Fondaparinux versus enoxaparin in acute coronary syndromes

Fondaparinux versus Enoxaparin - Which is the Best Anticoagulant for Acute Coronary Syndrome? - Brazilian Registry Data

Background:

Recent studies have shown fondaparinux's superiority over enoxaparin in patients with non-ST elevation acute coronary syndrome (ACS), especially in relation to bleeding reduction. The description of this finding in a Brazilian registry has not yet been documented.

Objective:

To compare fondaparinux versus enoxaparin in in-hospital prognosis of non-ST elevation ACS.

Methods:

Multicenter retrospective observational study. A total of 2,282 patients were included (335 in the fondaparinux group, and 1,947 in the enoxaparin group) between May 2010 and May 2015. Demographic, medication intake and chosen coronary treatment data were obtained. Primary outcome was mortality from all causes. Secondary outcome was combined events (cardiogenic shock, reinfarction, death, stroke and bleeding). Comparison between the groups were done through Chi-Square test and T test. Multivariate analysis was done through logistic regression, with significance values defined as p < 0.05.

Results:

With regards to treatment, we observed the performance of a percutaneous coronary intervention in 40.2% in the fondaparinux group, and in 35.1% in the enoxaparin group (p = 0.13). In the multivariate analysis, we observed significant differences between fondaparinux and enoxaparin groups in relation to combined events (13.8% vs. 22%. OR = 2.93, p = 0.007) and bleeding (2.3% vs. 5.2%, OR = 4.55, p = 0.037), respectively.

Conclusion:

Similarly to recently published data in international literature, fondaparinux proved superior to enoxaparin for the Brazilian population, with significant reduction of combined events and bleeding.

Transradial vs Transfemoral Percutaneous Coronary Intervention in ST-Segment Elevation Myocardial Infarction: A Systemic Review and Meta-analysis

BACKGROUND

The objective of this meta-analysis to evaluate safety and efficacy of transradial vs the transfemoral approach for primary percutaneous coronary intervention (PCI) in ST-segment elevation myocardial infarction (STEMI) patients.

METHODS

Randomized controlled trials that compared the transfemoral vs the transradial approach in STEMI patients who underwent PCI were searched in PubMed, Embase, CENTRAL, Cumulative Index to Nursing and Allied Health Literature, and clinicaltrials.gov. Random effect models were used to pool effect sizes.

RESULTS

Sixteen trials, comprising data from 9726 patients, were included in the meta-analysis. All-cause mortality (risk ratio [RR], 0.68; 95% confidence interval [CI], 0.54-0.85; relative risk reduction [RRR], 32.8%; I(2) = 0), major bleeding (RR 0.56; 95% CI, 0.42-0.74; RRR, 48.1%; I(2) = 0), access site bleeding (RR, 0.38; 95% CI, 0.29-0.50; RRR, 63.9%; I(2) = 0), major adverse cardiovascular events (RR, 0.80; 95% CI, 0.68-0.94; RRR, 19.3%; I(2) = 0), and length of hospital stay (standardized mean difference, -0.38 days; 95% CI, -0.46 to -0.31 days) were significantly lower with the transradial compared with the transfemoral approach. The greatest reduction in major bleeding was found in the subgroup with trials recruiting only primary PCI participants compared with varying proportions of rescue PCIs. Glycoprotein IIb/IIIa inhibitor use and cross-over rates did not have a significant association with outcome measures in the subgroup analysis. Incidence of stroke was numerically greater with the transradial approach but did not achieve statistical significance (RR, 1.22; 95% CI, 0.56-2.66; I(2) = 0). Overall statistical heterogeneity (I(2)) was very low except for length of hospital stay.

CONCLUSIONS

The transradial approach for PCI in STEMI patients significantly reduced all-cause mortality, major and access site bleeding, major adverse cardiovascular events, and length of hospital stay. Difference in stroke incidence was not statistically significant with the transradial vs the transfemoral approach.

Radial versus femoral access in patients with acute coronary syndromes undergoing invasive management: a randomised multicentre trial

BACKGROUND

It is unclear whether radial compared with femoral access improves outcomes in unselected patients with acute coronary syndromes undergoing invasive management.

METHODS

We did a randomised, multicentre, superiority trial comparing transradial against transfemoral access in patients with acute coronary syndrome with or without ST-segment elevation myocardial infarction who were about to undergo coronary angiography and percutaneous coronary intervention. Patients were randomly allocated (1:1) to radial or femoral access with a web-based system. The randomisation sequence was computer generated, blocked, and stratified by use of ticagrelor or prasugrel, type of acute coronary syndrome (ST-segment elevation myocardial infarction, troponin positive or negative, non-ST-segment elevation acute coronary syndrome), and anticipated use of immediate percutaneous coronary intervention. Outcome assessors were masked to treatment allocation. The 30-day coprimary outcomes were major adverse cardiovascular events, defined as death, myocardial infarction, or stroke, and net adverse clinical events, defined as major adverse cardiovascular events or Bleeding Academic Research Consortium (BARC) major bleeding unrelated to coronary artery bypass graft surgery. The analysis was by intention to treat. The two-sided α was prespecified at 0·025. The trial is registered at ClinicalTrials.gov, number NCT01433627.

FINDINGS

We randomly assigned 8404 patients with acute coronary syndrome, with or without ST-segment elevation, to radial (4197) or femoral (4207) access for coronary angiography and percutaneous coronary intervention. 369 (8·8%) patients with radial access had major adverse cardiovascular events, compared with 429 (10·3%) patients with femoral access (rate ratio [RR] 0·85, 95% CI 0·74-0·99; p=0·0307), non-significant at α of 0·025. 410 (9·8%) patients with radial access had net adverse clinical events compared with 486 (11·7%) patients with femoral access (0·83, 95% CI 0·73-0·96; p=0·0092). The difference was driven by BARC major bleeding unrelated to coronary artery bypass graft surgery (1·6% vs 2·3%, RR 0·67, 95% CI 0·49-0·92; p=0·013) and all-cause mortality (1·6% vs 2·2%, RR 0·72, 95% CI 0·53-0·99; p=0·045).

INTERPRETATION

In patients with acute coronary syndrome undergoing invasive management, radial as compared with femoral access reduces net adverse clinical events, through a reduction in major bleeding and all-cause mortality.

FUNDING

The Medicines Company and Terumo.

Design and rationale for the Minimizing Adverse haemorrhagic events by TRansradial access site and systemic Implementation of angioX program

BACKGROUND

Transradial intervention (TRI) and bivalirudin infusion compared with transfemoral coronary intervention or unfractionated heparin plus glycoprotein IIb/IIIa inhibitors decrease bleeding complications in patients with acute coronary syndromes (ACS). Although bleeding is thought to be associated with worse outcomes, it remains unclear whether TRI and bivalirudin both independently lower ischemic or combined ischemic and bleeding complications in ACS patients undergoing contemporary invasive management.

HYPOTHESES

The primary objectives of the MATRIX program are to assess whether TRI or bivalirudin as compared, respectively, with transfemoral coronary intervention (MATRIX access site) or unfractionated heparin plus provisional glycoprotein IIb/IIIa inhibitors, (MATRIX antithrombin) decrease the 30-day incidence of an ischemic (ie, death, myocardial infarction or stroke) or an ischemic and bleeding composite end point across the whole spectrum of ACS patients, including clarifying the optimal duration of bivalirudin infusion after percutaneous coronary intervention (MATRIX treatment duration).

STUDY DESIGN

The MATRIX (NCT01433627) study, which incorporates 3 randomized comparisons in a nonfactorial manner and primary end points at 30 days and clinical follow-up ≤ 1 year, is a large-scale, multicenter study with blind event adjudication conducted at approximately 100 European sites. With 8,200 patients in the randomized comparison of access sites and 6,800 individuals participating in the randomized comparison of antithrombin regimens, this study will have ≥ 85% power for the primary end points.

SUMMARY

The MATRIX program aims at conclusively ascertaining the role of TRI and bivalirudin infusion in the whole spectrum of ACS patients undergoing contemporary invasive management.

Cost effectiveness of anticoagulation in acute coronary syndromes

BACKGROUND

The benefit of unfractionated heparin (UFH) added to aspirin in patients with acute coronary syndromes (ACS) was described more than 20 years ago. Ever since, a wide variety of anticoagulant drugs have become available for clinical use, including low-molecular-weight heparins (LMWH), direct thrombin inhibitors and selective factor Xa inhibitors.

OBJECTIVE

The aim of this study was to critically review the available evidence on the cost and incremental cost effectiveness of anticoagulants in patients with ACS.

METHODS

Studies were identified using specialist databases (UK NHS Economic Evaluation Database [NHS EED] and Cost-Effectiveness Analysis [CEA] Registry), PubMed and the reference lists of recovered articles. Only studies based on randomized controlled trials were considered for inclusion. Finally, 22 studies were included in the review.

RESULTS

Enoxaparin is the only LMWH that has been shown to reduce the risk of death or myocardial infarction in patients with non-ST-elevation ACS (NSTE-ACS). In economic studies based on the ESSENCE trial conducted in the late 1990s, enoxaparin was consistently associated with a lower risk of coronary events, a reduction in the number of revascularization procedures and a lower cost per patient than UFH. However, these results refer to patients managed conservatively, with little use of thienopyridines and glycoprotein IIb/IIIa inhibitors, and the results are difficult to extrapolate to moderate-to-high-risk patients managed with the present day early invasive strategy. Available studies of LMWH in ACS with persistent elevation of ST-segment (STE-ACS) are limited to patients treated with thrombolysis. In this scenario, enoxaparin was shown to be a dominant alternative compared with UFH in a study based on the ASSENT-3 study and was considered an economically attractive alternative in three studies based on the ExTRACT-TIMI 25 study. However, these results should be interpreted cautiously due to the heterogeneity of the supportive randomized trials and the possible underestimation of bleeding costs. The effectiveness and safety of bivalirudin, a direct thrombin inhibitor, were evaluated in the ACUITY study (NSTE-ACS patients managed invasively) and the HORIZONS-AMI study (STE acute myocardial infarction patients planned for primary percutaneous coronary intervention). Bivalirudin monotherapy was not inferior to heparin plus a glycoprotein IIb/IIIa inhibitor and reduced the risk of major bleeding. The economic evaluations based on these studies suggest that bivalirudin is an attractive alternative to heparin plus a glycoprotein-IIb/IIIa inhibitor. In the OASIS-5 trial, compared with enoxaparin, fondaparinux reduced the mortality in patients with NSTE-ACS, probably because of a reduced risk of bleeding. In three economic evaluations of fondaparinux versus enoxaparin based on this trial, fondaparinux was the dominant strategy in two of them, and still economically attractive in a third. Taken as a whole, the usefulness of economic studies of anticoagulants in patients with ACS is undermined by the quality of the evidence about their effectiveness and safety; the narrow spectrum of the analysed scenarios; the lack of economic evaluations based on systematic reviews; the limitations of sensitivity analyses reported by the available economic evaluations; and their substantial risk of commercial bias.

CONCLUSIONS

The available studies suggest that enoxaparin is an economically attractive alternative compared with UFH in patients with NSTE-ACS treated conservatively and STE-ACS patients treated with thrombolysis. Bivalirudin in patients with ACS treated invasively is cost effective compared with heparin plus a glycoprotein IIb/IIIa inhibitor. In patients with NSTE-ACS, fondaparinux is cost effective compared with enoxaparin. The usefulness of these results for decision making in contemporary clinical practice is limited due to problems of internal and external validity.

[Bleeding risk in ST-segment elevation myocardial infarction]

Coronary reperfusion of acute coronary syndromes with ST segment elevation requires medical treatment involving potential thrombolysis as well as very potent anticoagulant and antiplatelet medications. In such a therapeutic setting, the risk of bleeding complications may be high and should be taken into account accordingly. An accurate definition of these bleeding complications is crucial in order to compare all currently available treatments and strategies appropriately. The heterogeneous definitions often published in the literature make any valid interpretations of the results very difficult. These bleeding complications, which affect negatively the outcome of patients undergoing treatment should be adequately anticipated in our treatment strategies. An exhaustive knowledge of the bleeding risk factors is necessary in order to adjust the treatment modalities. The occurrence of bleeding may be related to the vascular approach used for cardiac catheterization. In this respect, the superiority of the radial approach has been widely demonstrated. In addition, certain instances of bleeding are not related to the vascular approach, such as digestive and neurological bleeding which can have very severe consequences. Consequently, it is necessary to adapt treatments with heterogeneous potential for bleeding to individual bleeding risk factors, which may be quantified by scores measuring the bleeding risk. Finally, treatment combinations must often be carefully tailored to the characteristics of each individual patient.

The use of adjunctive anticoagulants in patients with acute coronary syndrome transitioning to percutaneous coronary intervention

Patients presenting to the Emergency Department (ED) need to be quickly diagnosed, risk-stratified, and treated accordingly. Anticoagulants used in the ED should be easy to use and suitable for all patients with acute coronary syndromes, regardless of treatment strategy. In patients with ST-segment myocardial infarction, current guidelines recommend unfractionated heparin regardless of reperfusion strategy or low-molecular-weight heparin (LMWH) as an alternative in patients undergoing percutaneous coronary intervention (PCI). The LMWH enoxaparin is approved for ST-segment elevation myocardial infarction patients managed medically or undergoing PCI. The recently updated American College of Cardiology/American Heart Association guidelines for patients with unstable angina or non-ST-segment elevation myocardial infarction recommend unfractionated heparin or the LMWH enoxaparin (class IA recommendation), or the factor Xa inhibitor fondaparinux or the direct thrombin inhibitor bivalirudin (class IB recommendation) for patients managed invasively. This review discusses each of these anticoagulant options in the context of patients transitioning to PCI.

Efficacy and safety of fondaparinux versus enoxaparin in patients with acute coronary syndromes undergoing percutaneous coronary intervention: results from the OASIS-5 trial

OBJECTIVES

This study reports a prospectively planned analysis of patients with acute coronary syndrome who underwent early percutaneous coronary intervention (PCI) in the OASIS-5 (Fifth Organization to Assess Strategies in Ischemic Syndromes) trial.

BACKGROUND

In the OASIS-5 trial, fondaparinux was similar to enoxaparin for short-term efficacy, but reduced major bleeding by one-half and 30-day mortality by 17%.

METHODS

The OASIS-5 trial was a double-blind, randomized comparison of fondaparinux and enoxaparin in 20,078 patients with acute coronary syndrome. A total of 12,715 patients underwent heart catheterization during the initial hospitalization, and 6,238 patients underwent PCI. In the fondaparinux group, intravenous fondaparinux was given for PCI. In the enoxaparin group, no additional anticoagulant was given if PCI was <6 h from last subcutaneous dose, and additional intravenous unfractionated heparin (UFH) was given if PCI was >6 h.

RESULTS

Fondaparinux compared with enoxaparin reduced major bleeding by more than one-half (2.4% vs. 5.1%, hazard ratio [HR] 0.46, p < 0.00001) at day 9, with similar rates of ischemic events, resulting in superior net clinical benefit (death, myocardial infarction, stroke, major bleeding: 8.2% vs. 10.4%, HR 0.78, p = 0.004). Fondaparinux reduced major bleeding 48 h after PCI irrespective of whether PCI was performed <6 h of the last enoxaparin dose (1.6% vs. 3.8%, HR 0.42, p < 0.0001) or >6 h when UFH was given (1.3% vs. 3.4%, HR 0.39, p < 0.0001). Catheter thrombus was more common in patients receiving fondaparinux (0.9%) than enoxaparin alone (0.4%), but was largely prevented by using UFH at the time of PCI, without any increase in bleeding.

CONCLUSIONS

Upstream therapy with fondaparinux compared with upstream enoxaparin substantially reduces major bleeding while maintaining efficacy, resulting in superior net clinical benefit. The use of standard UFH in place of fondaparinux at the time of PCI seems to prevent angiographic complications, including catheter thrombus, without compromising the benefits of upstream fondaparinux.

Myokardinfarkt und instabile Angina Pectoris

Acute coronary syndromes include ST-elevation and non-ST elevation myocardial infarction, and unstable angina pectoris. These are characterised by the acute onset of chest pain. For the diagnostic work up in the acute phase, ECG and the assessment of cardiac markers play a central role. For patients with ST-elevation, primary interventional therapy is the first choice. For patients with an acute coronary syndrome without ST-elevation, a risk adapted therapeutic strategy should be chosen. High risk patients (elevated troponins, clinical, rhythmological and hemodynamic instability, ST-depression and diabetes mellitus) should be treated by an early invasive approach with angiography performed within 48-72 h. Low risk patients should be treated conservatively. For all patients who are treated interventionally, the administration of an aggressive antiaggregatory therapy including aspirin, clopidogrel, glycoprotein IIb/IIIa inhibitors and heparin is indicated in the acute phase. In the chronic phase, the treatment of cardiovascular risk factors is of paramount importance.