Preoperative use of enoxaparin increases the risk of postoperative bleeding and re-exploration in cardiac surgery patients

Leveraging Human Genetics to Estimate Clinical Risk Reductions Achievable by Inhibiting Factor XI

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Coagulation factor XI (FXI) is a novel target for antithrombotic therapy addressed by various therapeutic modalities currently in clinical development. The expected magnitude of thrombotic event reduction mediated by targeting FXI is unclear.

Preoperative Low-Molecular-Weight Heparin Prophylaxis Associated with Increased Heparin Resistance Frequency in On-Pump Coronary Artery Bypass Graft Surgery

Background

Unfractionated heparin (UFH) and low-molecular-weight heparin (LMWH) are being used for preoperative management of critical coronary artery disease. However, preoperative UFH therapy may cause a reduction in antithrombin concentrations, leading to various degrees of heparin resistance (HR). The main purpose of this study is to investigate the effects of preoperative LMWH on HR during cardiopulmonary bypass (CPB).

Methods

Data were retrospectively reviewed from adult patients that underwent on-pump coronary artery bypass graft (CABG) surgery. Four hundred fifty-seven patients underwent CABG, and 139 of them, who had isolated on-pump CABG, were included in the study. The heparin sensitivity index was calculated if activated clotting time levels were discovered below 400 seconds. Values less than 1.3 were accepted as HR.

Results

Of 139 patients who underwent on-pump CABG, preoperative LMWH was administered in 59 patients (56.8%). Intraoperative HR occurred in 29 patients (20.9%). Patients who received preoperative LMWH had an increased risk of developing HR compared with patients who did not receive LMWH (odds ratio 4.8 and 95% confidence interval 1.7–13.5). CPB duration and aortic clamp duration were significantly longer in patients who developed intraoperative HR when compared to those in patients who did not develop HR.

Conclusion

Preoperative treatment with LMWH may cause intraoperative HR. Corrective and preventive arrangements with close follow-up should be performed in this group of patients.

Fish Oil and Perioperative Bleeding

Background Fish oil is among the most common natural supplements for treatment of hypertriglyceridemia or prevention of cardiovascular disease. However, concerns about theoretical bleeding risk have led to recommendations that patients should stop taking fish oil before surgery or delay in elective procedures for patients taking fish oil by some health care professionals. Methods and Results We tested the effect of fish oil supplementation on perioperative bleeding in a multinational, placebo-controlled trial involving 1516 patients who were randomized to perioperative fish oil (eicosapentaenoic acid+docosahexaenoic acid; 8-10 g for 2-5 days preoperatively, and then 2 g/d postoperatively) or placebo. Primary outcome was major perioperative bleeding as defined by the Bleeding Academic Research Consortium. Secondary outcomes include perioperative bleeding per thrombolysis in myocardial infarction and International Society on Thrombosis and Hemostasis definitions, chest tube output, and total units of blood transfused. Participants' mean (SD) age was 63 (13) years, and planned surgery included coronary artery bypass graft (52%) and valve surgery (50%). The primary outcome occurred in 92 patients (6.1%). Compared with placebo, risk of Bleeding Academic Research Consortium bleeding was not higher in the fish oil group: odds ratio, 0.81; 95% CI, 0.53-1.24; absolute risk difference, 1.1% lower (95% CI, -3.0% to 1.8%). Similar findings were seen for secondary bleeding definitions. The total units of blood transfused were significantly lower in the fish oil group compared with placebo (mean, 1.61 versus 1.92; P<0.001). Evaluating achieved plasma phospholipid omega-3 polyunsaturated fatty acids levels with supplementation (on the morning of surgery), higher levels were associated with lower risk of Bleeding Academic Research Consortium bleeding, with substantially lower risk in the third (odds ratio, 0.30 [95% CI, 0.11-0.78]) and fourth (0.36 [95% CI, 0.15-0.87]) quartiles, compared with the lowest quartile. Conclusions Fish oil supplementation did not increase perioperative bleeding and reduced the number of blood transfusions. Higher achieved n-3-PUFA levels were associated with lower risk of bleeding. These novel findings support the need for reconsideration of current recommendations to stop fish oil or delay procedures before cardiac surgery. Clinical Trial Registration URL: https://www.clinicaltrials.gov . Unique identifier: NCT00970489.

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.

Excessive bleeding predictors after cardiac surgery in adults: integrative review

AIMS AND OBJECTIVES

To integrate literature data on the predictors of excessive bleeding after cardiac surgery in adults.

BACKGROUND

Perioperative nursing care requires awareness of the risk factors for excessive bleeding after cardiac surgery to assure vigilance prioritising and early correction of those that are modifiable.

DESIGN

Integrative literature review.

METHODS

Articles were searched in seven databases. Seventeen studies investigating predictive factors for excessive bleeding after open-heart surgery from 2004-2014 were included.

RESULTS

Predictors of excessive bleeding after cardiac surgery were: Patient-related: male gender, higher preoperative haemoglobin levels, lower body mass index, diabetes mellitus, impaired left ventricular function, lower amount of prebypass thrombin generation, lower preoperative platelet counts, decreased preoperative platelet aggregation, preoperative platelet inhibition level >20%, preoperative thrombocytopenia and lower preoperative fibrinogen concentration. Procedure-related: the operating surgeon, coronary artery bypass surgery with three or more bypasses, use of the internal mammary artery, duration of surgery, increased cross-clamp time, increased cardiopulmonary bypass time, lower intraoperative core body temperature and bypass-induced haemostatic disorders. Postoperative: fibrinogen levels and metabolic acidosis.

CONCLUSIONS

Patient-related, procedure-related and postoperative predictors of excessive bleeding after cardiac surgery were identified.

RELEVANCE TO CLINICAL PRACTICE

The predictors summarised in this review can be used for risk stratification of excessive bleeding after cardiac surgery. Assessment, documentation and case reporting can be guided by awareness of these factors, so that postoperative vigilance can be prioritised. Timely identification and correction of the modifiable factors can be facilitated.

Predictive factors for bleeding-related re-exploration after cardiac surgery: A prospective cohort study

BACKGROUND

Bleeding-related re-exploration is a life-threatening complication after cardiac surgery. Nurses must be aware of important risk factors for this complication so that their assessment, monitoring and evaluation activities can be prioritized, focused and anticipated.

AIMS

To identify the predictive factors for bleeding-related re-exploration after cardiac surgery and to describe the sources of postoperative bleeding.

METHODS

This is a prospective cohort study at a tertiary cardiac school-hospital in São Paulo/SP, Brazil. Adult patients (n=323) submitted to surgical correction of acquired cardiac diseases were included. Potential risk factors for bleeding-related re-exploration within the 24 hours following admission to the intensive care unit were investigated in the patients' charts. A univariate analysis and a multiple analysis through logistic regression were conducted to identify the outcome predictors. The area under the receiver-operating characteristic curve was calculated as a measure of accuracy considering the cut-off points with the highest sensitivity and specificity.

RESULTS

The univariate factors significantly associated with bleeding-related re-exploration were a lower preoperative platelet count, a lower number of bypasses in coronary artery bypass surgery and postoperatively, a lower body temperature, infusion of lower intravenous volume, a higher positive end-expiratory pressure during mechanical ventilation and transfusion of blood products. The independent predictors of bleeding-related re-exploration included postoperative red blood cell transfusion, and transfusion of fresh frozen plasma, platelet or cryoprecipitate units. These predictors had a sensitivity of 87.5%, a specificity of 99.28% and an accuracy of 97.93%.

CONCLUSIONS

Blood product transfusion postoperatively is an independent predictor of bleeding-related re-exploration. Surgical errors prevailed as sources of bleeding.

Bridge with intravenous antiplatelet therapy during temporary withdrawal of oral agents for surgical procedures: a systematic review

Patients needing surgery within 1 year after drug-eluting cardiac stent implantation are challenging to manage because of an increased thrombotic and bleeding risk. A "bridge therapy" with short-acting antiplatelet agents in the perioperative period is an option. We assessed the outcome and safety of such a bridge therapy in cardiovascular and non-cardiovascular surgery. We performed a comprehensive search of MEDLINE, EMBASE, the Cochrane Library, and ongoing trial registers, irrespective of type of design. Our primary outcome was the success rate of bridge therapy in terms of freedom from cardiac ischaemic adverse events, whereas secondary outcome was freedom from bleeding/transfusion. We also performed combined success rate for each bridge therapy drug (tirofiban, eptifibatide, and cangrelor). We included eight case series and one randomised controlled trial. Among the 420 patients included, the technique was effective 96.2 % of the times [95 % confidence interval (CI) 94.4-98.0 %]. The success rate was 100 % for tirofiban (4 studies), 93.8 % for eptifibatide (4 studies), and 96.2 % for cangrelor (1 study). Freedom from bleeding/transfusion events was observed in 72.6 % of the times (95 % CI 68.4-76.9 %), and was higher with cangrelor (88.7 %; 95 % CI 82.7-94.7 %) than with other drugs (81.0 % for tirofiban and 58.6 % for eptifibatide). Evidence from case series and one randomised controlled trial suggests that, in patients with recent coronary stenting undergoing major surgery, perioperative bridge therapy with intravenous antiplatelet agents is an effective and safe treatment option to ensure low rate of ischaemic events.

Risk stratification in acute coronary syndromes

Accurate and readily available systems for risk stratification and a wide array of antithrombotic agents, on top of classical anti-ischemic drugs, provide the noninvasive cardiologist admitting the patient in the CCU with an effective and reliable armamentarium for the safe management of most patients with ACS. From the interventionalist's perspective, the immediate knowledge of the coronary anatomy yields the most valuable information to address the most appropriate treatment. The sooner angiography is performed the higher the benefit for patients at moderate to high risk, but if performed by expert teams and with the correct use of modern drugs and devices, the invasive approach has the potential to reduce costs and length of hospital stay also in low-risk patients. Although still some reluctance remains to equalize treatment strategies for patients with STEMI to those with NSTEMI, such differences will likely disappear in the near future with upcoming new evidence. Cardiac surgery may represent a life-saving alternative for patients presenting with NSTEMI evolving in cardiogenic shock or with mechanical complications, or in patients unsuitable for PCI or with failed PCI attempts. In stabilized conditions after the treatment of the culprit lesion, patients with severe multivessel disease may benefit from cardiac surgery to complete myocardial revascularization. Indications for CABG in this setting should be evaluated in the context of a local "heart team" or through prespecified protocols in centers without cardiac surgery on site.

Management of patients with recently implanted coronary stents on dual antiplatelet therapy who need to undergo major surgery

About 5% of patients undergoing coronary stenting need to undergo surgery within the next year. The risk of perioperative cardiac ischemic events, particularly stent thrombosis (ST), is high in these patients, because surgery has a prothrombotic effect and antiplatelet therapy is often withdrawn in order to avoid bleeding. The clinical and angiographic predictors of ST are well known, and the proximity to an acute coronary syndrome adds to the risk. The current guidelines recommend delaying non-urgent surgery for at least 6 weeks after the placement of a bare metal stent and for 6-12 months after the placement of a drug-eluting stent, when the risk of ST is reduced. However, in the absence of formal evidence, these recommendations provide little support with regard to managing urgent operations. When surgery cannot be postponed, stratifying the risk of surgical bleeding and cardiac ischemic events is crucial in order to manage perioperative antiplatelet therapy in individual cases. Dual antiplatelet therapy should not be withdrawn for minor surgery or most gastrointestinal endoscopic procedures. Aspirin can be safely continued perioperatively in the case of most major surgery, and provides coronary protection. In the case of interventions at high risk for both bleeding and ischemic events, when clopidogrel withdrawal is required in order to reduce perioperative bleeding, perioperative treatment with the short-acting intravenous glycoprotein IIb-IIIa inhibitor tirofiban is safe in terms of bleeding, and provides strong antithrombotic protection. Such surgical interventions should be performed at hospitals capable of performing an immediate percutaneous coronary intervention at any time in the case of acute myocardial ischemia.

Peri-operative management of antiplatelet therapy in patients with coronary artery disease: joint position paper by members of the working group on Perioperative Haemostasis of the Society on Thrombosis and Haemostasis Research (GTH), the working group on Perioperative Coagulation of the Austrian Society for Anesthesiology, Resuscitation and Intensive Care (ÖGARI) and the Working Group Thrombosis of the European Society for Cardiology (ESC)

An increasing number of patients suffering from cardiovascular disease, especially coronary artery disease (CAD), are treated with aspirin and/or clopidogrel for the prevention of major adverse events. Unfortunately, there are no specific, widely accepted recommendations for the perioperative management of patients receiving antiplatelet therapy. Therefore, members of the Perioperative Haemostasis Group of the Society on Thrombosis and Haemostasis Research (GTH), the Perioperative Coagulation Group of the Austrian Society for Anesthesiology, Reanimation and Intensive Care (ÖGARI) and the Working Group Thrombosis of the European Society of Cardiology (ESC) have created this consensus position paper to provide clear recommendations on the perioperative use of anti-platelet agents (specifically with semi-urgent and urgent surgery), strongly supporting a multidisciplinary approach to optimize the treatment of individual patients with coronary artery disease who need major cardiac and non-cardiac surgery. With planned surgery, drug eluting stents (DES) should not be used unless surgery can be delayed for ≥12 months after DES implantation. If surgery cannot be delayed, surgical revascularisation, bare-metal stents or pure balloon angioplasty should be considered. During ongoing antiplatelet therapy, elective surgery should be delayed for the recommended duration of treatment. In patients with semi-urgent surgery, the decision to prematurely stop one or both antiplatelet agents (at least 5 days pre-operatively) has to be taken after multidisciplinary consultation, evaluating the individual thrombotic and bleeding risk. Urgently needed surgery has to take place under full antiplatelet therapy despite the increased bleeding risk. A multidisciplinary approach for optimal antithrombotic and haemostatic patient management is thus mandatory.

Emergency cardiac surgery in patients with acute coronary syndromes: a review of the evidence and perioperative implications of medical and mechanical therapeutics

Patients with acute coronary syndromes who require emergency cardiac surgery present complex management challenges. The early administration of antiplatelet and antithrombotic drugs has improved overall survival for patients with acute myocardial infarction, but to achieve maximal benefit, these drugs are given before coronary anatomy is known and before the decision to perform percutaneous coronary interventions or surgical revascularization has been made. A major bleeding event secondary to these drugs is associated with a high rate of death in medically treated patients with acute coronary syndrome possibly because of subsequent withholding of antiplatelet and antithrombotic therapies that otherwise reduce the rate of death, stroke, or recurrent myocardial infarction. Whether the added risk of bleeding and blood transfusion in cardiac surgical patients receiving such potent antiplatelet or antithrombotic therapy before surgery specifically for acute coronary syndromes affects long-term mortality has not been clearly established. For patients who do proceed to surgery, strategies to minimize bleeding include stopping the anticoagulation therapy and considering platelet and/or coagulation factor transfusion and possibly recombinant-activated factor VIIa administration for refractory bleeding. Mechanical hemodynamic support has emerged as an important option for patients with acute coronary syndromes in cardiogenic shock. For these patients, perioperative considerations include maintaining appropriate anticoagulation, ensuring suitable device flow, and periodically verifying correct device placement. Data supporting the use of these devices are derived from small trials that did not address long-term postoperative outcomes. Future directions of research will seek to optimize the balance between reducing myocardial ischemic risk with antiplatelet and antithrombotics versus the higher rate perioperative bleeding by better risk stratifying surgical candidates and by assessing the effectiveness of newer reversible drugs. The effects of mechanical hemodynamic support on long-term patient outcomes need more stringent analysis.

Safety and Efficacy of Clopidogrel before Surgery

Clopidogrel is an antiplatelet drug that is used in patients who have had previous cerebrovascular events, acute coronary syndromes, or who underwent percutaneous coronary interventions (PCI) with bare metal or drug-eluting stents. About 5% of patients who undergo PCI have to undergo non-cardiac surgery within 1 year of coronary stent implantation. Patients who receive clopidogrel may be at increased risk of bleeding complications during surgery. The risk of coronary thrombosis after non-cardiac surgery increases, especially when surgery is performed early after stenting, and particularly when antiplatelet agents are withdrawn before surgery. The decision to continue or withhold clopidogrel should reflect a balance of the consequences of perioperative hemorrhage versus the risk of perioperative vascular complications. Close communication among surgeons, anesthesiologists, and cardiologist is necessary to minimize both adverse cardiac risk and surgical risk in those patients.

Dual antiplatelet therapy in patients requiring urgent coronary artery bypass grafting surgery: a position statement of the Canadian Cardiovascular Society

Acute coronary syndrome (ACS) guidelines recommend that most patients receive dual antiplatelet therapy with clopidogrel and acetylsalicylic acid (ASA) at the time of presentation to prevent recurrent ischemic events. Approximately 10% of ACS patients require coronary artery bypass grafting surgery (CABG) during the index admission. Most studies show that patients who receive ASA and clopidogrel within five days of CABG have an increase in operative bleeding. Current consensus guidelines recommend discontinuation of clopidogrel therapy at least five days before planned CABG to reduce bleeding-related events. However, high-risk individuals may require urgent surgery without delay, to reduce the risk of potentially fatal ischemic events. The present multidisciplinary position statement provides evidence- based recommendations for the optimal use of dual antiplatelet therapy to balance ischemic and bleeding risks in patients with recent ACS who may require urgent CABG.

RECOMMENDATIONS

1. All ACS patients should be considered for dual antiplatelet therapy with ASA and clopidogrel at the earliest opportunity, despite the possibility of a need for urgent CABG. 2. For patients who have received clopidogrel and ASA, and require CABG: * Those at high risk of an early fatal event (eg, with refractory ischemia despite optimal medical treatment, and with high-risk coronary anatomy (eg, severe left main stenosis with severe right coronary artery disease), should be considered for early surgery without discontinuation of clopidogrel. * In patients with a high bleeding risk (eg, previous surgery, complex surgery) who are also at high risk for an ischemic event, consideration should be given to discontinuing clopidogrel for three to five days before surgery. * Patients at a lower risk for ischemic events (most patients) should have clopidogrel discontinued five days before surgery. 3. For patients who have CABG within five days of receiving clopidogrel and ASA, the risk of major bleeding and transfusion can be minimized by applying multiple strategies before and during surgery. 4. Patients who receive clopidogrel pre-CABG for a recent ACS indication should have clopidogrel restarted after surgery to decrease the risk of recurrent ACS. 5. For patients with a recent coronary stent, the decision to continue clopidogrel until the time of surgery or to discontinue will depend on the risk and potential impact of stent thrombosis. Restarting clopidogrel after CABG will depend on whether the stented vessel was revascularized, the type of stent and the time from stent implantation. Clopidogrel should be restarted when hemostasis is assured to prevent recurrent acute ischemic events.

Blood coagulation: hemostasis and thrombin regulation

Perioperative bleeding is a major challenge particularly because of increasing clinical use of potent antithrombotic drugs. Understanding current concepts of coagulation is important in determining the preoperative bleeding risk of patients, and in managing hemostatic therapy perioperatively. The serine protease thrombin plays pivotal roles in the activation of additional serine protease zymogens (inactive enzymatic precursors), cofactors, and cell-surface receptors. Thrombin generation is closely regulated to locally achieve rapid hemostasis after injury without causing uncontrolled systemic thrombosis. During surgery, there are major disturbances in coagulation and inflammatory systems because of hemorrhage/hemodilution, blood transfusion, and surgical stresses. Postoperative bleeding often requires allogeneic blood transfusions, which support thrombin generation and hemostasis. However, procoagulant activity and inflammation are increased postoperatively; thus, antithrombotic therapy may be required to prevent perioperative thrombotic complications. There have been significant advances in the management of perioperative hemostasis and thrombosis because of the introduction of novel hemostatic and antithrombotic drugs. However, a limitation of current treatment is that conventional clotting tests do not reflect the entire physiological processes of coagulation making optimal pharmacologic therapy difficult. Understanding the in vivo regulatory mechanisms and pharmacologic modulation of thrombin generation may help control bleeding without potentially increasing prothrombotic risks. In this review, we focus on the regulatory mechanisms of hemostasis and thrombin generation using multiple, simplified models of coagulation.

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.

Prevention of premature discontinuation of dual antiplatelet therapy in patients with coronary artery stents: a science advisory from the American Heart Association, American College of Cardiology, Society for Cardiovascular Angiography and Interventions, American College of Surgeons, and American Dental Association, with representation from the American College of Physicians

Dual antiplatelet therapy with aspirin and a thienopyridine has been shown to reduce cardiac events after coronary stenting. However, many patients and healthcare providers prematurely discontinue dual antiplatelet therapy, which greatly increases the risk of stent thrombosis, myocardial infarction, and death. This advisory stresses the importance of 12 months of dual antiplatelet therapy after placement of a drug-eluting stent and educating the patient and healthcare providers about hazards of premature discontinuation. It also recommends postponing elective surgery for 1 year, and if surgery cannot be deferred, considering the continuation of aspirin during the perioperative period in high-risk patients with drug-eluting stents.

A caution regarding the use of low-molecular weight heparin in pediatric otogenic lateral sinus thrombosis

Lateral sinus thrombosis (LST), a rare complication of otitis media, is managed by antibiotics, surgery and anticoagulation. Traditionally, post-operative anticoagulation has been achieved by intravenous unfractionated heparin followed by oral warfarin. Fractionated, or low-molecular weight heparin derivatives (LMWH) have been introduced recently. There has been minimal literature to date regarding their use for the management of LST. We present use of the LMWH enoxaparin (Lovenox) for otogenic LST in two children, both of whom experienced hemorrhagic complications. On this basis and in the context of a literature review, we urge caution when using LMWH for pediatric otogenic LST.

Prevention of premature discontinuation of dual antiplatelet therapy in patients with coronary artery stents: a science advisory from the American Heart Association, American College of Cardiology, Society for Cardiovascular Angiography and Interventions, American College of Surgeons, and American Dental Association, with representation from the American College of Physicians

Dual antiplatelet therapy with aspirin and a thienopyridine has been shown to reduce cardiac events after coronary stenting. However, many patients and healthcare providers prematurely discontinue dual antiplatelet therapy, which greatly increases the risk of stent thrombosis, myocardial infarction, and death. This advisory stresses the importance of 12 months of dual antiplatelet therapy after placement of a drug-eluting stent and educating the patient and healthcare providers about hazards of premature discontinuation. It also recommends postponing elective surgery for 1 year, and if surgery cannot be deferred, considering the continuation of aspirin during the perioperative period in high-risk patients with drug-eluting stents.

Prevention of premature discontinuation of dual antiplatelet therapy in patients with coronary artery stents: A science advisory from the American Heart Association, American College of Cardiology, Society for Cardiovascular Angiography and Interventions, American College of Surgeons, and American Dental Association, with representation from the American College of Physicians

Dual antiplatelet therapy with aspirin and a thienopyridine has been shown to reduce cardiac events after coronary stenting. However, many patients and healthcare providers prematurely discontinue dual antiplatelet therapy, which greatly increases the risk of stent thrombosis, myocardial infarction, and death. This advisory stresses the importance of 12 months of dual antiplatelet therapy after placement of a drug-eluting stent and educating the patient and healthcare providers about hazards of premature discontinuation. It also recommends postponing elective surgery for 1 year, and if surgery cannot be deferred, considering the continuation of aspirin during the perioperative period in high-risk patients with drug-eluting stents.

Red blood cell transfusions in patients undergoing lower extremity artery bypass surgery

BACKGROUND AND AIMS

The purpose of this study was to search predictors of red blood cell transfusions in peripheral vascular surgical patients.

MATERIAL AND METHODS

All the patients who undergone infrainguinal bypass surgery at Helsinki University Hospital in the year 2000 were included. Of 266 records 261 (98%) were available for data review. Multiple stepwise regression model was created to identify independent predictors of blood use.

RESULTS AND CONCLUSIONS

174 (67%) of the patients received red blood cell transfusion. The lowest measured mean (SD) haemoglobin was 94 (11) g/l intraoperatively and 92 (+/- 10) g/l on the first two postoperative days. The median (range) number of units was 3 (1-19). Multivariate analysis showed that high age (p = 0.019), small body surface area (p = 0.017), low preoperative haemoglobin (p < 0.001), blood loss (p < 0.001), long lasting surgery (p<0.001), reoperation (p=0.018), femoro-distal reconstruction (p=0.048) and chronic obstructive pulmonary disease (p = 0.023) increased the risk to receive red blood cell transfusion. The frequent use of antithrombotic medication (72% of the patients) did not significantly increase red blood cell administration. The generous use of red blood cells despite relative safe haemoglobin levels indicates a need for a standardized multidisciplinary transfusion strategy in this patient population. Otherwise, most of the predictors for red blood cell administration were nonmodifiable.