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.     

Der Patient mit Koronarstent

Nowadays stents are implanted in over 90% of percutaneous coronary interventions. Depending on the type of stent implanted, dual antiplatelet therapy combining a cyclooxygenase inhibitor such as acetylsalicylic acid and an adenosine diphosphate receptor antagonist (thienopyridine) such as clopidogrel is required for 1–12 months. Premature termination of antiplatelet therapy during non-cardiac surgery significantly increases the risk of stent thrombosis and consequently myocardial infarction, whereas continuation of dual antiplatelet therapy during surgery increases the risk of severe bleeding. Accordingly, treatment recommendations have to be based on the individual relative risk. In cases with a high risk for major bleeding during surgery, interruption of antiplatelet therapy may be required, whereas in cases of a high risk of stent thrombosis, both antiplatelet drugs should be continued throughout surgery. Patients on dual antiplatelet therapy should be counseled by a team of anesthesiologists, surgeons and cardiologists, to devise the right point in time for the operation, the best perioperative antiplatelet therapy and the appropriate perioperative monitoring.     

Intraoperative drug-eluting stent thrombosis in a patient undergoing robotic prostatectomy

Insertion of drug-eluting stents is one of the strategies for treating patients with coronary artery disease. These patients can be a perioperative challenge in management as they need to be maintained on antiplatelet therapy to prevent stent thrombosis, which puts them at an increased risk for surgical bleeding. Recently revised guidelines on elective surgery following insertion of a drug-eluting stent recommend dual antiplatelet therapy for a period of twelve months. The management of a patient who presented for surgery more than two years after the insertion of a drug-eluting stent, and who developed in-stent thrombosis intraoperatively, is presented.     

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.     

Antiplatelet therapy and coronary stents in perioperative medicine--the two sides of the coin

New trends in interventional cardiology, e.g. the increasing practice of coronary intervention with stent implantation and the prolonged use of dual antiplatelet therapy--usually a combination of clopidogrel and aspirin--has also increased the number of patients presenting for non-cardiac surgery. The two most commonly used stent types, bare-metal stents (BMSs) and drug-eluting stents (DESs), mandate different lengths of dual antiplatelet drug therapy to avoid stent thrombosis. Perioperative caregivers face a knife-edge dilemma between perioperative stent thrombosis, due to preoperative discontinuation of antiplatelet drugs, or surgical bleeding, by continuation of therapy. Pre- and intraoperatively, the risk factors for thrombosis have to be balanced against the risk factors for surgical bleeding. As long as prospective trials are not available, the recommendations and guidelines of task forces and experts are based on retrospective studies and case reports. The perioperative management, decision trees and the importance of close interdisciplinary collaboration between cardiologists, surgeons and anaesthetists will be described.     

Perioperatives Management von Patienten mit Koronarstents bei nichtherzchirurgischen Eingriffen

In patients with coronary stents scheduled for surgery the question arises whether and how antiplatelet therapy should be continued. Risks of perioperative bleeding and of acute stent thrombosis have to be considered simultaneously. The bleeding risk depends primarily on the kind of surgery and on patient comorbidity. The risk of stent thrombosis is increased in these patients due to the thrombogenic surface of the stents. The main determinants are hereby the time duration after stent implantation, the kind of the stent [uncoated (bare-metal stent, BMS) or coated (drug-eluting stent, DES)], as well as angiographic and clinical patient factors. Therefore, perioperative antiplatelet therapy has to be individually adapted for each patient. Bridging with heparin is ineffective. Bridging with intravenous antiplatelet drugs during the perioperative interruption of oral antiplatelet therapy might be a potential procedure in high-risk patients. Whether bedside monitoring of antiplatelet therapy improves the perioperative management of these patients and reduces adverse outcome is object of current studies.     

Coronary stents and anaesthesia

The coronary stents are widely used to prevent coronary restenosis after percutaneous coronary intervention. Dual antiplatelet therapy (acetyl salicylic acid and a thienopyridine-clopidogrel or ticlopidine) are prescribed at least during six weeks after conventional stent and six months after drug eluting stent insertion to prevent stent thrombosis. When an invasive procedure is required, a risk of stent thrombosis arises after stopping antiplatelet therapy and a risk of bleeding when continuing this treatment. Therefore, cardiologists should choose carefully the type of coronary stent before insertion and concerned physicians (anaesthesiologists, surgeons, cardiologists) should decide a perioperative strategy in these high-risk patients.     

The Management of Patients on Dual Antiplatelet Therapy Undergoing Orthopedic Surgery

Cardiovascular disease is prevalent in patients undergoing orthopedic surgery. Many patients who have undergone previous percutaneous coronary intervention (PCI) with stenting are on dual antiplatelet therapy in order to minimize the risk of stent thrombosis. The optimal management of these patients in the perioperative setting remains unclear. We aim to provide information about the management of patients who have undergone a PCI with stents who are subsequently indicated for an orthopedic procedure. We will review the concerns from a cardiologist's and orthopedic surgeon's perspective in regards to the management of these patients in the perioperative setting. In addition, the current American Heart Association, American College of Cardiology, Society for Cardiovascular Angiography and Interventions, and American College of Surgeons guidelines are reviewed. The decision to discontinue dual antiplatelet therapy in a patient who has undergone a PCI with stent should be made only after careful review of the risks for thrombosis and bleeding. Best practice suggests that these risks should be jointly assessed by the orthopedic surgeon and cardiologist. Those patients with stents at high risk of thrombosis should have surgery delayed if possible. There is little data supporting a significantly increased bleeding risk associated with mortality in orthopedic patients when antiplatelet therapy is continued perioperatively.     

Coronary artery stents: II. Perioperative considerations and management

The management of patients with coronary artery stents during the perioperative period is one of the most important patient safety issues clinicians confront. Perioperative stent thrombosis is a life-threatening complication for patients with either bare-metal or drug-eluting stents. Noncardiac surgery appears to increase the risk of stent thrombosis, myocardial infarction, and death, particularly when patients undergo surgery early after stent implantation. The incidence of complications is further increased when dual-antiplatelet therapy is discontinued preoperatively. It is generally agreed that aspirin must be continued throughout the perioperative period, except in circumstances when the risk of bleeding significantly outweighs the benefit of continued anticoagulation, such as procedures performed in a closed space. We present considerations for regional anesthesia, as well as postoperative recommendations as the occurrence of perioperative stent thrombosis appears to be greatest during this period. Immediate percutaneous coronary intervention is the definitive treatment for perioperative stent thrombosis, and 24-h access to an interventional cardiology suite should be readily available. Algorithms for perioperative management of patients with bare-metal and drug-eluting stents are proposed.     

Coronary stent management in elective genitourinary surgery

What's known on the subject? and What does the study add? Withdrawal of dual antiplatelet therapy before the recommended, 12 months for drug‐eluting stents and 1 month for bare‐metal stents increases the rate of major adverse coronary events and mortality. However, in those undergoing surgery the risk of bleeding is increased substantially for those on antiplatelet agents. Successful management in patients with coronary stents who must undergo elective or non‐elective urological surgery should be a multidisciplinary decision. This article reviews the literature and recommends a protocol for clinical management of patients undergoing urological procedures after coronary stent placement. To review the literature on coronary stents and genitourinary surgery and provide a protocol for perioperative. The keywords, ‘elective surgery’, ‘aspirin’, ‘clopidogrel’, ‘guidelines for percutaneous coronary intervention’, and ‘antiplatelet therapy after coronary stent placement’ were used to search PubMed for any relevant articles relating to coronary stents. Recommendations were made based on the whether the procedures patients were exposed to placed them at low‐, moderate‐ or high‐bleeding risk based on the extent of the procedure. All elective procedures should be delayed for 1 month after bare‐metal stent placement and 1 year after drug‐eluting stent placement. In patients classified as low risk (endoscopy and laser prostatectomy), aspirin should be continued throughout the perioperative period and dual antiplatelet therapy should continue 24–48 h postoperatively, if there is no concern for active bleeding. In those classified as moderate risk (scrotal procedures, transurethral resection of bladder tumours, transurethral resection of the prostate, urinary sphincter placement) dual antiplatelet therapy should be discontinued 5–7 days before the procedure and continued within 7 days after procedure, if there is no concern for active bleeding, in consultation with cardiology. In high‐risk procedures (cystectomy, nephrectomy, prostatectomy, penile prosthesis placement) dual antiplatelet therapy should be discontinued 10 days before the procedure and continued postoperatively within 7–10 days of the procedure, when there is no longer a concern for active bleeding with the assistance of a cardiologist. Coronary artery disease is becoming more prominent in our society, increasing the use of coronary stents and antiplatelet agents. With the proposed protocol, it is safe to proceed with surgical intervention in those that have adequate stent endothelialisation.     

Coronary stents: factors contributing to perioperative major adverse cardiovascular events

Patients with coronary stents undergoing non-cardiac surgery are at increased risk of major adverse cardiovascular events perioperatively. Impeccable patient care and communication between all members of the healthcare team will minimize this risk. The dominant risk factor for stent thrombosis and major adverse cardiovascular events is the interruption of dual antiplatelet therapy (e.g. aspirin and clopidogrel). If clopidogrel therapy has to be interrupted due to increased risk of bleeding, continuation of aspirin is strongly recommended to reduce the risk of stent thrombosis. The interval between percutaneous coronary interventions and operation is the next major risk factor for stent thrombosis. The incidence of major adverse cardiovascular events is inversely related to this interval, with the highest mortality rate occurring <30 days after stent implantation. Ideally, for patients with drug-eluting stents, elective surgery should be delayed for at least 1 yr and for patients with bare-metal stents, the recommended minimum period is 6 weeks. The use of a neuraxial anaesthetic technique must be carefully considered due to the risk of an epidural haematoma. Perioperative monitoring should focus on early recognition of myocardial ischaemia, infarction, or both. If stent thrombosis is present, rapid triage to an interventional catheterization laboratory is essential for restoration of coronary blood flow.     

Perioperative management of antiplatelet agents

Perioperative management of antiplatelet agents is a common challenge with the increased number of patients requiring long-term therapy following coronary stenting. Debate currently exists regarding if and when to discontinue antiplatelet therapy prior to elective surgery. The delicate balance between decreasing the risk of bleeding intraoperatively and minimizing the risk of stent thrombosis in patients who are already at a high thrombotic risk is a major concern. This article summarizes the information available for perioperative management of common antiplatelet agents, as well as antiplatelet agents in development.     

Brief review: Coronary drug-eluting stents and anesthesia

Purpose

Anesthesiologists managing patients with drug-eluting stents (DES) face the challenge of balancing the risks of bleedingvs perioperative stent thrombosis (ST). This article reviews DES and the influence of antiplatelet medications related to their use. A perioperative management algorithm is suggested. Novel P2Y12 antagonists currently under investigation, including cangrelor and prasugrel are considered, as well as their potential role in modification of perioperative cardiovascular risks and management of patients with DES.

Source

A PubMed search of the relevant literature over the period 1985–2005 was undertaken using the terms “drug-eluting stent”, “coronary artery stent”, “bare metal stent”, “antiplatelet medication”, “aspirin”, “clopidogrel.”

Principal findings

Delayed re-endothelialization may render both sirolimus-eluting and paclitaxel-eluting stents susceptible to thrombosis for a longer duration than bare metal stents. Stent thrombosis may be associated with resistance to antiplatelet medication. In patients with a DES, a preoperative cardiology consultation is essential. Elective surgery should be postponed if the duration between DES placement and noncardiac surgery is less than six months. For semi-emergent procedures, both aspirin and clopidogrel should be continued during surgery unless clearly contraindicated by the nature of the surgery. If the risk of bleeding is high, then modification of antiplatelet medications should be considered on a case-by-case basis.

Conclusion

A profound increase in the number of patients with DES requires anesthesiologists to be familiar with their associated antiplatelet medications, and strategies for risk modification of ST and possible hemorrhagic complications in the perioperative setting.     

Coronary artery stents: Part I. Evolution of percutaneous coronary intervention

The subspecialty of interventional cardiology has made significant progress in the management of coronary artery disease over the past three decades with the development of percutaneous coronary transluminal angioplasty, atherectomy, and bare-metal and drug-eluting stents (DES). Bare-metal stents (BMS) maintain vessel lumen diameter by acting as a scaffold and prevent collapse incurred by angioplasty. However, these devices cause neointimal hyperplasia leading to in-stent restenosis and requiring reintervention in more than 20% of patients by 6 mo. DES (sirolimus and paclitaxel) prevent restenosis by inhibiting neointimal hyperplasia. However, DESs also delay endothelialization, causing the stents to remain thrombogenic for an extended, yet unknown, period of time. Late stent thrombosis is associated with a 45% mortality rate. Premature discontinuation of antiplatelet therapy, particularly clopidogrel, is the strongest predictor of stent thrombosis. Sixty percent of patients receive stents for off-label (unapproved) indications, which also increases the frequency of stent thrombosis. Clopidogrel and aspirin are the cornerstone of therapy in the prevention of stent thrombosis in both BMS and DES. Recommendations pertaining to the optimal duration of dual-antiplatelet therapy have been debated. Both the Food and Drug Administration and the American Heart Association/American College of Cardiologists, in association with other major societies, have made recommendations to extend the duration of dual-antiplatelet therapy in patients with DES to 1 yr. The 6-wk duration of dual-antiplatelet therapy in patients with BMS remains unchanged. All patients with coronary stents must remain on life-long aspirin monotherapy. Since the introduction of percutaneous transluminal coronary angioplasty for the treatment of coronary atherosclerosis, the practice of percutaneous coronary intervention has undergone a dramatic transformation from simple balloon dilation catheters to sophisticated mechanical endoprostheses. These advancements have impacted the practice of perioperative medicine. In this series of two articles, in Part I we will review the evolution of percutaneous coronary intervention and discuss the issues associated with percutaneous transluminal coronary angioplasty and coronary stenting; in Part II we will discuss perioperative issues and management strategies of coronary stents during noncardiac surgery.     

Perioperatives Pausieren der antithrombozytären Therapie bei Patienten mit koronaren Stents

According to the present guidelines, patients with coronary stents are to be treated with dual antiplatelet therapy. In case surgery is needed, the risk of a fatal stent thrombosis by withdrawing antithrombotics needs to be balanced in each individual case against the risk of haemorrhagic complications on continued antiplatelet medication. We present a case of fatal stent thrombosis and discuss the current evidence regarding perioperative continuation and interruption of antiplatelet therapy for this patient population. In summary the haemorrhagic risk with acetylsalicylic acid for secondary prevention seems very low, and it should be discontinued only in selected cases. Continued dual anticoagulation concepts are also discussed.     

Management of patients with coronary stents in elective thoracic surgery

Purpose  

Interruption of oral antiplatelet agents for noncardiac surgery places patients who have received coronary stent implantation at high risk of coronary events, including stent thrombosis. We investigated retrospectively perioperative management for patients with coronary stents undergoing thoracic surgery.     

Platelet function: new drugs, new assays : possible impacts on operative medicine?

Dual antiplatelet therapy with aspirin and a P2Y12 receptor blocker is a well-established strategy to prevent thrombotic complications in patients with acute coronary syndromes (ACS) and after percutaneous coronary interventions (PCI). Current practice guidelines for antiplatelet therapy advocate a 1 to 12-month dual antiplatelet therapy after bare metal stent PCI and an up to 12-month dual antiplatelet therapy after PCI in patients with ACS and drug-eluting stent PCI. Premature withdrawal of dual antiplatelet therapy carries a substantial risk of stent thrombosis but perioperative continuation of dual antiplatelet therapy is associated with an increased risk of bleeding, particularly in patients treated with the new potent drugs prasugrel and ticagrelor. Based on the various available assays, the lack of validated cut-offs and the disappointing results of targeted antiplatelet therapy as demonstrated by the GRAVITAS trial, current guidelines of international societies recommend platelet function testing only for selected high risk patients despite the known association between clopidogrel low responsiveness and ischemic events. However, for individual patients taking clopidogrel, platelet function monitoring may be considered to safely shorten the preoperative waiting period, to assess the risk of bleeding and transfusion and to initiate specific therapy in bleeding patients.     

冠脉支架患者非心脏手术的围手术期处理

背景 近三十年来,心脏冠脉支架患者日益增多,此类患者在接受非心脏手术时其围手术期将面临特殊挑战.目的 现将重点讨论支架血栓的病理生理以及冠脉支架患者非心脏手术围手术期的处理策略.内容 冠脉支架患者为预防支架内血栓的发生,通常接受由阿司匹林和氯吡格雷为主要药物的双联抗血小板治疗,其疗程为裸金属支架bare metal s...     

Thrombozytenfunktionshemmung nach koronarer Stentimplantation: Bedeutung in der Endoprothetik

Coronary stenting is an effective treatment for reopening atherosclerotic occlusions of coronary arteries. Depending on the manifestation of coronary artery disease (stable CAD or acute coronary syndrome) and on the type of implanted stent, dual antiplatelet therapy is recommended for a period of 4 weeks to 12 months. In this period total joint replacement is associated with high blood loss and high perioperative morbidity. Therefore antiplatelet therapy is often discontinued and replaced by higher dosages of heparin for prophylactic anticoagulation. However, with this treatment regimen protection of the stent is doubtful and there is a high risk of stent thrombosis with myocardial infarction. The surgery should be scheduled after the dual antiplatelet therapy is replaced by lifelong aspirin therapy. On the other hand, if surgery cannot be postponed perioperative bridging of dual antiplatelet therapy can be conducted to minimize bleeding complications with the best possible stent protection. Lifelong therapy with aspirin should not be discontinued in any case.     

Coronary stents and anaesthesia: it is time to have national data

We report 13 cases of coronary stent patients, undergoing a non cardiac surgery. Despite an heterogenous perioperative management of antiplatelet agents, none of these patients developed any significant complications. Recently, several case reports of postoperative drug eluting stent thrombosis have been reported. However, the actual incidence of this dramatic event is not known. This confirms the need to perform prospective studies or registries of patients with coronary stents undergoing non cardiac surgery, in order to propose evidence-based recommendations on perioperative antiplatelet management in such patients.