokinetic limits of oral P2Y12 inhibitors, should be considered in STEMI patients with early presentation before primary PCI.

Factors Associated With Infarct-Related Artery Patency Before Primary Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction (from the FAST-MI 2010 Registry)

Early infarct-related artery (IRA) patency is associated with better clinical outcomes in patients with ST-elevation myocardial infarction (STEMI). Using the French Registry of ST-elevation and non-ST-elevation Myocardial Infarction (FAST-MI) 2010 registry, we investigated factors related to IRA patency (thrombolysis in myocardial infarction [TIMI] 2/3 flow) at the start of procedure in patients admitted for primary percutaneous coronary intervention. FAST-MI 2010 is a nationwide French registry including 4,169 patients with acute MI. Of 1,452 patients with STEMI with primary percutaneous coronary intervention, 466 (32%) had TIMI 2/3 flow of IRA before the procedure. Mean age (62 ± 14 years in both groups), Global Registry of Acute Coronary Event score (141 ± 31 vs 142 ± 34), and time from onset to angiography (472 ± 499 vs 451 ± 479 minutes) did not differ according to IRA patency (TIMI 2/3 vs TIMI 0/1). Using multivariate logistic regression analysis, IRA patency was more frequently found in patients having called earlier (time from onset to electrocardiogram [ECG] <120 minutes; odds ratio [OR] 1.49; 95% confidence interval [CI] 1.17 to 1.89), or receiving rapid-onset of action (prasugrel or glycoprotein IIb-IIIa) antiplatelet therapy in the prehospital setting (OR 1.59, 95% CI 1.14 to 2.21). Increasing time from diagnostic ECG to angiography was also associated with IRA patency (>90 minutes; OR 1.37, 95% CI 1.08 to 1.75). In conclusion, preprocedural IRA patency is observed in one third of patients with STEMI, it is more frequently found in patients having received fast-acting antiplatelet therapy before angiography, and in patients having called early. Higher IRA patency with increasing time delays from qualifying ECG to angiography suggests an additional role of spontaneous or medication-mediated fibrinolysis.

Randomized evaluation of intralesion versus intracoronary abciximab and aspiration thrombectomy in patients with ST-elevation myocardial infarction: The COCTAIL II trial

BACKGROUND

Thrombus burden and distal embolization are predictive of no-reflow during primary percutaneous coronary intervention (PCI) in patients with acute ST-elevation myocardial infarction (STEMI). We sought to compare the efficacy of pharmacological and catheter-based strategies for thrombus in patients with STEMI and high atherothrombotic burden.

METHODS

Between January 2012 and December 2013, 128 STEMI patients undergoing primary PCI at 5 centers were randomly assigned in a 2 × 2 factorial design to intracoronary (IC) abciximab bolus (via the guide catheter) versus intralesion (IL) abciximab bolus, each with versus without aspiration thrombectomy (AT). Study end points were residual intrastent atherothrombotic burden, defined as the number of cross-sections with residual tissue area >10% as assessed by optical coherence tomography, and indices of angiographic and myocardial reperfusion.

RESULTS

Residual intrastent atherothrombotic burden did not significantly differ with IL versus IC abciximab (median [interquartile range] 6.0 [1-15] vs 6.0 [2-11], P = .806) and with AT versus no aspiration (6.0 [1-13] vs 6.0 [2-12], P = .775). Intralesion abciximab administration was associated with improved angiographic myocardial reperfusion in terms of thrombolysis in myocardial infarction (TIMI) flow (3 [3-3] vs 3 [2-3], P = .040), corrected TIMI frame count (12 ± 5 vs 17 ± 16, P = .021), and myocardial blush grade (3 [2-3] vs 3 [2-3], P = .035). In particular, IL abciximab was associated with higher occurrence of final TIMI 3 flow (90% vs 73.8%, P = .032) and myocardial blush grade 3 (71.6% vs 52.4%, P = .039). Conversely, AT had no significant effect on indices of angiographic or myocardial reperfusion.

CONCLUSIONS

In patients with STEMI and high thrombotic burden, neither IL versus IC abciximab nor AT versus no aspiration reduced postprocedure intrastent atherothrombotic burden in patients with STEMI undergoing primary PCI. However, IL abciximab improved indices of angiographic and myocardial reperfusion compared to IC abciximab, benefits not apparent with AT.

Individual Participant Data (IPD) Meta-analyses of Randomised Controlled Trials: Guidance on Their Use

Jayne Tierney and colleagues offer guidance on how to spot a well-designed and well-conducted individual participant data meta-analysis.

Efficacy and Safety of Intracoronary versus Intravenous Administration of Tirofiban during Percutaneous Coronary Intervention for Acute Coronary Syndrome: A Meta-Analysis of Randomized Controlled Trials

Background

Percutaneous coronary intervention (PCI) is known as the most effective treatment for acute coronary syndrome (ACS). However, without proper therapy and patient management, stent thrombosis after PCI may lead to another myocardial infarction. In addition to aspirin and clopidogrel, tirofiban is often used as an antiplatelet therapy in patients with ACS. To date, there has been no comprehensive evaluation of the efficacy and safety of intracoronary (IC) tirofiban administration for ACS patients undergoing PCI compared with intravenous (IV) administration. Therefore, this meta-analysis was conducted to investigate the clinical efficiency and safety of IC versus intravenous (IV) tirofiban in ACS patients undergoing PCI.

Methods

We searched PubMed and Medline for randomized controlled trials (RCTs) comparing IC versus IV administration of tirofiban in ACS patients undergoing PCI. We evaluated the effects of tirofiban on thrombolysis in myocardial infarction (TIMI) grade 3 flow after PCI, TIMI myocardial perfusion grade 3 (TMP grade 3), left ventricular ejection fraction (LVEF), major adverse cardiovascular events (MACE), target vessel revascularization (TVR), death, reinfarction and adverse drug effects (specifically bleeding events).

Results

Seven trials involving 1,027 patients were included in this meta-analysis. IC administration of tirofiban significantly increased TIMI grade 3 flow (OR 2.11; 95% CI 1.02 to 4.37; P = 0.04) and TMP grade 3 (OR 2.67; 95% CI 1.09 to 6.49; P = 0.03, I² = 64%) while reducing MACE (OR 0.46, 95% CI: 0.28 to 0.75; P = 0.002) compared with IV administration of tirofiban. No significant differences were observed in the occurrence of TVR, death, reinfarction and the incidence of bleeding events between the two groups.

Conclusions

This meta-analysis supports the use of IC over IV administration of tirofiban in patients with ACS to improve TIMI flow, TMP flow and MACE. However, there was no statistically significant difference in the risk of bleeding complications between the two groups.

Glycosylated hemoglobin and the risk of periprocedural myocardial infarction in non-diabetic patients

BACKGROUND

Alterations of glucose homeostasis have been reported to occur even in non-diabetic patients, thus increasing the risk of cardiovascular events and worsening the outcome after an acute myocardial infarction (AMI). Still debated is the role of impaired glucose control in patients undergoing percutaneous coronary intervention (PCI), as hyperglycemia, represents an important pro-thrombotic stimulus, increasing platelet reactivity and potentially procedural complications. Therefore, the aim of our study was to assess the association between glycosylated hemoglobin and periprocedural myocardial infarction (PMI) in non-diabetic patients undergoing PCI.

METHODS

We included patients without history of diabetes undergoing elective PCI. PMI was defined as creatine kinase-MB increase by 3 times the upper limit normal or by 50% of an elevated baseline value, whereas periprocedural myonecrosis as Troponin I increase by 3× ULN or 50% of baseline.

RESULTS

Our population is represented by 1199 patients, who were divided according to tertile values of glycosylated hemoglobin (HbA1c). Higher HbA1c was associated with ageing (p<0.001), hypertension (p=0.005), previous myocardial infarction (p=0.009), PCI (p<0.001) or CABG (p=0.001), treatment with diuretics (p<0.001), higher levels of glycemia (p<0.001) and white blood cells (p=0.02), multivessel coronary artery disease (p=0.03), higher rate of instent restenosis (p=0.02). HbA1c did not impact on periprocedural myocardial infarction (p=0.85; adjusted OR [95% CI]=0.91 [0.74-1.12], p=0.38) or myonecrosis (p=0.69; adjusted OR [95% CI]=0.95 [0.80-1.13], p=0.56). Similar results were obtained fasting glycemia for PMI (p=0.82, adjusted OR [95% CI]=0.90 [0.71-1.14], p=0.37) and myonecrosis (p=0.21, adjusted OR [95% CI]=1.02 [0.84-1.24], p=0.84) and confirmed in high-risk subsets of patients.

CONCLUSIONS

In non-diabetic patients undergoing elective PCI, neither glycosylated hemoglobin levels nor fasting glycemia are associated with the risk of periprocedural myocardial infarction and necrosis.

Impact of time from symptom onset to drug administration on outcome in patients undergoing glycoprotein IIb-IIIa facilitated primary angioplasty (from the EGYPT cooperation)

Contrasting data have been so far reported on facilitation with glycoprotein IIb-IIIa inhibitors (GpIIbIIIa) in patients who underwent primary percutaneous coronary intervention. However, it has been demonstrated a time-dependent composition of coronary thrombus in ST-segment elevation myocardial infarction, with more platelets in the first hours. Subsequently, the benefits of early administration of GpIIbIIIa may be affected by the time from symptoms onset to GpIIbIIIa, that therefore is the aim of this study. Our population is represented by 814 patients who underwent GpIIbIIIa facilitated primary angioplasty included in the Early glycoprotein IIb-IIIa inhibitors in primary angioplasty database. Patients were divided according to quartiles of time from symptom onset to GpIIbIIIa administration (≤65 minutes; 65 to 100 minutes; 101 to 178 minutes; and >178 minutes). Myocardial perfusion was evaluated by myocardial blush grade and ST-segment resolution. Time from symptoms onset to GpIIbIIIa was linearly associated with hypertension, diabetes, hypercholesterolemia, and previous myocardial infarction but inversely associated with smoking. Abciximab was more often administrated later from symptoms onset. Time from symptoms onset to GpIIbIIIa was significantly associated with the rate of preprocedural recanalization (thrombolysis in myocardial infarction [TIMI] 2 to 3; p <0.001), postprocedural TIMI 3 flow (p <0.001), the rate of complete ST-segment resolution (p <0.001), and the rate of myocardial blush grade 2 to 3 (p <0.001) and inversely associated with the occurrence of distal embolization (p <0.001). Follow-up data were collected at a median (twenty-fifth to seventy-fifth) of 360 (30 to 1,095) days. A total of 52 patients had died. Time to GpIIbIIIa had a significant impact on mortality (hazard ratio [95% confidence interval] 1.46 [1.11 to 1.92], p = 0.007) that was confirmed after correction for baseline confounding factors (adjusted hazard ratio [95% confidence interval] 1.41 [1.02 to 2.21], p = 0.042). In conclusion, this study showed that in patients who underwent primary angioplasty with upstream GpIIbIIIa, time from symptoms onset to GpIIbIIIa strongly impacts on preprocedural recanalization, distal embolization, myocardial perfusion, and long-term survival.

Uptake of systematic reviews and meta-analyses based on individual participant data in clinical practice guidelines: descriptive study

OBJECTIVE

To establish the extent to which systematic reviews and meta-analyses of individual participant data (IPD) are being used to inform the recommendations included in published clinical guidelines.

DESIGN

Descriptive study.

SETTING

Database maintained by the Cochrane IPD Meta-analysis Methods Group, supplemented by records of published IPD meta-analyses held in a separate database.

POPULATION

A test sample of systematic reviews of randomised controlled trials that included a meta-analysis of IPD, and a separate sample of clinical guidelines, matched to the IPD meta-analyses according to medical condition, interventions, populations, and dates of publication.

DATA EXTRACTION

Descriptive information on each guideline was extracted along with evidence showing use or critical appraisal, or both, of the IPD meta-analysis within the guideline; recommendations based directly on its findings and the use of other systematic reviews in the guideline.

RESULTS

Based on 33 IPD meta-analyses and 177 eligible, matched clinical guidelines there was evidence that IPD meta-analyses were being under-utilised. Only 66 guidelines (37%) cited a matched IPD meta-analysis. Around a third of these (n=22, 34%) had critically appraised the IPD meta-analysis. Recommendations based directly on the matched IPD meta-analyses were identified for only 18 of the 66 guidelines (27%). For the guidelines that did not cite a matched IPD meta-analysis (n=111, 63%), search dates had preceded the publication of the IPD meta-analysis in 23 cases (21%); however, for the remainder, there was no obvious reasons why the IPD meta-analysis had not been cited.

CONCLUSIONS

Our results indicate that systematic reviews and meta-analyses based on IPD are being under-utilised. Guideline developers should routinely seek good quality and up to date IPD meta-analyses to inform guidelines. Increased use of IPD meta-analyses could lead to improved guidelines ensuring that routine patient care is based on the most reliable evidence available.

Preprocedural TIMI flow and infarct size in STEMI undergoing primary angioplasty

Despite optimal epicardial recanalization, primary angioplasty for STEMI is still associated with suboptimal reperfusion in a relatively large proportion of patients. The aim the current study was to evaluate the impact of preprocedural TIMI flow on myocardial scintigraphic infarct size among STEMI undergoing primary angioplasty. Our population is represented by 793 STEMI patients undergoing primary PCI. Infarct size was evaluated at 30 days by technetium-99m-sestamibi. Poor preprocedural TIMI flow (TIMI 0-1) was observed in 645 patients (81.3%). Poor preprocedural TIMI flow was associated with more hypercholesterolemia (p = 0.012), and a trend in lower prevalence of diabetes (p = 0.081). Preprocedural TIMI flow significantly affected scintigraphic and enzymatic infarct size. Similar findings were observed in the analysis restricted to patients with postprocedural TIMI 3 flow. The impact of preprocedural TIMI flow on scintigraphic infarct size was confirmed when the analysis was performed according to the percentage of patients above the median (p < 0.001) and after adjustment for baseline confounding factors (Hypercholesterolemia and diabetes) [adjusted OR (95% CI) for pre preprocedural TIMI 3 flow = 0.59 (0.46-0.75), p < 0.001]. This study shows that among patients with STEMI undergoing primary angioplasty, poor preprocedural TIMI flow is independently associated with larger infarct size.

Prehospital ticagrelor in ST-segment elevation myocardial infarction

BACKGROUND

The direct-acting platelet P2Y12 receptor antagonist ticagrelor can reduce the incidence of major adverse cardiovascular events when administered at hospital admission to patients with ST-segment elevation myocardial infarction (STEMI). Whether prehospital administration of ticagrelor can improve coronary reperfusion and the clinical outcome is unknown.

METHODS

We conducted an international, multicenter, randomized, double-blind study involving 1862 patients with ongoing STEMI of less than 6 hours' duration, comparing prehospital (in the ambulance) versus in-hospital (in the catheterization laboratory) treatment with ticagrelor. The coprimary end points were the proportion of patients who did not have a 70% or greater resolution of ST-segment elevation before percutaneous coronary intervention (PCI) and the proportion of patients who did not have Thrombolysis in Myocardial Infarction flow grade 3 in the infarct-related artery at initial angiography. Secondary end points included the rates of major adverse cardiovascular events and definite stent thrombosis at 30 days.

RESULTS

The median time from randomization to angiography was 48 minutes, and the median time difference between the two treatment strategies was 31 minutes. The two coprimary end points did not differ significantly between the prehospital and in-hospital groups. The absence of ST-segment elevation resolution of 70% or greater after PCI (a secondary end point) was reported for 42.5% and 47.5% of the patients, respectively. The rates of major adverse cardiovascular events did not differ significantly between the two study groups. The rates of definite stent thrombosis were lower in the prehospital group than in the in-hospital group (0% vs. 0.8% in the first 24 hours; 0.2% vs. 1.2% at 30 days). Rates of major bleeding events were low and virtually identical in the two groups, regardless of the bleeding definition used.

CONCLUSIONS

Prehospital administration of ticagrelor in patients with acute STEMI appeared to be safe but did not improve pre-PCI coronary reperfusion. (Funded by AstraZeneca; ATLANTIC ClinicalTrials.gov number, NCT01347580.).

RUC-4: a novel αIIbβ3 antagonist for prehospital therapy of myocardial infarction

OBJECTIVE

Treatment of myocardial infarction within the first 1 to 2 hours with a thrombolytic agent, percutaneous coronary intervention, or an αIIbβ3 antagonist decreases mortality and the later development of heart failure. We previously reported on a novel small molecule αIIbβ3 antagonist, RUC-2, that has a unique mechanism of action. We have now developed a more potent and more soluble congener of RUC-2, RUC-4, designed to be easily administered intramuscularly by autoinjector to facilitate its use in the prehospital setting. Here, we report the properties of RUC-4 and the antiplatelet and antithrombotic effects of RUC-2 and RUC-4 in animal models.

APPROACH AND RESULTS

RUC-4 was ≈ 20% more potent than RUC-2 in inhibiting human ADP-induced platelet aggregation and much more soluble in aqueous solutions (60-80 mg/mL). It shared RUC-2's specificity for αIIbβ3 versus αVβ3, did not prime the receptor to bind fibrinogen, or induce changes in β3 identified by a conformation-specific monoclonal antibody. Both RUC-2 and RUC-4 prevented FeCl3-induced thrombotic occlusion of the carotid artery in mice and decreased microvascular thrombi in response to laser injury produced by human platelets infused into transgenic mice containing a mutated von Willebrand factor that reacts with human but not mouse platelets. Intramuscular injection of RUC-4 in nonhuman primates at 1.9 and 3.85 mg/kg led to complete inhibition of platelet aggregation within 15 minutes, with dose-dependent return of platelet aggregation after 4.5 to 24 hours.

CONCLUSIONS

RUC-4 has favorable biochemical, pharmacokinetic, pharmacodynamic, antithrombotic, and solubility properties as a prehospital therapy of myocardial infarction, but the possibility of increased bleeding with therapeutic doses remains to be evaluated.

Efficacy of pre-hospital use of glycoprotein IIb/IIIa inhibitors in ST-segment elevation myocardial infarction before mechanical reperfusion in a rapid-transfer network (from the Acute Myocardial Infarction Registry of Brittany)

Previous studies investigating prehospital use of glycoprotein IIb/IIIa inhibitors (GPIs) in patients with ST-segment elevation myocardial infarction reached conflicting conclusions. The benefit of this strategy in addition to in-ambulance loading of dual-antiplatelet therapy remains controversial. The aim of this study was to analyze data from a prospective registry of patients with ST-segment elevation myocardial infarctions admitted <24 hours after symptom onset (July 2006 to May 2012). A total of 2,052 patients managed in a physician-staffed mobile intensive care unit (MICU)<12 hours after symptom onset and scheduled for primary percutaneous coronary intervention (PPCI) were retrospectively included. Patients who received GPIs in the MICU were compared with those who did not. The primary end point was infarct-related artery patency, defined as pre-PPCI Thrombolysis In Myocardial Infarction (TIMI) flow grade 3. GPIs were administered in the MICU to 737 patients (36%), including 430<2 hours after symptom onset, and 1,315 patients (64%) did not received prehospital GPIs. Pre-PPCI TIMI flow grade 3 rate was lower in patients treated in the MICU (17.2% vs 21.3%, p=0.03) because of patients treated >2 hours after symptom onset, of whom only 12.7% reached the primary end point. There was no significant difference between groups in the rate of in-hospital major adverse cardiac events. In conclusion, prehospital GPI use in patients with ST-segment elevation myocardial infarctions<12 hours after symptom onset scheduled for PPCI neither improved pre-PPCI infarct-related artery patency nor reduced in-hospital major adverse cardiac events.

Are cardiovascular trial results systematically different between North America and Europe? A study based on intra-meta-analysis comparisons

BACKGROUND

It is often assumed that differences in the efficacy of treatments between countries (or regions) will be neither negligible nor minor and therefore cannot be overlooked when assessing the potential benefit of treatments in one country (or region) on the basis of trials conducted in another country (or region).

AIM

To assess differences in the results of cardiovascular trials between Europe and North America on the basis of data from an extensive collection of trials.

METHODS

A systematic search was conducted of Medline (from the year 2005 to 2008) and the Cochrane Library (from 2000 to 2008) for all meta-analyses of randomized controlled trials aimed at treating and preventing cardiovascular disease. Within each meta-analysis that satisfied given criteria, trial results were compared between Europe and North America with respect to a fatal and/or non-fatal endpoint by forming separate estimates of treatment efficacy for each of these continents.

RESULTS

The literature search found 59 meta-analyses that satisfied all the inclusion criteria. For most meta-analyses, it was the case that relative to the control, the intervention was more favoured in trials conducted in Europe than in North America with regard to both fatal endpoints (28 out of 43 meta-analyses) and non-fatal endpoints (28 out of 40 meta-analyses). However, it was only with regard to non-fatal endpoints that this imbalance turned out to be statistically significant at the 5% level (P=0.017). Also, the lack of statistically significant differences in trial results between Europe and North America within individual meta-analyses meant that it was not possible to determine for which types of intervention these intercontinental differences are likely to be more pronounced than others.

CONCLUSION

There is some evidence to support the theory that, relative to controls, interventions are more favoured in cardiovascular trials conducted in Europe than in North America, when treatment efficacy is measured in terms of a non-fatal endpoint. However, the overall support for systematic differences in cardiovascular trial results between Europe and North America is weak, which may be surprising given the amount of data collected.

Timely reperfusion for ST-segment elevation myocardial infarction: Effect of direct transfer to primary angioplasty on time delays and clinical outcomes

Primary percutaneous coronary intervention (PPCI) is the preferred reperfusion therapy for patients presenting with ST-segment elevation myocardial infarction (STEMI) when it can be performed expeditiously and by experienced operators. In spite of excellent clinical results this technique is associated with longer delays than thrombolysis and this fact may nullify the benefit of selecting this therapeutic option. Several strategies have been proposed to decrease the temporal delays to deliver PPCI. Among them, prehospital diagnosis and direct transfer to the cath lab, by-passing the emergency department of hospitals, has emerged as an attractive way of diminishing delays. The purpose of this review is to address the effect of direct transfer on time delays and clinical events of patients with STEMI treated by PPCI.

Angiographic outcomes with early eptifibatide therapy in non-ST-segment elevation acute coronary syndrome (from the EARLY ACS Trial)

Early administration of glycoprotein IIbIIIa inhibitors results in improved angiographic parameters, including thrombolysis in myocardial infarction (TIMI) flow grade, corrected TIMI frame count, and TIMI myocardial perfusion grade (TMPG) among patients with ST-segment elevation myocardial infarction. Whether the same is true in the setting of non-ST-segment elevation acute coronary syndrome is unknown. The goal of the early glycoprotein IIbIIIa inhibition in non-ST-segment elevation acute coronary syndrome (EARLY ACS) angiographic substudy was to compare angiographic outcomes among patients with non-ST-segment elevation acute coronary syndrome who were administered early routine versus delayed provisional eptifibatide. Of 9,406 patients in the EARLY ACS trial, 2,066 patients were included in the angiographic substudy (early routine eptifibatide [n=1,042] or early placebo [n=1,024] with delayed provisional eptifibatide after angiography and before percutaneous coronary intervention [PCI]). The angiographic substudy primary end point was the incidence of TMPG 3 before and after PCI. TMPG 3 before (43.7% vs 44.9%, p=0.58) and after PCI (52.4% vs 50.1%, p=0.73) was similar for early routine versus delayed provisional eptifibatide, respectively. Angiographic procedural complications consisting of a composite of loss of side branch, abrupt vessel closure, distal embolization, and no reflow occurred less frequently in early routine group versus delayed provisional group (9.3% vs 13.6%, respectively, p=0.01). In the EARLY ACS angiographic substudy, the use of early routine eptifibatide resulted in fewer angiographic procedural complications. These data provide support for the use of eptifibatide in the catheterization laboratory during high-risk cases merely to prevent angiographic procedural complications.

Effect of Early Treatment With Tirofiban on Initial TIMI Grade 3 Flow of Patients With ST Elevation Myocardial Infarction

Background:

Before primary percutaneous coronary intervention (PCI) in patients with ST elevation myocardial infarction (STEMI), it is not clear whether a routine early administration of glycoprotein IIb/IIIa inhibitors in the emergency ward is beneficial or their administration in selected cases in the catheterization laboratory.

Objectives:

The present randomized clinical trial sought to investigate whether an earlier administration of Tirofiban could exert any impact on TIMI grade 3 flows and ST resolution in the electrocardiography of patients with STEMI before primary PCI.

Materials and Methods:

Patients with STEMI within twelve hours of symptom commencement were included if primary PCI was planned to be performed within ninety minutes of admission and excluded if they had contraindications for Tirofiban. Seventy patients were randomized to receive 25 μg/kg of bolus Tirofiban early in the emergency ward (the early Tirofiban group) in three minutes and 70 did not receive Tirofiban (the control group). The primary endpoint of the study was a Thrombolysis in Myocardial Infarction (TIMI) grade 3 flows on the initial angiogram. The study is registered as IRCT201105126463N1 in: www.irct.ir.

Results:

The study population had a mean age of 57.17 ± 10.09 years and included 79.3 % males. TIMI grade 3 flow was seen in 15 (21.4 %) patients of the Tirofiban group and 7 (10 %) of the control group (P = 0.06, odds ratio = 0.407, and 95 % confidence interval = 0.155-1.072). Complete ST resolution was seen in 30 (42.9 %) patients of the Tirofiban group and 34 (48.6 %) of the control group (P = 0.5).

Conclusion:

Although TIMI grade 3 flows trended to be higher in the patients who received early Tirofiban in the emergency ward, the difference did not constitute statistical significance and possible benefits, therefore, require further clarification.

Early administration of abciximab reduces mortality in female patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention (from the EUROTRANSFER Registry)

The present study assessed the impact of early administration of abciximab in female and male patients with ST-segment elevation myocardial infarction (STEMI) transferred for primary angioplasty (PPCI). Data were gathered for 1,650 consecutive patients with STEMI transferred for PPCI from hospital networks in seven countries in Europe from November 2005 to January 2007 (the EUROTRANSFER Registry population). Among 1,086 patients who received abciximab, there were 186 women and 541 men who received abciximab early (>30 min before PPCI), and 86 women and 273 men treated with late abciximab. Female patients were high-risk individuals, with advanced age and increased rate of ischemic events. Early abciximab administration was associated with enhanced patency of the infarct-related artery before PPCI, and improved epicardial flow after PPCI in both women and men. Early abciximab in women led to the decrease in ischemic events, including 30 day (adjusted OR 0.26, 95 % CI 0.10–0.69, p = 0.007) and 1 year (adjusted OR 0.37, 95 % CI 0.16–0.84, p = 0.017) mortality reduction. In contrast, the reduction in 30 day (adjusted OR 0.69, 95 % CI 0.35–1.39, p = 0.27) and 1 year (adjusted OR 0.68, 95 % CI 0.38–1.22, p = 0.19) mortality was not significant in men. The frequency of bleeding events was similar in the early abciximab group compared to the late abciximab group in both women and men. Early administration of abciximab improved patency of the infarct-related artery before and after PPCI, and led to improved survival in female patients with STEMI.

Randomized trial of standard versus ClearWay-infused abciximab and thrombectomy in myocardial infarction: rationale and design of the COCTAIL II study

BACKGROUND

Patients with ST-elevation myocardial infarction (STEMI) are at substantial risk of suboptimal procedural results and late adverse events. Angiography and optical coherence tomography (OCT) studies have identified residual coronary thrombus and microcirculatory injury as potential culprits for these adverse outcomes. We hypothesized that coronary thrombectomy and local infusion of glycoprotein IIb/IIIa inhibitors by means of a dedicated infusion device can synergistically improve results of percutaneous coronary intervention (PCI) for STEMI, as appraised by OCT.

METHODS

A total of 128 patients with STEMI will be randomized, to one of the following: abciximab infusion with the ClearWay coronary catheter (C), standard abciximab infusion (A), thrombectomy followed by abciximab infusion with the ClearWay catheter (T+C), or thrombectomy followed by standard abciximab infusion (T+A). The primary objective is to demonstrate that abciximab infusion with the ClearWay catheter with or without manual thrombus aspiration (groups C or T+C) will result in a significant reduction of intrastent thrombus formations when compared with intravenous or intracoronary abciximab with or without thrombectomy (groups A or T+A). The primary endpoint will be the number of cross-sections with thrombus area more than 10% immediately after stent implantation as assessed with OCT. Additional angiographic, ECG and clinical endpoints will be collected and adjudicated.

CONCLUSION

This trial will provide important mechanistic insights on the most appropriate invasive treatment strategy for patients with STEMI and significant thrombus burden, by exploiting its factorial design and reliance on sensitive OCT endpoints.

Design and methods of European Ambulance Acute Coronary Syndrome Angiography Trial (EUROMAX): an international randomized open-label ambulance trial of bivalirudin versus standard-of-care anticoagulation in patients with acute ST-segment-elevation myocardial infarction transferred for primary percutaneous coronary intervention

BACKGROUND

In patients with ST-segment elevation myocardial infarction (STEMI) triaged to primary percutaneous coronary intervention (PCI), anticoagulation often is initiated in the ambulance during transfer to a PCI site. In this prehospital setting, bivalirudin has not been compared with standard-of-care anticoagulation. In addition, it has not been tested in conjunction with the newer P2Y12 inhibitors prasugrel or ticagrelor.

DESIGN

EUROMAX is a randomized, international, prospective, open-label ambulance trial comparing bivalirudin with standard-of-care anticoagulation with or without glycoprotein IIb/IIIa inhibitors in 2200 patients with STEMI and intended for primary percutaneous coronary intervention (PCI), presenting either via ambulance or to centers where PCI is not performed. Patients will receive either bivalirudin given as a 0.75 mg/kg bolus followed immediately by a 1.75-mg/kg per hour infusion for ≥30 minutes prior to primary PCI and continued for ≥4 hours after the end of the procedure at the reduced dose of 0.25 mg/kg per hour, or heparins at guideline-recommended doses, with or without routine or bailout glycoprotein IIb/IIIa inhibitor treatment according to local practice. The primary end point is the composite incidence of death or non-coronary-artery-bypass-graft related protocol major bleeding at 30 days by intention to treat.

CONCLUSION

The EUROMAX trial will test whether bivalirudin started in the ambulance and continued for 4 hours after primary PCI improves clinical outcomes compared with guideline-recommended standard-of-care heparin-based regimens, and will also provide information on the combination of bivalirudin with prasugrel or ticagrelor.

Efficacy and safety of tirofiban-supported primary percutaneous coronary intervention in patients pretreated with 600 mg clopidogrel: results of propensity analysis using the Clinical Center of Serbia STEMI Register

BACKGROUND

Studies with platelet glycoprotein IIb/IIIa receptor inhibitors (GPIs) showed conflicting results in primary percutaneous coronary intervention (PPCI) patients who were pretreated with 600 mg clopidogrel. We sought to investigate the short- and long-term efficacy and safety of the periprocedural administration of tirofiban in a largest Serbian PPCI centre.

METHODS

We analysed 2995 consecutive PPCI patients enrolled in the Clinical Center of Serbia STEMI Register, between February 2007 and March 2012. All patients were pretreated with 600 mg clopidogrel and 300 mg aspirin. Major adverse cardiovascular events, comprising all-cause death, nonfatal infarction, nonfatal stroke, and ischaemia-driven target vessel revascularization, was the primary efficacy end point. TIMI major bleeding was the key safety end point.

RESULTS

Analyses drawn from the propensity-matched sample showed improved primary efficacy end point in the tirofiban group at 30-day (OR 0.72, 95% CI 0.53-0.97) and at 1-year (OR 0.74, 95% CI 0.57-0.96) follow up. Moreover, tirofiban group had a significantly lower 30-day all-cause mortality (secondary end point; OR 0.63, 95% CI 0.40-0.90), compared with patients who were not administered tirofiban. At 1 year, a trend towards a lower all-cause mortality was observed in the tirofiban group (OR 0.74, 95% CI 0.53-1.04). No differences were found with respect to the TIMI major bleeding during the follow-up period.

CONCLUSIONS

Tirofiban administered with PPCI, following 600 mg clopidogrel pretreatment, improved primary efficacy outcome at 30 days and at 1 year follow up without an increase in major bleeding.

Impact of hypertension on distal embolization, myocardial perfusion, and mortality in patients with ST segment elevation myocardial infarction undergoing primary angioplasty

Hypertension is a well-known risk factor for atherosclerosis. However, data on the impact of hypertension in patients with ST elevation myocardial infarction (STEMI) are inconsistent and mainly related to studies performed in the thrombolytic era, with very few data on patients undergoing primary angioplasty. The aim of the present study was to evaluate the impact of hypertension on distal embolization, myocardial perfusion, and mortality in patients with STEMI undergoing primary percutaneous coronary intervention. Our population is represented by 1,662 patients undergoing primary angioplasty for STEMI included in the Early Glycoprotein IIb-IIIa inhibitors in Primary angioplasty database. Myocardial perfusion was evaluated by myocardial blush grade and ST segment resolution. Follow-up data were collected within 1 year after primary angioplasty. Hypertension was observed in 700 patients (42.1%). Hypertension was associated with more advanced age (p <0.001), female gender (p <0.001), diabetes (p <0.001), hypercholesterolemia (p <0.001), previous revascularization (p <0.001), anterior myocardial infarction (p = 0.006), longer ischemia time (p = 0.03), more extensive coronary artery disease (p = 0.002), more often treated with abciximab (p <0.001), and less often smokers (p <0.001). Hypertension was associated with impaired postprocedural myocardial blush grade 2 to 3 (68.2% vs 74.2%, p = 0.019) and complete ST segment resolution (51.7% vs 61.1%, p = 0.001). By a mean follow-up of 206 ± 158 days, 70 patients (4.3%) had died. Hypertension was associated with a greater mortality (6.2% vs 2.9%, hazard ratio 2.31, 95% confidence interval 1.42 to 3.73, p <0.001), confirmed after correction for baseline confounding factors (hazard ratio 1.82, 95% confidence interval 1.03 to 3.22, p <0.001). In conclusion, this study showed that among patients with STEMI undergoing primary angioplasty, hypertension is associated with impaired reperfusion and independently predicts 1-year mortality.

Impact of TIMI 3 patency before primary percutaneous coronary intervention for ST-elevation myocardial infarction on clinical outcome: results from the ASSENT-4 PCI study

BACKGROUND

Early restoration of blood flow of the infarct-related artery is associated with an improved outcome in patients with ST-elevation myocardial infarction (STEMI). Previous studies have shown a low mortality in patients with TIMI 3 flow before primary percutaneous coronary intervention (PCI). Most likely these patients had spontaneous recanalization of the infarct vessel and might constitute a low-risk subgroup. The purpose of the present analysis was to investigate whether TIMI 3 flow obtained with fibrinolysis before PCI is associated with a clinical outcome comparable to that in patients with spontaneous TIMI 3 flow.

METHODS

Patients with STEMI <6 hours enrolled in the ASSENT-4 PCI study were randomized to facilitated PCI with tenecteplase or primary PCI. For this analysis, patients were divided into three groups according to the TIMI flow of the infarct vessel before PCI: TIMI 0/1, TIMI 2, and TIMI 3.

RESULTS

From a total of 1617 patients, 861 had TIMI 0/1, 279 had TIMI 2, and 477 TIMI 3 flow. The rates of TIMI 3 flow after PCI were 84.6, 89.7, and 95.6%, respectively. Complete ST resolution was observed most often in the TIMI 3 flow group (47.5, 53.6, and 58.6%). The incidence of cardiogenic shock (6.2, 5.5, and 3.6%) and 90-day mortality (6.1, 4.7, and 4.0%) were lowest in the group with TIMI 3 patency before PCI, respectively. The rate of TIMI 3 flow before PCI was higher in the facilitated PCI group than in the primary PCI group (43.9 vs. 15.2%). The 90-day mortality in patients with TIMI 3 before PCI was identical in the facilitated and the primary PCI groups (14/353, 4.0% vs. 5/124, 4.0%).

CONCLUSION

In this post-hoc analysis of ASSENT-4 PCI, TIMI grade 3 flow in the infarct-related artery before PCI, occurring either spontaneously or obtained by fibrinolysis, is associated with a higher TIMI patency after PCI, better improved ST resolution and a trend towards a favourable clinical outcome after 90 days.

Cangrelor infusion is associated with an increased risk for bleeding: meta-analysis of randomized trials

CONTEXT

Aggressive antiplatelet strategies unquestionably cause extra hemorrhagic risks. Bleeding episodes are associated with poor outcomes including increased mortality. However, lack of uniform reporting and adjudication of bleeding events might prevent objective evaluation of the efficacy/safety profile of antithrombotic agents.

OBJECTIVE

We analyzed the bleeding rates by several previously used bleeding scales (TIMI, GUSTO, ACUITY, and BARC) after cangrelor in recent head-to-head randomized, controlled clinical trials (RCTs).

RESULTS

Data for meta-analyses were pooled from 3 RCTs (CHAMPION-PLATFORM, CHAMPION-PCI and CHAMPION-PHOENIX) including 25,106 patients. In addition, the bleeding risks were also assessed from the small (n=210) BRIDGE RCT. Cangrelor caused a significantly increased risk for major bleeding at 48 h according to the ACUITY scale (RR: 1.51, 95% CI: 1.32-1.72, p<0.00001); however, this impact was less prominent according to less sensitive bleeding scales (GUSTO severe: RR: 1.21, 95% CI: 0.70-2.11, p=0.49; TIMI major: RR: 1.00, 95% CI: 0.59-1.68, p=0.99). There was also an obvious trend towards an increased risk for any transfusions (RR: 1.31, 95% CI: 0.97-1.77, p=0.08) and TIMI major+minor bleeding events (RR: 1.30, 95% CI: 0.96-1.76, p=0.09).

CONCLUSIONS

Cangrelor on top of aspirin or/and clopidogrel increases the risk for early bleeding events after PCI; however, it largely depends on the bleeding definition used, and how this excess risk of bleeding was captured. The bleeding hazard needs to be verified in the ongoing FDA secondary cangrelor review.

Ambulance or in-catheterization laboratory administration of ticagrelor for primary percutaneous coronary intervention for ST-segment elevation myocardial infarction: rationale and design of the randomized, double-blind Administration of Ticagrelor in the cath Lab or in the Ambulance for New ST elevation myocardial Infarction to open the Coronary artery (ATLANTIC) study

Primary percutaneous coronary intervention (PCI) is the treatment of choice for patients presenting with acute ST-segment elevation myocardial infarction (STEMI). However, if catheterization facilities are not immediately available, the effectiveness of PCI can be affected by delays in transfer. Evidence suggests that antiplatelet therapy administered early, preferably in the ambulance during transfer, may provide better and earlier perfusion. Ticagrelor, a direct platelet P2Y12 receptor inhibitor, is indicated for the management of patients with acute coronary syndromes. The ATLANTIC study (NCT01347580; EudraCT 2011-000214-19) is a 30-day international, randomized, parallel-group, placebo-controlled study in male and female patients (aged ≥18 years) who are diagnosed as having STEMI, with intended primary PCI. In total, 1770 patients will be randomized immediately after diagnosis to prehospital administration of ticagrelor 180 mg followed by matching placebo administered in hospital, or prehospital administration of placebo followed by ticagrelor 180 mg administered in hospital. All patients will then receive ticagrelor 90 mg twice daily for 30 days. The coprimary end point is the percentage of patients reaching thrombolysis in myocardial infarction flow grade 3 in the infarct-related artery at initial angiography or achieving ≥70% ST-segment elevation resolution pre-PCI. The primary safety end point is major, life-threatening, or minor bleeding after ticagrelor administration. The results of this study may have an impact on future recommendations for treatment for patients with STEMI.