Effect of Low-Intensity vs Standard-Intensity Warfarin Prophylaxis on Venous Thromboembolism or Death Among Patients Undergoing Hip or Knee Arthroplasty: A Randomized Clinical Trial

Comparative Efficacy and Safety of Measures for the Treatment of Adults with Isolated Calf Muscular Vein Thrombosis: A Systematic Review and Network Meta-analysis

BACKGROUND

Isolated calf muscular vein thrombosis (ICMVT) can result in pulmonary embolism, but the treatment of ICMVT remains controversial. Therefore, the purpose of the present study was to investigate the optimal treatment for the ICMVT by comparing the efficacy and safety of different treatments.

METHODS

A network meta-analysis was conducted to search for studies published from database inception to April 30, 2022, that compared the outcomes of 2 or more treatments for ICMVT. The primary outcomes were efficacy (resolution rate) and safety (adverse reactions). Data were extracted following predefined hierarchy and the Cochrane Collaboration risk of bias tool was used to evaluate the methodological quality of the included studies. We estimated summary odds ratios with 95% credibility intervals using Bayesian network meta-analysis with random effects.

RESULTS

A total of 16 studies were enrolled in the study. In terms of efficacy and safety, urokinase thrombolysis combined with low-molecular-weight heparin (LMWH) was most effective but had the lowest safety, while physical therapy was safest but had the lowest efficacy. More important, direct oral factor Xa inhibitors were most likely to be second most effective and safe compared with other treatments. For the duration of treatment, anticoagulant therapy for at least 3 months could effectively increase the resolution rate of ICMVT.

CONCLUSIONS

Considering both efficacy and safety, taking direct oral factor Xa inhibitors for at least 3 months was the optimal treatment compared to LMWH, urokinase thrombolysis combined LMWH, physical therapy and warfarin for patients with ICMVT.

Subgroup analyses in venous thromboembolism trials reporting pharmacological interventions: A systematic review

INTRODUCTION

Randomized controlled trials (RCTs) that conduct subgroup analyses have the potential to provide information on treatment decisions in specific groups of patients from heterogeneous populations. Although we understand several factors can modify the incidence of venous thromboembolism (VTE) and the benefit/risk ratio of anticoagulation treatments, further evidence is warranted to show the heterogeneity of treatment effects in different subgroups of patients.

AIMS

The primary purpose was to evaluate the appropriateness and interpretation of subgroup analysis performed on VTE RCTs reporting pharmacological interventions.

MATERIALS AND METHODS

A systematic review of RCTs published between January 2017 and January 2022 was conducted. Claims of subgroup effects were evaluated with predefined criteria. High-quality claims of subgroup effect were further analyzed and discussed.

RESULTS

Overall, 28 RCTs with a generally low bias risk were included. The purposes of the treatments included pharmacologic thromboprophylaxis (17), therapeutic dose anticoagulation (9), and catheter-directed pharmacologic thrombolysis (2). The evaluated subgroup analyses generally presented: a high number of subgroup analyses reported, a lack of prespecification, and a lack of usage of statistical tests for interaction. The authors reported 13 claims of subgroup effect; only two were considered potentially reliable to represent heterogeneity in the direction or magnitude of treatment effect.

CONCLUSIONS

Subgroup analyses of VTE RCTs reporting pharmacologic interventions are generally methodologically poor. Most claims of subgroup effect did not meet critical criteria and lacked credibility. Clinicians in this field may proceed with scepticism when assessing claims of subgroup effects due to methodological concerns and misleading interpretations.

Established Clinical Prediction Rules for Bleeding had Mediocre Discrimination in Left Ventricular Assist Device Recipients

Left ventricular assist devices (LVAD) reduce mortality in patients with end-stage heart failure, but LVAD management is frequently complicated by bleeding. Bleeding prediction post-LVAD implantation is challenging as prediction rules for hemorrhage have not been rigorously studied in this population. We aimed to validate clinical prediction rules for bleeding, derived in the atrial fibrillation and venous thromboembolism populations, in an LVAD cohort. This was a retrospective cohort study of LVAD recipients at an academic center. The primary end-point was time to gastrointestinal bleed or intracranial hemorrhage after implant; the secondary end-point was time to any major hemorrhage after hospital discharge. Four hundred and eighteen patients received an LVAD (135 HeartMate II, 125 HeartMate 3, 158 HVAD) between November 2009 and January 2019. The primary end-point occurred in 169 (40.4%) patients with C-statistics ranging 0.55-0.58 (standard deviation [SD] 0.02 for all models). The secondary end-point occurred in 167 (40.0%) patients with C-statistics ranging 0.53-0.58 (SD 0.02 for all models). Modifying the age and liver function thresholds increased the C-statistic range to 0.56-0.60 for the primary and secondary end-points. In a sensitivity analysis of HeartMate 3 patients, prediction rules performed similarly. Existing prediction rules for major bleeding had mediocre discrimination in an LVAD cohort.

Predicting Postoperative Troponin in Patients Undergoing Elective Hip or Knee Arthroplasty: A Comparison of Five Cardiac Risk Prediction Tools

Background

Elderly patients undergoing hip or knee arthroplasty are at a risk for myocardial injury after noncardiac surgery (MINS). We evaluated the ability of five common cardiac risk scores, alone or combined with baseline high-sensitivity cardiac troponin I (hs-cTnI), in predicting MINS and postoperative day 2 (POD2) hs-cTnI levels in patients undergoing elective total hip or knee arthroplasty.

Methods

This study is ancillary to the Genetics-InFormatics Trial (GIFT) of Warfarin Therapy to Prevent Deep Venous Thrombosis, which enrolled patients 65 years and older undergoing elective total hip or knee arthroplasty. The five cardiac risk scores evaluated were the atherosclerotic cardiovascular disease calculator (ASCVD), the Framingham risk score (FRS), the American College of Surgeon's National Surgical Quality Improvement Program (ACS-NSQIP) calculator, the revised cardiac risk index (RCRI), and the reconstructed RCRI (R-RCRI).

Results

None of the scores predicted MINS in women. Among men, the ASCVD (C-statistic of 0.66; p=0.04), ACS-NSQIP (C-statistic of 0.69; p=0.01), and RCRI (C-statistic of 0.64; p=0.04) predicted MINS. Among all patients, spearman correlations (r_s) of the risk scores with the POD2 hs-cTnI levels were 0.24, 0.20, 0.11, 0.11, and 0.08 for the ASCVD, Framingham, ACS-NSQIP, RCRI, and R-RCRI scores, respectively, with p values of <0.001, <0.001, <0.001, 0.006, and 0.025. Baseline hs-cTnI predicted MINS (C-statistics: 0.63 in women and 0.72 in men) and postoperative hs-cTnI (r_s = 0.51, p=0.001).

Conclusion

In elderly patients undergoing elective hip or knee arthroplasty, several of the scores modestly predicted MINS in men and correlated with POD2 hs-cTnI.

Application of fresh frozen plasma transfusion in the management of excessive warfarin-associated anticoagulation

Warfarin is a commonly used oral anticoagulant. Patients with artificial valve replacement, atrial fibrillation, pulmonary embolism, deep vein thrombosis, and other diseases require long-term anticoagulant oral treatment with warfarin. As warfarin exhibits prompt action with long maintenance time, it has become a key drug for the treatment of patients at risk of developing thrombosis or thromboembolism. Warfarin is a bican coumarin anticoagulant, that exhibits competitive action against vitamin K as its mechanism of action, thereby inhibiting the synthesis of coagulation factors—predominantly the vitamin K-dependent coagulation factors II, VII, IX, and X—in hepatocytes. Long-term warfarin is known to significantly increase the risk of organ bleeding in some patients, while some patients may need to reverse the anticoagulation effect. For instance, patients scheduled for emergency or invasive surgery may require rapid anticoagulation reversal. During such medical circumstances, fresh frozen plasma (FFP) is clinically used for the reversal of excess warfarin-associated anticoagulation, as it contains all the coagulation factors that can alleviate the abnormal blood anticoagulation status in such patients. Accordingly, this article aims to perform an in-depth review of relevant literature on the reversal of warfarin with FFP, and insightful deliberation of the application and efficacy of this clinical intervention.

Venous Thromboembolic Prophylaxis After Total Hip and Knee Arthroplasty

➤

The selection of an agent for prophylaxis against venous thromboembolism (VTE) is a balance between efficacy and safety. The goal is to prevent symptomatic VTE while limiting the risk of bleeding.

➤

The optimal agent for VTE prophylaxis has not been identified. The American College of Chest Physicians guidelines recommend that, after total hip or total knee arthroplasty, patients receive at least 10 to 14 days of 1 of the following prophylaxis agents: aspirin, adjusted-dose vitamin K antagonist, apixaban, dabigatran, fondaparinux, low-molecular-weight heparin, low-dose unfractionated heparin, rivaroxaban, or portable home mechanical compression.

➤

The use of aspirin for VTE prophylaxis has increased in popularity over the past decade because it is effective, and it is an oral agent that does not require monitoring. The true efficacy of aspirin needs to be determined in multicenter randomized clinical trials.

➤

Validated risk stratification protocols are essential to identify the safest and most effective regimen for VTE prophylaxis for individual patients. There is no consensus regarding the optimal method for risk stratification; the selection of a prophylaxis agent should be determined by shared decision-making with the patient to balance the risk of thrombosis versus bleeding.

➤

Patients with atrial fibrillation being treated with chronic warfarin therapy or direct oral anticoagulants should stop the agent 3 to 5 days prior to surgery. Patients do not typically require bridging therapy prior to surgery.

Are the correct outcomes being measured in studies of oral anticoagulants? A systematic survey

INTRODUCTION

Oral anticoagulant (OAC) intervention trials have typically included clinical event outcomes. However, there is no standard list of outcomes to be used in OAC research. This study aimed to describe and classify the outcomes used in recent prospective clinical studies involving OACs.

MATERIALS AND METHODS

We searched MEDLINE, EMBASE, and CINAHL databases from January 2009 to July 2019 for prospective studies with an intervention or control group that included one or more oral anticoagulants. We abstracted details about each included study and the outcomes used from the study report and its accompanying protocol. Using the Core Outcome Measures in Effectiveness Trials (COMET) Initiative recommendations, we categorised each outcome into one of five domains (mortality/survival, physiological/clinical, life impact, resource use, and adverse events). Our primary outcome was the prevalence of use of an outcome domain across studies.

RESULTS

We included 70 prospective studies, including 52 randomized controlled trials and 18 prospective cohort studies. A total of 121 different outcomes were reported. The COMET domains were represented in the 70 studies as follows: mortality (63/70, 90.0%); physiological/clinical domain (70/70, 100%), life impact domain (43/70, 61.4%), resource use domain (26/70, 37.1%), and adverse events domain (55/70, 78.6%).

CONCLUSION

Outcome reporting in prospective studies of OACs more frequently concentrates on mortality, physiological/clinical domains, and adverse events compared to life impact and resource utilization domains, the latter uncommonly used. A priority for future research includes developing a core outcome set (COS) for OAC research that represents all domains.

Catheter-related obstruction of the right brachiocephalic vein following hemodialysis in a patient with lupus nephritis

Vascular access is necessary for hemodialysis, and in some cases where it is difficult to establish an arteriovenous fistula or arteriovenous graft, a permanent hemodialysis catheter may be used. However, serious catheter-related complications, such as central vein stenosis or thrombosis, can occur. We herein present a case of complete brachiocephalic vein obstruction in a patient with lupus nephritis receiving hemodialysis using a tunneled hemodialysis catheter. A 64-year-old patient underwent maintenance hemodialysis while taking an anticoagulant, with a tunneled hemodialysis catheter in the right internal jugular vein, because of arteriovenous fistula failure when hemodialysis was introduced. However, the catheter was removed because of a catheter-related bloodstream infection. Following the administration of antibiotics, an arteriovenous graft was implanted between the brachial artery and axillary vein in the right arm. Surprisingly, arteriovenous graft failure and complete obstruction of the right brachiocephalic vein were observed 3 days after arteriovenous graft creation. In conclusion, we report the case of tunneled hemodialysis catheter-related complete obstruction of the right brachiocephalic vein in a lupus nephritis patient undergoing hemodialysis. Clinicians should be aware of this potential complication when tunneled hemodialysis catheters are used and consider the next vascular access type before a tunneled hemodialysis catheter has been indwelled for the long term.