Factor Xa Inhibitors and Direct Thrombin Inhibitors Versus Low-Molecular-Weight Heparin for Thromboprophylaxis After Total Hip or Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

Venous Thromboembolism Prevention in Rehabilitation: A Review and Practice Suggestions

ABSTRACT

Venous thromboembolism is a frequent complication of acute hospital care, and this extends to inpatient rehabilitation. The timely use of appropriate thromboprophylaxis in patients who are at risk is a strong, evidence-based patient safety priority that has reduced clinically important venous thromboembolism, associated mortality and costs of care. While there has been extensive research on optimal approaches to venous thromboembolism prophylaxis in acute care, there is a paucity of high-quality evidence specific to patients in the rehabilitation setting, and there are no clinical practice guidelines that make recommendations for (or against) thromboprophylaxis across the broad spectrum of rehabilitation patients. Herein, we provide an evidence-informed review of the topic with practice suggestions. We conducted a series of literature searches to assess the risks of venous thromboembolism and its prevention related to inpatient rehabilitation as well as in major rehabilitation subgroups. Mobilization alone does not eliminate the risk of venous thromboembolism after another thrombotic insult. Low molecular weight heparins and direct oral anticoagulants are the principal current modalities of thromboprophylaxis. Based on the literature, we make suggestions for venous thromboembolism prevention and include an approach for consideration by rehabilitation units that can be aligned with local practice.

Comparative efficacy of aspirin versus direct oral anticoagulants for venous thromboembolism prophylaxis following primary total hip arthroplasty or total knee arthroplasty: A systematic review and meta-analysis of randomised controlled trials

Introduction

Venous thromboembolisms (VTEs), including deep vein thrombosis (DVT) and pulmonary embolisms (PE), are common after total knee (TKA) and hip arthroplasty (THA). Recent studies suggest that aspirin effectively prevents VTE following major orthopaedic surgery. This meta-analysis compares randomised controlled trials (RCTs) evaluating aspirin versus direct oral anticoagulants (DOACs) for VTE prevention after primary THA and TKA.

Methods

We included RCTs from 2017 to 2023 that looked at aspirin versus DOACs for VTE prophylaxis in primary THA and TKA. A search strategy was conducted which used Boolean operators and MESH terms. Primary outcomes included VTE rates, symptomatic, asymptomatic DVT and PE. Secondary outcomes were mortality and bleeding complications. Statistical analysis was performed using REVMAN software. An odds ratio with a 95% confidence interval was generated for the pooled studies. Heterogeneity was assessed using the I 2 variable, and publication bias was evaluated with a funnel plot.

Results

Seven RCTs with 3967 patients were included for analysis. Rivaroxaban 10 mg OD was compared to varying doses of aspirin (81-300 mg). There were no significant differences between the groups in the incidence of VTE (OR: 1.21, 95% CI: 0.72-2.01), PE (OR: 1.01, 95% CI: 0.39-2.61), asymptomatic DVT (OR: 1.39, 95% CI: 0.64-3.00), suspected DVT (OR: 1.13, 95% CI: 0.49-2.61) and major bleeding (OR: 0.84, 95% CI: 0.55-1.27).

Discussion

Aspirin is as effective as rivaroxaban for primary thromboprophylaxis post-THA and TKA, without increased incidence of complications. Further research is needed to determine the optimal dosing regimen of aspirin and its long-term efficacy in preventing VTE.

Level of Evidence

Level I.

A new strategy for anticoagulation: The factor XI inhibitors

Direct oral anticoagulants (DOACs) are currently the first-choice therapy for the prevention of cardioembolic events in patients with atrial fibrillation and for the treatment of venous thromboembolism (VTE) due to their more favorable efficacy to safety profile in comparison to vitamin K antagonists (VKA). DOACs did not show a clinical benefit when used for in stroke prevention in patients with mechanic or rheumatic valves or in those who underwent transcatheter aortic valve implantation (TAVI), in the treatment of VTE in patients with antiphospholipid antibody syndrome and in prevention of VTE in medically ill patients. There are some concerns for bleeding excess at the gastrointestinal site for some, but not all, DOACs. In recent years, in order to overcome the limitations of the available DOACs and to explore the advantages of anticoagulation in additional clinical settings, the development of factor XI and factor XII inhibitors as anticoagulant agents has been proposed. Emerging data show that factor XI has a minor role in the physiological process of hemostasis and an important role in the development of thrombosis. Bleeding has been viewed for several years as an unavoidable side effect of anticoagulant therapy. The aim of factor XI inhibitors is to challenge this dogma by favoring the uncoupling between hemostasis and thrombosis. This paper provides an update on the rationale for the use of factor XI inhibitors, their pharmacological properties and the preliminary clinical findings.

Key Elements of Enhanced Recovery after Total Joint Arthroplasty: A Reanalysis of the Enhanced Recovery after Surgery Guidelines

Recent guidelines have produced a consensus statement for perioperative care in hip and knee replacement. However, there is still a need for reanalysis of the evidence and recommendations. Therefore, we retrieved and reanalyzed the evidence of each recommended components of enhanced recovery after surgery (ERAS) based on the guidelines of total joint arthroplasty. For each one, we included for the highest levels of evidence and those systematic reviews and meta-analyses were preferred. The full texts were analyzed and the evidence of all components were summarized. We found that most of the recommended components of ERAS are supported by evidence, however, the implementation details of each recommended components need to be further optimized. Therefore, implementation of a full ERAS program may maximize the benefits of our clinical practice but this combined effect still needs to be further determined.

Benefits and harms of direct oral anticoagulation and low molecular weight heparin for thromboprophylaxis in patients undergoing non-cardiac surgery: systematic review and network meta-analysis of randomised trials

OBJECTIVE

To systematically compare the effect of direct oral anticoagulants and low molecular weight heparin for thromboprophylaxis on the benefits and harms to patients undergoing non-cardiac surgery.

DESIGN

Systematic review and network meta-analysis of randomised controlled trials.

DATA SOURCES

Medline, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL), up to August 2021.

REVIEW METHODS

Randomised controlled trials in adults undergoing non-cardiac surgery were selected, comparing low molecular weight heparin (prophylactic (low) or higher dose) with direct oral anticoagulants or with no active treatment. Main outcomes were symptomatic venous thromboembolism, symptomatic pulmonary embolism, and major bleeding. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used for network meta-analyses. Abstracts and full texts were screened independently in duplicate. Data were abstracted on study participants, interventions, and outcomes, and risk of bias was assessed independently in duplicate. Frequentist network meta-analysis with multivariate random effects models provided odds ratios with 95% confidence intervals, and GRADE (grading of recommendations, assessment, development, and evaluation) assessments indicated the certainty of the evidence.

RESULTS

68 randomised controlled trials were included (51 orthopaedic, 10 general, four gynaecological, two thoracic, and one urological surgery), involving 45 445 patients. Low dose (odds ratio 0.33, 95% confidence interval 0.16 to 0.67) and high dose (0.19, 0.07 to 0.54) low molecular weight heparin, and direct oral anticoagulants (0.17, 0.07 to 0.41) reduced symptomatic venous thromboembolism compared with no active treatment, with absolute risk differences of 1-100 per 1000 patients, depending on baseline risks (certainty of evidence, moderate to high). None of the active agents reduced symptomatic pulmonary embolism (certainty of evidence, low to moderate). Direct oral anticoagulants and low molecular weight heparin were associated with a 2-3-fold increase in the odds of major bleeding compared with no active treatment (certainty of evidence, moderate to high), with absolute risk differences as high as 50 per 1000 in patients at high risk. Compared with low dose low molecular weight heparin, high dose low molecular weight heparin did not reduce symptomatic venous thromboembolism (0.57, 0.26 to 1.27) but increased major bleeding (1.87, 1.06 to 3.31); direct oral anticoagulants reduced symptomatic venous thromboembolism (0.53, 0.32 to 0.89) and did not increase major bleeding (1.23, 0.89 to 1.69).

CONCLUSIONS

Direct oral anticoagulants and low molecular weight heparin reduced venous thromboembolism compared with no active treatment but probably increased major bleeding to a similar extent. Direct oral anticoagulants probably prevent symptomatic venous thromboembolism to a greater extent than prophylactic low molecular weight heparin.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018106181.

Comparison of Enoxaparin and Rivaroxaban in the Prophylaxis of Deep Venous Thrombosis in Arthroplasty

Background

Pulmonary embolism is a serious early complication of arthroplasty procedures that can develop after deep venous thrombosis. The present study aimed to compare rivaroxaban and enoxaparin in terms of preventing DV and PE, and also in this study, we compared the complications due to these drugs in patients undergoing elective arthroplasty.

Materials and Methods

214 patients were divided into three groups based on their treatment regimens. In group I, enoxaparin was used, in group II, rivaroxaban was used, and in group III, enoxaparin was used throughout hospitalization, and after hospital discharge, rivaroxaban was used. These three groups were compared according to the occurrence of deep venous thrombosis, pulmonary embolism, and major and minor complications.

Results

Major postoperative complications occurred in 5, 15, and 6 patients in group I, II, and III, respectively. Minor postoperative complications occurred in 10, 24, and 11 patients in group I, II, and III, respectively. No significant difference was found among the three groups. Deep venous thrombosis or pulmonary embolism was not observed in any patient.

Conclusion

Rivaroxaban was found to be as effective as enoxaparin in the prevention of deep venous thrombosis and other complications after arthroplasty. Moreover, oral rivaroxaban provided greater ease of use compared to subcutaneous enoxaparin. Based on these findings, we consider that rivaroxaban could be an effective alternative to enoxaparin.

Risk factors for deep vein thrombosis even using low-molecular-weight heparin after total knee arthroplasty

Background

With an increase in deep vein thrombosis (DVT) following total knee arthroplasty (TKA) in the Asian population, most surgeons today use a form of prophylactic anticoagulant agents in patients after TKA. Nevertheless, DVT occasionally develops even in these patients with prophylaxis. The purpose of this study was to identify the risk factors for DVT after TKA in cases of postoperative low-molecular-weight heparin (LMWH) use.

Methods

We designed a retrospective study with 103 patients who underwent primary TKA. From the second postoperative day, 60 mg of LMWH was subcutaneously injected into the patients daily. On the seventh postoperative day, patients had computed tomography angiography to check whether they had DVT. Regarding risk factors, we investigated patients’ gender, age, surgical site (unilateral/bilateral), body mass index, method of anesthesia, preoperative hypertension, diabetes, hypercholesterolemia status, and prothrombin time/international normalized ratio from electronic medical records. We analyzed the statistical significance of these risk factors.

Results

Statistically significant factors in the single-variable analysis were surgical site (unilateral/bilateral), body mass index, preoperative hypertension status, and anesthesia method. Multiple logistic regression analysis with these factors revealed that the surgical site (unilateral/bilateral, p = 0.024) and anesthesia method (p = 0.039) were significant factors for the occurrence of postoperative DVT after TKA.

Conclusions

Patients undergoing simultaneous bilateral TKAs and patients undergoing TKA with general anesthesia need more attention regarding DVT even with chemoprophylaxis using LMWH after TKA.

Thromboprophylaxis for orthopedic surgery; An updated meta-analysis

BACKGROUND

Venous thromboembolism (VTE) is a serious complication of orthopedic surgery. Low molecular weight heparin (LMWH) has been the standard of care for thromboprophylaxis in this population. However, direct oral anticoagulants (DOACs) are increasingly being used as alternatives.

OBJECTIVE

To assess the efficacy and safety of DOACs versus LMWH for thromboprophylaxis in orthopedic surgery.

METHODS

We searched MEDLINE, Embase, and the Cochrane Collaboration Central Register of Controlled Trials from inception until April 2020, for randomized controlled trials (RCTs) comparing DOACs with LMWH for thromboprophylaxis in orthopedic surgery.

RESULTS

Twenty-five RCTs met inclusion criteria, including 40,438 patients, with a mean age of 68 years and 50% were males. Compared to LMWH, DOACs were associated with a significant reduction of major VTE; defined as the composite events of proximal deep vein thrombosis (DVT), pulmonary embolism (PE), and VTE-related mortality (RR 0.33; 95% CI: 0.20-0.53; P<0.01), and total DVT (RR: 0.59; 95% CI: 0.48-0.73; P<0.01), but not PE (RR 0.81; 95% CI: 0.49-1.34; P=0.42). There was no statistically significant difference between both groups on the incidence of major bleeding (RR 0.99; 95% CI: 0.77-1.27; P=0.92), clinically relevant non-major bleeding (RR 1.04; 95% CI: 0.92-1.17; P=0.52), all-cause mortality (RR 1.06; 95% CI: 0.64-1.76; P=0.83), VTE-related mortality (RR 0.84; 95% CI: 0.40-1.74; P=0.64) and bleeding-related mortality (RR 1.24; 95% CI: 0.30-5.18; P=0.77).

CONCLUSION

For patients undergoing orthopedic surgery, thromboprophylaxis with DOACs is associated with a significant reduction of major VTE and DVT, compared to LMWH. Safety outcomes were not significantly different between both treatment groups.

Factors predisposing to thrombosis after major joint arthroplasty

BACKGROUND

Total joint arthroplasty is one of the most common options for end stage osteoarthritis of major joints. However, we must take into account that thrombosis after hip/knee arthroplasty may be related to mutations in genes encoding for blood coagulation factors and immune reactions to anticoagulants [heparin-induced thrombocytopenia (HIT)/thrombosis]. Identifying and characterizing genetic risk should help to develop diagnostic strategies or modify anticoagulant options in the search for etiological mechanisms that cause thrombophilia following major orthopedic surgery.

AIM

To evaluate the impact of patients’ coagulation profiles and to study specific pharmacologic factors in the development of post-arthroplasty thrombosis.

METHODS

In 212 (51 male and 161 female) patients that underwent primary total hip arthroplasty (100) or total knee arthroplasty (112) due to osteoarthritis during a period of 1 year, platelet counts and anti-platelet factor 4 (PF4)/heparin antibodies were evaluated pre/postoperatively, and antithrombin III, methylenetetrahydrofolate reductase, factor V and prothrombin gene mutations were evaluated preoperatively. In a minimum follow-up of 3 years, 196 patients receiving either low-molecular-weight heparins (173) or fondaparinux (23) were monitored for the development of thrombocytopenia, anti-PF4/heparin antibodies, HIT, and thrombosis.

RESULTS

Of 196 patients, 32 developed thrombocytopenia (nonsignificant correlation between anticoagulant type and thrombocytopenia, P = 0134.) and 18 developed anti-PF4/heparin antibodies (12/173 for low-molecular-weight heparins and 6/23 for fondaparinux; significant correlation between anticoagulant type and appearance of antibodies, P = 0.005). Odds of antibody emergence: 8.2% greater in patients receiving fondaparinux than low-molecular-weight heparins. Gene mutations in factor II or V (two heterozygotes for both factor V and II) were identified in 15 of 196 patients. Abnormal low protein C and/or S levels were found in 3 of 196 (1.5%) patients, while all patients had normal levels of von Willebrand factor, lupus anticoagulant, and antithrombin III. Four patients developed HIT (insignificant correlation between thrombocytopenia and antibodies) and five developed thrombosis (two had positive antibodies and two were heterozygotes for both factor II & V mutations). Thrombosis was not significantly correlated to platelet counts or HIT. The correlation of thrombosis to antibodies, factor II, factor V was P = 0.076, P = 0.043, P = 0.013, respectively.

CONCLUSION

Screening of coagulation profile, instead of platelet monitoring, is probably the safest way to minimize the risk of post-arthroplasty thrombosis. In addition, fondaparinux can lead to the formation of anti-PF4/heparin antibodies or HIT.

Risk of symptomatic venous thromboembolism after abdominal aortic aneurysm repair in long-term follow-up of 1021 consecutive patients

OBJECTIVE

Venous thromboembolism (VTE), including deep venous thrombosis and pulmonary embolism (PE), is an infrequent but consequential and potentially preventable complication after major surgical procedures. The aim of the study was to describe the long-term occurrence of symptomatic VTE in patients undergoing abdominal aortic aneurysm (AAA) repair and to ascertain patient-specific risk factors as well as to compare the rate with that of a reference population.

METHODS

The study included all patients who had undergone endovascular or open AAA repair, both elective and urgent/acute cases, at the Tampere University Hospital (Finland) between February 2001 and December 2016; 59% of patients had undergone endovascular and 41% open repair, and 23% of all cases had required urgent or emergency treatment. Information about later treatment episodes for symptomatic VTE and survival data were obtained from national registries. The reference population was obtained from national registries with a random sample of inhabitants matched for age, sex, and location of residence with a 4:1 ratio and was analyzed similarly.

RESULTS

Altogether, 1021 patients and 4065 controls were included (88% male; median age, 74 years in both groups). The high-risk period for VTE lasted for approximately 3 months, and during that time, its occurrence was highest in patients with coronary disease (2.5%), after open repair (2.4%), and in an urgent or emergency setting (2.6%), whereas the rate was low after endovascular aneurysm repair (1.0%). The cumulative incidence of VTE at 3 months, 1 year, 3 years, and 5 years was 1.1%, 1.6%, 2.7%, and 4.5% in patients and 0.1%, 0.3%, 1.0%, and 1.8% in the reference population, respectively (P < .001 each). Most VTE events were PE in the patient group. The 5-year mortality rates were 37.9% in patients and 23.8% in controls (P < .001).

CONCLUSIONS

The incidence of symptomatic VTE, particularly PE, after AAA repair is significant, in both short-term and long-term follow-up. Open surgery, acute setting, and concomitant coronary disease appear to increase the risk.

Trends in Total Knee Arthroplasty in a Developing Region: A Survey of Latin American Orthopaedic Surgeons

INTRODUCTION

A number of different total knee arthroplasty techniques are available. There is also a degree of surgeon preference for these, and the variation across orthopaedic surgeons in Latin America is currently unknown.

METHODS

A survey on members of Sociedad Latinoamericana de Artroscopia, Rodilla y Deporte was performed, with questions based on categories within worldwide national joint registries. In total, 315 Sociedad Latinoamericana de Artroscopia, Rodilla y Deporte members received the survey via e-mail, and the return answers were compared with the latest worldwide national joint registry annual reports.

RESULTS

The survey was completed in full by 262 surgeons (83%). It was answered that 19% of surgeons perform less than 10 total knee arthroplasties per year, 54% perform less than 30, and only 9% perform more than 100. Seventy-three percent of surgeons use a posterior stabilized total knee replacement, 18% use a cruciate retaining total knee replacement, and 9% use a medial pivot design. Forty-nine percent of surgeons resurface the patella, 27% never resurface it, and 24% choose to resurface it based on an individual case scenario. Ninety-eight percent of surgeons use cemented fixation in the femur and tibia, with the remaining 2% choosing hybrid fixation and 1% using fully noncemented fixation.

CONCLUSION

This survey among Latin American surgeons has demonstrated important differences in surgical technique and implants choice compared with worldwide national registries.