Safety and efficacy of switching from either unfractionated heparin or enoxaparin to bivalirudin in patients with non-ST-segment elevation acute coronary syndromes managed with an invasive strategy: results from the ACUITY (Acute Catheterization and Urgent Intervention Triage strategY) trial

Twenty Years of an Institutional Chest Pain Pathway: What's Come and What's Yet to Come

Acute coronary syndromes (ACS) remain one of the leading causes of cardiovascular morbidity and mortality in the United States and around the world. Because of the acute nature of ACS presentations, timely identification, risk stratification, and intervention are of the utmost importance. Twenty years ago, we published the first iteration of our institutional chest pain clinical pathway in this journal, which separated patients presenting with chest pain into one of the 4 levels of decreasing acuity, with associated actions and interventions for providers based on the level. This chest pain clinical pathway has undergone regular review and updates under a collaborative team of cardiologists, emergency department physicians, cardiac nurse practitioners, and other associated stakeholders in the treatment of patients presenting with chest pain. This review will discuss the key changes that our institutional chest pain algorithm has undergone over the last 2 decades and what the future holds for chest pain algorithms.

Anticoagulant Therapy for Acute Coronary Syndromes

Anticoagulation in conjunction with antiplatelet therapy is central to the management of acute coronary syndromes (ACS). When used effectively it is associated with a reduction in recurrent ischaemic events including myocardial infarction and stent thrombosis as well as a reduction in death. Effective ischaemic risk reduction whilst balancing bleeding risk remains a clinical challenge. This article reviews the current available evidence for anticoagulation in ACS and recommendations from the European Society of Cardiology.

Safety, efficiency and cost effectiveness of Bivalirudin: A systematic review

AIM

To review the early and more recent studies of Bivalirudin, to assess the safety, effectiveness, and cost benefits of this drug.

METHODS

Literature search of MEDLINE and PubMed databases from 1990 to 2017 using keywords as “bivalirubin” and “angiomax”, combined with the words “safety”, “effectiveness”, “efficiency”, “side effects”, “toxicity”, “adverse effect”, and “adverse drug reaction”.

RESULTS

A total of 66 publications were reviewed. The changes in clinical practice and differences in clinical protocols make it difficult to do direct comparisons of studies among each other. However, most trials showed decreased bleeding complications with bivalirudin, although ischemic complications and mortality were mostly comparable, with some favor towards bivalirudin.

CONCLUSION

Bivalirudin and heparin are both acceptable options according to current ACA/AHA guidelines. Authors conclude however, that that due to bivalirudin safer bleeding profile, it should be the preferred medication for anticoagulation.

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.

New Approaches to the Role of Thrombin in Acute Coronary Syndromes: Quo Vadis Bivalirudin, a Direct Thrombin Inhibitor?

The pathophysiology of acute coronary syndrome (ACS) involves platelet activation and thrombus formation after the rupture of atherosclerotic plaques. Thrombin is generated at the blood-plaque interface in association with cellular membranes on cells and platelets. Thrombin also amplifies the response to the tissue injury, coagulation and platelet response, so the treatment of ACS is based on the combined use of both antiplatelet (such as aspirin, clopidogrel, prasugrel and ticagrelor) and antithrombotic drugs (unfractionated heparin, enoxaparin, fondaparinux and bivalirudin). Bivalirudin competitively inhibits thrombin with high affinity, a predictable response from its linear pharmacokinetics and short action. However, a present remarkable controversy exists between the latest main Guidelines in Clinical Practice and the key trials evaluating the use of bivalirudin in ACS. The aim of this review is to update the development of bivalirudin, including pharmacological properties, obtained information from clinical trials evaluating efficacy and safety of bivalirudin in ACS; as well as the recommendations of clinical Guidelines.

Heparins crossover in percutaneous coronary interventions: a real issue with increasing rate of transradial procedures?

AIMS

Current guidelines give a class III recommendation to the intraprocedural use of unfractionated heparin (UFH) in patients pretreated with enoxaparin. The aim of our study was to evaluate bleeding complications in patients who underwent percutaneous coronary interventions (PCIs) performed using intraprocedural crossover of heparin therapy.

METHODS

We retrospectively evaluated all PCIs performed at two Italian hospitals since January 2011 to December 2013. After a propensity-matched analysis, patients were divided into two groups (with a ratio 1 : 2) according to intraprocedural crossover of heparins (from enoxaparin to UFH) (Group 1) or intraprocedural UFH alone (Group 2). The primary end-point was a haemoglobin drop of at least 3 g/dl within 48 h after the procedure.

RESULTS

During the 3 years analysed, 3224 patients underwent PCI, and after the propensity analysis, 309 patients were considered eligible for our study: 104 patients in Group 1 (69 ± 12 years, 78% men) and 205 patients in Group 2 (69 ± 13 years, 80% men, P = NS). There were no significant differences between the two groups for BMI, periprocedural use of antiplatelet therapy, baseline haemoglobin haematocrit or platelets levels. The primary end-point did not differ between the two groups (2.9% in Group 1 and 3.4% in Group 2, P = 0.550). Also, nadir of haematocrit or haemoglobin levels did not differ between the two groups. Finally, in hospital, major adverse cardio-cerebrovascular events did not differ between the two groups (1.9% in Group 1 and 3.9% in Group 2, P = 0.50).

CONCLUSION

In this retrospective analysis of a large PCI database, the 'heparins crossover' during PCI was not associated with increased bleeding risk.

Bivalirudin in stable angina and acute coronary syndromes

A parenteral anticoagulant is indicated in patients with acute coronary syndromes. Which anticoagulant should be preferred in each setting is not clearly established. Bivalirudin administration was considered in acute coronary syndromes after several clinical trials showed decreased bleeding risk with its use compared with the association of unfractionated heparin (UFH) with glycoprotein IIb/IIIa inhibitors (GPIs). Most recent data demonstrate that the bleeding benefit identified in the previous studies was not due to bivalirudin's properties but to higher bleeding incidence in the comparator arm due to the disproportional use of GPIs with heparin. This paper reviews clinical evidence on bivalirudin as anticoagulant in stable angina and acute coronary syndromes.

Current Antithrombotic Therapy in Patients with Acute Coronary Syndromes Undergoing Percutaneous Coronary Interventions

Acute coronary syndromes (ACS) represent a life-threatening complication of the systemic atherosclerotic process, affecting the coronary circulation. Thrombosis, defined as an uncontrolled activation of the endogenous thrombogenetic reparative process, often follows atherosclerotic plaque damage and is mainly engaged by two main pathways: platelet aggregation and coagulation. Therefore, antithrombotic therapy to modulate either pathway plays an important role for the reduction of ischaemic adverse events in ACS patients. Since the advent of aspirin and warfarin, numerous antiaggregant and anticoagulant molecules have been developed to achieve this goal, but their anti-ischaemic efficacy is often obtained at the price of augmented bleedings, which are known to be strong predictors of adverse outcome. This article briefly reviews the physiopathological mechanisms of thrombosis and presents an overview of the available literature supporting the use of these major drugs, as well as the European Society of Cardiology recommendations for their utilisation in the setting of non-ST and ST-elevation myocardial infarction undergoing invasive treatment.

Contemporary anticoagulation therapy in patients undergoing percutaneous intervention

The proper use of anticoagulants is crucial for ensuring optimal patient outcomes post percutaneous interventions in the cardiac catheterization laboratory. Anticoagulant agents such as unfractionated heparin, a thrombin inhibitor; low-molecular weight heparins, predominantly Factor Xa inhibitors; fondaparinux, a Factor Xa inhibitor and bivalirudin, a direct thrombin inhibitor have been developed to target various steps in the coagulation cascade to prevent formation of thrombin. Optimal anticoagulation achieves the correct balance between thrombosis and bleeding and is related to optimal outcomes with minimal complications. This review will discuss the mechanisms and appropriate use of current and emerging anticoagulant therapies used during percutaneous interventions.

Bivalirudin in acute coronary syndromes and percutaneous coronary intervention: should we use it?

Major bleeding remains a major risk factor for percutaneous coronary intervention of acute coronary syndromes and is associated with higher morbidity, mortality, prolonged hospital stay and costs. With the recognition that bleeding is an important factor in patient outcomes, the prevention of bleeding has become as important a goal as the prevention of ischaemia. The direct thrombin inhibitor bivalirudin has been shown to reduce ischaemia and importantly, is associated with less bleeding. In this article we review the evidence base that supports the use of bivalirudin across all spectrums of coronary syndromes and percutaneous coronary intervention. An algorithm for the use of bivalirudin in high risk subgroups and coronary syndromes is suggested.

Dabigatran for periprocedural anticoagulation following radiofrequency ablation for atrial fibrillation: a meta-analysis of observational studies

PURPOSE

Dabigatran is approved for prevention of stroke or systemic embolism in patients with nonvalvular atrial fibrillation (AF). The safety and effectiveness of periprocedural dabigatran in ablation for AF are unknown.

METHODS

We performed a meta-analysis of all studies comparing periprocedural dabigatran with warfarin for anticoagulation in AF ablation. Studies of >100 patients with post-procedure follow-up were included. Outcomes were compared by calculating maximum likelihood estimates with confidence intervals. The co-primary endpoints were neurological events and major bleeding.

RESULTS

Ten cohort studies were included, including a total of 1,501 patients receiving dabigatran and 2,356 receiving warfarin. The mean age was 59-64 years and inclusion of women varied (10-33 %). Intra-procedural unfractionated heparin and irrigated ablation catheters were used routinely. Adverse events were low overall; however, the dabigatran group demonstrated a numerical excess of neurological events (10/1,501 [0.7 %] versus 4/2,356 [0.2 %]), but equivalent major bleeding outcomes (24/1,501 [1.6 %] versus 40/2,356 [1.7 %]). In the meta-analysis, there was a nonsignificant trend towards higher rates of the composite primary endpoints (any neurological event or major bleeding) in the dabigatran group. Dabigatran demonstrated a significantly higher rate of neurological events (estimated absolute risk difference 0.0047, 95 % confidence interval 0.0007 to 0.0099).

CONCLUSIONS

Compared with warfarin, dabigatran may be associated with a higher frequency of periprocedural neurological events following radiofrequency ablation of AF. Randomized clinical trials are needed to definitively assess the safety and efficacy of novel oral anticoagulant use for periprocedural anticoagulation for ablation of AF.

Drug-drug interactions in cardiovascular catheterizations and interventions

Patients presenting for invasive cardiovascular procedures are frequently taking a variety of medications aimed to treat risk factors related to heart and vascular disease. During the procedure, antithrombotic, sedative, and analgesic medications are commonly needed, and after interventional procedures, new medications are often added for primary and secondary prevention of ischemic events. In addition to these prescribed medications, the use of over-the-counter drugs and supplements continues to rise. Most elderly patients, for example, are taking 5 or more prescribed medications and 1 or more supplements, and they often have some degree of renal insufficiency. This polypharmacy might result in drug-drug interactions that affect the balance of thrombotic and bleeding events during the procedure and during long-term treatment. Mixing of anticoagulants, for instance, might lead to periprocedural bleeding, and this is associated with an increase in long-term adverse events. Furthermore, the range of possible interactions with thienopyridine antiplatelets is of concern, because these drugs are essential to immediate and extended interventional success. The practical challenges in the field are great-some drug-drug interactions are likely present yet not well understood due to limited assays, whereas other interactions have well-described biological effects but seem to be more theoretical, because there is little to no clinical impact. Interventional providers need to be attentive to the potential for drug-drug interaction, the associated harm, and the appropriate action, if any, to minimize the potential for medication-related adverse events. This review will focus on drug-drug interactions that have the potential to affect procedural success, either through increases in immediate complications or compromising longer-term outcome.

Saphenous vein graft percutaneous coronary intervention via radial artery access: safe and effective with reduced hospital length of stay

BACKGROUND

Although percutaneous coronary intervention (PCI) via radial artery access confers many advantages over the femoral artery, PCI to saphenous vein grafts (SVG) is commonly performed via the femoral route. We compared outcomes in patients undergoing SVG PCI from the radial and femoral routes.

METHODS

We performed a retrospective analysis of patients who underwent SVG PCI between January 2006 and December 2010 in 2 large interventional centers in the United Kingdom. All radial and femoral operators selected for this analysis performed high-volume (>200 PCIs per year) procedures via either vascular route.

RESULTS

Of 305 patients (260 males) who underwent SVG PCI, 208 (68.2%) had the procedure completed from the femoral route and 97 (32.8%) radially. There was no difference between groups in fluoroscopy time (femoral vs radial 1095 vs 1125 seconds, P nonsgnificant), but radiation doses were greater (43.87 ± 2.83 Gy/cm(2) vs 56.92 ± 4.52 Gy/cm(2), P = .012) as was body mass index in the radial group (27.99 ± 0.33 vs 29.05 ± 0.42, P = .048). Three femoral access patients had vascular access complications, whereas the radial route group had none. There were no differences in no flow/slow flow (femoral 3.86% vs radial 2.54%, P nonsignificant). The mean length of hospital stay was significantly shorter in the radial access cohort (1.09 vs 2.09 days, P < .001). Three patients converted from radial to femoral artery, whereas one converted from femoral to radial after technical failure to complete the procedure.

CONCLUSION

Saphenous vein graft PCI can be safely and effectively performed via radial artery access with comparable fluoroscopy times but not radiation doses. Of clinical significance, use of the radial artery access was associated with decreased hospital stay and arterial complications. These data suggest that a routine radial approach for SVG PCI is feasible and could offer clinical and economic benefits.

Bivalirudin versus unfractionated heparin in percutaneous coronary interventions of patients having received initial fondaparinux treatment: a propensity matched study

AIMS

Fondaparinux is an indirect, Factor Xa inhibitor that requires co-administration of another anticoagulant with anti-Factor IIa activity for percutaneous coronary intervention (PCI) per guideline recommendations. In this setting, the use of bivalirudin, a direct Factor IIa inhibitor, is not well established.

METHODS AND RESULTS

Using the Premier hospital database, we identified 971 patients who underwent elective or urgent PCI after receiving fondaparinux as the initial anticoagulant. They were treated with either bivalirudin ± glycoprotein IIb/IIIa inhibitor (GPI) (Group A=618) or unfractionated heparin (UFH) ± GPI (Group B=353) during PCI. A 2:1 propensity score matching (PSM) process was performed to control for patient and hospital level characteristics. The primary endpoints were to determine in-hospital death, bleeding and post-PCI length of stay (LOS) between treatment groups. After PSM, 512 matched patients were analysed (Group A=348 and Group B=174). In-hospital death was 1.4% in Group A vs. 2.9% in Group B (p=0.26). Clinically apparent bleeding occurred in 4.0% of Group A vs. 9.2% of Group B patients (p<0.02). Clinically apparent bleeding requiring transfusion was lower in Group A patients (0.6% vs. 2.9%; p=0.04). Post-PCI LOS was 1.9 ± 3.8 days for Group A and 2.4 ± 5.8 days for Group B (p=0.36). GPI use during PCI occurred in 9.2% of Group A vs. 44.8% of Group B patients (p<0.0001).

CONCLUSIONS

After initial administration of fondaparinux, a bivalirudin-based strategy for PCI is associated with significantly reduced bleeding, with similar mortality and post-PCI LOS when compared with an UFH-based strategy.

Bleeding avoidance strategies. Consensus and controversy

Bleeding complications after coronary intervention are associated with prolonged hospitalization, increased hospital costs, patient dissatisfaction, morbidity, and 1-year mortality. Bleeding avoidance strategies is a term incorporating multiple modalities that aim to reduce bleeding and vascular complications after cardiovascular catheterization. Recent improvements in the rates of bleeding complications after invasive cardiovascular procedures suggest that the clinical community has successfully embraced specific strategies and improved patient care in this area. There remains controversy regarding the efficacy, safety, and/or practicality of 3 key bleeding avoidance strategies for cardiac catheterization and coronary intervention: procedural (radial artery approach, safezone arteriotomy), pharmacological (multiple agents), and technological (vascular closure devices) approaches to improved access. In this paper, we address areas of consensus with respect to selected modalities in order to define the role of each strategy in current practice. Furthermore, we focus on areas of controversy for selected modalities in order to define key areas warranting cautious clinical approaches and the need for future randomized clinical trials in this area.

Effect of switching antithrombin agents for primary angioplasty in acute myocardial infarction: the HORIZONS-SWITCH analysis

OBJECTIVES

We investigated the outcomes of switching to bivalirudin after initial administration of heparin in patients with acute ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention.

BACKGROUND

Unfractionated heparin (UFH) is frequently administered early in ST-segment elevation myocardial infarction. Whether the benefits of bivalirudin documented in the HORIZONS-AMI (Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction) trial persist in patients previously administered UFH is unknown.

METHODS

We analyzed the outcomes of the 2,357 patients from HORIZONS-AMI treated with UFH before enrollment according to their subsequent randomization to bivalirudin (switch group, n = 1,178) or UFH plus a glycoprotein IIb/IIIa inhibitor (control group, n = 1,179).

RESULTS

At 30 days, major bleeding occurred in 7.6% of the switch group versus 12.3% of the control group (p = 0.0001). Switch patients had lower 30-day rates of cardiac mortality (1.6% vs. 2.9%, p = 0.04). At 2-year follow-up, switch patients experienced lower rates of major bleeding (8.4% vs. 13.0%, p = 0.0003), cardiac mortality (2.3% vs. 3.8%, p = 0.04), and reinfarction (4.0% vs. 7.1%, p = 0.0002). Two-year rates of definite/probable stent thrombosis were similar in switch and control patients (3.1% vs. 4.3%, p = 0.17).

CONCLUSIONS

In ST-segment elevation myocardial infarction patients who receive early treatment with UFH, switching to bivalirudin before primary percutaneous coronary intervention results in reduced rates of major bleeding and improved early and late cardiac survival.

Use of anticoagulant agents and risk of bleeding among patients admitted with myocardial infarction: a report from the NCDR ACTION Registry--GWTG (National Cardiovascular Data Registry Acute Coronary Treatment and Intervention Outcomes Network Registry--Get With the Guidelines)

OBJECTIVES

The aim of this study was to evaluate anticoagulant use patterns and bleeding risk in a contemporary population of patients with acute coronary syndrome.

BACKGROUND

Current practice guidelines support the use of unfractionated heparin, low molecular weight heparin, bivalirudin, or fondaparinux in non-ST-segment elevation myocardial infarction (NSTEMI) and ST-segment elevation myocardial infarction (STEMI). Little is known about how these agents are selected in clinical practice.

METHODS

Between January 2007 and June 2009, data were captured for 72,699 patients with NSTEMI and 48,943 patients with STEMI at 360 U.S. hospitals for the NCDR ACTION Registry-GWTG (National Cardiovascular Data Registry Acute Coronary Treatment and Intervention Outcomes Network Registry-Get With the Guidelines). Patients were categorized based on anticoagulant strategy selected during hospitalization and their CRUSADE (Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of ACC/AHA [American College of Cardiology/American Heart Association] Guidelines) bleeding risk category.

RESULTS

At least 1 anticoagulant was administered to 66,279 patients (91.2%) with NSTEMI and 46,149 patients (94.3%) with STEMI. Among STEMI patients, unfractionated heparin was most commonly used (66%), followed by bivalirudin (14%) and low molecular weight heparin (8%). In NSTEMI patients, unfractionated heparin was also the most commonly used anticoagulant (42%), followed by low molecular weight heparin (27%) and then bivalirudin (13%). There were significant differences in anticoagulant use by age, risk factors, concomitant medications, and invasive care. There was a 5-fold difference in the rate of bleeding between patients in the lowest and highest CRUSADE bleeding risk groups, which was consistently observed in most anticoagulant groups.

CONCLUSIONS

There is a wide variability in the use of anticoagulant regimens with significant differences according to baseline characteristics and concomitant therapies. Major bleeding is common, though a great degree of the variability in the rate of bleeding is largely based on differences in baseline characteristics, comorbidities, and invasive treatment strategies, rather than specific anticoagulant regimens.

Antiplatelet and anticoagulant therapies in acute coronary syndromes

The combination of aspirin and clopidogrel is the mainstay antiplatelet therapy for acute coronary syndromes (ACS). However, the dosing of aspirin, the dosing of clopidogrel, the timing of clopidogrel initiation as well as the duration of clopidogrel therapy remain controversial matters. Clopidogrel resistance is an emerging concept with potential clinical implications. In the era of clopidogrel and bivalirudin, the role of glycoprotein IIb/IIIa antagonists is being challenged, yet they are still indicated in a select high-risk population. Concerning anticoagulant use in ACS, newer agents, bivalirudin and fondaparinux, have improved outcomes in comparison to heparin in patients managed with an invasive or conservative strategy, respectively. Combining multiple antiplatelet agents and an anticoagulant is the standard of care for ACS.

Antithrombotic therapy in patients with coronary artery disease and with type 2 diabetes mellitus

Diabetes mellitus (DM) is a life-threatening disease. Patients with DM have a 2- to 4-fold higher risk of developing cardiovascular disease compared to their non-diabetic counterparts. Several drugs are available for the treatment of stable coronary artery disease (CAD) and acute coronary syndrome (ACS). Among oral antiplatelet agents (acetylsalicylic acid, ticlopidine, clopidogrel, and prasugrel), prasugrel has shown the highest efficacy in patients with DM and ACS. The use of glycoprotein IIb-IIIa receptor inhibitors in diabetic subjects with ACS undergoing percutaneous coronary intervention (PCI) reduces adverse clinical events in a greater extent than in non-diabetics. Several direct and indirect antithrombins are recommended for the treatment of ACS such as unfractionated heparin (UFH), enoxaparin, fondaparinux, and bivalirudin. Enoxaparin and bivalirudin have been shown to be superior to UFH among patients with ST-elevation MI (STEMI) and non-ST elevation MI (NSTEMI) also in diabetic subgroup analyses.

Practical strategies for the management of anticoagulation therapy: unsolved issues in the cardiac catheterization laboratory

PURPOSE

Percutaneous coronary intervention (PCI) is the preferred reperfusion strategy in the management of patients with ST-elevation myocardial infarction (STEMI) and higher-risk patients with unstable angina/non-STEMI (UA/NSTEMI). Recent updates have been issued for guidelines from the American College of Cardiology and American Heart Association delineating the appropriate use of anticoagulants as ancillary therapies to PCI. This manuscript reviews the recent clinical trial data supporting the updated guidelines and highlights remaining areas of uncertainty.

METHODS

SCOPUS and Pubmed were searched for relevant English-language reports of clinical trials, registries, articles and case reports. Search terms included but were not limited to: PCI, anticoagulation, ancillary, STEMI, NSTEMI, angina, acute coronary syndrome. The reference lists of identified articles were searched for additional relevant publications.

RESULTS

Unfractionated heparin (UFH), the historical standard of care for anticoagulation in STEMI and NSTEMI patients undergoing PCI, is sub-optimal and the list of anticoagulants recommended for alternatives in the current guidelines has expanded to include superior anticoagulants, including the low-molecular-weight heparin enoxaparin and the direct thrombin inhibitor bivalirudin. Additionally, fondaparinux is recommended if supplemented during PCI by an additional agent with anti-IIa activity. However, uncertainties in the guidelines remain. Clinical discretion is still required when deciding which anticoagulant to use, ensuring seamless transitions throughout the care pathway, and how to correctly identify the risk status of a patient and modify anticoagulant regimens accordingly, such as in special patient populations.

CONCLUSIONS

The published evidence supports the updates to the guidelines. Updated guidelines still have knowledge gaps which require the application of clinical discretion by the cardiologist.

Predictors of outcomes in medically treated patients with acute coronary syndromes after angiographic triage: an Acute Catheterization And Urgent Intervention Triage Strategy (ACUITY) substudy

BACKGROUND

Outcomes of patients presenting with acute coronary syndromes are improved with an early invasive approach; however, approximately one third of these patients are treated medically after angiographic screening. We sought to assess the predictors of adverse cardiac events in patients with acute coronary syndrome assigned to medical management.

METHODS AND RESULTS

This substudy of the Acute Catheterization and Urgent Intervention Triage Strategy (ACUITY) trial included 4491 acute coronary syndrome patients treated medically after angiographic triage. Rates of bleeding and composite ischemia (death, myocardial infarction, revascularization) were compared among the 3 antithrombotic treatment arms. Composite ischemia occurred in 399 patients (9.5%) at 1 year. Treatment with bivalirudin glycoprotein IIb/IIIa inhibitors significantly reduced major bleeding at 30 days (2.5% bivalirudin monotherapy; P=0.005, 2.0% bivalirudin plus glycoprotein IIb/IIIa inhibitors; P=0.0002 versus 4.4% heparin with glycoprotein IIb/IIIa inhibitors). Composite ischemic events at 1 year were not significantly different in the 3 groups (bivalirudin monotherapy, 9.6%; bivalirudin plus glycoprotein IIb/IIIa inhibitors, 9.7%; heparin plus glycoprotein IIb/IIIa inhibitors, 9.1%). Independent predictors of composite ischemia were mostly angiographic factors at 30 days, including jeopardy score and coronary ectasia, and at 1 year, including previous percutaneous coronary intervention, jeopardy score, coronary ectasia, and increasing number of diseased vessels.

CONCLUSIONS

Among the ACUITY acute coronary syndrome patients treated medically after angiographic triage, bivalirudin therapy significantly reduced bleeding complications compared with heparin without any negative impact on ischemic outcomes at 1 year. The most powerful predictors of ischemic outcomes were angiographic rather than traditional clinical parameters, supporting the early use of angiographic screening in the moderate- and high-risk but medically treated acute coronary syndrome population. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00093158.

Routine use of fondaparinux in acute coronary syndromes: a 2-year multicenter experience

BACKGROUND

Fondaparinux has recently been approved in patients with acute coronary syndromes. The primary aim of this study was to describe the changes in use of anticoagulants between January 2006 and December 2007. The secondary aim was to compare 30-day mortality and rate of a combined end point (30-day death or major bleeding) according to the initial and final anticoagulant agent used.

METHODS

The rates of use of unfractionated heparin (UFH), enoxaparin, and fondaparinux were compared by periods of 1 month in a multicenter registry. The initial anticoagulant (first used at admission), the final anticoagulant (last used during hospitalization), and switches in anticoagulation were recorded. Temporal trends in monthly use of each anticoagulant were assessed; 30-day mortality rates and the combined end point were compared according to initial and final anticoagulant.

RESULTS

Among 2,874 patients included, the first anticoagulant used was UFH in 26%, enoxaparin in 59%, and fondaparinux in 15%. Respective figures for final anticoagulant were 17%, 56%, and 27%. Although 3 centers did not use fondaparinux (community centers with catheterization laboratory), the overall rate of use of fondaparinux, as initial and final anticoagulant, increased at the expense of the use of enoxaparin. We observed a growing proportion of patients with a switch from UFH to either enoxaparin or fondaparinux, ranging from 5% at the beginning to 25% at the end of the study. Patients treated with UFH were older, had more comorbidities, were at higher risk, and received fewer guidelines-recommended treatments. In patients submitted to angioplasty and treated with fondaparinux, a bolus of 60 IU/kg of UFH was added. After adjustment, 30-day mortality and combined end point rates were higher in patients treated with UFH. Irrespective of the type of acute coronary syndromes, patients treated with enoxaparin or fondaparinux had similar outcomes.

CONCLUSIONS

Between 2006 and 2007, the use of fondaparinux in patients with acute coronary syndromes increased considerably, either because it was used instead of enoxaparin or because of a switch from UFH. Adjusted mortality in patients treated with fondaparinux was lower than with UFH and similar to enoxaparin.

Emerging drugs for acute myocardial infarction

IMPORTANCE OF THE FIELD

The present review is aimed at going over the pharmacological profile (and the clinical impact) of the emerging drugs involved in the management of patients with ST-elevation myocardial infarction (STEMI) in order to provide the cardiologists who deal with these patients in the early phase with the most recent evidence on this topic.

AREAS COVERED IN THIS REVIEW

Anticoagulant and antiplatelet drugs are the main cornerstones of therapy in the treatment of STEMI patients undergoing primary percutaneous coronary intervention (PCI). The main issues that clinicians have to deal with are represented by balancing thrombotic and bleeding risks. In tailoring therapy, variables such as age, sex and previous disease should be taken into account, as well as ongoing complications (such as acute renal failure) that could affect hemostasis. Despite the well-established clinical benefits of antiplatelet agents, questions remain, mainly surrounding potential for variable platelet response, which are strictly related to non-genetic (i.e., diet, drug-drug interaction, clinical factors such as obesity, diabetes mellitus, and inflammation) and genetic determinants.

WHAT THE READER WILL GAIN

In their daily practice, cardiologists cannot abstract from the knowledge and updating on the ongoing research fields as well as the newly developed drugs, which they should frame in the very patient in the attempt to the develop a personalized medical strategy. These include also the pharmacological option(s) in the treatment of the reperfusion injury, the metabolic aspects and the stem cell therapy. TAKE HOME MASSAGE: In our opinion, the goal of ongoing research on the pharmacological approach to STEMI patients is a personalized medical strategy that relies on critical clinicians who merge newly developed acquisitions on this topic and a more complete, systemic and critical approach to the patient.

Hematomas of at least 5 cm and outcomes in patients undergoing elective percutaneous coronary intervention: insights from the SafeTy and Efficacy of Enoxaparin in PCI patients, an internationaL randomized Evaluation (STEEPLE) trial

BACKGROUND

Major bleeding significantly impacts outcomes in patients undergoing percutaneous coronary intervention (PCI). No uniform definitions exist for major and minor bleeding. Hematomas > or =5 cm at the femoral puncture site are considered major bleeding events in some trials and minor in others. Limited information is available on the incidence and clinical relevance of hematomas > or =5 cm in PCI patients.

METHODS

Data from the STEEPLE trial in patients undergoing elective PCI were used to assess the impact of hematomas > or =5 cm on ischemic outcomes (mortality, nonfatal myocardial infarction, or urgent target vessel revascularization) up to day 30 and all-cause 1-year mortality. Hematoma data were available for 3,342 of 3,528 patients in STEEPLE. Patients with (n = 103) and without (n = 3,239) hematomas > or =5 cm were evenly distributed across treatment groups.

RESULTS

No differences were observed in 30-day ischemic outcomes between patients with and without hematomas (5.8% vs 5.9%, respectively; P = .96). No transfusions were observed in patients with hematomas as compared with patients without hematomas (0% and 0.4%, respectively; P = .52). A greater reduction in hemoglobin was observed (pre- vs post-PCI) in patients with hematomas as compared with patients without hematomas (-0.84 vs -0.35 g/L, P < or = .001). No significant difference in all-cause 1-year mortality was observed between patients with and without hematomas (0.0% vs 1.7%, P = .98).

CONCLUSIONS

After PCI, hematomas > or =5 cm had no effect on 30-day ischemic events or 1-year mortality. Although there is no agreed classification for large hematomas, the lack of a relationship between hematomas > or =5 cm and clinical outcome after PCI justifies the classification of these hematomas as minor bleeds in STEEPLE.

Selecting the optimal antithrombotic regimen for patients with acute coronary syndromes undergoing percutaneous coronary intervention

The wide variety of anticoagulant and antiplatelet agents available for clinical use has made choosing the optimal antithrombotic regimen for patients with acute coronary syndromes undergoing percutaneous coronary intervention a complex task. While there is no single best regimen, from a risk-benefit ratio standpoint, particular regimens may be considered optimal for different patients. We review the mechanisms of action for the commonly prescribed antithrombotic medications, summarize pertinent data from randomized trials on their use in acute coronary syndromes, and provide an algorithm (incorporating data from these trials as well as risk assessment instruments) that will help guide the decision-making process.

Frequency and safety of switching antithrombin therapy at a regional PCI center

The impact of switching antithrombin therapy in patients presenting with acute coronary syndromes (ACS) and undergoing percutaneous intervention (PCI) has varied in clinical trials. We sought to assess the incidence and safety of switching antithrombin therapy in ACS patients undergoing PCI at a regional medical center. All patients with ACS undergoing PCI (n = 728) during a specified time period in 2005 and 2007 were identified. Patients who were switched to the antithrombin bivalirudin were defined as the "switch" group (n = 323) and all others were defined as the "consistent" therapy group (n = 405). Primary endpoints were major adverse cardiac event (MACE) (death, MI or urgent revascularization), major bleeding and net adverse clinical event (NACE) (MACE or major bleeding). Multivariate analysis was performed to determine if switching antithrombotic therapy predicted primary outcomes. Among 728 patients undergoing PCI for ACS, 44% were switched to bivalirudin. Switch patient were more likely to be transfers from outside hospitals, older, female, and diabetic. Angiographic characteristics were similar in the two groups. Switch patients had a similar incidence of MACE (7 vs. 8%, P = 0.72), major bleeding (2 vs. 2%) and NACE (9 vs. 10%, P = 0.51) when compared to those who received consistent therapy. On multivariate analysis, switching did not predict MACE (OR = 0.94, 95% CI = 0.53-1.67, P = 0.84) or NACE (OR = 0.82, 95%CI = 0.48-1.41, P = 0.47). In a regional clinical practice of patients presenting with ACS and undergoing PCI, switching of antithrombin therapy to bivalirudin is a common practice and patient who are switched have similar outcomes compared to patients who receive consistent therapy.

Pharmacological and clinical profile of bivalirudin in the treatment of patients with acute coronary syndrome

BACKGROUND

Bivalirudin is a direct thrombin inhibitor with several pharmacological advantages over heparin. It has been studied extensively in non-ST elevation acute 60 coronary syndromes (NSTE-ACS) and in percutaneous coronary intervention. Bivalirudin has also recently been investigated in patients with ST-elevation myocardial infarction (STEMI) treated with primary angioplasty and stenting. More than 27,000 patients were randomized in these trials.

OBJECTIVE

To provide an overview of the pharmacological properties of bivalirudin and its efficacy and safety profile in patients across the spectrum of acute coronary syndromes (ACS).

METHODS

All published, peer-reviewed clinical trials were reviewed and as relevant were included.

RESULTS AND CONCLUSIONS

Bivalirudin with provisional IIb/IIIa antagonists provides consistent results across the full spectrum of ACS, with similar or non-inferior protection from ischemic events and significantly reduces bleeding complications compared with heparin and IIb/IIIa antagonists. In STEMI, mortality at 30 days and 1 year is significantly reduced. The unique pharmacokinetic profile of bivalirudin allows for simultaneous reductions in both ischemic and hemorrhagic events and makes it an appropriate alternative to heparin.

New antithrombotic agents in acute coronary syndromes

PURPOSE OF REVIEW

Acute coronary syndromes still account for high mortality in many countries. Antithrombotic therapy represents a cornerstone in the therapy of acute coronary syndromes. Recent research has focussed on improving anti-ischemic potency and reducing bleeding complications as well as improving predictability of antithrombotic efficacy.

RECENT FINDINGS

New antithrombotic drugs such as the factor Xa antagonists and the direct thrombin inhibitors have been developed and evaluated in clinical trials. Fondaparinux and bivalirudin are approved for clinical use in acute coronary syndromes. They improve the risk/benefit ratio and make routine control of their antithrombotic effect unnecessary. Other agents are being developed to further improve and facilitate antithrombotic therapy in acute coronary syndromes.

SUMMARY

Antithrombotic therapy is essential in acute coronary syndrome. New drugs are being developed to enter clinical practice and improve efficacy and safety of this therapeutic strategy.