Effects of preoperative enoxaparin versus unfractionated heparin on bleeding indices in patients undergoing coronary artery bypass grafting

Perioperative Bleeding in Patients With Acute Coronary Syndrome Treated With Fondaparinux Versus Low-Molecular-Weight Heparin Before Coronary Artery Bypass Grafting

The perioperative bleeding risk in patients receiving fondaparinux versus low-molecular weight heparin before coronary artery bypass grafting has not been reported. We evaluated perioperative coronary artery bypass grafting-related bleeding in patients with acute coronary syndrome preoperatively treated with fondaparinux or low-molecular weight heparin. All patients with acute coronary syndrome from the prospective, European multicenter registry on coronary artery bypass grafting preoperatively treated with fondaparinux or low-molecular weight heparin undergoing isolated primary CABG were eligible. The primary outcome measure was severe or massive bleeding defined according to the Universal Definition of Perioperative Bleeding stratified by P2Y₁₂ inhibitor discontinuation. Secondary outcome measures included 3 additional definitions of major bleeding used in cardiac surgery trials. Propensity score matching was performed to adjust for differences in pre- and perioperative covariates. 1,525 patients were included, of whom 276 (18.1%) received fondaparinux and 1,249 (81.9%) low-molecular weight heparin preoperatively. In the propensity score-matched cohort (245 pairs), the risk of major bleeding according to the universal definition of perioperative bleeding severe or massive bleeding (11.8 vs 9.0%, p = 0.285) and the 3 other major bleeding definitions was similar between the fondaparinux and low-molecular weight heparin cohorts. In conclusion, preoperative treatment with fondaparinux compared with low-molecular weight heparin was associated with similar incidence of perioperative bleeding in patients with acute coronary syndrome who underwent coronary artery bypass grafting.

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.

Use of adenosine diphosphate receptor inhibitor prior to left ventricular assist device implantation is not associated with increased bleeding

Current guidelines recommend adenosine diphosphate receptor inhibitors (ADPRi) be discontinued 5-7 days prior to cardiac surgery due to increased bleeding events, rates of re-exploration, and transfusions. However, the risks of left ventricular assist device (LVAD) implantation in patients taking an ADPRi have not previously been studied. We retrospectively identified 134 eligible patients with ischemic cardiomyopathy that underwent LVAD implantation between July 2009 and August 2013. The cohorts received an ADPRi ≤5 days of surgery (n = 25) versus >5 days prior or not at all (n = 109). Subgroup analyses adjusted for differences in frequency of redo sternotomy between cohorts, excluded patients that received an ADPRi >1 year prior to surgery, and excluded patients with a redo sternotomy. The ADPRi and control groups did not have significant differences in the primary outcomes, intraoperative PRBC units transfused (3.0 vs. 4.0, p = 0.12) or chest tube output within 24 h of surgery (1.66 L vs. 1.80 L, p = 0.61). After adjusting for differences in frequency of redo sternotomy (ADPRi vs. control, 12 vs. 52%, p ≤ 0.001), no significant difference in PRBC units transfused (3.1 vs. 3.5, p = 0.59) or chest tube output (2.04 L vs. 2.04 L, p = 0.98) was seen. No significant difference in 30-day mortality (8.0 vs. 11.0%, p = 0.63), 90-day mortality (16.4 vs. 23.3%, p = 0.42), or length of stay (29.0 vs. 28.0, p = 0.61) was seen. In this single-center experience, use of an ADPRi ≤5 days prior to LVAD implantation was not associated with increased bleeding, length of stay, or mortality.

Effects of Preoperative Abciximab and Eptifibatide on Bleeding Indices in Coronary Artery Bypass Graft Patients

Background:

Glycoprotein (GP) IIb/IIIa antagonists are used routinely for the treatment of acute coronary syndrome and to prevent thromboses during percutaneous coronary interventions. It is not uncommon for patients who initially require a GP IIb/IIIa inhibitor to eventually receive a surgical intervention.

Objective:

To compare the difference in bleeding indices in patients who undergo coronary artery bypass grafting (CABG) after receiving either eptifibatide or abciximab.

Methods:

A retrospective chart review was completed on all adults who received abciximab or eptifibatide within 24 hours prior to undergoing CABG. Patients were excluded if they had received a dose of warfarin within 96 hours prior to the procedure or if they had an incomplete medical record, an off-pump procedure, a known hypercoagulable disorder, or hemophilia. A total of 54 patients were included and preoperative data, including doses of anticoagulant and antiplatelet agents, were recorded. Intraoperative and postoperative data collected for analysis included hemoglobin level, chest tube output, and the amount of blood products transfused for 24 hours postprocedure.

Results:

There was a statistically significant difference between the eptifibatide and abciximab groups in the amount of fresh frozen plasma (mean ± SD, 21 ± 31 vs 187 ± 125 mL, respectively; p < 0.05) and platelets (212 ± 81 vs 433 ± 118 mL, respectively; p < 0.01) transfused during the intraoperative period. However, when the total amount of blood products transfused intraoperatively (769 ± 243 vs 1395 ± 316 mL, respectively; p = 0.47) was evaluated, no significant difference was detected. Likewise, markers for bleeding that were collected during the 24-hour postoperative window (immediate and 24-h postoperative hemoglobin and total 24-h chest tube output) were not significantly different.

Conclusions:

Although there is an increased risk of bleeding when abciximab or eptifibatide is administered prior to CABG, no significant difference in the total amount of blood products used was detected between the 2 agents in this study.

Patients with non-ST-elevation acute coronary syndromes undergoing coronary artery bypass grafting in the modern era of antithrombotic therapy

BACKGROUND

Many high-risk patients with non-ST-elevation acute coronary syndromes within the SYNERGY trial required coronary artery bypass grafting (CABG) for optimal revascularization. We explored the clinical outcomes among high-risk patients undergoing CABG and the impact of modern pharmacology.

METHODS

We evaluated 180-day rates of death and myocardial infarction (MI) and 30-day GUSTO severe bleeding among patients undergoing CABG, contrasting them with patients undergoing percutaneous coronary intervention (PCI) or medical management. The relationships between perioperative MI, bleeding events, and 6-month mortality were explored. The effect of random assignment to unfractionated heparin or enoxaparin and the relationships between use of clopidogrel and glycoprotein IIb/IIIa inhibitors and clinical outcomes were assessed.

RESULTS

Death or MI at 6 months was more common among patients requiring CABG (CABG 31.2%, PCI 15.9%, medical 9.9%). Thirty-day GUSTO severe bleeding was also higher (CABG 6.4%, PCI 1.1%, medical 0.9%). Perioperative MI and GUSTO severe bleeding were associated with excess 6-month mortality (hazard ratio 2.1, 95% CI 1.27-3.53 and hazard ratio 7.6, CI 4.78-12.09, respectively). Randomization to enoxaparin was not associated with an increase in bleeding or a reduction in death or MI. No differences in ischemic outcomes were observed among patients given glycoprotein IIb/IIIa inhibition or clopidogrel.

CONCLUSIONS

High-risk patients still commonly require CABG with greater bleeding and ischemic event rates observed. Current definitions of perioperative MI and GUSTO severe bleeding portend an increased in 6-month mortality among CABG patients. Modern pharmacotherapies do not appear to impact these higher event rates.

Perioperative blood transfusion and blood conservation in cardiac surgery: the Society of Thoracic Surgeons and The Society of Cardiovascular Anesthesiologists clinical practice guideline

BACKGROUND

A minority of patients having cardiac procedures (15% to 20%) consume more than 80% of the blood products transfused at operation. Blood must be viewed as a scarce resource that carries risks and benefits. A careful review of available evidence can provide guidelines to allocate this valuable resource and improve patient outcomes.

METHODS

We reviewed all available published evidence related to blood conservation during cardiac operations, including randomized controlled trials, published observational information, and case reports. Conventional methods identified the level of evidence available for each of the blood conservation interventions. After considering the level of evidence, recommendations were made regarding each intervention using the American Heart Association/American College of Cardiology classification scheme.

RESULTS

Review of published reports identified a high-risk profile associated with increased postoperative blood transfusion. Six variables stand out as important indicators of risk: (1) advanced age, (2) low preoperative red blood cell volume (preoperative anemia or small body size), (3) preoperative antiplatelet or antithrombotic drugs, (4) reoperative or complex procedures, (5) emergency operations, and (6) noncardiac patient comorbidities. Careful review revealed preoperative and perioperative interventions that are likely to reduce bleeding and postoperative blood transfusion. Preoperative interventions that are likely to reduce blood transfusion include identification of high-risk patients who should receive all available preoperative and perioperative blood conservation interventions and limitation of antithrombotic drugs. Perioperative blood conservation interventions include use of antifibrinolytic drugs, selective use of off-pump coronary artery bypass graft surgery, routine use of a cell-saving device, and implementation of appropriate transfusion indications. An important intervention is application of a multimodality blood conservation program that is institution based, accepted by all health care providers, and that involves well thought out transfusion algorithms to guide transfusion decisions.

CONCLUSIONS

Based on available evidence, institution-specific protocols should screen for high-risk patients, as blood conservation interventions are likely to be most productive for this high-risk subset. Available evidence-based blood conservation techniques include (1) drugs that increase preoperative blood volume (eg, erythropoietin) or decrease postoperative bleeding (eg, antifibrinolytics), (2) devices that conserve blood (eg, intraoperative blood salvage and blood sparing interventions), (3) interventions that protect the patient's own blood from the stress of operation (eg, autologous predonation and normovolemic hemodilution), (4) consensus, institution-specific blood transfusion algorithms supplemented with point-of-care testing, and most importantly, (5) a multimodality approach to blood conservation combining all of the above.

Trends in Emergency Coronary Artery Bypass Grafting After Percutaneous Coronary Intervention, 1994–2003

BACKGROUND

In the last decade, percutaneous coronary intervention (PCI) has undergone profound changes in techniques used to achieve revascularization and in patient selection. We examine trends in emergency surgical revascularization after PCI.

METHODS

Using The Society of Thoracic Surgeons National Cardiac Surgery Database, we examined patients undergoing coronary artery bypass grafting within 6 hours of PCI from 1994 to 2003. Stratifying into groups of patients who had and had not suffered myocardial infarction within 24 hours of PCI followed by coronary artery bypass grafting (CABG), we tracked trends in characteristics, predicted risk, and clinical outcomes.

RESULTS

The proportion of isolated CABG procedures done emergently after PCI decreased over 1994 to 1999 from 3,357 of 115,679 (2.9%) to 1,227 of 155,831 (0.8%), remaining stable through 2003. Those suffering myocardial infarction within 24 hours made up a constant proportion of isolated CABG as emergency after PCI (3,352 of 1,042,864; 0.3%) since 1997. Over the decade, the preoperative risk profile worsened, including more elderly patients and more with cerebrovascular disease and congestive heart failure. Operative mortality among these patients has risen with time (from 8.0% to 9.3%; p < 0.0001 for trend), particularly in the setting of acute myocardial infarction (from 14.1% to 16.6%; p < 0.0001 for trend). Similarly, postoperative complications have increased over time, most notably seen in the need for reoperation (10.62% to 24.56%), prolonged postoperative ventilation (25.65% to 54.58%), and renal failure (10.22% to 18.55%).

CONCLUSIONS

In 2005, there remains a low but real need for emergent CABG after PCI, in which operative outcomes are less than ideal, especially in the postinfarction patient, representing an area for cross-specialty collaboration.

Role of low-molecular-weight heparin in invasive management of non-ST-elevation acute coronary syndromes

OBJECTIVE

To review the available literature addressing the role of low-molecular-weight heparin (LMWH) as an alternative to unfractionated heparin (UFH) in percutaneous coronary intervention (PCI) for treatment of non-ST-elevation acute coronary syndromes (NSTEACS).

DATA SOURCES

A MEDLINE search (1966-March 2004) identified pertinent articles using the key words acute coronary syndromes, unstable angina, non-ST-elevation myocardial infarction, low-molecular-weight heparin, enoxaparin, dalteparin, glycoprotein IIb/IIIa receptor antagonists, abciximab, tirofiban, eptifibatide, percutaneous transluminal coronary angioplasty, and percutaneous coronary intervention. The references of these articles were reviewed for additional pertinent references.

STUDY SELECTION AND DATA EXTRACTION

All human trials of LMWH in PCI for treatment of NSTEACS were evaluated. All pertinent studies were included in the review.

DATA SYNTHESIS

Administration of LMWH with or without a glycoprotein IIb/IIIa inhibitor during PCI appears to be similar to UFH in terms of efficacy. LMWH, especially in combination with a glycoprotein IIb/IIIa inhibitor, may increase risk of bleeding compared with UFH.

CONCLUSIONS

Available clinical trials do not provide definitive evidence to suggest superiority of LMWH over UFH when managing NSTEACS during PCI; however, dosing strategies are available if an LMWH is to be used in this setting.