Strategies to optimize initial P2Y12 inhibitor therapy in STEMI patients

INTRODUCTION

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

PURPOSE

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

SUMMARY

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

CONCLUSION

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

Pretreatment with P2Y12 Receptor Inhibitors in Acute Coronary Syndromes-Is the Current Standpoint of ESC Experts Sufficiently Supported?

Excessive platelet reactivity plays a pivotal role in the pathogenesis of acute myocardial infarction. Today, the vast majority of patients presenting with acute coronary syndromes qualify for invasive treatment strategy and thus require fast and efficient platelet inhibition. Since 2008, in cases of ST-elevation myocardial infarction, the European Society of Cardiology guidelines have recommended pretreatment with a P2Y₁₂ inhibitor. This approach has become the standard of care in the majority of centers worldwide. Nevertheless, the latest guidelines for the management of patients presenting with acute coronary syndrome without persisting ST-elevation preclude routine pretreatment with the P2Y₁₂ receptor inhibitor. Those who oppose pretreatment support their stance with trials failing to prove the benefits of this strategy at the cost of an increased risk of major bleeding, especially in individuals inappropriately diagnosed with an acute coronary syndrome, thus having no indication for platelet inhibition. However, adequate platelet inhibition requires even up to several hours after application of a loading dose of P2Y₁₂ receptor inhibitors. Omission of data from pharmacokinetic and pharmacodynamic studies in the absence of data from clinical studies makes generalization of the pretreatment recommendations difficult to accept. We aimed to review the scientific evidence supporting the current recommendations regarding pretreatment with P2Y₁₂ inhibitors.

Aortic Stiffness, Inflammation, and Incidence of Cardiovascular Events in Elderly Participants From the General Population

Low-grade inflammation and arterial stiffness are key factors in the development of vascular aging. However, the interplay between arterial stiffness and inflammation for cardiovascular (CV) disease is unclear. Aortic pulse wave velocity (aPWV) and the inflammatory markers, high-sensitivity C-reactive protein (CRP) and orosomucoid, were measured in 2710 participants (median age: 72 years). These participants were followed up for a mean of 7.6 years for a composite CV disease end point. Per 1 interquartile range increment of CRP and orosomucoid, respectively, aPWV increased by 0.19 m/s (95% CI: 0.07-0.32) and 0.19 m/s (0.11-0.27), after multifactorial adjustment. Mediation analysis showed that aPWV, after multifactorial adjustment, mediated 8% (-4, 20) of the CV disease risk associated with CRP and 8% (-4, 18) of orosomucoid risk. The associated risk increased with combinations of high aPWV and high CRP or orosomucoid. We found no evidence that arterial PWV acted as an important mediator of the relationship between systemic inflammation and CV disease risk in this elderly population. The results instead indicate an additive effect. Our study supports the view that arterial stiffness and chronic inflammation affects CV risk mainly through separate causal pathways.

The influence of pre-hospital medication administration in ST-elevation myocardial infarction patients on left ventricular ejection fraction and intra-hospital death

Introduction

Currently, invasive cardiology techniques are the preferred method of treatment for patients with ST-elevation myocardial infarction (STEMI). Improving the care of patients with STEMI is possible by minimizing the time that elapses from the onset of pain to the start of treatment. As studies indicate, early pharmacotherapy, especially with antiplatelet and anticoagulant medications, allows for their early effectiveness.

Aim

To assess the influence of early administration of antiplatelet (clopidogrel) and anticoagulant medications in the pre-hospital period in patients with ST-elevated myocardial infarction on the frequency of in-hospital deaths and on the left ventricular ejection fraction evaluated at hospital discharge.

Material and methods

In this study, a retrospective analysis of 573 patients hospitalized due to ST-segment elevation myocardial infarction in one of Krakow’s hospitals from January 2011 to December 2015 (excluding the whole of 2013) was used as a research method.

Results

As many as 97% of patients received pre-hospital pharmacotherapy, but only 46.0% of respondents received unfractionated heparin, and 19.2% received clopidogrel. The in-hospital mortality rate was 6.7%, but among patients prehospitally treated with clopidogrel and unfractionated heparin, the in-hospital mortality rate was 1.1%. Prehospital administration of clopidogrel significantly decreased the possibility of reduced left ventricular ejection fraction (OR = 0.27; 95% CI: 0.09–0.90).

Conclusions

Among pre-hospital procedures, only administration of a second antiplatelet drug (clopidogrel) significantly decreased the risk of reduced left ventricular ejection fraction, and administration of clopidogrel or heparin, or a combination of both, significantly decreased the risk of in-hospital death in patients with STEMI.

P2Y12 inhibitor loading dose before catheterization in ST-segment elevation myocardial infarction: Is this the best strategy?

INTRODUCTION AND OBJECTIVES

In ST-segment elevation myocardial infarction (STEMI) the benefit of dual antiplatelet therapy is unequivocal, but the optimal time to administer the loading dose (LD) of a P2Y₁₂ inhibitor is the subject of debate and disagreement. The main aim of this study was characterize current practice in Portugal and to assess the prognostic impact of P2Y₁₂ inhibitor LD administration strategy, before versus during or after primary percutaneous coronary intervention (PCI).

METHODS

This multicenter retrospective study based on the Portuguese National Registry on Acute Coronary Syndromes included patients with STEMI and PCI performed between October 1, 2010 and September 19, 2017. Two groups were established: LD before PCI (LD-PRE) and LD during or after PCI (LD-CATH).

RESULTS

A total of 4123 patients were included, 66.3% in the LD-PRE group and 32.4% in the LD-CATH group. Prehospital use of a P2Y₁₂ inhibitor was a predictor of the composite bleeding endpoint (major bleeding, need for transfusion or hemoglobin [Hb] drop >2g/dl), Hb drop >2g/dl and reinfarction. There were no differences between groups in major adverse events (MAE) (in-hospital mortality, reinfarction and stroke) or in-hospital mortality.

CONCLUSIONS

Prehospital use of a P2Y₁₂ inhibitor was associated with an increased risk of bleeding, predicting the composite bleeding outcome and Hb drop >2g/dl, with no differences in mortality or MAE, calling into question the benefit of this strategy.

Acute Coronary Syndrome, Antiplatelet Therapy, and Bleeding: A Clinical Perspective

Inhibition of platelet function by means of dual antiplatelet therapy (DAPT) is the cornerstone of treatment of acute coronary syndrome (ACS). While preventing ischemic recurrences, inhibition of platelet function is clearly associated with an increased bleeding risk, a feared complication that may lead to significant morbidity and mortality. Since bleeding risk management is intrinsically associated with therapeutic adjustments undertaken during the whole clinical history of patients with acute coronary syndrome, single decisions taken from the very first day to years of follow-up might be decisive. This review aims at providing a clinically oriented, patient-tailored approach in reducing the risk and manage bleeding complications in ACS patients treated with DAPT. The steps in clinical decision making from the day of ACS to follow-up are analyzed. New treatment strategies to enhance the safety of DAPT are also described.

2020 Focused Update of the 2012 Guidelines of the Taiwan Society of Cardiology for the Management of ST-Segment Elevation Myocardial Infarction

One of the major missions of the Taiwan Society of Cardiology is to publish practice guidelines that are suitable for local use in Taiwan. The ultimate purpose is to continuously improve cardiovascular health care from the implementation of the recommendations in the guidelines. Despite recent improvement of medical care, patients with ST-segment elevation myocardial infarction (STEMI) still carry a high morbidity and mortality. There have been many changes in the concepts of STEMI diagnosis and treatment in recent years. The 2020 focused update of the 2012 guidelines of the Taiwan Society of Cardiology for the management of STEMI is an amendment of the 2012 guidelines based on the newest published scientific data. The recommendations in this focused update provide the diagnosis and treatment strategy for STEMI that should be generally implemented in Taiwan. Nevertheless, guidelines never completely replace clinical judgment and medical decision still should be determined individually.

Exploring and comparing definitions of healthy vascular ageing in the population: characteristics and prospective cardiovascular risk

Different methods can be used to define healthy vascular ageing (HVA). In this prospective cohort study, we explored three different definitions in order to provide guidance for which to use. 2718 subjects were included from the Cardiovascular (CV) arm of the Malmö Diet Cancer Study (MDCS; median age 71.9 years, 62.2% females). Three different definitions of HVA were used: HVA-1 (<15th percentile of aortic pulse wave velocity (aPWV) distribution from age-quintiles); HVA-2 (<35th percentile of aPWV+ <35th percentile of carotid Intima-Media Thickness. cIMT); and HVA-3 (aPWV < 7.6 m/s + no hypertension). The HVA-1 and HVA-2 groups were compared with the HVA-3, and to the corresponding groups without HVA (non-HVA), in cross-sectional analyses for baseline characteristics and using Cox regressions for prospective risk, yielding hazard ratios (HRs) adjusted for conventional risk factors. A composite CVD endpoint was used, consisting of myocardial infarctions, ischemic heart disease mortality, and coronary artery procedures. The baseline characteristics were, with minor exceptions, similar across HVA groups. In the fully adjusted model, the HRs (95%CI) were 0.62 (0.41-0.93), 0.45 (0.26-0.76), and 0.56 (0.34-0.91) for HVA-1, HVA-2, and HVA-3, respectively. In summary, this observational study of elderly subjects provides examples of integrating hypertension and cIMT in the definition of HVA, as compared with only using aPWV. As aPWV itself is such a robust marker of HVA, it is demanding to find additional markers which improve the definition. There is a need to create a generally accepted definition of HVA.

Safety of Ticagrelor Compared to Clopidogrel after Prehospital Initiation of Treatment

Objectives  The objective of this registry was to study the safety of prehospital initiation of ticagrelor compared with clopidogrel. Background  Ticagrelor has replaced clopidogrel in many hospitals as the routinely used antiplatelet drug in patients with ST-segment elevation myocardial infarction (STEMI). Nevertheless, in the PLATelet inhibition and patient Outcomes (PLATO) trial, ticagrelor was associated with an increase in non-CABG (non-coronary artery bypass grafting)-related major bleeding. Data comparing the safety of ticagrelor and clopidogrel after prehospital initiation of treatment are not available. Methods  A retrospective, multicenter registry was performed. Selection criteria were the administration of a prehospital loading dose of ticagrelor or clopidogrel according to the ambulance STEMI treatment protocol and the presentation to a percutaneous coronary intervention-capable hospital in our region between January 2011 and December 2012. Follow-up was performed using the electronic patient files for the time period between the antiplatelet loading dose and hospital discharge. The data were analyzed using a primary bleeding end point (any bleeding) and a secondary thrombotic end point (all-cause mortality, spontaneous myocardial infarction, definite stent thrombosis, stroke, or transient ischemic attack). Results  Data of 304 clopidogrel-treated and 309 ticagrelor-treated patients were available for analysis. No significant difference in bleeding rate was observed between both groups, using univariate (17.8 vs. 20.1%; p  = 0.47; odds ratio, 1.16 [95% confidence interval, 0.78-1.74]) and multivariate ( p  = 0.42) analysis. Also for the secondary thrombotic end point (6.3 vs. 4.9%, p  = 0.45), no significant differences were observed. Conclusion  In this real-world registry, no significant differences in bleeding or thrombotic event rate were found between ticagrelor and clopidogrel after prehospital initiation of treatment.

A Vascular Aging Index as Independent Predictor of Cardiovascular Events and Total Mortality in an Elderly Urban Population

The morphology and function of the arteries can be directly measured using different established methods. This prospective cohort study aimed to translate 2 of these, aortic pulse wave velocity (aPWV) and carotid intima-media thickness (cIMT), into a combined Vascular Aging Index (VAI) and then evaluate the predictive power of aPWV, cIMT, and VAI. Patients (n = 2718) were included from the cardiovascular arm of the Malmö Diet and Cancer Study (median age 71.9 years, 62.2% females). Total follow-up time was 16 448 person-years and a composite cardiovascular disease (CVD) end point was used. Cox regressions yielded adjusted hazard ratios (95% confidence interval) per 1 standard deviation increment of log_e aPWV, log_e cIMT, and log_e VAI of 1.25 (1.08-1.45, P = .003), 1.27 (1.13-1.44, P < .001), and 1.45 (1.26-1.68, P < .001), respectively. The C-statistics increased from 0.714 to 0.734 when adding aPWV and cIMT to a model of conventional risk factors. Net Reclassification Index also showed a significant (P < .001) improvement for the classification of event-free patients and no change for patients with events. A VAI based on aPWV and cIMT had a good predictive performance. Used together, aPWV and cIMT incrementally and significantly improve the prediction of CVD events by correctly down-adjusting the predicted risk for noncases.

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

Background—

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

Methods and Results—

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

Conclusions—

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

Early ambulance initiation versus in-hospital initiation of high dose clopidogrel in ST-segment elevation myocardial infarction

Pre-hospital infarct diagnosis gives the opportunity to start anti-platelet and anti-thrombotic agents before arrival at the PCI centre. However, more evidence is necessary to demonstrate whether high dose (HD) clopidogrel (600 mg) administered in the ambulance is associated with improved initial patency of the infarct related vessel (IRV) and/or clinical outcome compared to in-hospital initiation of HD clopidogrel. From 2001 until 2009 all consecutive ST-Segment Elevation Myocardial Infarction (STEMI) patients who underwent pre-hospital diagnosis and therapy in the ambulance were prospectively included in our single-centre cohort study. We compared initial patency of the IRV and clinical outcome in patients treated from 2001 until June 2006 (in-hospital HD clopidogrel) with patients treated from July 2006 until 2009 (ambulance HD clopidogrel). A total of 2,475 patients with STEMI were registered; of these 1,110 (44.8%) received in-hospital HD clopidogrel and 1,365 (55.2%) received ambulance HD clopidogrel. Ambulance HD clopidogrel was not independently associated with initial patency (TIMI-2/3-flow pre-PCI (odds ratio: 1.18, 95% confidence interval [CI] 0.96–1.44); however, it was associated with fewer recurrent myocardial infarctions at 30 days (hazard ratio [HR]: 0.45, 95% CI 0.22–0.93) and at one year (HR: 0.45, 95% CI 0.25–0.80). No difference in TIMI 2/3 flow post-PCI, major bleeding, mortality, MACE – and the combination of mortality and recurrent myocardial infarction at 30-days and at one year was present between the two groups. In conclusion, early in-ambulance as compared to in-hospital initiation of HD clopidogrel in STEMI patients did not improve initial patency of the IRV or clinical outcome, except for a reduction of recurrent myocardial infarction. Therefore, early administration of HD clopidogrel seems to have net clinical benefit for these patients .

Clinical pathways and management of antithrombotic therapy in patients with acute coronary syndrome (ACS): a Consensus Document from the Italian Association of Hospital Cardiologists (ANMCO), Italian Society of Cardiology (SIC), Italian Society of Emergency Medicine (SIMEU) and Italian Society of Interventional Cardiology (SICI-GISE)

Antiplatelet therapy is the cornerstone of the pharmacologic management of patients with acute coronary syndrome (ACS). Over the last years, several studies have evaluated old and new oral or intravenous antiplatelet agents in ACS patients. In particular, research was focused on assessing superiority of two novel platelet ADP P2Y12 receptor antagonists (i.e., prasugrel and ticagrelor) over clopidogrel. Several large randomized controlled trials have been undertaken in this setting and a wide variety of prespecified and post-hoc analyses are available that evaluated the potential benefits of novel antiplatelet therapies in different subsets of patients with ACS. The aim of this document is to review recent data on the use of current antiplatelet agents for in-hospital treatment of ACS patients. In addition, in order to overcome increasing clinical challenges and implement effective therapeutic interventions, this document identifies all potential specific care pathway for ACS patients and accordingly proposes individualized therapeutic options.

Mortality in primary angioplasty patients starting antiplatelet therapy with prehospital prasugrel or clopidogrel: a 1-year follow-up from the European MULTIPRAC Registry

Aim

MULTIPRAC was designed to provide insights into the use and outcomes associated with prehospital initiation of antiplatelet therapy with either prasugrel or clopidogrel in the context of primary percutaneous coronary intervention. After a previous report on efficacy and safety outcomes during hospitalization, we report here the 1-year follow-up data, including cardiovascular (CV) mortality.

Methods and results

MULTIPRAC is a multinational, prospective registry of patients with ST-elevation myocardial infarction (STEMI) from 25 hospitals in nine countries, all of which had an established practice of prehospital start of dual antiplatelet therapy in place. The key outcome was CV death at 1 year. Among 2,036 patients followed-up through 1 year, 49 died (2.4%), 10 during the initial hospitalization and 39 within 1 year after hospital discharge. The primary analysis was based on the P2Y₁₂-inhibitor, used from prehospital loading dose through hospital discharge. Prasugrel (n=824) was more commonly used than clopidogrel (n=425). The observed 1-year rates for CV death were 0.5% with prasugrel and 2.6% with clopidogrel. After adjustment for differences in baseline characteristics, treatment with prasugrel was associated with a significantly lower risk of CV death than treatment with clopidogrel (odds ratio 0.248; 95% confidence interval 0.06–0.89).

Conclusion

In STEMI patients from routine practice undergoing primary angioplasty, who were able to start oral antiplatelet therapy prehospital, treatment with prasugrel as compared to clopidogrel was associated with a lower risk of CV death at 1-year follow-up.

Upstream clopidogrel, prasugrel, or ticagrelor for patients treated with primary angioplasty: Results of an angiographic randomized pilot study

OBJETIVES

The main objective of the present randomized pilot study was to explore the effects of upstream prasugrel or ticagrelor or clopidogrel for patients with ST-segment-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI).

BACKGROUND

Administration of clopidogrel "as soon as possible" has been advocated for STEMI. Pretreatment with prasugrel and ticagrelor may improve reperfusion. Currently, the angiographic effects of upstream administration of these agents are poorly understood.

METHODS

A total of 132 patients with STEMI within the first 12 hr of chest pain referred to primary angioplasty were randomized to upstream clopidogrel (600 mg), prasugrel (60 mg), or ticagrelor (180 mg) while still in the emergency room. All patients underwent protocol-mandated thrombus aspiration.

RESULTS

Macroscopic thrombus material was retrieved in 79.5% of the clopidogrel group, 65.9% of the prasugrel group, and 54.3% of the ticagrelor group (P = 0.041). At baseline angiography, large thrombus burden was 97.7% vs. 87.8% vs. 80.4% in the clopidogrel, prasugrel, and ticagrelor groups, respectively (P = 0.036). Also, at baseline, 97.7% presented with an occluded target vessel in the clopidogrel group, 87.8% in the prasugrel group and 78.3% in the ticagrelor group (P = 0.019). At the end of the procedure, the percentages of patients with combined TIMI grade III flow and myocardial blush grade III were 52.3% for clopidogrel, 80.5% for prasugrel, and 67.4% for ticagrelor (P = 0.022).

CONCLUSIONS

In patients with STEMI undergoing primary PCI within 12 hr, upstream clopidogrel, prasugrel or ticagrelor have varying angiographic findings, with a trend toward better results for the latter two agents. © 2015 Wiley Periodicals, Inc.

Effectiveness of Pretreatment With Dual Oral Antiplatelet Therapy

Several observational studies, randomized controlled trials, and meta-analyses suggested that pretreatment with clopidogrel in addition to aspirin could reduce the rate of ischemic events, especially in the setting of acute coronary syndromes. Newer P2Y12 inhibitors like prasugrel and ticagrelor, which provide faster and stronger platelet inhibition compared with clopidogrel, would enhance the benefits of pretreatment. However, 2 recent randomized trials, A Comparison of Prasugrel at PCI or Time of Diagnosis of Non-ST Elevation Myocardial Infarction and the Administration of Ticagrelor in the Cath Lab or in the Ambulance for New ST Elevation Myocardial Infarction to Open the Coronary Artery studies, aimed at assessing the effects of the timing of administration of novel P2Y12 inhibitors in acute coronary syndromes, failed to meet their primary end points. In this report, we review clinical data on pretreatment with dual oral antiplatelet therapy and comment on some criticisms raised from recent trials.

Early P2Y12 inhibition in ST-segment elevation myocardial infarction: Bridging the gap

Rapid and consistent platelet inhibition represents the cornerstone of pharmacologic treatment in the early hours of ST-segment elevation myocardial infarction (STEMI). Oral P2Y12 inhibitors are recommended to be administered as early as possible in patients with STEMI undergoing primary percutaneous coronary intervention. However, a delay in the onset of antiplatelet agent effects has been recently described in the first several hours after oral administration of clopidogrel, prasugrel, and ticagrelor. As a result, primary percutaneous coronary intervention is performed in most cases with P2Y12 inhibition that may be inadequate. Several strategies may be applied in order to "bridge the gap" in platelet inhibition after oral P2Y12 inhibitors in STEMI, such as upstream administration of P2Y12 inhibitors, loading dose modification, use of an intravenous P2Y12 inhibitor, or glycoprotein IIb/IIIa inhibitors' administration. These strategies may further improve clinical outcomes in this high-risk "golden window."

Perspectives on the 2014 ESC/EACTS Guidelines on Myocardial Revascularization : Fifty Years of Revascularization: Where Are We and Where Are We Heading?

The joint European Society of Cardiology and European Association of Cardio-Thoracic Surgery (ESC/EACTS) guidelines on myocardial revascularization collect and summarize the evidence regarding decision-making, diagnostics, and therapeutics in various clinical scenarios of coronary artery disease, including elective, urgent, and emergency settings. The 2014 document updates and extends the effort started in 2010, year of the first edition of these guidelines. Importantly, this latest edition provides a systematic review of all randomized clinical trials performed since 1980, comparing different strategies of myocardial revascularization, including coronary artery bypass graft (CABG), balloon angioplasty, percutaneous coronary intervention (PCI) with bare-metal stents (BMS) and first- and second-generation drug-eluting stents (DES). This review aims to highlight the most relevant novelties introduced by the 2014 edition of the ESC/EACTS myocardial revascularization guidelines as compared with the previous edition and to describe similarities and differences with the American societies' guidelines.

Prognostic impact of clopidogrel pretreatment in patients with acute coronary syndrome managed invasively

Pretreatment with antiP2Y12 agents before angiography in acute coronary syndrome (ACS) is associated with a reduction in thrombotic events. However, recent evidences have questioned the benefits of upstream antiP2Y12, reporting a higher incidence of bleeding. We analyzed the prognostic impact of clopidogrel pretreatment in a large cohort of invasively managed patients with ACS. In hospital, safety and efficacy of clopidogrel pretreatment were retrospectively analyzed in patients included in the ARIAM-Andalucía Registry (Analysis of Delay in Acute Myocardial Infarction). Propensity score and inverse probability of treatment weighting analysis were performed to control treatment selection bias. Results were stratified by ACS type. Sensitivity analyses were used to explore stability of the overall treatment effect. Of 9,621 patients managed invasively, 69% received clopidogrel before coronary angiography. In the ST-elevation myocardial infarction group, pretreatment was associated with a significant reduction in reinfarction (odds ratio 0.53, 95% confidence interval [CI] 0.27 to 0.96; p = 0.027), stent thrombosis (odds ratio 0.15, 95% CI 0.06 to 0.38; p <0.0001), and mortality (odds ratio 0.67, 95% CI 0.48 to 0.94; p = 0.020), with an increase in minor bleeding but remained as a net clinical benefit strategy. Those benefits were not present in patients without ST elevation (non-ST elevation ACS). The weighting and propensity analysis confirmed the same results. An interaction between pretreatment duration and bleeding was observed. In conclusion, pretreatment with clopidogrel reduced the occurrence of death and thrombotic outcomes at the cost of minor bleeding. Those benefits exclusively affected ST-elevation myocardial infarction cases. The potential benefit of routine upstream pretreatment in patients with non-ST-elevation ACS should be reappraised at the present.

A pharmacodynamic comparison of 5 anti-platelet protocols in patients with ST-elevation myocardial infarction undergoing primary PCI

Background

Despite advances in anti-platelet treatments, there still exists an early increase in both ischemic as well as bleeding events following primary PCI in patients with ST-elevation myocardial infarction (STEMI). Platelet inhibition data of different anti-platelet treatments in the acute phase of a myocardial infarction might offer some insight into these problems. The aim of this study was to evaluate the pharmacodynamic profile of 5 different anti-platelet treatments in the acute phase of STEMI in patients undergoing primary PCI.

Methods

A total of 223 STEMI patients undergoing primary PCI were prospectively included. Patients received either pre-hospital clopidogrel only, pre-hospital clopidogrel followed by prasugrel switch in the cath lab, prasugrel treatment only, pre-hospital clopidogrel followed by ticagrelor switch in the cath lab or pre-hospital ticagrelor only. Platelet reactivity was measured serially using vasodilator-stimulated phosphoprotein (VASP).

Results

Patients receiving pre-hospital clopidogrel followed by prasugrel switch showed similar platelet inhibition data as patients receiving prasugrel only, with more than 90% being good responders the day after PCI. Average time from prasugrel administration to a VASP value of <50% was 1.5 hours. In patients receiving pre-hospital ticagrelor, 50% were good responders at completion of PCI and average time to a VASP-value of <50% was 2.3 hours. Only 32% of patients receiving clopidogrel only were responders the day after PCI.

Conclusions

Switching from an upstream bolus dose of clopidogrel to prasugrel at the time of PCI, appeared as a safe and feasible option with no tendency for overshoot or attenuation of platelet inhibition. Pre-hospital administration of ticagrelor was associated with a 50% good responder rate at completion of PCI.

Reappraisal of thienopyridine pretreatment in patients with non-ST elevation acute coronary syndrome: a systematic review and meta-analysis

OBJECTIVE

To investigate the effect of pretreatment with P2Y12 receptor inhibitors compared with no pretreatment on efficacy and safety of treatment of non-ST elevation acute coronary syndrome (ACS).

DATA SOURCES

Two reviewers independently searched Medline, Embase, Cochrane Controlled Trials, and BioMed Central databases for randomized placebo controlled trials and observational studies from August 2001 to March 2014.

STUDY ELIGIBILITY

Studies must have reported both all-cause mortality (primary efficacy endpoint) and major bleeding (safety endpoint) outcomes.

DATA EXTRACTION

Data on sample size, characteristics, drug dose and delay of administration, and outcomes were independently extracted and analyzed.

DATA SYNTHESIS

A random-effect model was applied. The analysis was performed (i) in all patients independently of the management strategy and (ii) only in patients undergoing percutaneous coronary intervention.

RESULTS

Of the 393 titles identified, seven (four randomized controlled trials, one observational analysis from a randomized controlled trial, and three observational studies) met the inclusion criteria. No study was identified for ticagrelor or cangrelor, and analyses were thus limited to thienopyridines. A total of 32,383 non-ST elevation ACS patients were included, 18,711 coming from randomized controlled trials. Of these, 55% underwent percutaneous coronary intervention (PCI). Pretreatment was not associated with a significant lower risk of mortality in all patients (odds ratio 0.90 (95% confidence interval 0.75 to 1.07), P=0.24), in particular when considering only the randomized controlled trials (odds ratio 0.90 (0.71 to 1.14), P=0.39). Similar results were observed in the cohort of patients undergoing PCI. A significant 30-45% excess of major bleeding was consistently observed in all patients (odds ratio 1.32 (1.16 to 1.49), P<0.0001) and in those undergoing PCI, as well as in the subset analyses of randomized controlled trials of these two cohorts of patients. There was a reduction in major adverse cardiovascular events in the analysis of all patients (odds ratio 0.84 (0.72 to 0.98), P=0.02), driven by the old clopidogrel studies (CURE and CREDO), but the difference was not significant for the cohort of patients undergoing PCI. Stent thrombosis, stroke, and urgent revascularization did not differ between groups (pretreatment v no pretreatment). The results were consistent for both thienopyridines and confirmed in sensitivity analyses.

LIMITATIONS

Analysis was not performed on individual patient's data.

CONCLUSION

In patients presenting with non-ST elevation ACS, pretreatment with thienopyridines is associated with no significant reduction of mortality but with a significant excess of major bleeding no matter the strategy adopted, invasive or not. Our results do not support a strategy of routine pretreatment in patients with non-ST elevation ACS.

[Antiplatelet therapy in acute coronary syndrome. Prehospital phase: nothing, aspirin or what?]

In most cases of ST segment elevation myocardial infarction (STEMI) a major coronary vessel is occluded by a thrombus. This is why early and effective antiplatelet therapy plays a key role. The current guidelines recommend the administration of dual antiplatelet therapy as early as possible. Despite the lack of convincing clinical evidence, prehospital administration appears reasonable, primarily because of pharmacokinetic considerations. Ticagrelor should be preferentially administered because the largest amount of evidence is available and it appears to be safe. In high-risk patients undergoing transfer to a catheterization laboratory, upstream use of a glycoprotein (GP) IIb/IIIa receptor antagonist (tirofiban) may be considered. Acute coronary syndrome without ST segment elevation (NSTE-ACS) represents a clinically heterogeneous group. Current guidelines recommend that antiplatelet therapy should be initiated as early as possible when the diagnosis of NSTE-ACS is made. If there is high clinical suspicion of NSTE-ACS acetylsalicylic acid (ASA) should be given before hospital admission. In high-risk patients prehospital administration of ticagrelor may be considered.

Cangrelor: an emerging therapeutic option for patients with coronary artery disease

OBJECTIVES

To perform a systematic up-to-date review and critical discussion of potential clinical applications of cangrelor based on its pharmacologic properties and the main findings from randomized clinical studies.

METHODS

A database search (PubMed, CENTRAL and Google Scholar) by two independent investigators, including proceedings from scientific sessions of ACC, AHA, ESC, TCT and EuroPCR, from January 1998 through December 2013.

RESULTS

Cangrelor is a potent, intravenous, direct-acting P2Y12 antagonist with rapid onset and quickly reversible action. In contrast to ticagrelor, cangrelor's interaction with thienopiridines requires termination of cangrelor infusion before switching to clopidogrel or prasugrel. According to randomized trials, a cangrelor-clopidogrel combination is relatively safe and more effective than the standard clopidogrel regimen in both urgent and elective percutaneous coronary intervention (PCI) settings, with the advantage of this drug combination fully evident when the universal definition of myocardial infarction is applied. In contrast to available antiplatelet drugs with delayed onset and offset of action, its favorable properties make cangrelor a desirable agent for ad hoc elective PCI, high risk acute coronary syndromes treated with immediate coronary stenting and for bridging those surgery patients who require periprocedural P2Y12 inhibition. Current evidence on cangrelor therapy is limited by the lack of adequately powered studies assessing cangrelor co-administration either with prasugrel or ticagrelor, suboptimal design of some of the trials favoring cangrelor, potentially attenuated benefits with modern stent design, and finally, by the lack of survival advantage.

CONCLUSIONS

With its pharmacokinetic and pharmacodynamic advantages, allowing consistent and strong P2Y12 inhibition, and with its rapid onset and swift reversal of action devoid of need for an antidote, cangrelor might improve clinical outcomes in clopidogrel-treated patients by reducing ischemic events, while maintaining a favorable safety profile. However, further studies, addressing the safety and efficacy of cangrelor on top of novel oral P2Y12 inhibitors, are warranted.

Soluble urokinase plasminogen activator receptor: a risk factor for carotid plaque, stroke, and coronary artery disease

BACKGROUND AND PURPOSE

Recent studies indicate that the urokinase system could have an important role in atherogenesis and plaque rupture. The relationships among the soluble urokinase plasminogen activator receptor (suPAR), carotid plaque, and incidence of ischemic stroke and coronary artery disease (CAD) events were studied in a prospective cohort.

METHODS

Occurrence of carotid plaque and plasma levels of suPAR were assessed in 5166 men and women, aged 45 to 68 years, participating in the Malmö Diet and Cancer study. Incidences of ischemic stroke and CAD were monitored during a mean follow-up of 15 years.

RESULTS

Subjects with carotid plaque had significantly higher levels of suPAR compared with those without carotid plaque. suPAR was associated with increased incidence of ischemic stroke (hazard ratio [HR] for third versus first tertile, 1.50; 95% confidence interval [CI], 1.06-2.11) and CAD (HR, 1.55; 95% CI, 1.13-2.13) after adjustment for risk factors. The risk factor-adjusted HR for ischemic stroke was 2.21 (95% CI, 1.52-3.22) in subjects with carotid plaque and high suPAR (ie, third tertile) and 1.51 (95% CI, 1.05-2.17) in subjects with carotid plaque and low suPAR compared with those without carotid plaque and low suPAR (reference). High levels of suPAR significantly increased the risk of ischemic stroke and CAD in subjects with carotid plaque.

CONCLUSIONS

suPAR is associated with increased occurrence of carotid plaque and increased incidence of ischemic stroke and CAD. Presence of both elevated levels of suPAR and carotid plaque increases the risk of ischemic stroke in an additive way.

Dual antiplatelet therapy with prasugrel or ticagrelor versus clopidogrel in interventional cardiology

For several years, clopidogrel plus aspirin has been the dual antiplatelet therapy (DAPT) of choice for patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) with stent implantation. More recently, prasugrel and ticagrelor have demonstrated greater efficacy than clopidogrel. In TRITON-TIMI 38, the risk of TIMI major bleeding unrelated to coronary artery bypass graft (CABG) surgery was similar for prasugrel and clopidogrel after excluding subgroups with increased bleeding risk (previous stroke or transient ischemic event; age ≥75 years; weight <60 kg). In the PLATO trial, rates of TIMI major bleeding were similar for ticagrelor and clopidogrel, but ticagrelor was associated with a significantly higher rate of non-CABG-related TIMI major bleeding. Current evidence suggests that prasugrel or ticagrelor plus aspirin should be the DAPT of choice in patients with ACS undergoing PCI unless they are at particularly high risk of bleeding. No studies have yet compared prasugrel and ticagrelor in ACS patients, however prasugrel and ticagrelor have different side effect profiles, and the choice of agent should be made either as a default choice and/or on an individual patient basis. Ongoing trials in ACS patients will increase the evidence base for new P2Y(12) receptor inhibitors and help to establish the most effective DAPT regimens.

Prehospital treatment of ST-segment elevated myocardial infarction patients

Providing optimal care to patients with ST-segment elevated myocardial infarction is challenging. If a patient experiences chest pain and calls the emergency number, a cascade of actions is initiated that should lead to a diagnosis, start of treatment and reperfusion of the infarcted myocardium. This should all happen within 90 min after first medical contact, irrespective of the location of the patient or the time of day. The complex organization that is needed to achieve this goal in every ST-segment elevated myocardial infarction patient accounts for a fascinating interplay between prehospital and in-hospital care, in a situation when every minute counts. State-of-the-art care should be provided according to the latest insights and guidelines.

Oral antiplatelet therapy in acute coronary syndromes: recent developments

The purpose of this article is to summarize the current knowledge about treatment with oral platelet inhibitors in patients with acute coronary syndrome (ACS). Antiplatelet therapy has been shown to improve the prognosis of patients with ACS with ST segment elevation myocardial infarction (STEMI) and non-ST segment elevation ACS (NSTE-ACS). Aspirin should be given with a loading dose of 250–500 mg, followed by 75–100 mg/day. Dual antiplatelet therapy is recommended for all patients with ACS for 12 months regardless of the initial revascularization strategy. Clopidogrel should be administered at first medical contact in STEMI with a loading dose of 600 mg. In patients with ACS and percutaneous coronary intervention (PCI) 2 × 75 mg clopidogrel should be given daily over 7 days, while in all other patients 75 mg per day appears to be sufficient. The two newer adenosine diphosphate-receptor antagonists prasugrel and ticagrelor lead to a more rapid and effective inhibition of platelet aggregation compared with clopidogrel, which was associated with an improved clinical outcome in two large randomized studies. Prasugrel is indicated in patients with ACS undergoing PCI and was most effective in diabetics and in patients with STEMI. In the recent TaRgeted platelet Inhibition to cLarify the Optimal strateGy to medicallY manage Acute Coronary Syndromes trial in medically treated patients with NSTE-ACS, prasugrel did not significantly reduce ischemic events compared with clopidogrel. Ticagrelor has been studied in the whole spectrum of ACS patients and reduced cardiovascular and total mortality in comparison with clopidogrel. The greatest benefit has been observed in patients with planned conservative treatment and in patients with impaired renal function. Expanding antiplatelet therapy from dual to triple therapy including a platelet thrombin receptor antagonist in the thrombin receptor antagonist for clinical event reduction in acute coronary syndrome trial was not associated with a significant reduction in the primary combined endpoint but an increase in bleeding complications. However, in the Thrombin Receptor Antagonist in Secondary Prevention of atherothrombotic ischemic events study in patients with prior myocardial infarction, vorapaxar on top of standard antiplatelet therapy was effective.

Platelet function normalization after a prasugrel loading-dose: time-dependent effect of platelet supplementation

BACKGROUND

Hemostatic benefits of platelet transfusions in thienopyridine-treated acute coronary syndrome (ACS) patients may be compromised by residual metabolite in circulation.

OBJECTIVES

To estimate the earliest time after a prasugrel loading-dose when added platelets are no longer inhibited by prasugrel's active metabolite.

METHODS

Baseline platelet reactivity of healthy subjects (n=25, 30 ± 5 years, 68% male) on ASA 325 mg was tested using maximum platelet aggregation (MPA, ADP 20 μm) and VerifyNow(®) P2Y12 and was followed by a 60 mg prasugrel loading-dose. At 2, 6, 12 and 24 h post-dose, fresh concentrated platelets from untreated donors were added ex-vivo to subjects' blood, raising platelet counts by 0% (control), 40%, 60% and 80%. To estimate the earliest time when prasugrel's active metabolite's inhibitory effect on the added platelets ceases, platelet function in supplemented samples was compared across time-points to identify the time when effect of supplementation on platelet function stabilized (i.e. the increase in platelet reactivity was statistically similar to that at the next time-point).

RESULTS

Supplemented samples showed concentration-dependent increases in platelet reactivity vs. respective controls by both MPA and VerifyNow(®) at all assessment time-points. For each supplementation level, platelet reactivity showed a sharp increase from 2 to 6 h but was stable (P=NS) between 6 and 12 h.

CONCLUSIONS

The earliest measured time when supplemented platelets were not inhibited by circulating active metabolite of prasugrel was 6 h after a prasugrel loading-dose. These findings may have important implications for prasugrel-treated ACS patients requiring platelet transfusions during surgery.

Microvascular effect of intracoronary eptifibatide in acute myocardial infarction

OBJECTIVES

In this prospective, randomized trial in patients with acute myocardial infarction (AMI) admitted for primary percutaneous coronary intervention (PPCI), loaded with 600 mg clopidogrel, we hypothesized that eptifibatide administered downstream of the coronary occlusion leads to a lower degree of microvascular obstruction compared with no additional eptifibatide.

METHODS

Fifty patients with AMI, loaded with 600 mg of clopidogrel at the first hospital contact, with occlusion of the left anterior descending artery (LAD), were randomized to an eptifibatide group (EG) or a control group (CG). In both groups, stenting was performed after thrombus aspiration. Microvascular reperfusion was assessed by angiography, electrocardiography, and transthoracic Doppler ultrasonography of the LAD.

RESULTS

TIMI myocardial perfusion grade 2-3 was not different between the EG (72%) and the CG (84%) (p = 0.31). ST segment resolution >70% was similarly detected in both groups (32 vs. 40%; p = 0.56). The mean diastolic deceleration time did not differ significantly between the CG (856.36 ± 397.88 ms) and the EG (935.72 ± 252.22 ms) (p = 0.41). Multivariate logistic regression revealed no significant influence of the treatment with eptifibatide on ST segment resolution (OR 0.47; 95% CI 0.11-2.10, p = 0.32), TIMI myocardial perfusion (OR 0.52; 95% CI 0.10-2.59, p = 0.42), and diastolic deceleration time (OR 0.21; 95% CI 0.03-1.51, p = 0.12).

CONCLUSIONS

In AMI patients loaded with 600 mg of clopidogrel undergoing PPCI, intracoronary administration of eptifibatide does not clearly improve microvascular obstruction.

Management of acute coronary syndrome: achievements and goals still to pursue. Novel developments in diagnosis and treatment

Acute coronary syndromes contribute a substantial part of the global disease burden. To realize a reduction in mortality and morbidity, the management of patients with these conditions involves the integration of several different approaches. Timely delivery of appropriate care is a key factor, as the beneficial effect of reperfusion is greatest when performed as soon as possible. Innovations in antithrombotic therapy have also contributed significantly to improvements in the prevention of ischaemic complications. However, with the use of such treatment, an increase in the risk of bleeding is inevitable. Therefore, the greatest challenge is now to obtain an optimal balance between the prevention of ischaemic complications and the risk of bleeding. In this regard, identification of patients at highest risk of either one is essential.