Venous Thromboembolism In High-risk Patients Research Articles

Risks of major bleeding and venous thromboembolism in patients undergoing total hip or total knee arthroplasty using therapeutic dosages of DOACs.

About 1.5% of patients undergoing total hip (THA) or total knee arthroplasty (TKA) still develop postoperative venous thromboembolism (VTE), indicating that the current thromboprophylaxis strategy is not optimal. To evaluate the feasibility of therapeutic dosages of direct oral anticoagulants (DOACs) as thromboprophylaxis for high VTE risk patients, we determined the risks of major bleeding and VTE in patients who underwent THA/TKA and were treated with DOACs in therapeutic dosages for atrial fibrillation (AF). We conducted a registry-based cohort study from 2010 to 2018 in Denmark and included AF patients on therapeutic DOACs dose who underwent THA/TKA. AF patients were utilized as proxy since they have a life-long indication for therapeutic anticoagulant medication. The 49-days cumulative incidence (with death as competing risk) of major bleeding was assessed. The same was done for VTE at 49- and 90-days. 1,354 THA and TKA procedures were included. The 49-days cumulative incidence of major bleeding was 1.40% (95%Confidence Interval[CI] 0.88-2.14%). Most bleeding events occurred at the surgical site. The cumulative incidence of VTE at 49-days was 0.59% (95%CI 0.28-1.13%) and 0.74% (95%CI 0.38-1.32%) at 90-days. The incidence of major bleeding in THA/TKA patients on DOACs in therapeutic dosages was in line with previously reported incidences among THA/TKA patients on thromboprophylaxis dosages, while the incidence of VTE was relatively low. These data provide a solid basis for the design of randomized controlled trials to establish the safety and efficacy of therapeutic dosages of DOACs to prevent VTE in high-risk patients.

Implementation of an Electronic Medical Record Tool for Early Detection of Deep Vein Thrombosis in the Ambulatory Oncology Setting: The Cleveland Clinic Experience

BACKGROUND:Venous thromboembolism (VTE) is a major cause of morbidity, and the second leading cause of mortality in cancer patients. VTE is associated with delay in cancer directed therapy, increased frequency and duration of hospitalization and overall healthcare costs. However, validated scoring systems for assessing risk of VTE are not widely used in clinical practice. We hypothesized that creation of a computerized risk calculator could help identify at-risk individuals in the ambulatory oncology setting; further, screening for VTE in high risk patients could lead to early detection of deep vein thrombosis (DVT) and avoid potential emergent consequences, including hospitalization.METHODS:A computerized alert was built into the electronic medical record system (EPIC) that automatically calculates a score using a validated risk tool [Khorana Score (KS), Blood 2008] based on the primary site of cancer, leukocyte and platelet counts, hemoglobin, and body mass index. During silent lead-in phase I (8/2016-1/17), we evaluated the accuracy of the electronic alert to detect high-risk patients and prospectively followed them for events. During this period, we limited the test to patients presenting to gastrointestinal, thoracic, genitourinary and lymphoma clinics. Patients presenting for consultation without planned treatment/follow up of at least 3 months at our institution were excluded. In phase II (6/17-12/17), we improved the electronic alert to warn physicians in real time about high risk patients and offered lower extremity ultrasonography as a screening test for early detection. In this phase, we only included patients with KS ≥ 3, and an available CBC <2 weeks from alert.RESULTS:During phase I, the alert identified 194 consecutive patients as being at risk (see table 1). The majority of the patients with a positive alert were male (54%) with the most prevalent malignancy being lung and pancreatic adenocarcinomas. The subsequent rate of DVTs at 6 months in patients with a KS of 4 was 18.75% (3/17), patients with KS of 3 was 16.9% (11/65), KS of 2, 13.1% (8/61), and KS of 1, 6.25% (3/48) (Figure 1). See table 1.Time from score calculation to DVT was an average of 33.2 days. 30% of patients developed a DVT within 4 weeks of alert, 50% within 60 days, and 65% within 90 days. 45% of patients diagnosed with DVT were alerted during their initial or second clinic visit. 55% of patients were diagnosed while inpatient and another 30% in the emergency room. Mean emergency room visits for patients with DVT were 1.75 compared to 0.89 for all patients. Mean all cause admissions and length of stay during this period were 2.43 and 15.01 days for patients with DVT, compared to 0.93 and 5.06 respectively for all 194 patients. Mortality rates were 45% for patients with DVT compared to 17% for the study population.In phase II, 59 patients have been identified as high risk by the alert. Of these, 6 were already on therapeutic anticoagulation or had a recent history of DVT. Of the remainder, screening lower extremity ultrasonography was ordered on 10 patients; three (30%) had a LE DVT and were started on therapeutic anticoagulation. One other patient did not have screening ultrasonography ordered, and was diagnosed with DVT within 14 days and started on therapeutic anticoagulation. Additional data collection is ongoing and will be presented at the meeting.CONCLUSION:An electronic medical record risk calculator can be a valuable clinical tool in earlier detection of DVTs in high-risk cancer patients. An initial silent run-in phase demonstrates the ability of this tool to identify high-risk patients at substantially increased risk for VTE, emergency room visits, hospitalization and mortality. An ongoing phase II pilot of early screening demonstrates high rates of subclinical DVT but low rates of ordering screening tests by providers. Ongoing efforts to increase acceptance of screening ultrasonography and data collection may potentially reduce subsequent hospitalization and other adverse consequences for cancer patients. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

No Increased Risk of Venous Thromboembolism in High-Risk Patients Continuing Their Dose of 75 mg Aspirin Compared to Healthier Patients Given Low-Molecular-Weight Heparin

Optimum venous thromboembolism (VTE) prophylaxis for patients undergoing total hip or knee arthroplasty remains undefined. The purpose of this study is to compare complication rates among total joint arthroplasty patients using either low-dose aspirin (75 mg once daily) or low-molecular-weight heparin (LMWH; Fragmin/dalteparin 5000 U) for VTE prophylaxis. This is a prospective observational study. All total hip or knee arthroplasties from 2014 to 2020 were included. One thousand eighty-four patients already taking aspirin 75 mg as primary or secondary prophylaxis for cardiovascular disease continued their daily aspirin dose throughout their hospital stay and after discharge without any other kind of thromboprophylaxis. Five thousand ten patients not already taking aspirin were given LMWH for 12-14 days starting the day of surgery. Both groups consisted of patients undergoing either primary or revision total hip or knee arthroplasty. The aspirin group was older (73 ± 7.8 vs 66 ± 10.2 years, P < .01, 95% CI-7.6,-6.3) with more comorbidities but otherwise did not differ from the LMWH group. Outcome measures were recorded at 3-month follow-up and included the following complications: clinically deep venous thrombosis (DVT), pulmonary embolism (PE), deep infection, blood transfusion, and death. The aspirin group had 0.28% DVT and 0.28% PE, and the LMWH group had 0.24% DVT and 0.16% PE (P= .42 and .74, respectively). No difference in deep infection, allogenic blood transfusion, or mortality was found. No statistically significant difference in complication rates was found between aspirin 75 mg and LMWH used for VTE prophylaxis. Aspirin 75 mg daily is safe for VTE prophylaxis after total hip or knee arthroplasty.

Association of Prolonged-Duration Chemoprophylaxis With Venous Thromboembolism in High-risk Patients With Head and Neck Cancer

Venous thromboembolism (VTE) is associated with substantial morbidity and is the most common factor associated with preventable death among hospitalized patients. Data from otolaryngologic studies suggest that the risk of VTE may be underestimated among high-risk patients, particularly among those undergoing oncologic procedures. The incorporation of prolonged-duration chemoprophylaxis (PDC) into preventive therapy has been associated with substantial decreases in VTE incidence among patients undergoing oncologic surgery. However, bleeding remains a major concern among otolaryngologists, and substantial variation exists in the use of thromboprophylaxis. To assess the association between PDC and VTE in high-risk patients with head and neck cancer undergoing oncologic procedures. This retrospective cohort study identified 750 patients with biopsy-confirmed head and neck cancer and a Caprini risk score of 8 or higher who underwent inpatient oncologic surgery at a tertiary care referral center between January 1, 2014, and February 1, 2020. After exclusions, 247 patients were included in the study; patients were divided into 2 cohorts, traditional and PDC, based on the duration of prophylaxis. Univariate and multivariate analyses were performed to examine the development of VTE and bleeding-associated complications during the 30-day postoperative period. Data were analyzed from April 1 to April 30, 2020. PDC, defined as 7 or more postoperative days of chemoprophylaxis. VTE and bleeding events during the 30-day postoperative period. Among 247 patients (mean [SD] age, 63.1 [11.1] years; 180 men [72.9%]) included in the study, 106 patients (42.9%) received traditional prophylaxis, and 141 patients (57.1%) received PDC. The incidence of VTE was 5 of 106 patients (4.7%) in the traditional cohort and 1 of 141 patients (0.7%) in the PDC cohort (odds ratio [OR], 0.15; 95% CI, 0.003-1.33). In the multivariate logistic regression analysis, PDC was independently associated with reductions in the risk of VTE (OR, 0.04; 95% CI, 0.001-0.46). The incidence of bleeding events was 1 of 106 patients (0.9%) in the traditional cohort and 6 of 141 patients (4.3%) in the PDC cohort (OR, 4.64; 95% CI, 0.55-217.00). The use of chemoprophylaxis for high-risk patients with head and neck cancer remains a high-priority topic. The results of this study suggest that PDC may be associated with reductions in VTE among this patient population. However, the associated increase in nonfatal bleeding events warrants careful consideration and further highlights the need to determine an optimal duration for chemoprophylaxis among this distinct cohort.

Venous thromboembolism prophylaxis-prescribing patterns among elderly medical patients in a Saudi tertiary care center: success or failure?

BackgroundHospitalized elderly patients are at high risk of venous thromboembolism (VTE), and the appropriate use of thromboprophylaxis can significantly reduce the incidence of VTE in high-risk patients. We investigated the pattern of VTE prophylaxis administration among elderly medical patients and assessed its appropriateness based on the American College of Chest Physicians (ACCP) recommendations.MethodsA cross-sectional single-center study was conducted between October 2019 and March 2020, including hospitalized (> 48 h), elderly (≥ 60 years), medical patients, and excluding patients receiving anticoagulant for other reason, having contraindication to thromboprophylaxis, or had VTE diagnosed within 48 h. The Padua prediction score was used to determine the patients' risk for VTE, and thromboprophylaxis use was assessed against the ACCP recommendations.ResultsThe study included 396 patients with an average age of 75.0 ± 9.01 years, and most patients (71.7%) were classified as high risk for VTE development (Padua score ≥ 4 points). Thromboprophylaxis use was inappropriate in 27.3% of patients, of whom 85.2% were ineligible but still received thromboprophylaxis. Patients who were classified as low risk of VTE were more likely to receive inappropriate thromboprophylaxis (AOR = 76.5, 95% CI: 16.1-363.2), whereas patients with acute infection or rheumatologic disorder were less likely to receive inappropriate thromboprophylaxis (AOR = 0.46, 95% CI: 0.22-0.96).ConclusionsAlthough the use of thromboprophylaxis among high-risk elderly patients was reasonably adequate, a large proportion of low-risk patients were exposed to unnecessary risk through inappropriate overutilization of thromboprophylaxis. Thus, healthcare providers should accurately assess patients' risk before prescribing thromboprophylaxis to ensure patient safety.

Venous thromboembolism in burns patients: Are we underestimating the risk and underdosing our prophylaxis?

Burns patients exhibit all factors of Virchow's triad and are thus at high theoretical risk of venous thromboembolism (VTE). At our tertiary referral burns unit, a standard dose of low molecular weight heparin, which acts primarily by inhibiting Factor Xa, is given for thromboprophylaxis. However, the pharmacokinetics of enoxaparin are altered following a burn injury, and thus burns patients are likely underdosed on their thromboprophylaxis. The objectives of this study were to determine the incidence and risk factors for VTE among burns patients at the Victorian Adult Burns Service (VABS) and to determine the adequacy of the current enoxaparin thromboprophylaxis regimen through measurement of anti-factor Xa (AFXa) levels and comparison with established reference ranges. This study consisted of two parts. In part 1, the Burns Registry of Australia and New Zealand (BRANZ) was reviewed for cases of VTE in burns patients admitted to the VABS from 2013 - 2018. Part 2 was a prospective study that determined peak and trough AFXa levels in patients admitted to the VABS with >10% total body surface area (TBSA) burns. Part 1. Totally, 1,475 patients were admitted to the VABS between 2013 - 2018. There were 20 cases of VTE (1.36%). Percent TBSA of burn (OR = 1.04, 95% CI: 1.03 - 1.06), full thickness burns (OR = 2.78, 95% CI: 1.15 - 6.73), ICU admission (OR = 15.08, 95% CI: 5.01 - 45.44), mechanical ventilation (OR = 10.62, 95% CI: 4.05 - 27.91), operative procedures (OR = 1.43, 95% CI: 1.29 - 1.59), and a longer hospital stay (OR = 1.05, 95% CI: 1.04 - 1.07) were all associated with an increased VTE risk. Part 2. A total of 20 participants with >10% TBSA burns were recruited to the prospective study. Peak anti Factor Xa (AFXa) levels were measured for all 20 participants with 15% recording an initial prophylactic peak AFXa level within reference range. Upon subsequent measurements, 50% of participants reached a prophylactic peak AFXa level. Trough AFXa levels were measured for 17 participants with no participant recording an initial or subsequent trough AFXa level at or above the prophylactic threshold. Our study demonstrates a high incidence of VTE among burns patients at the VABS, especially among the major burns patients, and a thromboprophylaxis protocol that is ineffective in achieving prophylactic levels of AFXa level. The evidence suggests a need to evaluate different dosing protocols among burns patients in order to improve AFXa levels, with the aim of decreasing incidence of VTE in high-risk patients.

Current Challenges in Diagnosis of Venous Thromboembolism.

In patients with suspected venous thromboembolism, the goal is to accurately and rapidly identify those with and without thrombosis. Failure to diagnose venous thromboembolism (VTE) can lead to fatal pulmonary embolism (PE), and unnecessary anticoagulation can cause avoidable bleeding. The adoption of a structured approach to VTE diagnosis, that includes clinical prediction rules, D-dimer testing and non-invasive imaging modalities, has enabled rapid, cost-effective and accurate VTE diagnosis, but problems still persist. First, with increased reliance on imaging and widespread use of sensitive multidetector computed tomography (CT) scanners, there is a potential for overdiagnosis of VTE. Second, the optimal strategy for diagnosing recurrent leg deep venous thrombosis remains unclear as is that for venous thrombosis at unusual sites. Third, the conventional diagnostic approach is inefficient in that it is unable to exclude VTE in high-risk patients. In this review, we outline pragmatic approaches for the clinician faced with difficult VTE diagnostic cases. In addition to discussing the principles of the current diagnostic framework, we explore the diagnostic approach to recurrent VTE, isolated distal deep-vein thrombosis (DVT), pregnancy associated VTE, subsegmental PE, and VTE diagnosis in complex medical patients (including those with impaired renal function).

A postdischarge venous thromboembolism risk calculator for inflammatory bowel disease surgery

BackgroundGuidelines recommend extended chemoprophylaxis for venous thromboembolism in high-risk patients having operations for inflammatory bowel disease. Quantifying patients' risk of venous thromboembolism, however, remains challenging. We sought (1) to identify factors associated with postdischarge venous thromboembolism in patients undergoing colorectal resection for inflammatory bowel disease and (2) to develop a postdischarge venous thromboembolism risk calculator to guide prescribing of extended chemoprophylaxis. MethodsPatients who underwent an operation for inflammatory bowel disease from 2012 to 2018 were identified from the American College of Surgeons National Surgical Quality Improvement Program for colectomy and proctectomy procedure targeted modules. Postdischarge venous thromboembolism included pulmonary embolism or deep vein thrombosis diagnosed after discharge from the index hospitalization. Multivariable logistic regression estimated the association of patient/operative factors with postdischarge venous thromboembolism. A postdischarge venous thromboembolism risk calculator was subsequently constructed. ResultsOf 18,990 patients, 199 (1.1%) developed a postdischarge venous thromboembolism within the first 30 postoperative days. Preoperative factors associated with postdischarge venous thromboembolism included body mass index (1.9% with body mass index ≥35 vs 0.8% with body mass index 18.5–24.9; odds ratio 2.34 [95% confidence interval 1.49–3.67]), steroid use (1.3% vs 0.7%; odds ratio 1.91 [95% confidence interval 1.37–2.66]), and ulcerative colitis (1.5% vs 0.8% with Crohn’s disease; odds ratio 1.76 [95% confidence interval 1.32–2.34]). Minimally invasive surgery was associated with postdischarge venous thromboembolism (1.2% vs 0.9% with open; odds ratio 1.42 [95% confidence interval 1.05–1.92]), as was anastomotic leak (2.8% vs 1.0%; odds ratio 2.24 [95% confidence interval 1.31–3.83]) and ileus (2.1% vs 0.9%; odds ratio 2.60 [95% confidence interval 1.91–3.54]). The predicted probability of postdischarge venous thromboembolism ranged from 0.2% to 14.3% based on individual risk factors. ConclusionPreoperative, intraoperative, and postoperative factors are associated with postdischarge venous thromboembolism after an operation for inflammatory bowel disease. A postdischarge venous thromboembolism risk calculator was developed which can be used to tailor extended venous thromboembolism chemoprophylaxis by individual risk.

Identification and Outcomes of Hospitalized Medically Ill Patients Who Are Candidates for Extended Duration Thromboprophylaxis.

Background Extended duration thromboprophylaxis (ET) for approximately 30 days can effectively and safely reduce venous thromboembolism (VTE) risk in appropriately selected medically ill patients. We sought to estimate the proportion of hospitalized medically ill patients potentially qualifying for ET and assess their post-discharge clinical and economic outcomes using a large claims database. Methods Using MarketScan claims from January 2012 to September 2018, we identified medically ill patients hospitalized with a primary diagnosis of heart failure, respiratory insufficiency, ischemic stroke, infection, or inflammatory disease and ≥1-additional risk factor for VTE. Patients < 40 years old, a length-of-stay < 3 or >30 days, receiving oral anticoagulation prior to index hospitalization or having an indication for full-dose anticoagulation were excluded, as were patients deemed high-risk for bleeding due to active, in-hospital treated cancer, gastroduodenal ulcer or bleeding within the prior 3 months, bronchiectasis, pulmonary cavitation or hemorrhage, or dual antiplatelet therapy use. Results We identified 2,782,988 patients ≥40 years of age and admitted for a high-risk medical illness. Of these, 724,531 patients (26.0%) were identified as ET candidates. Patients' VTE risk appeared highest in the first 30 days post-discharge (1,532/724,531, 0.2%). Adjusted post-index hospitalization costs (2018 US$) for patients with a VTE within 30 days were higher than those without VTE (Δ = $32,623 at 30 days, Δ = $43,325 at 90 days, Δ = $53,668 at 365 days; p < 0.001 for all). Conclusion Post-discharge VTE in high-risk patients with medical illness is associated with substantially increased costs.

Rates of primary prophylaxis for venous thromboembolism in high-risk patients with pancreatic and gastric cancer: A single tertiary care academic center experience.

e19274 Background: Venous thromboembolism (VTE) causes significant morbidity and mortality in patients with cancer. The International Society of Thrombosis and Hemostasis published guidelines in 2014 recommending a risk-based approach to VTE prophylaxis in ambulatory cancer patients, but uptake in real-world clinical practice is unknown. This study's objective was to describe rates of primary VTE prophylaxis in ambulatory patients with gastric and pancreatic cancer receiving chemotherapy and at increased risk of VTE. Methods: We identified patients at a single academic tertiary care center who received chemotherapy from 1/1/2015 to 10/1/2018 for a diagnosis of pancreatic or gastric cancer through retrospective query of electronic health records. Data abstracted included the Khorana score components (body mass index, leukocyte, hemoglobin, and platelet counts) on day of chemotherapy initiation, anticoagulation prescription, and VTE diagnosis within 6 months of chemotherapy initiation. Patients were excluded if they had contraindications to anticoagulation or alternate indications for anticoagulation. Results: We identified 437 patients, of which 72% had pancreatic cancer and 29% had gastric cancer. Mean (standard deviation) age was 64.2 (11.7) years, and patients were predominately male (54%) and white (75%). Overall, only 13% of patients received a prescription for anticoagulation with similar rates in patients with pancreatic cancer (14%) compared to gastric cancer (9%). Anticoagulation prescription rates by Khorana score (2 or ≥3) are shown in Table. Approximately 10% of patients had a VTE within 6 months of chemotherapy initiation. Conclusions: Our results show that in a cohort of patients with gastric and pancreatic cancer at intermediate to high-risk of VTE by Khorana score (≥2), only 1 in 10 received a prescription for prophylactic anticoagulation. In addition, we observed high rates of incident VTE in 6-month follow-up confirming the high-risk nature of this group. Opportunity remains to enhance implementation of primary VTE prevention in clinical practice to reduce VTE morbidity and mortality in patients with cancer. [Table: see text]

Experience of King Abdullah Medical City in Placement of Inferior Vena Cava Filter Prior to Bariatric Surgery in Extremely High-Risk Patients for Thromboembolic Events.

Bariatric surgery is used to treat morbid obese patients. Venous thromboembolism (VTE) is considered to be one of the leading causes of postoperative morbidity and mortality. Therefore, inferior vena cava filter (IVCF) is used to minimize the risk of VTE in high-risk patients. Medical information was collected for the preoperative, operative and postoperative stages for all patients underwent bariatric surgery at KAMC from March 2013 to July 2017. Five cases with IVCF were included in this study. Age ranged from 35 to 66 years old; 4 (80%) were female. Preoperative body mass index ranged from 42 to 64 kg/m2. Postoperative findings were reported. IVCF seems to be beneficial for patients undergoing bariatric surgery.

Trends and Inpatient Outcomes of Venous Thromboembolism-Related Admissions in Patients with Philadelphia-Negative Myeloproliferative Neoplasms.

Background Patients with Philadelphia-negative myeloproliferative neoplasms (MPNs), including polycythemia vera (PV), essential thrombocytosis (ET), and primary myelofibrosis (MF), have a significant risk of venous thromboembolism (VTE). We aim to determine the trends in annual rates of VTE-related admissions, associated cost, length of stay (LOS), and in-hospital mortality in patients with MPN. Methods We identified patients with PV, ET, and MF from the Nationwide Inpatient Sample (NIS) database from 2006 to 2014 using ICD-9CM coding. Hospitalizations where VTE was among the top-three diagnoses were considered VTE-related. We compared in-hospital outcomes between VTE and non-VTE hospitalizations using chi-square and Mann–Whitney U -test and used linear regression for trend analysis. Results We identified 1,046,666 admissions with a diagnosis of MPN. Patients were predominantly white (65.6%), females (52.7%), with a median age of 66 years (range: 18–108). The predominant MPN was ET (54%). There was no difference in in-hospital mortality between groups (VTE: 3.4% vs. non-VTE: 3.2%; p = 0.12); however, VTE admissions had a longer LOS (median: 6 vs. 5 days; p < 0.01) and higher cost (median: VTE US$32,239 vs. 28,403; p ≤ 0.01). The annual rate of VTE admissions decreased over time (2006: 3.94% vs. 2014: 2.43%; p ≤ 0.01), compared with non-VTE–related admissions. Conclusion In our study, VTE-related admissions had similar in-hospital mortality as compared with non-VTE–related admissions. The rates of hospitalizations due to VTE have decreased over time but are associated with a higher cost and LOS. Newer risk assessment tools may assist in preventing VTE in high-risk patients and optimizing resource utilization.

Potent Anticoagulation Does Not Reduce Venous Thromboembolism in High-Risk Patients.

Based on current guidelines from the American Academy of Orthopaedic Surgeons (AAOS), a number of prophylactic modalities for the prevention of venous thromboembolism in total joint arthroplasty may be used. It is common practice that more potent prophylactic agents are used for patients at higher risk of venous thromboembolism. However, we are aware of no studies that have investigated the efficacy of potent anticoagulation in higher-risk individuals. Therefore, the purpose of our study was to test the hypothesis that low-molecular-weight heparin and warfarin result in a reduction in venous thromboembolism events in high-risk patients. A retrospective, multi-institutional study of 60,467 primary and revision total joint arthroplasties from 2000 to 2015 was performed. Identified medications were classified as aspirin, low-molecular-weight heparin, or warfarin. Patients with unavailable venous thromboembolism prophylaxis information or those not receiving the aforementioned prophylaxis were excluded. Information pertinent to the objective of this study was collected and a venous thromboembolism risk score was calculated based on 26 variables. Treatment outcomes assessed included 90-day rate of symptomatic venous thromboembolism and periprosthetic joint infection. Propensity score matching was performed (1:1), as well as logistic regression analysis on the total sample. Aspirin prophylaxis demonstrated a lower rate of deep vein thrombosis, pulmonary embolism, and venous thromboembolism than warfarin and low-molecular-weight heparin alone throughout all risk scores. In the matched propensity score analysis, low-molecular-weight heparin and warfarin demonstrated increased odds of venous thromboembolism for both standard-risk and high-risk patients undergoing total knee arthroplasties compared with aspirin. For primary total hip arthroplasty, warfarin demonstrated an increased risk for high-risk patients and low-molecular-weight heparin demonstrated an increased risk for standard-risk patients. The prevalence of periprosthetic joint infection was higher in patients receiving warfarin (p < 0.001 for both comparisons of warfarin with aspirin and low-molecular-weight heparin). The results of this multi-institutional study demonstrate that the use of warfarin and low-molecular-weight heparin in higher-risk patients does not necessarily result in a reduction in symptomatic venous thromboembolism. Aspirin administered to higher-risk patients seems to be as effective as potent anticoagulation and more effective than warfarin. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Low-Molecular-Weight Heparin in Cancer Patients: Overview and Indications.

Although venous thromboembolism (VTE) is a well-known cause of death in patients with cancer, both its treatment and prevention remain a challenge in daily practice. Direct oral anticoagulants have emerged as safe and efficacious alternatives to vitamin K antagonists in the general population, and recent clinical trials also support their use in select patients with cancer-associated VTE. Despite this, low-molecular-weight heparins (LMWHs), a comparatively ancient class of antithrombotic drugs, remain the anticoagulants of choice in many indications relevant to modern haematology and oncology. In addition to the treatment of established VTE, these indications include VTE prophylaxis in surgical or acutely ill, hospitalized medical cancer patients as well as the prevention of VTE in high-risk patients undergoing ambulatory chemotherapy. In a constantly changing landscape of approved anticancer agents, this review article summarizes pivotal clinical trial data and guideline recommendations regarding the use of LMWH in haematological and oncological patients, who constitute a highly vulnerable patient population due to their increased risk for both bleeding and VTE recurrence.

PROSPECTIVE STUDY OF ASPIRIN FOR THROMBOEMBOLISM PROPHYLAXIS IN TOTAL HIP ARTHROPLASTY.

ABSTRACTObjectives:To evaluate the effectiveness of aspirin as prophylaxis for deep venous thrombosis (DVT) in patients undergoing total hip arthroplasty (THA), and to analyze the incidence of bleeding during the post-operative period. Methods:This prospective study carried out in 2017 consisted of 37 patients indicated for THA with high risk for DVT. Immediately after the procedure, aspirin, elastic compression socks and early deambulation were initiated. Doppler ultrasound was performed in the legs 6 days and 6 weeks post-procedure to rule out venous thromboembolism. Hematometric variables and clinical criteria were used to detect bleeding. Results:The incidence of VTE (venous thromboembolism) 6 days post-procedure was 21.6%. By 6 weeks post-procedure, it dropped to 8.1%, (p = 0.102). Only 2.7% were diagnosed with VTE, 6 days and also 6 weeks post-procedure. Within the immediate postoperative period, hemoglobin was lower (p < 0.001), in contrast to 6 weeks after surgery, when it returned to baseline levels. Conclusion:Aspirin was an effective chemical prophylaxis for venous thromboembolism in high-risk patients who underwent THA. There was no clinical record of postoperative bleeding and hematometric levels suggested that there was no chronic bleeding. Level of Evidence II; Prospective study.

Venous Thromboembolism in High-Risk Patients: Are We Doing Enough for Prevention?

Objectives: CEA in asymptomatic patients is recommended only when postoperative complications and mortality are kept low; but predicting CEA complications in a specific patient remains elusive. To better predict 30-day postoperative outcomes, we calculated a novel point-weight ordinal Frailty Risk Score (FRS) by an analysis of 20 preoperative risk factors based on their individual odds ratios (ORs) as predictors of postoperative complications using all vascular surgery cases in the 2005 to 2011 American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database (n 1⁄4 121,015). Methods: To compare the predictive value of this calculated FRS with that of patient demographics and surgical variables alone, we examined the predictive contribution value of five levels of FRS on four outcomes (stroke, myocardial infarction [MI], and mortality), and a composite of the three outcomes in all primary asymptomatic CEAs in the 2005 to 2011 ACSNSQIP database (n 1⁄4 39,859). Results: Thirty-day mortality occurred in 273 patients (0.7%), stroke in 527 (1.3%), MI in 301 (0.8%), and the composite outcome was positive in 1008 (2.5%). We found that by itself, the FRS level was strongly and significantly associated with all four outcomes (Table). For stroke, we used only three levels of frailty because the stroke rate no longer increased after this point, and found that for the lowest vs highest frailty levels, the rate of stroke was 1.1% vs 2.4% (P < .0001). Percentage of patients that were positive for the composite outcome was 1.7% in lowest vs 15.2% in the highest FRS group (P < .0001). Conclusions: An easy-to-calculate FRS can help stratify risk based on preoperative patient characteristics and will help to identify asymptomatic patients for whom CEA is risky.

One-year adherence to warfarin treatment for venous thromboembolism in high-risk patients and its association with long-term risk of recurrent events.

Warfarin is the predominant oral anticoagulant used for the prevention of recurrent venous thromboembolism (VTE) events. However, its long-term use is complicated by the need to manage the drug within a narrow therapeutic range and by possible food and drug interactions. To examine the association between 1-year adherence, measured through compliance with and persistence on warfarin treatment for VTE, and long-term risk of recurrent events among patients at high risk. Medical and pharmacy claims for patients with commercial or Medicare supplemental insurance in the Thomson Reuters MarketScan database were analyzed. Adult patients with medical claims with an associated VTE diagnosis between January 1, 2006, and March 31, 2008, were identified. The index date was defined as the date of the first observed VTE claim or the date of discharge if the index event was a hospital stay. High-risk patients (patients with cancer, or noncancer patients who did not have reversible risk factors during the 3-month period prior to the index date) who filled a warfarin prescription within 2 weeks of the index date were included. Persistence was evaluated in terms of discontinuation, defined as a 90-day gap in warfarin supply during a 1-year assessment period following the index date. Compliance was measured by the proportion of days covered (PDC) over the 1-year assessment period, with PDC less than 0.8 defined as noncompliance. Recurrent VTE events were identified as hospitalizations where VTE was the primary diagnosis after the 1-year assessment period and until patients were lost to follow-up. The association between adherence to warfarin therapy and VTE recurrence was evaluated descriptively via Kaplan-Meier curves and a Cox proportional hazards model, adjusted for patient demographic and clinical characteristics. A similar analysis using the medication possession ratio (MPR) as a measure of compliance was also performed in a subset of patients who had filled at least 2 warfarin prescriptions. The study included 8,040 VTE patients identified as being at high risk of recurrence (mean age 61 years, 59.4% male), of whom 76.9% were not compliant with warfarin therapy based on PDC, and 51.5% discontinued therapy. Among those with at least 2 warfarin prescriptions (n = 7612), 34.1% of high-risk patients were not compliant with warfarin therapy between the first and last refills based on MPR. Kaplan-Meier curves showed that patients who were compliant or continued warfarin therapy were less likely to experience a VTE event (all P less than 0.05). Noncompliant patients had a 3 times greater risk of VTE recurrence than compliant patients, based on PDC (hazard ratio [HR] = 3.01, 95% confidence interval [CI]: 1.28-4.97). Among the subpopulation who filled at least 2 warfarin prescriptions, noncompliant patients (based on MPR) were also found to be more likely to have recurrent VTE events, compared with compliant patients (HR = 1.60, 95% CI: 1.18-2.16). Patients who discontinued warfarin were more likely to have recurrent VTE events compared with patients who did not discontinue on warfarin treatment (HR = 1.48, 95% CI: 1.09-2.01). Adherence to a year of therapy was low in patients at high risk of recurrent VTE, even though long-term therapy should be considered in this population. Noncompliance and discontinuation of warfarin treatment over a 1-year period was associated with a higher risk of recurrent VTE. Future research should investigate and differentiate between patient and provider discontinuation to develop strategies to improve compliance and persistence with appropriate anticoagulation therapy that may potentially reduce recurrent VTE.

Efficacy and Safety of Low Molecular Weight Heparin Prophylaxis for Venous Thromboembolism Following Lumbar Decompression Surgery

To evaluate the efficacy and safety of low molecular weight heparin (LMWH) prophylaxis for venous thromboembolism (VTE) after lumbar decompression surgery. Patients at high or the highest risk of VTE who underwent lumbar spine surgery in Peking Union Medical College Hospital from January 2004 to April 2011 were included in the present study. All the patients received a half dose of LMWH 6 hours after surgery followed by a full dose LMWH once per day until discharge. We recorded incidences of deep venous thrombosis (DVT), pulmonary embolism (PE), bleeding complications, and medication side effects. Seventy-eight consecutive patients were eligible and enrolled in this study. The mean hospital stat was 8.5±4.5 days. No symptomatic DVT, PE, or major bleeding events were observed. One patient developed wound ecchymosis, another developed wound bleeding, four had mild hepatic aminotransferase level elevation, and one developed a suspicious allergic reaction. LMWH may be applied as an effective and safe prophylaxis for VTE in high-risk patients undergoing lumbar decompression surgery.

Optional inferior vena cava filter use in surgical patients: a Western Australian experience

The optional filter is gaining ground, supplementing anticoagulation in the management of venous thromboembolism (VTE) in high-risk surgical patients, this despite knowledge gaps relating to its efficacy. We studied the literature and audited our experience with inferior vena cava filters to educate ourselves on this mode of VTE prophylaxis, particularly its practical implications, if any, for the surgeon. A retrospective clinical study on inferior vena cava filter (IVCF)-related events in a Western Australian tertiary centre in 2008 was performed. Literature on IVCFs was reviewed. The 118 IVCF-related events at our centre in 2008, involved either Recovery-G2 75(88%) or Cook-Celect nine (11%). Of these, 78 were insertions and 36 were retrievals with four failed retrievals (10% of the attempts). Major indications for insertion included multi-trauma 32 (38%), prothrombotic state 29 (34%), head injury/intracranial bleeding 16 (19%) and others eight (9%). The mean dwelling time was 100 days (12–349 days). The mean age was 43 and the retrieval rate was 58%. Optional filters have presented both versatility and challenge to the management of VTE in high-risk patients. An underlying concern about the quintessential efficacy of IVCFs lingers on, while the impact of lost follow-ups in young patients is still at large. Class 1 studies on optional filters would add certainty to the use of this generation of filters, be a step forward in relevance from the seminal work of Decousus and garner the willingness needed to engage teamwork and institutional proactiveness against loopholes such as lost follow-ups that can undermine the portrayed benefits of a potentially lifesaving device.

A risk assessment model for the identification of hospitalized medical patients at risk for venous thromboembolism: the Padua Prediction Score.

Prophylaxis of venous thromboembolism (VTE) in hospitalized medical patients is largely underused. We sought to assess the value of a simple risk assessment model (RAM) for the identification of patients at risk of VTE. In a prospective cohort study, 1180 consecutive patients admitted to a department of internal medicine in a 2-year period were classified as having a high or low risk of VTE according to a predefined RAM. They were followed-up for up to 90 days to assess the occurrence of symptomatic VTE complications. The primary study outcome was to assess the adjusted hazard ratio (HR) of VTE in high-risk patients who had adequate in-hospital thromboprophylaxis in comparison with those who did not, and that of VTE in the latter group in comparison with low-risk patients. Four hundred and sixty-nine patients (39.7%) were labelled as having a high risk of thrombosis. VTE developed in four of the 186 (2.2%) who received thromboprophylaxis, and in 31 of the 283 (11.0%) who did not (HR of VTE, 0.13; 95% CI, 0.04-0.40). VTE developed also in two of the 711 (0.3%) low-risk patients (HR of VTE in high-risk patients without prophylaxis as compared with low-risk patients, 32.0; 95% CI, 4.1-251.0). Bleeding occurred in three of the 186 (1.6%) high-risk patients who had thromboprophylaxis. Our RAM can help discriminate between medical patients at high and low risk of VTE. The adoption of adequate thromboprophylaxis in high-risk patients during hospitalization leads to longstanding protection against thromboembolic events with a low risk of bleeding.