Risk Of Perioperative Thromboembolism Research Articles

Coagulation Response and Prothrombotic Effect of Uninterrupted Oral Anticoagulant Administration AfterCatheter Ablation for VT.

Catheter ablation for ventricular tachycardia (VT) is associated with perioperative thromboembolic risk. However, the strategy for postprocedural management remains unknown. The aim of this study was to evaluate the prothrombotic response after VT ablation in various coagulation biomarkers in patients with and without the administration of oral anticoagulation (OAC). Data from 112 patients (58 with uninterrupted OAC and 54 without) with structural heart disease who underwent endocardial VT ablation were retrospectively analyzed. We also included 41 patients who underwent ablation for premature ventricular contraction from the right ventricle and 13 patients who underwent electrophysiology study (the control group). Blood samples of coagulation markers were collected before and 3days after the procedure in all patients. The percentage of D-dimer levels≤1.0μg/mL at baseline was lower in the VT ablation groups (76% and 50% in the OAC and non-OAC groups, respectively) than in the other groups (100%). After 3days, the percentage remained at 67% in the OAC group; however, the non-OAC VT group demonstrated a remarkable decrease of 20%. Similarly, fibrin monomer complex, thrombin antithrombin, and prothrombin fragment 1+2 levels were well suppressed in the control, premature ventricular contraction, and OAC groups. However, the non-OAC group demonstrated increased coagulation markers both before and after 3days. Multivariate analysis demonstrated that OAC administration and normal coagulation markers at baseline were independent predictors of stable coagulation status after ablation. The coagulation cascade was significantly activated in patients undergoing VT ablation. Uninterrupted OAC administration suppressed the coagulation response, which might be associated with a reduction in perioperative prothrombotic risk.

Perioperative management of patients receiving long-term antithrombotic therapy. Clinical practice recommendations of the national “Federation of Anesthesiologists and Reanimatologists”

The review presents the methodological recommendations of the Federation of Anesthesiologists and Resuscitators for the management of patients receiving long-term antithrombotic therapy, revised in 2021. The classification of complications and the degree of hemorrhagic risk, stratification of perioperative thromboembolic risk are presented. Taking into account modern concepts, the principles of interruption and resumption of antithrombotic, anticoagulant and antiplatelet therapy are described. Approaches to the emergency interruption of antithrombotic therapy during urgent surgical interventions, including emergency reversion of the effects of drugs received by the patient, are presented. The features of the appointment and changes in the tactics of antithrombotic therapy depending on the thromboembolic and hemorrhagic risk in such concomitant diseases and conditions as the presence of artificial heart valves, atrial fibrillation, ischemic stroke, myocardial infarction, coronary stenting are described. A separate section is devoted to thrombohemorrhagic safety when performing regional anesthesia against the background of antithrombotic therapy. Indications, contraindications and limitations for regional anesthesia in the context of antithrombotic therapy are given. Criteria for the quality of the provided medical care are given.
 

Management of Anticoagulation and Antiplatelet Therapy in Glaucoma Surgery.

The use of antithrombotic therapy is rising as the population of older adults grows and novel agents with wider indications emerge. Likewise, surgical treatment of glaucoma may become increasingly common as the prevalence of glaucoma increases and innovative treatment options are developed. These trends highlight the need to understand how best to manage antithrombotic therapy in the context of glaucoma surgery. This review article describes current literature on antithrombotic therapy and perioperative thromboembolic risk evaluation based on individual factors. In addition, guidance is offered on the management of antithrombotic therapy in the setting of each type of glaucoma surgery, with an emphasis on a multidisciplinary approach involving the patients' treating physicians.

A novel scoring system for stroke risk stratification in Japanese patients with low CHADS2 scores: Study using a transesophageal-echocardiogram endpoint.

BackgroundCatheter ablation is an effective treatment for atrial fibrillation (AF), but it carries risk of perioperative thromboembolism even in cases with low CHADS2 scores. Here, we examined whether a combination of clinical variables can predict stroke risk factors that are assessed by transesophageal echocardiography (TEE).MethodsThe study population consisted of 209 consecutive AF patients with a CHADS2 score of 0 or 1 (58.7 ± 10.6 years old; persistent AF, 33.0%). All patients underwent TEE, and TEE‐determined stroke risk (TEE risk) was defined as cardiac thrombus/sludge, dense spontaneous echo contrast (SEC), and/or peak left atrial appendage (LAA) flow velocity <0.25 m/s.ResultsTransesophageal echocardiography risk was observed in 10.5% of the patients. In multivariate logistic analysis, persistent AF [odds ratio (OR): 11.5, CI: 3.14‐42.1, P = .0002], left atrial diameter (LAD) (OR: 1.10, CI: 1.01‐1.20, P = .0293), contrast medium defect (CMD) in the LAA detected by computed tomography (OR: 20.2, CI: 6.3‐65.0, P < .0001), and serum brain natriuretic peptide (BNP) level (OR: 1.00, CI: 1.00‐1.01, P = .0056) were independent predictors of TEE risk. A new scoring system comprising LAD > 41 mm (1 point), BNP > 47 pg/mL (1 point), CMD (2 points), and persistent AF (2 points) was constructed and defined as TEE‐risk score. The area under the curve (AUC) for prediction of TEE risk was 0.631 in modified CHADS2 score and it was 0.852 in TEE‐risk score.ConclusionTransesophageal echocardiography risk is predictable by TEE‐risk score, and its combination with CHADS2 score may improve the stroke risk stratification in AF patients with a low CHADS2 score.

Anticoagulation Bridge Therapy in Patients with Atrial Fibrillation: Recent Updates Providing a Rebalance of Risk and Benefit.

In 2011 we reviewed clinical updates and controversies surrounding anticoagulation bridge therapy in patients with atrial fibrillation (AF). Since then, options for oral anticoagulation have expanded with the addition of four direct oral anticoagulant (DOAC) agents available in the United States. Nonetheless, vitamin K antagonist (VKA) therapy continues to be the treatment of choice for patients who are poor candidates for a DOAC and for whom bridge therapy remains a therapeutic dilemma. This literature review identifies evidence and guideline and consensus statements from the last 5 years to provide updated recommendations and insight into bridge therapy for patients using a VKA for AF. Since our last review, at least four major international guidelines have been updated plus a new consensus document addressing bridge therapy was released. Prospective trials and one randomized controlled trial have provided guidance for perioperative bridge therapy. The clinical trial data showed that bridging with heparin is associated with a significant bleeding risk compared with not bridging; furthermore, data suggested that actual perioperative thromboembolic risk may be lower than previously estimated. Notably, patients at high risk for stroke have not been adequately represented. These findings highlight the importance of assessing thrombosis and bleeding risk before making bridging decisions. Thrombosis and bleeding risk tools have emerged to facilitate this assessment and have been incorporated into guideline recommendations. Results from ongoing trials are expected to provide more guidance on safe and effective perioperative management approaches for patients at high risk for stroke.

The safety profile of preoperative administration of heparin for thromboprophylaxis in Chinese patients intended for thoracoscopic major thoracic surgery: a pilot randomized controlled study

Patients undergoing major thoracic surgery especially for cancers are at a high risk of perioperative thromboembolism. Current guidelines recommended either heparin sodium (unfractionated heparin) or low-molecular-weight heparin (LMWH) for those patients at high risk of deep vein thrombosis (DVT). However, the rational timing of starting heparin has not yet been well established, because DVT can be caused by not only surgery but also comorbidities as well as prolonged hospital stay, and thoracic surgeons always concerned about heparin-related increased risk of intra- or post-operative bleeding. Therefore, this study aimed to establish the safety profile of preoperative administration of heparin for thromboprophylaxis in Chinese patients intended for thoracoscopic major thoracic surgery. From June to August 2016, patients intended for thoracoscopic lobectomy, esophagectomy, and thymectomy were randomly assigned into two groups: the case group (starting heparin sodium 5,000 U, bid preoperatively upon the admission into our department) and the control group (starting heparin sodium 5,000 U, bid postoperatively from postoperative day 1). The baseline data including demographic data and preoperative conditions were collected. The end points included operation time, intraoperative bleeding volume, postoperative chest tube drainage volume and duration as well as lab coagulation function data. A total of 58 qualified patients were randomized into case group (29 patients) and control group (29 patients), and after excluding 6 conversion patients, the case group and control group each had 26 patients for analysis. The baseline data of the two groups were comparable. Operation time (P=0.368), intraoperative bleeding volume (P=0.231), postoperative drainage days (P=0.466), and mean drainage volume per day (P=0.108) were not significantly increased in case group compared with those of control group. Moreover, there were no significant differences of perioperative coagulation function between these two groups. Preoperative administration of heparin for thromboprophylaxis in Chinese patients intended for thoracoscopic major thoracic surgery was safe and feasible. NCT02940444 (https://register.clinicaltrials.gov/).

Viscoelastic testing inside and beyond the operating room.

Hemorrhage is a major contributor to morbidity and mortality during the perioperative period. Current methods of diagnosing coagulopathy have various limitations including long laboratory runtimes, lack of information on specific abnormalities of the coagulation cascade, lack of in vivo applicability, and lack of ability to guide the transfusion of blood products. Viscoelastic testing offers a promising solution to many of these problems. The two most-studied systems, thromboelastography (TEG) and rotational thromboelastometry (ROTEM), offer similar graphical and numerical representations of the initiation, formation, and lysis of clot. In systematic reviews on the clinical efficacy of viscoelastic tests, the majority of trials analyzed were in cardiac surgery patients. Reviews of the literature suggest that transfusions of packed red blood cells (pRBC), plasma, and platelets are all decreased in patients whose transfusions were guided by viscoelastic tests rather than by clinical judgement or conventional laboratory tests. Mortality appears to be lower in the viscoelastic testing groups, despite no difference in surgical re-intervention rates and massive transfusion rates. Cost-effectiveness studies also seem to favor viscoelastic testing. Viscoelastic testing has also been investigated in small studies in other clinical contexts, such as sepsis, obstetric hemorrhage, inherited bleeding disorders, perioperative thromboembolism risk assessment, and management of anticoagulation for patients on mechanical circulatory support systems or direct oral anticoagulants (DOACs). While the results are intriguing, no systematic, larger trials have taken place to date. Viscoelastic testing remains a relatively novel method to assess coagulation status, and evidence for its use appears favorable in reducing blood product transfusions, especially in cardiac surgery patients.

Preventing bleeding and thromboembolic complications in atrial fibrillation patients undergoing surgery.

Neurologists feel uneasy when asked about temporary anticoagulant interruption for surgery in patients with atrial fibrillation (AF). Rational decisions can be made based on current scientific evidence. Method Critical review of international guidelines and selected references pertaining to bleeding and thromboembolism during periods of oral anticoagulant interruption. Results Withholding oral anticoagulants leads to an increased risk of perioperative thromboembolism, depending on factors such as age, renal and liver function, previous ischemic events, heart failure etc. Surgeries are associated with a variable risk of bleeding - from minimal to very high. Individualized decisions about preoperative drug suspension, bridging therapy with heparin and time to restart oral anticoagulants after hemostasis can significantly reduce these opposing risks. Conclusion Rational decisions can be made after discussion with all Health care team professionals involved and consideration of patient fears and expectations. Formal written protocols should help managing antithrombotic treatment during this delicate period.

Bridging Protocol for Surgical Patients: One Clinic's Experience Facilitating a Safe Anticoagulation Intervention.

Surgical candidates often present with complex medical histories that necessitate an individualized approach to care to minimize surgical and anesthetic risk. Patients on warfarin require exceptionally careful clinical assessment, consideration, and consistency to reduce the risk of perioperative thromboembolism and bleeding complications. In response to this need, Victoria General Hospital in Winnipeg, Manitoba, Canada developed a bridging protocol based on evidence-based guidelines and a checklist tool to incorporate and communicate the necessary tasks among the interprofessional team. The purpose of this initiative was to create a patient-focused process to assist those at risk for a thromboembolic event to navigate through a clear, consistent, and collaborative surgical experience whenever cessation and resumption of warfarin administration was required.

Rotational thromboelastometry predicts thromboembolic complications after major non-cardiac surgery

Thromboembolic complications contribute substantially to perioperative morbidity and mortality. Routine laboratory tests do not detect patients with acquired or congenital hypercoagulability who may be at increased risk of perioperative thromboembolism. Rotational thromboelastometry (ROTEM) is a digitized modification of conventional thromboelastography that is stable and technically easy to use. We designed a prospective observational study to evaluate whether preoperative ROTEM can identify patients at increased risk for postoperative thromboembolic complications after major non-cardiac surgery. Preoperative ROTEM analysis using extrinsic rotational thromboelastometry (EXTEM), intrinsic rotational thromboelastometry (INTEM), and fibrinogen rotational thromboelastometry (FIBTEM) activators was performed on 313 patients undergoing major non-cardiac surgery. Patients’ medical records were reviewed after discharge for results of standard coagulation studies - partial thromboplastin time (PTT), international normalized ratio (INR), platelet count - and evidence of thromboembolic complications during their hospital stay. A thromboembolic complication was defined as a new arterial or deep venous thrombosis, catheter thrombosis, or pulmonary embolism diagnosed by ultrasound or spiral chest computed tomography. Ten patients developed postoperative thromboembolic complications, of whom 9 had received standard prophylaxis with subcutaneous enoxaparin or heparin. There was no indication of by PTT, INR, or platelet count. Preoperative EXTEM and INTEM activators that assess fibrin clot formation and platelet interaction indicated that these patients had significantly lower clot formation time (CFT) and significantly higher alpha angle (α) and maximum clot firmness (MCF), compared to patients without thromboembolic complications. There was no significant difference for any parameter using FIBTEM activator, which excludes platelet interaction. Receiver operating characteristic (ROC) curves were constructed for these variables. INTEM clot firmness at 10 min (A10) was the best predictor of thromboembolic complications, with an ROC area under the curve of 0.751. Our results indicate that preoperative ROTEM assays that include fibrin clot and platelet interaction may detect patients at increased risk for postoperative thromboembolic complications after major non-cardiac surgery. Future studies need to evaluate the clinical utility and cost effectiveness of preoperative ROTEM and better define the association between ROTEM values and specific hypercoagulable conditions.

Outcome of Noncardiac and Nonvascular Surgery in Patients With Mechanical Heart Valves

There is a tendency to avoid noncardiac surgery in patients with mechanical heart valves (MHVs) owing to the increased risk of perioperative thromboembolism, infective endocarditis, and bleeding. We aimed to determine the risk of cardiac and noncardiac complications in patients with MHVs who underwent noncardiothoracic, nonvascular surgery. A total of 140 patients with MHVs (77 aortic, 46 mitral, and 17 double valve) and 1,200 patients with native valves (control group) were prospectively followed up for a minimum of 3 months after noncardiothoracic and nonvascular surgery. Patients with bioprostheses were excluded. Those patients aged >18 years who underwent an elective, non-outpatient, open surgical procedure were enrolled. Subcutaneous enoxaparin 1 mg/kg, twice daily, was used as bridging anticoagulation. The demographics, co-morbidities, and preoperative (medications, echocardiographic findings, laboratory results) and postoperative data were evaluated for their association with the occurrence of perioperative adverse events. The incidence of perioperative adverse cardiovascular (10.8% vs 10.7%, p = 0.985) and noncardiovascular (11.9% vs 11.4%, p = 0.989) events was similar in those patients with and without MHVs. Bleeding (18.6% vs 14.2%, p = 0.989), thromboembolism (3.6% vs 2%, p = 0.989), and mortality at 3 months (1.4% vs 1.3%, p = 0.825) were also similar for the 2 groups. In conclusion, with close follow-up and strict adherence to the guidelines, patients with MHVs and patients with native heart valves undergoing noncardiac and nonvascular surgery have a similar risk of mortality and morbidity.

Incidence of clinical pulmonary embolism after laparoscopic surgery

This study aimed to determine the incidence of pulmonary embolism (PE) following laparoscopic surgery and its potential risk factors. Data concerning 44 453 patients from 114 surgical institutions were collected by the Swiss Association of Laparoscopic and Thoracoscopic Surgery. The incidence of postoperative PE despite thromboprophylaxis was evaluated and potential risk factors were assessed singly, and then in a consecutive stepwise logistic multiple regression analysis. Among 44 453 patients assessed, 55.8 per cent were female and 44.2 per cent were male. Interventions included cholecystectomy (52.8 per cent), hernia repair (17.7 per cent), appendicectomy (12.4 per cent), colonic surgery (4.6 per cent) and oesophageal surgery (5.5 per cent). Postoperative PE occurred in 86 patients (0.2 per cent), and the incidence tended to decrease during this study (P = 0.016). A total of 149 patients died (0.3 per cent) of which nine (6.0 per cent) were due to PE. Significant predictive risk factors were female sex (P < 0.001), age (P < 0.001), weight above 90 kg (P < 0.001), emergency procedure (P < 0.001) and operating time exceeding 150 min (P < 0.001). The low incidence of PE after laparoscopy, with a further decrease over the past decade, suggests a tendency towards improved perioperative thromboembolic risk management.

Risk of Thromboembolism and Bleeding After General Surgery in Patients With Atrial Fibrillation

We provide insight into the risk of perioperative thromboembolism and bleeding in patients who have atrial fibrillation, use anticoagulants, and undergo a surgical procedure. Ninety-four patients underwent 121 noncardiac operations during a mean follow-up of 29 months. There was a 3.6-fold increased risk for all bleeding complications within 1 month after surgery compared with the control period (95% confidence interval 1.05 to 12.0). No thromboembolic event occurred in the first month after surgery compared with 11 events in the remaining period (0.4% per month).

Cost-effectiveness of combination thromboembolism prophylaxis in gynecologic oncology surgery

Objective. To compare the cost-effectiveness of external pneumatic compression devices with and without the addition of low-molecular-weight heparin for the prevention of deep vein thrombosis in high-risk surgical patients with gynecologic cancer. Methods. A Markov decision analytic model was used to estimate the costs and outcomes associated with the prophylactic use of external pneumatic compression with and without low-molecular-weight heparin in patients undergoing gynecologic surgery. We estimated cost per fatal pulmonary embolus prevented, cost per deep vein thrombus prevented, and cost per life-year saved. Probability estimates for various outcomes and efficacies were obtained from the literature, using data specific for gynecologic surgery patients when available. Results. In the base case scenario, cost-effectiveness estimates for combination prophylaxis varied from $10,091 per life-year saved for a 35-year-old patient with IB cervix cancer patient to $50,181 for a 65-year-old patient with stage IIIC ovarian cancer, costs within the $50,000–65,000 per life-year saved threshold considered to be cost-effective. Combination prophylaxis appeared to be cost-effective in gynecologic oncology patients as long as the risk of perioperative thromboembolism using this method of prevention was less than or equal to 4%. Sensitivity analysis indicated that variation of the marginal cost of low-molecular-weight heparin and the marginal effectiveness to extremes did not change the conclusions of the statistical model. Conclusion. The use of combination therapy external pneumatic compression is estimated to be cost-effective for high-risk gynecologic oncology patients undergoing surgery. Clinical trials to determine the efficacy of perioperative combination therapy in gynecologic surgery are justified.

Anticoagulation in elective surgery.

Several categories of patients may be receiving anticoagulation therapy and require surgery. Many patients take cardioprotective aspirin or warfarin for atrial fibrillation, the presence of a mechanical heart valve, prior thromboembolism, a documented left ventricular thrombus, or a history of venous thromboembolism with or without a pulmonary embolism. Inpatients may be receiving injectable forms of anticoagulation to reduce risk of deep venous thrombosis or for other conditions, such as atrial fibrillation. Patients receiving any type of anticoagulation present a problem when they require surgery because the interruption of anticoagulant therapy increases their risk of thromboembolism and stroke (Schanbacher & Bennett, 2000). Rational decisions regarding the appropriateness of perioperative anticoagulation depend on individual patient factors and can only be made when the risk of perioperative thromboembolism is balanced against the risk of perioperative bleeding.

Surgery in patients treated with anticoagulation during emergency and elective interventions

Patients under oral anticoagulation with coumarin derivatives have a variable perioperative thromboembolic risk which necessitates continuation of their thromboembolic prophylaxis during elective and emergency surgery. Because of their better handling unfractionated heparin and low-molecular-weight heparins are used most often for this purpose. The overlapping effect of coumarin and heparin therapy requires a close daily monitoring of the clotting inhibition (partial thromboplastin time, thromboplastin time, thrombin time). In elective surgery coumarin therapy is interrupted 2-3 days preoperatively; in emergency cases vitamin K or fresh frozen plasma have to be substituted. Patients under heparin therapy or prophylaxis are easier to handle, because the effect of heparin disappears in a few hours after stopping the treatment. In the immediate postoperative phase the heparin application is interrupted for 6 h because of increased bleeding risk. It is important to take into account additional risk factors like the underlying disease, disturbances of platelet function, liver diseases and renal insufficiency.