Recommendations from the ICM-VTE: General

Low-versus high-dose aspirin for venous thromboembolic prophylaxis after total joint arthroplasty: a systematic review and meta-analysis

BACKGROUND

The adverse effects of aspirin are dose-dependent, and there is controversy surrounding the use of low-dose (LD) aspirin to prevent venous thromboembolism (VTE) following total joint arthroplasty (TJA). This meta-analysis sought to compare the efficacy and complication rate of low-dose (162 mg per day) versus high-dose (HD, 650 mg per day) aspirin after TJA surgery.

METHODS

In four main databases, we searched from inception until September 2024 for articles comparing the rate of VTE following TJA(TKA/THA) using only aspirin chemoprophylaxis with different dosages. We meta-analyzed and compared the VTE and complication rates of LD aspirin (162 mg per day) with HD aspirin (650 mg per day) and presented our results as odds ratio (ORs) in forest plot diagrams.

RESULTS

There were 14 eligible studies, comprising 43,518 patients in the LD group and 62,645 patients in the HD group. DVT (OR: 1.37, CI: 0.93-2.02, P = 0.11) and PE (OR: 1.86, CI: 0.73-4.72, P = 0.19) rates were similar between the groups. However, taking VTE as the total number of cases with DVT or PE, the incidence was significantly higher in the HD group than in the LD group (OR:1.53, CI: 1.17-2.00, P = 0.002). HD also had a significantly higher rate of PJI (OR:2.68 CI:1.5-4.6 P = 0.001), but gastrointestinal bleeding (GIB) was similar between the two groups (OR: 0.97, CI: 0.42-2.22, P = 0.95).

CONCLUSION

The findings suggest that LD aspirin may be a viable option for VTE chemoprophylaxis following TJA, potentially offering comparable efficacy with a lower risk of PJI compared to HD aspirin regimens.

LEVEL OF EVIDENCE

Therapeutic Level II.

Low-Dose Enteric-Coated and Chewable Aspirin Are Not Equally Effective in Preventing Venous Thromboembolism in Total Knee and Hip Arthroplasty

BACKGROUND

Low-dose aspirin is an effective venous thromboembolism (VTE) prophylactic medication in primary total joint arthroplasty, but the efficacy and safety of the formulations of chewable and enteric-coated aspirin have not been compared. The purpose of this study was to investigate the VTE and gastrointestinal (GI) complication rates of chewable and enteric-coated 81 mg aspirin bis in die for VTE prophylaxis in primary total joint arthroplasty.

METHODS

A retrospective, single-institution cohort study was performed on patients who underwent primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) from 2017 to 2021. Comparisons were made between 4,844 patients who received chewable, noncoated aspirin 81 mg and 4,388 patients who received enteric-coated 81 mg aspirin. Power analysis demonstrated 1,978 and 3,686 patients were needed per group to achieve a power of 80% for 90-day VTE rates (using inferiority testing) and GI complications (using superiority testing), respectively. Patients had similar baseline characteristics. Statistical analyses were done using t-tests and Chi-squared tests, with statistical significance defined as a P value < .05.

RESULTS

There were no significant differences in the incidences of postoperative VTE (0.31% versus 0.55%; P = .111) or GI complications (0.14% versus 0.14%; P = 1.000) between patients who received either chewable or enteric-coated 81 mg aspirin bis in die in the overall comparison that included both THA and TKA patients combined, or THA patients alone. However, the VTE incidence for TKA patients alone was significantly lower with chewable than enteric-coated aspirin (0.22% versus 0.62%; P = .037), with no difference in GI complications (0.13% versus 0.19%; P = .277).

CONCLUSIONS

Low-dose aspirin in enteric-coated formulation is inferior to chewable aspirin for VTE prophylaxis in primary TKA, but not inferior in THA patients. Both formulations have a similar GI complication rate. Therefore, it is reasonable to consider a transition from enteric-coated to uncoated chewable low-dose aspirin.

Low-Dose Aspirin Is the Safest Prophylaxis for Prevention of Venous Thromboembolism After Total Knee Arthroplasty Across All Patient Risk Profiles

BACKGROUND

The International Consensus Meeting on Venous Thromboembolism (ICM-VTE) in 2022 proclaimed low-dose aspirin as the most effective agent in patients across all risk profiles undergoing joint arthroplasty. However, data on large patient populations assessing trends in chemoprophylactic choices and related outcomes following total knee arthroplasty (TKA) remain scant. The present study was designed to characterize the clinical use of various chemoprophylactic agents in patients undergoing TKA and to determine the efficacy of aspirin compared with other agents in patient groups stratified by VTE risk profiles.

METHODS

This study utilized a national database to determine the proportion of patients undergoing TKA who received low-dose aspirin versus other chemoprophylaxis between 2012 and 2022. VTE risk profiles were determined on the basis of comorbidities established in the ICM-VTE. The odds ratios (ORs) and 95% confidence intervals (CIs) between various classes of thromboprophylaxis in patients with high and low risk of VTE were calculated. The odds of deep-vein thrombosis (DVT), pulmonary embolus (PE), bleeding events, infections, mortality, and hospitalizations were also assessed in the 90-day postoperative period for propensity-matched cohorts receiving low-dose (81 mg) aspirin only versus other prophylaxis, segregating patients by VTE risk profile.

RESULTS

A total of 126,692 patients undergoing TKA across 60 health-care organizations were included. The proportion of patients receiving low-dose aspirin increased from 7.65% to 55.29% between 2012 and 2022, whereas the proportion of patients receiving other chemoprophylaxis decreased from 96.25% to 42.98%. Low-dose-aspirin-only use increased to approximately 50% in both high-risk and low-risk populations but was more likely in low-risk populations (OR, 1.17; 95% CI, 1.15 to 1.20) relative to high-risk populations. Both low-risk and high-risk patients in the low-dose-aspirin-only cohorts had decreased odds of DVT, PE, bleeding, infections, and hospitalizations compared with other prophylaxis regimens.

CONCLUSIONS

The findings of the present study on a very large population of patients undergoing TKA support the recent ICM-VTE statement by showing that low-dose aspirin is a safe and effective method of prophylaxis in patients across various risk profiles.

LEVEL OF EVIDENCE

Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Current trends for venous thromboembolic prophylaxis for hip arthroscopy: a modified Delphi and nominal group technique consensus study

The overall risk of venous thromboembolism (VTE) after hip arthroscopy (HA) is reported to range from 0.2% to 9.5%, but a clear set of recommendations for VTE prophylaxis in HA patients remains scarce. The aim is to survey high-volume hip arthroscopists about their current trends regarding VTE prophylaxis use. A combination of two consensus group methods was used in this study: nominal group technique (NGT) and modified Delphi. A preliminary questionnaire was prepared, and rounds of discussion were completed between NGT members. The final version of the survey was administered to 35 high-volume hip surgeons. Delegates' mean volume of annual hip arthroscopic surgery was 109. Approximately 22% of their patients are revision HA procedures. A total of 91.4% of delegates use chemoprophylaxis, 28.6% use sequential compression devices and 91.4% believed that chemoprophylaxis is necessary for more prolonged and complex procedures (strong consensus). Aspirin was the choice for all participants, and the duration was 2-3 weeks (31.4%), 1 month (65.7%) and 2-3 months (2.9%). History of VTE, hypercoagulable status, and malignancy were considered risk factors. No consensus was achieved for the discontinuation of oral contraceptive and smoking preoperatively. However, the optimal length of VTE prophylaxis is unclear. A total of 97.1% of the experts responded that they administer aspirin between 2 and 4 weeks. High-volume arthroscopic surgeons do consider VTE prophylaxis to be important and warranted in the postoperative setting. Aspirin is the mainstay of chemoprophylaxis, although the appropriate duration is unknown.

Patients Who Have a Prior History of Pulmonary Embolism Require Increased Postoperative Care Following Total Joint Arthroplasty

BACKGROUND

This study examined the effect of prior pulmonary embolism (PE) on total joint arthroplasty (TJA) outcomes.

METHODS

We reviewed patients who had a prior PE undergoing TJA at a single tertiary medical center between January 1, 2012 and January 1, 2021. There were 177 TJA patients who had a prior PE who underwent 1:3 propensity-matching to patients without a history of prior PE. Bivariable and multivariable analyses were performed. Changes over time were evaluated.

RESULTS

Patients undergoing total knee arthroplasty who had a prior PE had more complications (25.3% versus 2.0%, P < .001), and postoperative PE (17.3% versus 0.0%, P < .001).and longer hospitalizations (3.15 versus 2.32 days, P = .006). Patients undergoing total hip arthroplasty who had a prior PE demonstrated more complications (14.7% versus 1.77%, P < .001) more postoperative PE (17.3% versus 0.0%, P < .001), and longer hospitalizations (3.30 versus 2.11 days, P < .001). Over the study, complication rates and hospitalizations lengths remained elevated in patients who had a prior PE. On multivariate analyses, prior PE was associated with longer hospitalizations (β: 0.67, P = .015) and increased complications (odds ratio [OR]: 9.44, P < .001) among total hip arthroplasty patients. Total knee arthroplasty patients had increased readmission (OR: 4.89, P = .003) and complication rates (OR: 21.4, P < .001).

CONCLUSIONS

Patients undergoing TJA who had a prior PE are at higher risk of requiring postoperative care. Therefore, thorough preoperative evaluation must be implemented, especially in clinical environments lacking resources for acute care escalation.

Aspirin prophylaxis is not associated with increased risk of venous thromboembolism in arthroplasty for femoral neck fractures: a non-inferiority study

PURPOSE

Venous thromboembolism (VTE) is a known complication of hip arthroplasty for femoral neck fractures (FNF) with various prophylactic anticoagulants utilized to decrease risk. The purpose of this study was to assess the efficacy and perioperative outcomes associated with aspirin for VTE prophylaxis following arthroplasty for FNF.

METHODS

Medical records of 1,220 patients who underwent hip hemiarthroplasty (HHA) or total hip arthroplasty (THA) at an urban academic center from 2011 to 2022 were retrospectively reviewed. Patient characteristics and perioperative outcomes, including length of stay (LOS), VTE, 90-day hospital encounters, and discharge disposition, were collected. Outcomes for patients prescribed aspirin (n = 214) were compared to those prescribed non-aspirin VTE prophylaxis (n = 1006) using propensity score matching.

RESULTS

Patients who received aspirin had higher rates of THA (36.0 vs 26.7%; p = 0.008). There were no significant risk-adjusted differences in the incidence of VTE (0.5 vs 0.5%, p = 1.000) and 90-day readmissions (10.4 vs 12.3%, p = 0.646) between patients prescribed aspirin and non-aspirin VTE prophylaxis, respectively. Patients prescribed non-aspirin agents had higher rates of non-home discharge (73.9 vs 58.5%; p < 0.001) and longer LOS (143.5 vs 124.9 h; p = 0.005). Sub-analysis of patients prescribed aspirin and non-aspirin prophylaxis based on comorbidity scores demonstrated no difference in VTE incidence for low (0.0 vs 1.6%, p = 1.000) and high scores (0.0 vs 0.0%, p = 1.000), respectively.

CONCLUSION

Aspirin is not associated with increased incidence of VTE after HHA or THA for FNF. Aspirin prophylaxis should be considered in hip fracture patients to mitigate bleeding risk, particularly those with low to intermediate VTE risk.

LEVEL OF EVIDENCE

Level III, Retrospective study.

While the Incidence of Venous Thromboembolism After Shoulder Arthroscopy Is Low, the Risk Factors Are a Body Mass Index Greater than 30 and Hypertension

Purpose

This study aims to determine the overall incidence of venous thromboembolism (VTE) following shoulder arthroscopy and to define potential risk factors associated with its development that may help define guidelines for the use of thromboprophylaxis.

Methods

A systematic review was performed using PubMed, Embase, Web of Science, CINAHL, and Cochrane databases per PRISMA guidelines. The search terms consisted of variations of "Venous Thromboembolism" and "Shoulder Arthroscopy." Information regarding arthroscopy indication, risk factors, outcomes, and patient demographics was recorded and analyzed, and pooled odds ratios were reported for each variable.

Results

Six hundred eighty-five articles were identified in the initial search, and 35 articles reported DVT, PE, or VTE incidence following shoulder arthroscopy. Seventeen nonoverlapping articles with a unique patient population incidence rates. Four articles were then used for subgroup meta-analysis. The incidence rate of VTE was 0.24%, ranging from 0.01% to 5.7%. BMI >30 (OR = 1.46; 95% CI = [1.22, 1.74]; I2 = 0%) and hypertension (OR = 1.64; 95% CI = [1.03, 2.6]; I2 = 75%) were significant risk factors (P < .05) for developing VTE following shoulder arthroscopy. Diabetes (OR = 1.2; 95% CI = [0.97, 1.48]; I2 = 0%), insulin-dependent diabetes (OR = 5.58; 95% CI = [0.12, 260.19]; I2 = 85%), smoking (OR = 1.04; 95% CI = [0.79, 1.37]; I2 = 12%), male sex (OR = 0.95; 95% CI = [0.49, 1.85]; I2 = 86%) and age over 65 (OR = 4.3; 95% CI = [0.25, 72.83]; I2 = 85%) were not associated with higher VTE risk.

Conclusion

The VTE incidence following shoulder arthroscopy is low at 0.24%. Patients with BMI >30 and hypertension are at a higher risk for VTE after shoulder arthroscopy.

Level of Evidence

Level IV, systematic review and meta-analysis of Level I-IV studies.

Venous Thromboembolism Prophylaxis in Foot and Ankle Surgery: A Worldwide Survey

Current recommendations on thromboprophylaxis for foot and ankle (FA) surgery are often inconsistent and generally based on weak evidence. The aim of this survey study was to evaluate the current practice among orthopedic surgeons regarding venous thromboembolism (VTE) prophylaxis following FA surgery. From February 2019 to March 2020, an online questionnaire was sent by e-mail to orthopedic societies across the world. The questionnaire was hosted by the International Society of Thrombosis and Haemostais RedCAP platform. Topics of interest were VTE rates following FA surgery, duration and type of thromboprophylaxis, bleeding complications, VTE risk factors for prophylaxis and use of risk assessment. A total of 693 FA orthopedic surgeons from all continents completed the survey of whom 392 (57%) performed more than 200 FA procedures per year. A total of 669/693 (97%) respondents stated that thromboprophylaxis is necessary in FA surgeries. When thromboprophylaxis was prescribed, half of surgeons prescribed it for the duration of immobilization. Acetylsalicylic acid, low molecular weight heparin and direct-oral anticoagulants were, in this order, the preferred choice. Acetylsalicylic acid and low molecular weight heparin were predominantly prescribed in North America and Europe, respectively. Previous deep vein thrombosis, immobility, obesity and inherited thrombophilia were considered the main risk factors indicative of thromboprophylaxis use. In this survey, most surgeons agree that thromboprophylaxis is indicated for FA surgery, but the prescription, type and duration of prophylaxis differs greatly with a large intercontinental discrepancy. These survey results could be a foundation for developing uniform guidelines to optimize thromboprophylactic strategies in FA procedures around the world.

Initiating versus delaying treatment-dose anticoagulation in suspected venous thromboembolism (VTE) in post-operative hip and knee arthroplasty patients: Outcomes and risks

Background

Hip and knee arthroplasty is a risk factor for venous thromboembolism (VTE). Initiation of treatment-dose anticoagulation in the post-operative period in suspected cases prior to confirmed diagnosis involves balancing increased bleeding risk to VTE-associated morbidity.

Methods

A single-centre retrospective cohort study was undertaken comparing outcomes of empirical treatment of suspected VTE in post-operative elective lower-limb arthroplasty patients as opposed to delaying treatment until diagnosis is confirmed. All patients undergoing ultrasonography (US) or CT-pulmonary-angiogram (CTPA) for suspected VTE following elective total hip arthroplasty (THA) or total knee arthroplasty (TKA) between 05/05/17 and 19/07/21 were identified. Primary outcomes were surgical site infection (SSI), readmission, and other wound problems within 30-days of surgery.

Results

107 patients were included for analysis. 93 patients had suspected deep venous thrombosis (DVT), 21 had suspected pulmonary embolism (PE), and 7 were investigated for both DVT and PE. Empirical treatment-dose anticoagulation was initiated in 4 patients with suspected pulmonary embolism (PE) prior to CTPA, and 34 patients with suspected deep venous thrombosis (DVT) prior to US. No significant differences were noted in 30-day readmission rate ([DVT: 12 % vs 23 %, p = 0.41], [PE: 50 % vs 33 %, p = 1.00]), SSI rate ([DVT: 6 % vs 3 %, p = 1.00], [PE: 0 % vs 11 %, p = 1.00]) or other wound complication rate ([DVT: 3 % vs 3 %, p = 1.00), [PE 0 % vs 11 %, p = 1.00]) between empirically and non-empirically treated groups respectively.

Conclusion

Empirical initiation of therapeutic anticoagulation in post-operative lower limb arthroplasty patients with suspected VTE appears to be safe practice prior to a definitive diagnosis.

Use of Preoperative CT Scans and Patient-Specific Instrumentation May Not Improve Short-Term Adverse Events After Shoulder Arthroplasty: Results from a Large Integrated Health-Care System

Ongoing innovation leads to a continuous influx of new technologies related to shoulder arthroplasty. These are made available to surgeons and marketed to both health-care providers and patients with the hope of improving outcomes. We sought to evaluate how preoperative planning technologies for shoulder arthroplasty affect outcomes.

Methods

This was a retrospective cohort study conducted using data from an integrated health-care system's shoulder arthroplasty registry. Adult patients who underwent primary elective anatomic or reverse total shoulder arthroplasty (2015 to 2020) were identified. Preoperative planning technologies were identified as (1) a computed tomography (CT) scan and (2) patient-specific instrumentation (PSI). Multivariable Cox regression and logistic regression were used to compare the risk of aseptic revision and 90-day adverse events, respectively, between procedures for which technologies were and were not used.

Results

The study sample included 8,117 procedures (in 7,372 patients) with an average follow-up of 2.9 years (maximum, 6 years). No reduction in the risk of aseptic revision was observed for patients having either preoperative CT scans (hazard ratio [HR] = 1.22; 95% confidence interval [CI] = 0.87 to 1.72) or PSI (HR = 1.44; 95% CI = 0.71 to 2.92). Patients having CT scans had a lower likelihood of 90-day emergency department visits (odds ratio [OR] = 0.84; 95% CI = 0.73 to 0.97) but a higher likelihood of 90-day venous thromboembolic events (OR = 1.79; 95% CI = 1.18 to 2.74). Patients with PSI use had a higher likelihood of 90-day deep infection (OR = 7.74; 95% CI = 1.11 to 53.94).

Conclusions

We found no reduction in the risk of aseptic revision with the use of these technologies. Patients having CT scans and PSI use had a higher likelihood of venous thromboembolism and deep infection, respectively. Ongoing research with extended follow-up is being conducted to further examine the effects of these technologies on patient outcomes.

Level of Evidence

Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Incidence of Symptomatic Venous Thromboembolism (VTE) in 8,885 Elective Total Hip Arthroplasty Patients Receiving Post-operative Aspirin VTE Prophylaxis

BACKGROUND

Venous thromboembolism (VTE) is a potentially reducible cause of morbidity and mortality in patients undergoing elective hip arthroplasty surgery. The balance of post-operative VTE prophylaxis and risk of post-operative haemorrhage remains at the forefront of surgeon's mind. The National Institute for Health and Care Excellence (NICE) published updated guidelines in 2018 which recommend the use of both mechanical and pharmacological methods in patients undergoing elective total hip arthroplasty (THA).

OBJECTIVES

The aim of this study was to present the symptomatic VTE incidence in 8,885 patients who underwent THA between January 1998 and March 2018 with Aspirin as the primary agent for pharmacological thromboprophylaxis. Intermittent calf compression stockings are routinely used from the time of surgery until mobilization (usually the following day) with prophylactic doses of low molecular weight heparin (LMWH) during inpatient stay (from 2005 onwards) and then Aspirin 150mg once daily for six weeks on hospital discharge (or Aspirin only prior to 2005), with use of other therapies occasionally as required.

METHODS

Analysis of prospective data collection from consecutive patients at a single institution undergoing THA was performed with the incidence of symptomatic deep vein thrombosis (DVT) and pulmonary embolism (PE) occurring within six months of the index operation as the primary outcome measure. Ninety-day all-cause mortality of this cohort of patients was also analysed.

RESULTS

8,885 patients were reviewed. This included 7230 primary, 224 complex primary and 1431 revision cases. The overall incidence of symptomatic VTE after elective THA was 1.11% (99/8885) - with the incidence of symptomatic DVT of 0.59% (52/8885) and the incidence of symptomatic PE of 0.53% (47/8885). There was no significant difference (χ² test, p=0.239) in the symptomatic VTE incidence between primary (1.20% - 89/7230), complex primary (0.89% - 2/224) and revision cases (0.70% - 10/1431). The 90-day all-cause mortality was 0.88% (78/8885). Cardiovascular and respiratory disease were the main causes of death following surgery. Only 0.03% of deaths (n= 3) within 90 days of index surgery were due to PE. There was no significant difference (p=0.327) in length of stay (and hence amount of pharmacologic prophylaxis with LMWH received by patients before commencement of Aspirin) with the average length of stay for those patients who did not suffer a VTE of 6.8 days compared with 7.6 days for those who did suffer a VTE.

CONCLUSION

Our results support the use of aspirin as an effective form of prophylaxis against symptomatic VTE following THA in contradiction to NICE and American Academy of Orthopaedic Surgery (AAOS) recommendations. It is not associated with an increased incidence in symptomatic DVT, PE or death compared to other published studies. The fact that it is inexpensive, readily available, requires no monitoring and does not pose an increased risk of bleeding are other advantages of using aspirin for VTE prophylaxis.