Antiplatelet agents and perioperative bleeding

Acquired bleeding disorders through antithrombotic therapy: the implications for dental practitioners

Antithrombotic medications are one of the most common causes of an acquired bleeding disorder. The majority of these medications are administered orally for a variety of clinical indications. It is important that dental surgeons are aware of these medications, their mechanisms of action and how they can influence the dental management of patients, particularly when undertaking procedures which carry a risk of bleeding.

Perioperative dual antiplatelets management for ventriculoperitoneal shunt operation in patients with hydrocephalus after stent-assisted coil embolization of the ruptured intracranial aneurysm

OBJECTIVE

Ventriculoperitoneal shunt (VPS) surgery is sometimes necessary in patients who present with symptomatic hydrocephalus after undergoing stent-assisted coil embolization of ruptured intracranial aneurysms. However, there are no guidelines for the perioperative management of VPS using dual antiplatelet therapy (DAPT) and balancing between the thromboembolic and hemorrhagic complications. Studies regarding discontinuation of DAPT and its substitution with a less potent drug for reducing the risk of hemorrhage have been previously attempted; however, the sample size in these studies was small. This study investigates the safety and feasibility of ibuprofen bridging therapy with discontinuation of DAPT for five days in patients who have recently received a neurovascular stent and require VPS.

METHODS

Forty-one patients, who were administered DAPT after neurovascular stent placement and later underwent VPS, were retrospectively enrolled. Patients were divided into two groups based on the perioperative DAPT therapy: (1) Bridge: discontinuing DAPT and substituting it with ibuprofen 600 mg bid for five days, and (2) Continue: maintaining DAPT during surgery. The groups were compared and risk factors for hemorrhagic complication were investigated.

RESULTS

On comparison analysis, no ischemic complications were observed in both groups; however, hemorrhagic complications were significantly higher in the continue than in the bridge group (p = 0.004). On multivariate logistic regression analysis, "ibuprofen bridging" was identified as a significant factor negatively associated with hemorrhagic complications (p = 0.019).

CONCLUSION

"Ibuprofen bridging therapy with discontinuation of DAPT for 5 days" is a potential treatment strategy for patients having recently undergone neurovascular stent placement and are scheduled for VPS surgery.

Association of Continued Preoperative Aspirin Use and Bleeding Complications in Patients Undergoing Thyroid Surgery

Importance

No evidence exists to direct the management of preoperative aspirin (acetylsalicylic acid) use in patients undergoing thyroid surgery. Nevertheless, a considerable number of patients interrupt receiving aspirin therapy during the preoperative period to minimize bleeding complications despite the increased risk of experiencing major adverse cardiac events.

Objective

To determine whether aspirin therapy continued preoperatively increases bleeding complications in patients undergoing thyroid surgery.

Design, Setting, and Participants

Retrospective analysis of a consecutive sample of 570 patients, aged 18 to 100 years, who underwent thyroid surgery for benign and malignant disease from January 1, 2010, to December 31, 2015, by a single surgeon at a tertiary referral hospital center in New Orleans, Louisiana.

Exposures

Patients receiving aspirin therapy and patients not receiving aspirin therapy (aspirin naive) preoperatively.

Main Outcomes and Measures

Comparison of estimated blood loss, substantial blood loss, operative hematoma, nonoperative hematoma, and recurrent laryngeal nerve injury.

Results

Of 570 patients who underwent thyroid surgery, 106 (18.6%) were performed in patients receiving aspirin; of these, 23 (21.7%) were men and 105 (99.1%) were older than 45 years. Those receiving aspirin therapy displayed a 14.4-year difference in age (95% CI, 11.6-17.1). The aspirin group displayed a 20.3% absolute increase (95% CI, 9.3-30.7) in African American patients. Aspirin therapy was not associated with a statistically significant or clinically meaningful increase in intraoperative blood loss (2.5 mL; 95% CI, -0.4 to 5.3). Aspirin therapy was associated with a statistically significant increase in total hematoma formation (3.3%; 95% CI, 0.4-9.0), but the results were inconclusive. Aspirin therapy was not associated with a statistically significant increase in recurrent laryngeal nerve injury (2.6%; 95% CI, -1.1 to 8.6), but the results were inconclusive.

Conclusions and Relevance

These results suggest that aspirin therapy can be maintained prior to thyroid surgery without increased intraoperative bleeding. Further research with a larger sample size and more outcome events are required to make definitive conclusions regarding the association between aspirin use and complications, including hematoma and recurrent laryngeal nerve injury.

Regional Anesthesia in Patients of Aged 99 Years in Clopidogrel Use

The risk of neuraxial block in patients treated with antiplatelet drugs are uncertain. Elderly patients often have low physiological reserve, delaying surgery can lead to a high rate of morbidity and mortality. The aim of this paper is to present a case of a patient with 99 years using clopidogrel undergoing regional anesthesia for surgical treatment of hip fracture without complications.

Dual anti-platelet therapy and dento-alveolar surgery. How do we manage patients on anti-platelet medication?

OBJECTIVE

The optimum management of dual anti-platelet therapy (DAPT) in patients undergoing dentoalveolar surgery is controversial. The lack of guidelines has meant clinicians have been left to manage these cases from specialist advice or past experience. In view of this the British Association of Oral Surgeons (BAOS) membership was surveyed to assess current practice.

DESIGN

An electronic survey consisting of nine closed multiple-choice questions was circulated to all 435 registered BAOS members. A section for open comments was also included. The data was transcribed, organised and reduced to themes by hand and finally analysed.

RESULTS

One hundred and eighty members completed the questionnaire giving a response rate of 41%. Ninety-two percent of clinicians had direct involvement in managing patients on DAPT and of these 80% had not encountered a bleeding complication. DAPT was continued for simple dental extraction under local anaesthetic by 83% of respondents and 73% for surgical extractions. Two thirds of the respondents did not follow any guidelines but for those that did the most common was the UK Medicines Information protocols. Only 10% of respondents reported a significant post-operative bleeding complication following surgery in patients on DAPT.

CONCLUSION

This survey confirmed the continued variable management of patients on DAPT undergoing dentoalveolar surgery. Reported bleeding rates were low with over 75% of patients not having their DAPT treatment interrupted.

Perioperative management of a patient with recently placed drug-eluting stents requiring urgent spinal surgery

Patients receiving drug-eluting coronary stents (DES) require antiplatelet therapy for at least 12 months to prevent stent thrombosis (ST), a potentially calamitous event. Since interruption of antiplatelet therapy is the greatest risk factor for ST, it is imperative that the decision to discontinue these agents be based on an accurate assessment of the patient's risk for bleeding complications. Individuals who are regarded as being at a high risk are those undergoing intracranial, spinal or intraocular surgeries. These patients require alternative agents during the perioperative period to minimize both their risk of perioperative thrombosis and intraoperative hemorrhage. We report the case of a woman who required spinal surgery 3 months after she underwent placement of two drug-eluting stents. The patient's clopidogrel was stopped 5 days prior to surgery and an infusion of eptifibatide was used to "bridge" antiplatelet therapy during the perioperative period. Postoperatively, anticoagulation therapy was reinstituted using aspirin with clopidogrel. This case serves as a successful example of bridging therapy using a short acting and gycoprotein (GP) IIb/IIIa inhibitor as a means of maintaining antiplatelet therapy during the perioperative period to minimize the risk of stent thrombosis and the risk of intraoperative bleeding.

Perioperative management of a neurosurgical patient requiring antiplatelet therapy

In patients who undergo neurovascular stent placement with postoperative dual antiplatelet therapy to prevent in-stent thrombosis, there is no protocol for balancing the risk of acute stent thrombosis and bleeding if urgent neurosurgical procedures are required. We detail perioperative management of dual antiplatelet therapy in a 66-year-old man with a dolichoectatic aneurysm of the basilar artery treated with a Pipeline stent. Postoperatively, the patient was placed on aspirin and clopidogrel to prevent in-stent thrombosis. One month after the procedure, his neurological status declined secondary to obstructive hydrocephalus. His condition necessitated urgent placement of a ventriculoperitoneal shunt, despite the dual antiplatelet therapy for the flow-diverting Pipeline stent. Aspirin and clopidogrel were discontinued seven days prior to the planned shunt placement. To minimize time off antiplatelet therapy, aspirin was immediately replaced with ibuprofen. Eptifibatide was then started three days prior to surgery. The ibuprofen/eptifibatide bridge was discontinued at midnight prior to surgery. Aspirin was restarted on the first postoperative day and clopidogrel was restarted on the second postoperative day. The patient tolerated shunt placement without excessive bleeding or hemorrhagic complications. During the remainder of his hospital course, no evidence of stent thrombosis or intracranial hemorrhage was noted. We conclude that management of antiplatelet prophylaxis for neurovascular stent thrombosis in patients requiring urgent neurosurgical procedures may be successfully achieved by bridging aspirin and clopidogrel with ibuprofen and eptifibatide in the preoperative period.

Perioperative antiplatelet management in patients with coronary artery stenting

Coronary artery disease is the primary cause of mortality in men and women in the United States. Transcatheter coronary intervention is the mainstay of treatment for patients with acute coronary artery disease presentations and patients with stable disease. Although percutaneous intervention initially only included balloon angioplasty, it now typically involves the placement of intracoronary stents. To overcome the limitations of bare-metal stents, namely in-stent restenosis, stents have been developed that remove pharmaceuticals that reduce neointimal hyperplasia and in-stent restenosis. However, these pharmaceutical agents also delay stent endothelialization, posing a prolonged risk of in situ thrombosis. Placement of an intracoronary stent (eg, bare-metal or drug-eluting stent) requires dual antiplatelet therapy to prevent the potentially life-threatening complication of stent thrombosis. The optimal duration of dual antiplatelet therapy following stent placement is unknown. This article discusses the factors to be considered when deciding when dual antiplatelet therapy can be safely discontinued. Unfortunately, in the hospital setting, this decision to interrupt dual antiplatelet therapy frequently must be made shortly after stent placement because of unanticipated surgical procedures or other unforeseen complications. The decision of when dual antiplatelet therapy can be safely interrupted needs to be individualized for each patient and involves factoring in the type of stent; the location and complexity of the lesion stented; post-stent lesion characteristics; the amount of time since stent placement; and the antiplatelet regimen currently in use, along with its implication for bleeding during the proposed procedure. Having a protocol in place, such as the protocol described in this article, can help guide this decision-making process and avoid confusion and potential error.

Blood component support in acquired coagulopathic conditions: is there a method to the madness?

Acquired coagulopathies are often detected by laboratory investigation in clinical practice. There is a poor correlation between mild to moderate abnormalities of laboratory test and bleeding tendency. Patients who are bleeding due to coagulopathy are often managed with various blood components including plasma, platelets, and cryoprecipitate. However, prophylactic transfusion of these products in a nonbleeding patient to correct mild to moderate abnormality of a coagulation test especially preprocedure is not evidence-based. This article reviews the management of bleeding due to oral anticoagulants and antiplatelet agents, disseminated intravascular coagulation, chronic liver disease, and trauma.

Massive Bleeding and Massive Transfusion

Massive bleeding in trauma patients is a serious challenge for all clinicians, and an interdisciplinary diagnostic and therapeutic approach is warranted within a limited time frame. Massive transfusion usually is defined as the transfusion of more than 10 units of packed red blood cells (RBCs) within 24 h or a corresponding blood loss of more than 1- to 1.5-fold of the body's entire blood volume. Especially male trauma patients experience this life-threatening condition within their productive years of life. An important parameter for clinical outcome is to succeed in stopping the bleeding preferentially within the first 12 h of hospital admission. Additional coagulopathy in the initial phase is induced by trauma itself and aggravated by consumption and dilution of clotting factors. Although different aspects have to be taken into consideration when viewing at bleedings induced by trauma compared to those caused by major surgery, the basic strategy is similar. Here, we will focus on trauma-induced massive hemorrhage. Currently there are no definite, worldwide accepted algorithms for blood transfusion and strategies for optimal coagulation management. There is increasing evidence that a higher ratio of plasma and RBCs (e.g. 1:1) endorsed by platelet transfusion might result in a superior survival of patients at risk for trauma-induced coagulopathy. Several strategies have been evolved in the military environment, although not all strategies should be transferred unproven to civilian practice, e.g. the transfusion of whole blood. Several agents have been proposed to support the restoration of coagulation. Some have been used for years without any doubt on their benefit-to-risk profile, whereas great enthusiasm of other products has been discouraged by inefficacy in terms of blood transfusion requirements and mortality or significant severe side effects. This review surveys current literature on fluid resuscitation, blood transfusion, and hemostatic agents currently used during massive hemorrhage in order to optimize patients' blood and coagulation management in emergency medical aid.

Antiplatelet therapy in ENT surgery: a review

INTRODUCTION

Antiplatelet agents such as aspirin and clopidogrel are increasingly encountered in clinical practice. Otorhinolaryngological surgeons are involved in the peri-operative decision of whether to continue treatment and risk haemorrhage or to discontinue treatment and risk thrombosis.

METHODS

Literature relating to the risk of spontaneous or operative haemorrhage was reviewed. The morbidity and mortality associated with cessation of agents was evaluated. Published guidelines were also evaluated. A protocol for the management of antiplatelet agents in the peri-operative period, with particular reference to ENT operations, is presented.

CONCLUSION

SIGNIFICANT morbidity and mortality is associated with the premature cessation of antiplatelet agents. Data from cardiac surgery suggest that operative blood loss only marginally increases in patients on aspirin and clopidogrel. However, the management of antiplatelet agents in the peri-operative period should be made after multidisciplinary consultation.

Duration of dual antiplatelet therapy after percutaneous coronary intervention with drug-eluting stent implantation: a review of the current guidelines and literature

Dual antiplatelet therapy is the mainstay of medical treatment after percutaneous coronary intervention regarding the risk of stent thrombosis occurrence. Since the beginning of the stenting era, antiplatelet regimens have evolved according to the emerging and widespread diffusion of new devices and more challenging indications for their use. In the past years, concerns have been raised about the safety of drug-eluting stent implantation with regard to late and very late stent thrombosis. Thus, the length of dual antiplatelet therapy has been progressively increased with marked individual and local differences. However, prolonged antiplatelet therapy leads to increased risk of bleeding, especially in the setting of surgical procedures, traumas, and/or other diseases. To date, the exact duration of dual antiplatelet therapy after drug-eluting stent implantation is still debated in the literature. The aim of this article is to review the literature and the current guidelines on the risks and benefits of pursuing dual antiplatelet therapy after percutaneous coronary intervention with drug-eluting stent implantation.

Perioperative management of antiplatelet-drugs in cardiac surgery

The management of coronary patients scheduled for a coronary artery bypass grafting (CABG), who are receiving one or more antiplatelet drugs, is plenty of controversies. It has been shown that withdrawal of antiplatelet drugs is associated with an increased risk of a thrombotic event, but surgery under an altered platelet function also means an increased risk of bleeding in the perioperative period. Because of the conflict recommendations, this review article tries to evaluate the outcome of different perioperative antiplatelet protocols in patients with coronary artery disease undergoing CABG.

A randomised controlled trial to evaluate and optimize the use of antiplatelet agents in the perioperative management in patients undergoing general and abdominal surgery--the APAP trial (ISRCTN45810007)

Background

Due to the increase of cardiovascular diseases acetylsalicylic acid (ASA) has become one of the most frequently prescribed drugs these days. Despite the rising number of patients with ASA medication presenting for elective general and abdominal surgery and the potentially increased risk of hemorrhage in these patients, there are no clear, evidence-based guidelines for the perioperative use of antiplatelet agents. The present randomised controlled trial was designed to evaluate the safety and optimize the use of ASA in the perioperative management of patients undergoing general and abdominal surgery.

Methods/Design

This is a two-arm, monocenter randomised controlled trial. Patients scheduled for elective surgical treatment (i.e. inguinal hernia repair, cholecystectomy and colorectal resections) with ASA as a permanent medication are randomised equally to perioperative continuation or discontinuation of ASA. Patients who are randomised in the discontinuation group stop the administration of ASA five days prior to surgical treatment and start intake of ASA on postoperative day 5. Fifty-two patients will be enrolled in this trial. The primary outcome is the incidence of postoperative bleeding and cardiovascular events at 30 days after surgery. In addition a set of general as well as surgical variables are analysed.

Discussion

This is a randomised controlled two-group parallel trial designed to assess the safety and optimize the use of ASA in the perioperative management of patients undergoing general and abdominal surgery. The results of this pilot study build the basis for a confirmative randomised controlled trial that may help to clarify the use and potential risk/benefits of perioperative ASA medication in patients undergoing elective surgery.

Trial registration

The trial is registered with Current Controlled Trials ISRCTN45810007.

Peri-operative management of anti-platelet agents and anti-thrombotic agents in geriatric patients undergoing semi-urgent hip fracture surgery

Hip fractures are common events in the geriatric population and are often associated with significant morbidity and mortality. Over the coming decades, the size of the greying population is forecast to increase and hence, the annual incidence of hip fracture is expected to rise substantially. Several studies have shown that hip fracture surgery performed within 24 to 48 h of hospitalisation significantly reduces mortality. Medical specialists including cardiologists are often involved in the care of these geriatric patients as most of them have comorbid conditions that must be managed concomitantly with their fracture. Cardiovascular and thromboembolic complications are among some of the commonest adverse events that could be experienced by these elderly patients during hospitalisation. We review in this article the current recommendations and controversies on the peri-operative management of anti-platelet agents and anti-thrombotic agents in geriatric patients undergoing semi-urgent hip fracture surgery.

The Management of Antiplatelet Therapy in Patients With Coronary Stents Undergoing Noncardiac Surgery

Whereas the development of coronary stents has been a major breakthrough in the treatment of coronary artery disease, stent thrombosis, associated with myocardial infarction and death, has introduced a new challenge in the care of patients with coronary stents undergoing noncardiac surgery. This review presents the authors’ recommendations regarding the optimal management of such patients. Elective surgery should be postponed for at least 6 weeks and optimally 3 months for a bare-metal stent and at least 1 year for a drug-eluting stent. On the other hand, managing a patient undergoing non-elective surgery is more difficult and necessitates a case-by-case assessment of bleeding risk versus thrombotic risk based on patient comorbidities, type of stents present, details of the coronary intervention, and type of surgical procedure. Patients with a risk of bleeding that outweighs the risk of stent thrombosis should discontinue at least clopidogrel, whereas all other patients should continue dual antiplatelet therapy throughout the perioperative period.

Prevention of the renarrowing of coronary arteries using drug-eluting stents in the perioperative period: an update

The management of patients scheduled for surgery with a coronary stent, and receiving 1 or more antiplatelet drugs, has many controversies. The premature discontinuation of antiplatelet drugs substantially increases the risk of stent thrombosis (ST), myocardial infarction, and cardiac death, and surgery under an altered platelet function could also lead to an increased risk of bleeding in the perioperative period. Because of the conflict in the recommendations, this article reviews the current antiplatelet protocols after positioning a coronary stent, the evidence of increased risk of ST associated with the withdrawal of antiplatelet drugs and increased bleeding risk associated with its maintenance, the different perioperative antiplatelet protocols when patients are scheduled for surgery or need an urgent operation, and the therapeutic options if excessive bleeding occurs.

Early antiplatelet therapy in coronary artery bypass grafting: a calculated benefit

Studies have demonstrated that antagonists of platelet activity, including aspirin and clopidogrel, reduce the risk of major adverse events in patients with acute coronary syndromes. Although antiplatelet agents also convey an increased risk of bleeding, particularly in patients proceeding to coronary artery bypass graft surgery, in most cases, the benefits of early initiation of antiplatelet therapy outweigh the risks. The purpose of this review is to distinguish perceived and actual risk versus the benefit associated with early antiplatelet therapy to help clinicians make informed decisions on using these agents in an acute setting where patients may require coronary artery bypass grafting.

Coagulation concepts update

OBJECTIVE

Since the previous comprehensive radiology review on coagulation concepts that was done in 1990, many studies have been published in the medical and surgical literature that can guide the approach of a radiology practice. The purpose of this article is to provide an analysis of these works, updating the radiologist on proper use and interpretation of coagulation assessment tools, medications that modify the hemostatic system, and the use of transfusions prior to interventions.

CONCLUSION

The basic tools for coagulation assessment have not changed; however, results from subspecialty research have suggested ways in which the use of these tools can be modified and streamlined to safely reduce time and expense for the patient and the health care system.

[Antiplatelet agents and anticoagulants: management of the anticoagulated surgical patient]

Among the drugs most widely consumed by patients are both antiplatelet agents (aspirin, clopidogrel, ticlopidine) and anticoagulants (acenocoumarol, warfarin, low molecular weight heparin, fondaparinux). The use of these drugs in the perioperative period is an essential concern in patient care due to the need to balance the risk of bleeding against thrombotic risk (arterial or venous), which is increased in surgical patients. The present review highlights three main aspects. Firstly, withdrawal of antiplatelet agents is recommended between 1 week and 10 days before surgery to minimize perioperative bleeding. However, this practice has been questioned because patients without the required antiplatelet coverage may be at greater risk of developing cardiac, cerebral or peripheral vascular complications. Therefore, the recommendation of systematic antiplatelet withdrawal for a specific period should be rejected. Currently, risks should be evaluated on an individual basis to minimize the time during which the patient remains without adequate antiplatelet protection. Secondly, thromboprophylaxis is required in most surgical patients due to the high prevalence of venous thromboembolic disease. This implies the use of anticoagulants and the practice of regional anesthesia has been questioned in these patients. However, with the safety recommendations established by the various scientific societies, this practice has been demonstrated to be safe. Finally, "bridge therapy" in patients anticoagulated with acenocoumarol should be performed on an individual basis rather than systematically without taking into account the thrombotic risks of each patient. The perioperative period involves high arterial and venous thrombotic risk and the optimal use of antiplatelet agents and anticoagulants should be a priority to minimize this risk without increasing hemorrhagic risk. Multidisciplinary consensus is essential on this matter.

Perioperative management of antiplatelet agents in noncardiac surgery

It is common that patients who are scheduled for surgery are treated with antiplatelet agents (APAs) due to their wide indications. The management of these APAs in the perioperative period (acetylsalicylic acid alone, a thienopyridine alone or, in most cases, a combination of them) has a dual perspective: the risk of bleeding when the patient is operated under the effect of the APA against the risk of thrombosis if it has been withdrawn. The main challenges for the anaesthesiologist and the surgeon include patients with a coronary stent (mainly, new drug-eluting coronary stents), those undergoing urgent surgery and those undergoing high bleeding risk surgery. We review current protocols and discuss the most recent proposals for the management of APAs in patients undergoing noncardiac surgery. Current recommendations include the maintenance of aspirin if possible throughout the perioperative period, in order to limit the risks of cardiological, vascular or neurological postoperative events, although this makes it necessary to assume a small risk for haemorrhagic complications in some patients. Nevertheless, there are many circumstances that are not clear yet and, in this situation, it is crucial that patients are treated with a multidisciplinary approach (anaesthesiologists, surgeons, cardiologists and haematologists).

Laboratory assessment and perioperative management of patients on antiplatelet therapy: from the bench to the bedside

The contribution of platelets in the pathophysiology of thromboses has established antiplatelet therapy as a cornerstone for prevention or treatment of these disorders. However, patients on antiplatelet drugs undergoing surgery face the life-threatening dilemma between the risk of perioperative thrombosis by ceasing therapy and restoring platelet function versus the risk of surgical bleeding by its continuation. According to their mechanism of action, antiplatelet drugs can be conventionally classified as agents that inhibit cyclooxygenase, block the platelet adenosine diphosphate P2Y12 receptor, inhibit phosphodiesterase, or block platelet glycoprotein IIb/IIIa. Although several tests have been developed to assess platelet inhibition by most of these compounds, studies to date have not been able to reliably evaluate the diagnostic efficiency of these tests to predict hemorrhage and/or blood loss, and accordingly perioperative assessment of drug-induced platelet inhibition cannot be recommended as yet. Although several management options are available to counteract the hemorrhagic risk of surgical patients using antiplatelet agents, perioperative discontinuation of these drugs is the preferable choice wherever possible. The use of platelet transfusions should be limited where necessary to the treatment of major, life-threatening bleeding. The contribution of newer hemostatic agents, such as desmopressin and recombinant activated factor VII, is yet to be fully determined, and there remain many challenges and unresolved issues in the clinical care of these patients.

Clopidogrel and Bleeding after General Surgery Procedures

Although many studies in the cardiothoracic literature exist about the relationship between clopidogrel and postoperative bleeding, there is scarce data in the general surgery literature. We assessed whether there are increased bleeding complications, morbidity, mortality, and resource utilization in patients who are on clopidogrel (Plavix®) within 1 week before undergoing a general surgery procedure. Fifty consecutive patient charts were retrospectively reviewed after identifying patients who had pharmacy orders for clopidogrel and who underwent a general surgery procedure between 2003 and 2007. Patients who took clopidogrel within 6 days before surgery (group I, n = 28) were compared with patients who stopped clopidogrel for 7 days or more (group II, n = 22). A larger percentage of patients who took their last dose of clopidogrel within 1 week of surgery (21.4% vs 9.5%) had significant bleeding after surgery requiring blood transfusion. However, there were no significant differences between the groups in operative or postoperative blood transfusions ( P = 0.12, 0.53), decreases in hematocrit ( P = 0.21), hospital stay ( P = 0.09), intensive care unit stay ( P = 0.41), late complications ( P = 0.45), or mortality ( P = 0.42). Although our cohort is limited in size, these results suggest that in the case of a nonelective general surgery procedure where outcomes depend on timely surgery, clopidogrel taken within 6 days before surgery should not be a reason to delay surgery. However, careful attention must be paid to meticulous hemostasis, and platelets must be readily available for transfusion in the operating room.

Antiplatelet therapy for postdischarge medical management of acute coronary syndrome

Postdischarge management of patients with acute coronary syndrome is often suboptimal, despite their high risk of a subsequent event. Updated American College of Cardiology/American Heart Association guidelines emphasize the need for aggressive modification of risk factors and treatment with antiplatelet, antihypertensive, and lipid-lowering agents commenced in-hospital and continued long-term. Antiplatelet therapy involving aspirin and clopidogrel is the mainstay of secondary risk reduction. Increased adherence to medication and risk factor modification at discharge has been demonstrated with acute care quality improvement initiatives. Extension of these initiatives to postdischarge care will provide data on medication adherence post acute coronary syndrome and functional outcomes in the community setting. Successful secondary prevention of cardiovascular events requires implementation of evidence-based guidelines by physicians, and adherence to pharmacotherapy and lifestyle modifications by patients. Primary care physicians are well placed to influence adherence through their ongoing relationships with patients and can save lives by implementing secondary risk reduction measures after discharge.

[Anesthetic management in a patient previously diagnosed with takotsubo cardiomyopathy]

Takotsubo cardiomyopathy (transient apical ballooning of the left ventricle) is a recently described and often underdiagnosed entity. The syndrome is observed predominately in postmenopausal women and the clinical signs are similar to those of an acute anterior myocardial infarction. In most of the reported cases an emotional or physical stress event has been identified as a trigger, and perioperative stress has been suggested as the trigger in some of these cases. Outcome is favorable with the right treatment, though recurrences are possible. We report the anesthetic management of a 79-year-old woman with a previously diagnosed episode of Takotsubo cardiomyopathy, who was admitted to our hospital for total hip replacement. Care was taken to provide proper preoperative sedation before provision of hyperbaric spinal anesthesia, followed by sedation with intravenous propofol. Surgery and the early postoperative period were uneventful. We believe that minimizing perioperative anxiety should be a priority in these patients due to the possibility that a catecholamine discharge might trigger an episode of Takotsubo cardiomyopathy.

Antiplatelet therapy in patients undergoing coronary stent implantation: Italian Society of Interventional Cardiology consensus document

The Italian Society of Interventional Cardiology is aware of the existence of significant local and individual disparities and discordant prescriptions in antiplatelet therapy administered with coronary stents, a critical issue due to the large use of drug-eluting stents (DES), the increasing complexity of percutaneous coronary interventions and the more stringent requirement to avoid stent thrombosis. Current percutaneous coronary intervention is attempting more aggressively to treat difficult lesions and patient cohorts with a high procedural success rate. Double antiplatelet therapy with aspirin (ASA) and thienopyridine is the best current treatment to reduce the risk of coronary stent thrombosis. Due to the lower incidence of side-effects compared to ticlopidine, clopidogrel should be the thienopyridine of choice in association with ASA in the double antiplatelet regimen. However, the combination of delayed healing with DES and the increasing complexity of the stent implantation raises more demanding safety concerns about the dosage and duration of dual antiplatelet therapy.

Risk of massive upper gastrointestinal bleeding in gastric bypass patients taking clopidogrel

BACKGROUND

The antiplatelet drug clopidogrel (Plavix) is widely used in patients who have undergone coronary artery stenting or had a stroke. Because morbid obesity is associated with atherosclerosis, some of these patients are candidates for weight loss surgery. We chose to determine the risk of upper gastrointestinal bleeding after gastric bypass in patients taking clopidogrel.

METHODS

Patients who took clopidogrel after gastric bypass were identified by specific review of the subset of patients who had had upper gastrointestinal bleeding requiring hospital admission and transfusion. All who bled underwent emergency endoscopy.

RESULTS

Of 11 patients taking clopidogrel, 4 (36%) presented with significant upper gastrointestinal bleeding 25-234 days after gastric bypass. All stopped bleeding with discontinuation of the drug and treatment with an intravenous proton pump inhibitor.

CONCLUSION

Gastric bypass patients appear to be at high risk of bleeding complications when taking clopidogrel. On the basis of the available published data from another high-risk group (i.e., those with a history of peptic ulcer disease), co-treatment with omeprazole may be indicated when clopidogrel must be continued.

Koronare Stents, duale Antiplättchentherapie und die perioperative Problematik

Up to 90% of all percutaneous coronary interventions include coronary artery stenting. Dual antiplatelet therapy, usually involving acetylsalicyl acid combined with clopidogrel, is mandatory for patients with coronary artery stents. The duration of antiplatelet therapy for bare metal stents is 3-4 weeks, for drug eluting stents 6-12 months. Preoperative discontinuation of both drugs increases the risk of stent thrombosis, continuation the risk of relevant bleeding. According to the recommendations of anaesthesiological and cardiological societies, perioperative management has to balance the risk of bleeding vs stent thrombosis. Surgery involving a high risk of bleeding can require the discontinuance of both substances. In cases of high thrombosis risk, at least the acetylsalicyl acid should be continued until the day of surgery. For patients under antiplatelet therapy scheduled for local anaesthesia, national recommendations exist. A close collaboration between the anaesthesiologist, cardiologist and surgeon is essential for appropriate pre-, intra- and postoperative management.

Bcl-2 family proteins are essential for platelet survival

Platelets are relatively short-lived, anucleated cells that are essential for proper hemostasis. The regulation of platelet survival in the circulation remains poorly understood. The process of platelet activation and senescence in vivo is associated with processes similar to those observed during apoptosis in nucleated cells, including loss of mitochondrial membrane potential, caspase activation, phosphatidylserine (PS) externalization, and cell shrinkage. ABT-737, a potent antagonist of Bcl-2, Bcl-X(L), and Bcl-w, induces apoptosis in nucleated cells dependent on these proteins for survival. In vivo, ABT-737 induces a reduction of circulating platelets that is maintained during drug therapy, followed by recovery to normal levels within several days after treatment cessation. Whole body scintography utilizing ([111])Indium-labeled platelets in dogs shows that ABT-737-induced platelet clearance is primarily mediated by the liver. In vitro, ABT-737 treatment leads to activation of key apoptotic processes including cytochrome c release, caspase-3 activation, and PS externalization in isolated platelets. Despite these changes, ABT-737 is ineffective in promoting platelet activation as measured by granule release markers and platelet aggregation. Taken together, these data suggest that ABT-737 induces an apoptosis-like response in platelets that is distinct from platelet activation and results in enhanced clearance in vivo by the reticuloendothelial system.