Rate Of Proximal Deep Vein Thrombosis Research Articles

Prevalence of Preoperative Lower Extremity Deep Vein Thrombosis in Bilateral Calcaneal Fractures

There are no studies on epidemiologic characteristics of deep vein thrombosis (DVT), when specified at in patients with bilateral calcaneal fractures. This study aimed to address the preoperative DVT in bilateral calcaneal fractures. Between October 2014 and December 2018, adult patients presenting with bilateral calcaneal fractures and having preoperative Duplex ultrasound (DUS) of bilateral lower extremities for detection of DVT were included. Their medical data were collected, with regards to demographics, comorbidities, injury-related data and biomarkers. Baseline characteristics between patients with and without DVT were compared using bivariate tests. The further multivariate logistics regression analysis was conducted to identify independent factors associated with DVT. In total, 258 patients with bilateral calcaneal fractures were included, with 21 (8.1%) having preoperative DVT, diagnosed at 7.7 ± 4.2 days after injury. The prevalence rate of proximal DVT was 1.9% and of distal DVT was 6.2%. Thirty five thrombi were found, with 6 (17.1%) in proximal veins and 29 (82.9%) in distal veins. Nine patients had DVTs in multiple veins, and 2 patients had bilateral DVTs. The multivariate analyses showed history of allergy (odds ratio [OR] = 2.17), concurrent other fractures (OR = 4.53), prolonged time since injury (for each day, OR = 1.16), elevated plasma D-dimer level (≥1.73 vs <1.73 mg/L, OR = 3.74) and reduced albumin level (<34.2 g/L vs ≥34.2 g/L, OR = 2.92) were independent factors associated with DVT. Multiple factors were identified to be associated with DVT and greater consideration should be given to the use of pharmacologic prophylaxis in patients involving these factors, to reduce DVT occurrence.

Foot Pump Versus Low-Molecular-Weight Heparin for Preventing Deep Vein Thrombosis Following Surgery for Hip and Knee Replacement

Objective To evaluate the comparative efficacy and safety of the use of foot pump versus low-molecular-weight heparin (LMWH) for preventing deep vein thrombosis (DVT) and pulmonary embolism (PE) in total knee replacement (TKR) and total hip replacement (THR). Summary of background data The use of chemoprophylactic agents in TKR and THR has been shown to result in increased complications like bleeding and wound drainage. Methods Relevant publications indexed in PubMed, Cochrane Library, Embas, Web of Science, Wanfang Data, CNKI, and VIPI were identified. Appropriate articles identified from the reference lists of the above searches were also reviewed. Results No significant difference in the rate of distal in the lower extremity was observed between the 2 groups (OR: 0.99; CI: 0.61–1.61; Z = 0.03; P = 0.97). No significant difference in the rate of proximal DVT in the lower extremity was observed between 2 groups (OR: 1.60, CI: 0.85–3.03, Z = 1.44, P = 0.15). No significant difference in the rate of PE was observed between 2 groups (OR 3.84, CI: 0.42 to 34.80, Z = 1.20, P = 0.23). But we found that postoperative drainage in foot pump group was less than that in LMWH group (OR -68.93, CI: −73.81 to −64.05, Z = 27.68, P &amp;lt; 0.00001), and oozing in foot pump group was less than that in LMWH group (OR: 0.21; CI: 0.10–0.47; Z = 3.86, P = 0.0001). Conclusion The foot pump is a suitable alternative for TKR and THR patients in preventing DVT and PE, and can get less postoperative drainage and oozing side effects that are associated with LWMH.

Multimodal thromboprophylaxis in low-risk patients undergoing lower limb arthroplasty: A retrospective observational cohort analysis of 1400 patients with ultrasound screening.

This study reports the results of a multimodal thromboprophylaxis protocol for lower limb arthroplasty involving risk stratification, intraoperative calf compression, aspirin prophylaxis and early (within 4 h) post-operative mobilisation facilitated by the use of local infiltration analgesia. The study also aimed to identify risk factors for venous thromboembolism (VTE) within a 3-month period following surgery for patients deemed not at elevated risk. Patients undergoing knee/hip arthroplasty or hip resurfacing were preoperatively screened for VTE risk factors, and those at standard risk were placed on a thromboprophylaxis protocol consisting of intraoperative intermittent calf compression during surgery, 300 mg/day aspirin for 6 weeks from surgery and early mobilisation. Patients were screened bilaterally for deep vein thrombosis (DVT) on post-operative days 10-14. If proximal DVT was detected, patients were anticoagulated and outcomes were recorded. Symptomatic VTE within 3 months of surgery were recorded separately. Patient notes were retrospectively collated and cross-validated against ultrasound reports. At initial screening, the rate of proximal DVT was 0.54% (1.1% for knee and 0.27% for hip), and distal DVT was 6.63% (20.11% for knee and 2.31% for hip). One small, nonfatal pulmonary embolism (PE) was detected within 3 months of surgery (0.28% of total knee arthroplasty patients or 0.07% of total). All proximal DVTs were treated successfully with anticoagulants; however, one patient suffered a minor PE approximately 10 months post-operatively. Regression analysis identified knee implant and advanced age as independent risk factors for VTE in this cohort. Although knee arthroplasty patients remained at higher risk than hip replacement/resurfacing patients, the incidence and outcomes of VTE remained positive compared with protocols involving extended immobilisation, and episodes of PE were extremely rare. Thus, we conclude that patients at standard preoperative risk of VTE may safely be taken through the post-operative recovery process with a combination of intraoperative mechanical prophylaxis, early mobilisation and post-operative aspirin, with closer attention required for older patients and those undergoing knee surgery.

Extended thromboprophylaxis with low-molecular weight heparin (LMWH) following abdominopelvic cancer surgery.

Venous thromboembolism (VTE) includes deep vein thrombosis (DVT) and pulmonary embolism (PE). Certain abdominopelvic cancer surgeries are associated with a six to 14-fold increased risk of DVT versus surgeries for benign disease, and extended thromboprophylaxis using perioperative LMWHs may further reduce VTE rates over standard duration administration. This review assesses the value of extended low molecular weight heparin (LMWH) thromboprophylaxis as a recommended strategy after abdominopelvic cancer surgery. Six eligible randomized controlled trials (RCTs), seven meta-analyses (MAs), and five non-randomized cohort studies were identified evaluating extended versus standard thromboprophylaxis following abdominopelvic cancer surgery. Available evidence showed significantly reduced rates of VTE for extended versus standard LMWH thromboprophylaxis following abdominopelvic cancer surgery, with some studies showing trends toward reduced rates of symptomatic VTE events. Many of these studies showed significantly reduced rates of proximal DVT and some showed trends toward reduced PE, suggesting potentially important clinical benefits.

Thrombosis rates using aspirin and a compression device as multimodal prophylaxis for lower limb arthroplasty in a screened population

BackgroundVenous thromboembolism (VTE) (Deep vein thrombosis (DVT), and pulmonary embolism (PE)), is a common complication in patients undergoing total joint arthroplasty (TJA). Recently, aspirin was recommended by the American Academy of Orthopaedic Surgeons (AAOS) as VTE prophylaxis following TJA. This study investigates VTE rates in TJA patients using as thromboprophylaxis. MethodsDVT was screened for in 396 consecutive total hip or knee arthroplasty procedures. Patients were treated with early mobilisation, calf compression device and 300 mg aspirin for 5 days and then 100 mg aspirin for 5 weeks. All patients received lower-limb duplex ultrasonography prior to discharge. Patients were clinically evaluated at 6 weeks post-op documenting any VTE. Results51 TJA's (12.87%) were complicated by VTE: one proximal, 47 distal DVT and 3 PE. No fatal PE occurred. Only four DVT were symptomatic. Of 159 THA, 2 (1.25%) had VTE: one distal DVT and one PE. Of 237 TKA, 49 (20.67%) had VTE: 1 proximal, 46 distal DVT and 2 PE. Patients with a history of diabetes and those receiving TKA were at higher risk of DVT. ConclusionMultimodal VTE prophylaxis demonstrated a low rate of proximal DVT, PE and bleeding complications. The rate of asymptomatic DVT was high, but most were distal and unlikely to be clinically significant. Patients with diabetes and those receiving TKA could be at higher risk of asymptomatic DVT, and may benefit from closer clinical assessment. These findings suggest aspirin is safe and efficacious when used in combination with mechanical compressors and early mobilisation. However, our findings require further validation, particularly with larger, prospective comparative studies.

Statistical analysis plan for the Pneumatic CompREssion for PreVENting Venous Thromboembolism (PREVENT) trial: a study protocol for a randomized controlled trial

BackgroundThe Pneumatic CompREssion for Preventing VENous Thromboembolism (PREVENT) trial evaluates the effect of adjunctive intermittent pneumatic compression (IPC) with pharmacologic thromboprophylaxis compared to pharmacologic thromboprophylaxis alone on venous thromboembolism (VTE) in critically ill adults.Methods/designIn this multicenter randomized trial, critically ill patients receiving pharmacologic thromboprophylaxis will be randomized to an IPC or a no IPC (control) group. The primary outcome is “incident” proximal lower-extremity deep vein thrombosis (DVT) within 28 days after randomization. Radiologists interpreting the lower-extremity ultrasonography will be blinded to intervention allocation, whereas the patients and treating team will be unblinded. The trial has 80% power to detect a 3% absolute risk reduction in the rate of proximal DVT from 7% to 4%.DiscussionConsistent with international guidelines, we have developed a detailed plan to guide the analysis of the PREVENT trial. This plan specifies the statistical methods for the evaluation of primary and secondary outcomes, and defines covariates for adjusted analyses a priori. Application of this statistical analysis plan to the PREVENT trial will facilitate unbiased analyses of clinical data.Trial registrationClinicalTrials.gov, ID: NCT02040103. Registered on 3 November 2013;Current controlled trials, ID: ISRCTN44653506. Registered on 30 October 2013.

Analysis of contributing factors influencing thromboembolic events after total knee arthroplasty.

Venous thromboembolic events (VTE) are a known and well-described complication following total knee arthroplasty (TKA). We sought to validate the American College of Chest Physicians thromboprophylaxis recommendations after elective TKA, paying special attention to our dose adjustments for weight, and their impact on VTE in our population. We retrospectively investigated risk factors in patients undergoing TKA, focusing mainly on symptomatic VTE occurrence rates from deep vein thrombosis (DVT) or pulmonary embolism (PE). The anticoagulation protocol consisted of starting low molecular-weight heparin (LMWH) therapy, with dalteparin administered 12 h after surgery in patients who received general anesthesia or 24 h later in patients who received single-dose regional anesthesia. Data from 346 patients (mean age 66.8 [range 24-91] yr) who underwent primary or revision TKA depicted an overall symptomatic VTE rate of 15%. The proximal DVT rate was 1.7%, and the nonfatal PE rate was 0.9%. The mean time to VTE diagnosis was 5.6 days. The first dalteparin dose was administered 19.5 (range 10-48) h after surgery in patients without VTE and 22.6 (range 11.5-52) h after surgery in patients with VTE (p = 0.003). With a first dose of dalteparin administered 12 h postoperatively, patients presented significantly lower DVT and PE rates than if it was administered 24 h postoperatively (8.5% v. 16.3%, p = 0.048). Delayed administration of LMWH has deleteriously impacted the VTE rate after TKA at our institution. Prompt initiation of LMWH (≤ 12 h after surgery) is appropriate, without increasing the risk of major bleeding.

Therapeutic Anticoagulation for Isolated Calf Deep Vein Thrombosis.

Deep vein thrombosis (DVT) isolated to the calf veins (distal to the popliteal vein) is frequently detected with duplex ultrasonography and may result in proximal thrombosis or pulmonary embolism (PE). To evaluate whether therapeutic anticoagulation is associated with a decreased risk for proximal DVT or PE after diagnosis of an isolated calf DVT. All adult patients with ultrasonographic detection of an isolated calf DVT from January 1, 2010, to December 31, 2013, at the Vascular Laboratory of the University of California, Davis, Medical Center were included. Patients already receiving therapeutic anticoagulation and those with a chronic calf DVT, a contraindication to anticoagulation, prior venous thromboembolism within 180 days, or diagnosis of a PE suspected at the time of calf DVT diagnosis were excluded. Data were analyzed from August 18, 2015, to February 14, 2016. Intention to administer therapeutic anticoagulation. Proximal DVT or PE within 180 days of the diagnosis of the isolated calf DVT. From 14 056 lower-extremity venous duplex studies, we identified 697 patients with an isolated calf DVT and excluded 313 of these. The remaining 384 patients were available for analysis (222 men [57.8%]; 162 women [42.2%]; mean [SD] age, 60 [16] years). The calf DVT involved an axial vein (anterior tibial, posterior tibial, or peroneal) in 243 patients (63.2%) and a muscular branch (soleus or gastrocnemius) in 215 (56.0%). Physicians attempted to administer therapeutic anticoagulation in 243 patients (63.3%), leaving 141 control participants. Proximal DVT occurred in 7 controls (5.0%) and 4 anticoagulation recipients (1.6%); PE, in 6 controls (4.3%) and 4 anticoagulation recipients (1.6%). Therapeutic anticoagulation was associated with a decreased risk for proximal DVT or PE at 180 days (odds ratio [OR], 0.34; 95% CI, 0.14-0.83) but an increased risk for bleeding (OR, 4.35; 95% CI, 1.27-14.9), findings that persisted after adjustment for confounding factors (ORs, 0.33 [95% CI, 0.12-0.87] and 4.87 [95% CI, 1.37-17.3], respectively) and sensitivity analyses. Rates of proximal DVT or PE are low after isolated calf DVT. Therapeutic anticoagulation is associated with a reduction of these outcomes but an increase in bleeding.

Combination Prophylaxis versus Pharmacologic Prophylaxis Alone for Preventing Deep Vein Thrombosis in Hip Surgery

To evaluate the comparative efficacy and safety of combination pharmacologic and graduated compression stockings (GCS) prophylaxis versus pharmacological prophylaxis alone for preventing deep vein thrombosis (DVT) and pulmonary embolism (PE) in hip surgery. Relevant publications indexed in PubMed, Cochrane Library, Embase, Web of Science, Wanfang Data, CNKI and Sinomed (CBM) were identified. Appropriate articles identified from the reference lists of the above searches were also reviewed. Significant differences in the rate of distal DVT were observed between combination prophylaxis and pharmacological groups. When data from Fredin 1989 was excluded no significant difference in the rate of distal DVT was seen between groups. No significant difference in the rate of proximal DVT or PE was observed between combination and pharmacologic prophylaxis groups. A combination of pharmacological prophylaxis and GCS can decrease distal DVT in the lower extremity when compare to pharmacological prophylaxis alone, but it is not useful in decreasing proximal DVT and PE. If we use currently recommended pharmacologic prophylaxis it is not necessary to combine this with GCS.

Use of a pneumatic tourniquet in total knee arthroplasty increases the risk of distal deep vein thrombosis: A prospective, randomized study

BackgroundThere has been controversy regarding the incidence of deep vein thrombosis (DVT) after total knee arthroplasty (TKA) with or without the use of a tourniquet. The aim of this randomized, prospective study was to clarify the effects of tourniquet use on DVT in TKA. MethodsThe subjects were 109 patients scheduled to undergo TKA from April 2008 to March 2009 before the establishment of the American Association of Orthopedic Surgeons (AAOS) practice guidelines. They were randomized into two groups: 51 patients in the tourniquet group (group T) and 52 patients in the control group without a tourniquet (group C). We investigated the thrombotic presence using ultrasonography one week after surgery and compared both groups. ResultsThere was no difference in the rate of proximal DVTs (P=0.63). However, the risk of distal DVT was significantly higher in group T than in group C (52.9% vs. 23.1%; P=0.002). ConclusionsUse of the tourniquet in TKA increased the risk of distal DVT.

Post Hoc Analysis of Desirudin Versus Enoxaparin for Thromboprophylaxis in High-Risk Patients Undergoing Elective Hip Replacement Surgery

INTRODUCTION. Desirudin is a recombinant direct thrombin inhibitor (DTI) approved in the US for the prophylaxis of deep vein thrombosis (DVT), which may lead to pulmonary embolism (PE), in elective hip replacement surgery, and approved in European Union for the prevention of DVT in elective hip or knee replacement surgery. A multicenter, double-blind, randomized, controlled trial comparing the safety and efficacy of desirudin with enoxaparin in elective total hip replacement (THR) surgery demonstrated that desirudin has a safety profile similar to enoxaparin but is more effective in preventing both overall and proximal DVT (Eriksson et al, 1997). The objective of this study was to conduct post hoc analyses of the efficacy of desirudin versus enoxaparin in high-risk patient subgroups.METHODS. Data were collected from 2079 patients randomized at medical centers in 10 European countries. Desirudin was administered 15 mg subcutaneously (SC) twice daily (BID) on the day of the surgery, once within 30 minutes prior to surgery and once in the evening, and 15 mg BID thereafter, postoperatively (n=1043). Enoxaparin was administered 40 mg SC once daily (QD) on the day prior to surgery (12 hours preoperatively), then at the same dose on the day of the surgery and QD thereafter, postoperatively for 9-12 days. The primary outcome was major thromboembolic event (proximal DVT, PE, or death) during the prophylaxis period; secondary outcomes were any thromboembolic event (proximal and distal DVT, PE, or death) during this same period. Confirmatory venography was performed if clinical symptoms occurred. Subsequent post hoc efficacy analyses for desirudin versus enoxaparin were performed for higher-risk patient subgroups, including variables such as age, smoking, obesity, cardiovascular diseases, type of anesthesia, and concomitant medications. Adverse events studied included serious bleeding episodes, wound dehiscence, wound hematoma, and infections.RESULTS. Post hoc analyses for intent-to-treat patients evaluable for the primary outcome (desirudin n=802; enoxaparin n=785) reveal favorable odds ratios (OR) for desirudin versus enoxaparin in VTE incidence (Figure 1) across a range of high-risk patient subgroups, including (1) patients aged 65 or older (OR 0.70); (2) obese patients (BMI >27.2 kg/m2 for males and >26.9 kg/m2 for females) (OR 0.73); (3) smokers (OR 0.38); (4) patients with cardiovascular disease (OR 0.49); (5) patients who had epidural or spinal anesthesia (OR 0.69); and (6) patients who received concomitant medications such as NSAIDs, antiplatelet or anticoagulant agents, or plasma expanders (OR 0.63). In addition, risk factor analysis by logistic regression showed that factors associated with a statistically significant increase in the probability of adverse events included: age 65 or over (OR 1.93, P=.0001); history of venous thromboembolic disease (OR 1.80, P=.02); and obesity (OR 1.46, P=.0046). Post hoc analyses of hemorrhagic events revealed no statistically significant difference between patients who received desirudin and those who received enoxaparin (desirudin 336/1042, enoxaparin 341/1036; P=.779).CONCLUSION. Favorable ORs for VTE incidence with desirudin compared with enoxaparin were found for patients ≥65 years of age, who were obese, who smoked, had cardiovascular disease, received epidural or spinal anesthesia, or were receiving various concomitant medications. Eriksson’s previous report noted a significantly lower rate of proximal DVT (4.5% versus 7.5%, P=.01) and a lower overall rate of DVT (18.4% versus 25.5%, P=.001) for desirudin compared with enoxaparin. The efficacy results reported here in higher-risk patients, together with the finding that desirudin has a hemorrhagic event profile similar to that of enoxaparin, suggest that desirudin may be a preferred agent over enoxaparin for thromboprophylaxis in higher-risk patients undergoing THR. [Display omitted] DisclosuresLevy:Marathon Pharmaceuticals, LLC: Consultancy. Nutescu:Marathon Pharmaceuticals, LLC: Consultancy. Meyer:Marathon Pharma: Employment.

The Utility of Screening for Asymptomatic Lower Extremity Deep Venous Thrombosis during Inflammatory Bowel Disease Flares

Asymptomatic deep vein thrombosis (DVT) occurs in up to 11% of medical inpatients. The incidence of asymptomatic DVT among patients with inflammatory bowel disease (IBD) is unknown but may be even higher. D-dimer is effective for DVT screening, but its utility has not been studied in the IBD population. Hospitalized and ambulatory patients with IBD during flares were recruited between 2009 and 2011. Those with clinical symptoms of venous thromboembolism or previous venous thromboembolism were excluded. We determined the prevalence of DVT among asymptomatic subjects using lower extremity Doppler ultrasound and assessed the performance characteristics of the D-dimer in this high-risk study population. We enrolled 101 hospitalized and 49 ambulatory patients with IBD during active flares. There were no cases of proximal DVT detected by lower extremity Doppler ultrasound. The 95% confidence interval (CI) for the rate of proximal DVT was 0% to 2%. D-dimer was elevated in 60% of subjects without DVT, occurring more frequently among hospitalized than ambulatory subjects [89% versus 65%, P = 0.01; adjusted odds ratio (aOR), 4.16, 95% CI, 1.58-10.9]. Other predictors of elevated D-dimer were incremental decade in age (aOR, 1.97; 95% CI, 1.24-3.14); ulcerative colitis versus Crohn's disease diagnosis (aOR, 3.38; 95% CI, 1.29-8.84); and every 10-unit increase in C-reactive protein (aOR, 1.33; 95% CI, 1.09-1.62). From this pilot study, there appears to be low prevalence of asymptomatic DVTs among patients with IBD during flares. The high prevalence of elevated D-dimer in DVT-negative patients limits its utility in IBD.

Lower limb deep vein thrombosis in patients with suspected pulmonary embolism detected with (99m)Tc-MAA simultaneously with lung perfusion scan.

The aim of this study was to evaluate the incidence of deep vein thrombosis (DVT) in patients with suspected pulmonary embolism (PE) and the relation between PE and the site of DVT by using technetium-99m-macroaggregated human serum albumin ((99m)Tc-MAA) radionuclide venography (RNV). Technetium-99m-MAA RNV was performed simultaneously with lung perfusion scintigraphy in 123 patients with suspected PE. The incidence of DVT in patients with suspected PE was 58.54%. The incidence of DVT in patients with PE was 77.46%, while in patients without PE was 32.69%. The rate of proximal DVT in patients with PE was 74.55%, while in patients without PE was 47.06%. The average embolic lung segments in patients with proximal DVT and patients with distal DVT were 6.2±2.3 and 3.1±1.2, respectively. In conclusion, lower limb (99m)Tc-MAA RNV demonstrated a high incidence (58.54%) of DVT in patients with suspected PE. The prevalence of DVT was higher in patients with PE than in patients without PE. Pulmonary embolism was more likely to occur in patients with proximal DVT, and more embolic lung segments were detected in patients with proximal DVT.

A Prospective Study of Venous Thromboembolic Prophylaxis Using Foot Pumps Following Total Knee Replacement in a Chinese Population

PurposeThe purpose of this study was to evaluate foot pumps as mechanical prophylaxis for deep vein thrombosis (DVT) following total knee replacement (TKR) in a Chinese population. MethodsAll consecutive patients following TKR during 2002–2006 received routine duplex ultrasound surveillance for DVT 9 days postoperatively. The demographic data and risk factors were recorded. No medication was given for DVT prophylaxis in all patients. ResultsWe evaluated 91 consecutive TKRs in 85 patients. Although 44 knee replacements (Group 1) done before December 2004 were not given foot pumps, 47 knee replacements (Group 2) done afterwards were given foot pumps. All patients were followed up for more than 6 months. DVT was detected in three cases (6.8%) in Group 1 compared with four knees (8.5%) in Group 2. Proximal thrombosis was observed in two knees (4.5%) in Group 1 compared with two knees (4.3%) in Group 2. No patient had pulmonary embolism. Six out of 59 (10.2%) patients who underwent the operations under general anaesthesia suffered from DVT, whereas one in 28 (3.6%) patients operated under spinal anaesthesia had DVT. All had no statistical significance. ConclusionThe rate of proximal DVT after TKR was low (4.5%) without pharmacological prophylaxis. We advise against the use of pharmacological prophylaxis in Chinese population for TKRs because of the low risk of proximal DVT and its possible bleeding complications. Foot pump did not lower the rate of DVTfurther, and its use for DVT prophylaxis in TKR is not necessary.

Screening and Prevention of Venous Thromboembolism in Critically Ill Patients

Venous thromboembolism is difficult to diagnose in critically ill patients and may increase morbidity and mortality. To evaluate the cost-effectiveness of strategies to reduce morbidity from venous thromboembolism in critically ill patients. A Markov decision analytic model to compare weekly compression ultrasound screening (screening) plus investigation for clinically suspected deep vein thrombosis (DVT) (case finding) versus case finding alone; and a hypothetical program to increase adherence to DVT prevention. Probabilities were derived from a systematic review of venous thromboembolism in medical-surgical intensive care unit patients. Costs (in 2010 $US) were obtained from hospitals in Canada, Australia, and the United States, and the medical literature. Analyses were conducted from a societal perspective over a lifetime horizon. Outcomes included costs, quality-adjusted life-years (QALY), and incremental cost-effectiveness ratios. In the base case, the rate of proximal DVT was 85 per 1,000 patients. Screening resulted in three fewer pulmonary emboli than case-finding alone but also two additional bleeding episodes, and cost $223,801 per QALY gained. In sensitivity analyses, screening cost less than $50,000 per QALY only if the probability of proximal DVT increased from a baseline of 8.5-16%. By comparison, increasing adherence to appropriate pharmacologic thromboprophylaxis by 10% resulted in 16 fewer DVTs, one fewer pulmonary emboli, and one additional heparin-induced thrombocytopenia and bleeding event, and cost $27,953 per QALY gained. Programs achieving increased adherence to best-practice venous thromboembolism prevention were cost-effective over a wide range of program costs and were robust in probabilistic sensitivity analyses. Appropriate prophylaxis provides better value in terms of costs and health gains than routine screening for DVT. Resources should be targeted at optimizing thromboprophylaxis.

Low-Molecular-Weight Heparin Prophylaxis of Deep Vein Thrombosis for Older Patients with Restricted Mobility

Although older patients with restricted mobility are at increased risk for venous thromboembolism, they are under-represented in clinical trials evaluating prophylactic treatments against deep vein thrombosis (DVT). To determine whether prolonged prophylaxis with low-molecular-weight heparin (LMWH) is associated with a lower rate of DVT in older patients with restricted mobility. Two cross-sectional studies were conducted in 50 hospital-based, post-acute care facilities in France in 2001 and 2003. The studies included 1603 evaluable patients aged >or=65 years, including 866 LMWH users (median treatment duration 23 days; interquartile range 13-42) and 737 LMWH non-users. All patients underwent complete compression ultrasonography performed by board-certified vascular medicine physicians. The primary study outcome was proximal DVT. Propensity analyses were used to control for bias in LMWH treatment assignment. The rate of proximal DVT was 4% (35/866) and 5.7% (42/737) for LMWH users and non-users, respectively (p = 0.16). Prophylaxis with LMWH was associated with decreased odds of proximal DVT after adjusting for baseline characteristics (odds ratio [OR] 0.56; 95% CI 0.33, 0.95; p = 0.03) or quintile of propensity score (OR 0.58; 95% CI 0.35, 0.99; p = 0.04). In propensity matched analysis, 342 LMWH users were at decreased odds of proximal DVT compared with 342 non-users (OR 0.50; 95% CI 0.24, 1.00; p = 0.04). The decrease in proximal DVT was paralleled by a similar decrease in distal DVT. Compared with non-users, only high-risk dose users had decreased odds of DVT. In this observational study, prophylaxis with a high-risk dose of LMWH was associated with decreased odds of proximal DVT in older patients with restricted mobility. Further study is needed before recommending routine prophylaxis with LMWH in these patients.

Fondaparinux combined with intermittent pneumatic compression vs. intermittent pneumatic compression alone for prevention of venous thromboembolism after abdominal surgery: a randomized, double-blind comparison.

The benefit of combined mechanical and pharmacologic methods for venous thromboembolism prevention after abdominal surgery has not been clearly established. To compare the efficacy and safety of fondaparinux in conjunction with intermittent pneumatic compression vs. intermittent pneumatic compression alone in this context. This was a randomized, double-blind, placebo-controlled superiority trial. Patients aged at least 40 years undergoing abdominal surgery were randomized to receive either fondaparinux 2.5 mg or placebo s.c. for 5-9 days, starting 6-8 h postoperatively. All patients received intermittent pneumatic compression. The primary efficacy outcome was venous thromboembolism up to day 10. The main safety outcomes were major bleeding and all-cause mortality. Follow-up lasted 32 days. Of the 1309 patients randomized, 842 (64.3%) were evaluable for efficacy. The venous thromboembolism rate was 1.7% (7/424) in the fondaparinux-treated patients and 5.3% (22/418) in the placebo-treated patients (odds ratio reduction 69.8%; 95% confidence interval 27.9-87.3; P = 0.004). Fondaparinux significantly reduced the proximal deep vein thrombosis rate from 1.7% (7/417) to 0.2% (1/424; P = 0.037). Major bleeds occurred in 1.6% (10/635) and 0.2% (1/650) of fondaparinux-treated and placebo-treated patients, respectively (P = 0.006), none being fatal or involving a critical organ. By day 32, eight patients (1.3%) receiving fondaparinux and five (0.8%) receiving placebo had died. In patients undergoing abdominal surgery and receiving intermittent pneumatic compression, fondaparinux 2.5 mg reduced the venous thromboembolism rate by 69.8% as compared to pneumatic compression alone, with a low bleeding risk as compared to placebo.

Deep-vein thrombosis rates after major orthopedic surgery in Asia. An epidemiological study based on postoperative screening with centrally adjudicated bilateral venography

The incidence of postsurgical venous thromboembolism is thought to be low in Asian ethnic populations. We studied the incidence of deep-vein thrombosis (DVT) in Asian patients undergoing major orthopedic surgery of the lower limbs. We performed a prospective epidemiological study in 19 centers across Asia (China, Indonesia, South Korea, Malaysia, Philippines, Taiwan, and Thailand) in patients undergoing elective total hip replacement (THR), total knee replacement (TKR) or hip fracture surgery (HFS) without pharmacological thromboprophylaxis. The primary endpoint was the rate of DVT of the lower limbs documented objectively with bilateral ascending venography performed 6-10 days after surgery using a standardized technique and evaluated by a central adjudication committee unaware of local interpretation. Overall, of 837 Asian patients screened for this survey, 407 (48.6%, aged 20-99 years) undergoing THR (n = 175), TKR (n = 136) or HFS (n = 96) were recruited in 19 centers. DVT was diagnosed in 121 of 295 evaluable patients [41.0%, (95% confidence interval (CI): 35.4-46.7)]. Proximal DVT was found in 30 patients [10.2% (7.0-14.2)]. Total DVT and proximal DVT rates were highest in TKR patients (58.1% and 17.1%, respectively), followed by HFS patients (42.0% and 7.2%, respectively), then THR patients (25.6% and 5.8%, respectively). DVT was more frequent in female patients aged at least 65 years. Pulmonary embolism was clinically suspected in 10 of 407 patients (2.5%) and objectively confirmed in two (0.5%). The rate of venographic thrombosis in the absence of thromboprophylaxis after major joint surgery in Asian patients is similar to that previously reported in patients in Western countries.

Fondaparinux Combined with Intermittent Pneumatic Compression (IPC) Versus IPC Alone in the Prevention of Venous Thromboembolism after Major Abdominal Surgery: The Randomized APOLLO Study.

Background: The selective factor Xa inhibitor fondaparinux has been shown to be at least as effective and as safe as the low-molecular-weight heparin dalteparin for venous thromboembolism (VTE) prevention after major abdominal surgery (Agnelli GA, et al. Br J Surg, 2005, In press). The benefit of fondaparinux in addition to intermittent pneumatic compression (IPC) in VTE prevention after abdominal surgery has not been evaluated.Objective: We performed a randomized, double-blind, placebo-controlled, superiority trial to compare the efficacy and safety of fondaparinux in conjunction with IPC versus IPC alone in patients undergoing major abdominal surgery.Methods: Patients aged at least 40 years undergoing abdominal surgery of at least 45 minutes were included. Patients at highest risk of VTE, requiring pharmacologic prophylaxis in addition to IPC were excluded at the investigator's discretion. Patients were randomized to receive either fondaparinux 2.5 mg or placebo once daily subcutaneously for 5 to 9 days, starting 6 to 8 hours postoperatively. All patients received IPC. The primary efficacy outcome was the composite of deep-vein thrombosis detected by mandatory bilateral venography, or documented symptomatic deep-vein thrombosis or pulmonary embolism up to day 10. The main safety outcome was major bleeding during the treatment period. A blinded independent committee adjudicated all these outcomes. Follow-up lasted 32 days.Results: Of the 1309 patients randomized between November 2001 and October 2004 (fondaparinux+IPC, n=650; placebo+IPC, n=659), 842 (64.3%) were evaluable for efficacy. The treatment groups were comparable with regard to VTE risk factors, demographic and surgical characteristics; 82% had at least one VTE risk factor (over and above being at least 40 years old and undergoing abdominal surgery). Fondaparinux significantly reduced the VTE rate from 5.3% (22/418) with placebo to 1.7% (7/424), an odds ratio reduction of 69.8% (95% CI: 27.9 to 87.3; p=0.004). Similarly, fondaparinux significantly reduced the proximal deep-vein thrombosis rate from 1.7% (7/417) to 0.2% (1/423; p=0.037). Major bleeding occurred in 1.6% (10/635) and 0.2% (1/650) of fondaparinux- and placebo-treated patients, respectively (p=0.006). None of the bleeding events were fatal or involved a critical organ.Conclusions: Fondaparinux combined with IPC was significantly more effective than IPC alone for VTE prevention after major abdominal surgery. Although the bleeding risk was increased with fondaparinux compared with placebo, this risk was low and consistent with that observed in previous fondaparinux studies in surgical patients.

High Rate of Deep-Vein Thrombosis in Asia after Major Orthopedic Surgery: The AIDA Study Final Results.

Background: The incidence of post-surgical venous thromboembolism is thought to be low in Asian populations and routine thromboprophylaxis is not implemented.Objective: In this large multinational, multiethnic study, we evaluated the incidence of deep-vein thrombosis (DVT) patients undergoing major orthopedic surgery of the lower limbs.Methods: We performed a prospective epidemiological study in 19 centers across Asia (China, Indonesia, South Korea, Malaysia, Philippines, Taiwan and Thailand) in patients undergoing elective total hip replacement (THR), total knee replacement (TKR) or hip fracture surgery (HFS) not receiving pharmacological thromboprophylaxis. The primary endpoint was the rate of DVT of the lower limbs objectively documented by mandatory bilateral ascending venography performed 6 to 10 days after surgery and evaluated by a blinded central adjudication committee.Results: Overall, 407 Asian patients (20–99 years) undergoing THR (n=175), TKR (n=136) or HFS (n= 96) were recruited in 19 centres. 72.5% of the enrolled patients had adequate venograms. Total DVT was diagnosed in 121 of 295 evaluable patients (41.0%, [95% confidence interval: 35.4–46.7]). Proximal DVT was found in 30 patients (10.2% [7.0–14.2]). Total DVT and proximal DVT rates were the highest in TKR patients (58.1% and 17.1%, respectively), followed by HFS patients (42.0% and 7.2%, respectively), then THR patients (25.6% and 5.8%, respectively). DVT was more frequent in female patients aged at least 65 years. By-country analysis showed that the highest DVT rate was observed in Indonesia (78.6%) and the lowest in China (24.3%). By ethnic group, the lowest DVT rate was observed in Koreans (29.8%), while similar results were found in Chinese (45.0%) and in other non-Korean non-Chinese (46.3%) ethnic groups. Pulmonary embolism was clinically suspected in 10 of 407 patients (2.5%) and objectively confirmed in two patients (0.5%).Conclusions: Venographically detected thrombosis is well recognized as an appropriate surrogate for symptomatic outcomes and is the basis for the recommendation for routine prophylaxis in Western patients. The high rate of venographic thrombosis in Asian patients is similar to that observed in patients in Western countries. Thrombosis prophylaxis should therefore be considered in Asian patients undergoing major orthopedic procedures.