Deep Vein Thrombosis In Outpatients Research Articles

Oral rivaroxaban for the treatment of deep vein thrombosis in outpatients: a propensity score-matched comparison with a historical inpatient population.

Despite the guidelines' appeal to treat patients with deep vein thrombosis and low-risk pulmonary embolism in outpatient settings, the real-world evidence shows a high prevalence of inpatient therapy leading to unwarranted health resource utilization. The study aimed to assess the efficacy and safety of rivaroxaban in outpatient settings compared to inpatient treatment. A propensity score-matched comparison with a historical inpatient population was performed based on a retrospective analysis of patients with deep vein thrombosis and without pulmonary embolism treated as outpatients with oral rivaroxaban. Inpatient controls were treated with oral rivaroxaban following a short-term initial therapy with low-molecular-weight heparins. The relevant outcomes extracted from electronic medical records were as follows: recurrent deep vein thrombosis and symptomatic pulmonary embolism, major bleeding, clinically relevant non-major bleeding, minor bleeding, unscheduled hospitalization, and death. Among 209 outpatients who were never admitted to the hospital the deep vein thrombosis recurrence rate was 3.3% (95%CI, 1.6-6.8%), clinically relevant non-major bleeding rate 2.9% (95%CI, 1.3-6.1), minor bleeding rate 6.2% (95%CI, 3.7-10.0%), unscheduled hospitalization rate 1.4% (95%CI, 0.5- 4.1%), mortality rate 1.4% (95%CI, 0.5-4.1%). No symptomatic pulmonary embolism or major bleeding was detected. No statistically significant differences were observed when compared with inpatient controls. The outpatient use of rivaroxaban for deep vein thrombosis treatment is a safe and effective approach for patients without pulmonary embolism, with no significant differences when compared to inpatient therapy with oral rivaroxaban following a short-term initial therapy with low-molecular-weight heparins.

Commentary on “Diagnosis of Deep Vein Thrombosis in Outpatients With Musculoskeletal Disorders: A Survey of Orthopedic and Sports Academies”

Commentary on “Diagnosis of Deep Vein Thrombosis in Outpatients With Musculoskeletal Disorders: A Survey of Orthopedic and Sports Academies”

Deferring diagnostic evaluation of suspected deep vein thrombosis using direct oral anticoagulant or low-molecular-weight heparin as a single dose anticoagulant: A prospective real-world study in a regionwide care pathway

BackgroundPatients with suspected deep vein thrombosis (DVT) are typically referred to the emergency department for immediate evaluation. To enhance efficiency, our hospital implemented a regional, general practitioner (GP)-driven DVT care pathway, deferring diagnostic evaluation to a scheduled outpatient DVT clinic appointment the following day. Patients receive a single dose anticoagulant from their GP to prevent thrombosis progression while awaiting diagnostic workup. This prospective study aimed to evaluate the safety and patient preferences regarding the DVT care pathway and the type of single dose anticoagulant (low-molecular-weight heparin (LMWH) vs. direct oral anticoagulant (DOAC)). MethodsPatients enrolled in the DVT care pathway between June 2021 and July 2023 were eligible. Until July 2022, LMWH was administered, and thereafter, the protocol recommended DOAC as the single dose anticoagulant. Patients completed questionnaires, incorporating patient-reported outcome and experience measures (PROMs/PREMs), during their DVT clinic visit and after five days. The primary endpoint was bleeding events within 72 h of receiving the single dose anticoagulant. ResultsOf 460 included patients, 229 received LMWH and 231 received DOAC as the single dose anticoagulant. DVT was confirmed in 24.8 % of patients. No major or clinically relevant non-major bleeding were reported. LMWH was associated with more minor bleedings (22.3 % vs. DOAC 13.4 %), primarily attributed to injection site hematomas. Patients reported high satisfaction with the DVT care pathway (96.5 %) and generally preferred DOAC over LMWH. ConclusionDeferring diagnostic evaluation for DVT using a single dose of either LMWH or DOAC in a real-world population is deemed safe. Considering practical advantages, patient preferences, and fewer skin hematomas, we favor DOACs as the single dose anticoagulant in this care pathway.

Diagnosis of Deep Vein Thrombosis in Outpatients With Musculoskeletal Disorders: A Survey of Orthopaedic and Sports Academies

PURPOSE: Venous thromboembolism can present as either a deep vein thrombosis (DVT) or a pulmonary embolism. The purpose of this study was to determine if there was a difference in physical therapists' estimation of the probability of a patient having a DVT in patient vignettes as compared with the modified Wells criteria prediction. METHODS: Members of the American Academy of Orthopaedics, Academy of Orthopaedic Physical Therapists (AOPT), and American Academy of Sports Physical Therapy (AASPT) completed patient vignettes. Descriptive statistics were calculated, and sign tests assessed for differences between responses of the presence of DVT (likely or unlikely) and whether referral was necessary. RESULTS: Six hundred and seventy consented, and 521 completed the survey of 24,028 members from the AOPT and AASPT. In total, 7.2% did not feel competent to screen for DVT. Descriptive statistics revealed difficulty in determining whether a DVT was likely or unlikely in 4/5 vignettes as compared with the modified Wells criteria, with only vignette 2 having 95.9% correctly answering as DVT being unlikely. In the other 4 vignettes, approximately 60% to 70% of respondents estimated DVT to be likely, despite 2 of these being unlikely. Across the vignettes, between 2.3% and 19.2% more respondents chose to refer when they determined if a DVT was likely. Across vignettes, statistically significant differences between DVT being likely or unlikely and decision to refer were present. Respondents consistently chose to refer even when a DVT was unlikely (P < .001 for vignettes 1, 3–5. P = .038 for vignette 2). CONCLUSIONS: Venous thromboembolisms are potentially life-threatening conditions seen by physical therapists. Members of the AOPT and AASPT have difficulty in determining the presence or absence of DVT in clinical case vignettes, with some demonstrating a conservative management decision to refer despite low probability of DVT. Efforts to educate members should be considered to improve the understanding of DVT assessment. Clinical Pearls: Members of the AOPT and AASPT appear to have difficulty in determining the presence of a DVT in clinical patient vignettes. Respondents chose to refer patients perhaps with conservative caution. Efforts to educate therapists should be considered to improve the understanding of DVT assessment.

Prevalence of chronic venous insufficiency and deep vein thrombosis in cirrhotic patients.

People with cirrhosis of the liver are at risk for complications that can worsen their quality of life and increase morbidity and mortality. Contrary to previous beliefs, cirrhosis does not protect against the development of thromboembolic events, and cirrhotic patients may have higher rates of deep vein thrombosis (DVT). The study of chronic venous disease and its impact on patients with cirrhosis is unknown in the literature and may be an important fact since this condition also had impact on quality of life and morbidity. The aim of this study is to evaluate the prevalence of DVT (Deep Venous thrombosis) in outpatients with cirrhosis and the degree of chronic venous insufficiency, evaluating possible correlations between clinical and laboratory aspects of cirrhotic patients with these pathologies. Patients with cirrhosis were evaluated in the outpatient clinic of the Liver Transplantation and Hepatology Service of HC-FMUSP from November 2018 to November 2022, with clinical evaluation, venous disease questionnaires, data collection of imaging and laboratory tests, and venous color Doppler ultrasound. The information was analyzed by the University of São Paulo (USP) Statistics Department. There was a prevalence of 7.6% of DVT in studied patients, VCSS score 6.73 and severe CEAP classification (C4-6) 32.1%. There was no association of DVT with qualitative variables by the Fisher test such as Child Turcotte Pugh Scale (CTP) (p = 0.890), dichotomized INR values (p = 0.804), etiology of cirrhosis (p = 0.650) and chronic kidney disease (p > 0.999), nor with quantitative variables by t-student's such as age (p = 0.974), Body Mass Index (BMI) (p = 0.997), MELD score (p = 0.555), Albumin (p = 0.150) and Platelets (p = 0.403). We found that as the severity of ascites increases, there is an increase in the proportion of patients classified in the category indicating more severe clinical manifestations of chronic venous disease (C4 to C6). The mean age (54 years) was higher in patients with DVT than in those without. The mean BMI of patients without DVT (25.7 kg/m2) is lower than that of patients with DVT (27.0 kg/m2). The prevalence of DVT is higher in patients with thrombophilia (20.0%) than in those without (7.0%). This suggests an association between the two variables. The descriptive measures of the MELD score, the cirrhosis scale used for liver transplant waiting lists, did not indicate an association of this scale with the occurrence of DVT. The incidence of VTE (Venous Thromboembolic Events) and CVD (Chronic Venous Disease) within the sample surpassed that of the general population; nevertheless, more studies are required to validate these results. Concerning venous thromboembolism, no correlation was observed between the variables within the sample and the augmented risk of VTE. Regarding chronic venous disease, studies have shown that edema and orthostatism are correlated with increased severity of CVD on the VCSS scales. Statistical dispersion methods suggest that patients with higher BMI and more severe liver disease (according to the Child-Pugh score) are more likely to experience worsening of CVD. About chronic venous disease, studies have shown that edema and orthostatism are correlated with increased severity of CVD on the VCSS scales.

HSD72 Identification of Uncomplicated DVT Patient Characteristics Treated in the Outpatient Setting

Uncomplicated deep vein thrombosis (DVT) can be treated in the outpatient setting with oral anticoagulants. However, emergency department (ED) visits for uncomplicated DVT are often managed through hospitalization initially rather than ED discharge with appropriate anticoagulation and outpatient follow-up. Providers have varying degrees of comfort with outpatient DVT treatment. This study aims to examine characteristics of patients treated as outpatients without an ED visit to better understand differentiators between patients sent to the ED and those managed by outpatient providers.

Thrombotic burden, D-dimer levels and complete compression ultrasound for diagnosis of acute symptomatic deep vein thrombosis of the lower limbs

BackgroundDiagnostic algorithms for deep vein thrombosis (DVT) include D-dimer for its high negative predictive value, thus reducing the need for imaging. Small thrombi may be associated with low D-dimer levels, increasing false negatives. AimTo assess the sensitivity and thus the false negative rates of standard and age-adjusted D-dimer cut offs for isolated distal DVT (IDDVT) in outpatients. Materials and methodsWe enrolled consecutive outpatients with suspected DVT of the lower limbs referring to our vascular emergency department from 2009 to 2018. Patients underwent D-dimer testing (STA, Stago, cut-off: 500 μg/L), pretest clinical probability (PTP) evaluation and complete compression ultrasonography. Follow-up was 3 months. ResultsAmong 3948 patients (M:1554–39%, median age 69), 486 proximal DVTs (12.3%) and 348 IDDVTs (8.8%) were diagnosed. Median D-dimer was higher in proximal than IDDVT (3960 vs 1400 μgr/L; p = 0.001). The false negative rate of the standard D-dimer cut-off was 2% (95%CI: 0.8–3.2%) for proximal DVT and 14.7% (95% CI: 11–81%) for IDDVT. The false negative rate of the age-adjusted cut-off was 4.9% (3–7%) for proximal DVT and 19.5% (95% CI: 15.4–24.7%) for IDDVT. Conclusions: Small calf thrombi are associated with low D-dimer levels, and age-adjusted D-dimer may be below the cut-off more frequently in subjects with IDDVT than standard cut-off D-dimer, although such D-dimer levels might exclude IDDVT that require treatment.

A new pre-test probability score for diagnosis of deep vein thrombosis in patients before surgery

BackgroundVenous thromboembolism is a serious perioperative complication. We developed a new pre-test probability score for predicting deep vein thrombosis (DVT) before surgery. MethodsWhole leg ultrasonography was performed on 973 inpatients and outpatients with suspected DVT based on a preoperative D-dimer cut-off value of ≥ 1 μg/ml. We allocated two-thirds (n = 651) of the study participants to a derivation cohort and one-third (n = 322) to a validation cohort. The pre-test probability model was developed from the derivation cohort data. ResultsThe pre-test probability model for DVT assigned 2 points to D-dimer ≥ 1.5 μg/mL and 1 point each to age ≥ 60 years, female sex, ongoing glucocorticoid therapy, prolonged immobility, and cancer with high risk of DVT. The area under the curve of the pre-test probability score was 0.72 and 0.70 in the derivation and validation cohorts, respectively. The rates of DVT according to pre-test probability scores in the derivation and validation cohorts were 7% and 6% in the low (score = 0-2), 23% and 22% in the intermediate (score = 3-4), and 47% and 50% in the high probability group (score ≥ 5), respectively (p < 0.0001). ConclusionsThe pre-test probability score (Kagoshima-DVT score) was helpful in detecting preoperative DVT in both inpatients and outpatients. We identified low probability group to reduce whole-leg ultrasonography and high probability group to detect more DVT before surgery.

Safety of a strategy combining D-dimer testing and whole-leg ultrasonography to rule out deep vein thrombosis

AbstractGuidelines for the diagnostic workup of deep vein thrombosis (DVT) recommend assessing the clinical pretest probability before proceeding to D-dimer testing and/or compression ultrasonography (CUS) if the patient has high pretest probability or positive D-dimer. Referring only patients with positive D-dimer for whole-leg CUS irrespective of pretest probability may simplify the workup of DVT. In this prospective management outcome study, we assessed the safety of such a strategy. We included consecutive outpatients referred to the Emergency Department at Østfold Hospital, Norway, with suspected DVT between February 2015 and November 2018. STA-Liatest D-Di Plus D-dimer was analyzed for all patients, and only patients with levels ≥0.5 µg/mL were referred for CUS. All patients with negative D-dimer or negative CUS were followed for 3 months to assess the venous thromboembolic rate. One thousand three hundred ninety-seven patients were included. Median age was 64 years (interquartile range, 52-73 years), and 770 patients (55%) were female. D-dimer was negative in 415 patients (29.7%) and positive in 982 patients (70.3%). DVT was diagnosed in 277 patients (19.8%). Six patients in whom DVT was ruled out at baseline were diagnosed with DVT within 3 months of follow-up for a thromboembolic rate of 0.5% (95% confidence interval, 0.2-1.2). A simple diagnostic approach with initial stand-alone D-dimer followed by a single whole-leg CUS in patients with positive D-dimer safely ruled out DVT. We consider this strategy to be a valuable alternative to the conventional workup of DVT in outpatients. This trial was registered at www.clinicaltrials.gov as #NCT02486445.

D-dimer as a stand-alone test to rule out deep vein thrombosis

BackgroundCurrent guidelines recommend the use of clinical decision rules, such as Wells score, in combination with D-dimer to assess the need for objective imaging to rule out deep vein thrombosis (DVT). However, the clinical decision rule has limitations, and use of D-dimer as a stand-alone test has been suggested. ObjectiveWe aimed to assess the safety and efficiency of D-dimer as a stand-alone test to rule out DVT in outpatients referred with suspected DVT. MethodsWe collected data from consecutive outpatients referred to our hospital with suspected DVT in 2008–2018. D-dimer levels were analyzed using STA® Liatest® D-Di assay. D-dimer as a stand-alone test was theoretically applied in retrospect, and the number of misdiagnosed events were estimated as if such an approach had been initially used. All patients were followed for three months. ResultsOf 1765 included patients, 293 (16.6%) were diagnosed with DVT. A total of 491 patients (27.8%) had a negative D-dimer (<500 ng/mL). Of these, nine were diagnosed with DVT, yielding a failure rate for D-dimer as a stand-alone test of 1.8% (95% CI 0.8%–3.5%). The majority of the misdiagnosed patients had distal DVT. In analyses restricted to proximal DVTs, the failure rate was 0.6% (95% CI 0.1%–1.8%). D-dimer as a stand-alone approach reduced the proportion of required ultrasounds from 81.8% to 72.2%. ConclusionD-dimer as a stand-alone test may be safe for excluding proximal DVT and reduce the proportion of required ultrasounds. Prospective management studies are needed to confirm our findings.

Development and Evaluation of a Pharmacist-Driven Screening Tool to Identify Patients Presenting to the Emergency Department Who Are Eligible for Outpatient Treatment of Deep Vein Thrombosis

Background: Deep vein thrombosis (DVT) is a critical and costly health issue. Treatment in the outpatient setting is preferred compared to the inpatient setting. However, there is a lack of evidence regarding how best to identify patients who are ideal for outpatient DVT treatment. Objective: To design and evaluate a pharmacist-driven screening tool for the identification of patients presenting to the emergency department (ED) at a community hospital with DVT who are appropriate for outpatient treatment. Methods: This study was conducted in sequential phases: compilation and vetting of screening criteria, descriptive evaluation of criteria through retrospective chart review, and quantification of potential cost savings by avoiding admissions. Criteria were collected via literature search and assembled into a screening tool, which was applied retroactively to a cohort of ED patients admitted with DVT diagnosis. Results: A screening tool was developed with multidisciplinary input and consisted of 5 categories with individual patient and disease state criteria. The majority (91%) of patients reviewed would not have qualified for outpatient DVT treatment based on the retrospective application of the screening tool. The most common disqualification criteria category was high risk of bleeding/clotting (n = 81), and the most frequently represented parameter within that category was antithrombotic therapy prior to admission (n = 53). Conclusion: A screening tool may not be the most efficient method for health-care practitioners such as pharmacists to identify ED patients appropriate for outpatient management of DVT. Other avenues should be explored for improving the cost-effective management of these patients.

Systematic Review of Real-World Studies Evaluating Characteristics Associated With or Programs Designed to Facilitate Outpatient Management of Deep Vein Thrombosis.

Select patients with acute deep vein thrombosis (DVT) can be managed as outpatients. We sought to conduct a systematic review of real-world studies describing either (1) the clinical characteristics associated with outpatient DVT treatment in all-comers or (2) emergency department (ED) programs designed to facilitate outpatient DVT treatment. MEDLINE and SCOPUS were searched (January 1, 2012, to May 1, 2018) to identify citations meeting the aforementioned criteria. Twenty-one real-world studies were included. The proportion of all-comer patients with DVT managed as outpatients was ≤50% in 11 of 15 studies. With the exception of younger age, no characteristics were consistently associated with outpatient treatment across the 13 studies reporting these characteristics. We identified 8 studies describing ED programs aimed at facilitating DVT outpatient treatment, all of which provided education and included measures to encourage early outpatient follow-up after ED discharge. In conclusion, the proportion of patients with DVT managed as outpatients across real-world studies was low. Several ED programs aimed at facilitating this treatment have been described. It is possible that programs similar to these will increase the proportion of patients with DVT that can be safely managed as outpatients.

D-dimer for the diagnosis of upper extremity deep and superficial venous thrombosis

BackgroundD-dimer role is well established in the diagnostic work-up for lower limb deep vein thrombosis (DVT), however it has not been formally tested for clinically suspected upper extremity DVT and/or superficial vein thrombosis (SVT). AimTo ascertain D-dimer diagnostic accuracy for upper extremity DVT and/or SVT. Study designWe performed a single centre management study in outpatients referred by emergency or primary care physicians for clinically suspected upper extremity DVT. All patients underwent D-dimer testing (cut-off value: ≤500ng/mL), and a B-mode and color Doppler ultrasonography examination. In case of either technical problems or anatomical barriers, ultrasonography was repeated after 5-7days. All patients were followed up for three months for the occurrence of symptomatic DVT and/or SVT and/or pulmonary embolism. ResultsWe enrolled 239 patients (F: 63.6%; mean±SD age: 58.3±16.8). At the initial diagnostic work-up, DVT was detected in 24 (10%) patients while SVT in 35 (14.6%) patients. During follow-up, one upper extremity DVT was found. D-dimer levels were higher in patients with DVT than in those without. Sensitivity and specificity of D-dimer for DVT were 92% (95%CI: 73-99%) and 60% (95%CI: 52-67%) respectively, with a negative predictive value of 98% (95%CI: 93-100%), whereas for SVT they were 77% (95%CI: 59-89%) and 60% (95%CI: 52-67%) respectively, with a negative predictive value of 93% (95%CI: 86-97%). ConclusionsD-dimer has a negative predictive value ≥93% for excluding DVT in symptomatic outpatients and it can be a useful test in the diagnostic work-up of suspected upper extremity DVT.

Efficacy of Dabigatran for Dissolving Deep Vein Thromboses in Outpatients With a Deteriorated General Condition.

Non-vitamin K antagonist oral anticoagulants (NOACs) have been widely used for the prevention of ischemic strokes in patients with nonvalvular atrial fibrillation (AF). At present, NOACs have been evaluated for the treatment of deep vein thrombosis (DVT). We examined the efficacy of dabigatran, the first NOAC for anticoagulation of AF in Japan, in outpatients who suffered from DVTs under a deteriorated general condition.Thirty-six consecutive outpatients diagnosed with DVT at our institute were enrolled. Not all patients could be hospitalized due to other clinical problems; 15 (42%) had malignant tumors, 9 (25%) psychological disorders, and 6 (17%) postoperative orthopedic disease. Dabigatran was administered at a dose of 110-150 mg once or twice daily, depending on the renal function and age. The mean dosage of dabigatran was 211.7 ± 36.6 mg per day. In 18 (50%) patients, the DVTs were completely dissolved and disappeared over a treatment term of 4.3 ± 4.3 months. In 9 patients (25%), the DVTs partly dissolved, but in the remaining 9 (25%) patients, dabigatran was totally ineffective. During a follow-up of 30.5 ± 5.3 months, DVTs did not recur with dabigatran in 18 patients with an effective efficacy. In a multivariate analysis, patients with small sized thromboses and those without malignant tumors were significantly associated with the DVTs dissolving (P = 0.003 and P = 0.006, respectively).Dabigatran was effective for dissolving DVTs in outpatients with a poor condition, particularly when the size of the DVT was small and malignant tumors were absent.

Safety of Desirudin Administered in the Immediate Postoperative Period Following Joint Replacement Surgery: An Observational Study

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 patients undergoing elective hip replacement surgery, and approved in the EU for the prevention of DVT in patients undergoing elective hip or knee replacement surgery. Evidence suggests that desirudin may possess a better safety profile in higher risk patients than other thromboprophylactic agents, and trials evaluating the safety of desirudin have indicated good tolerability without frequent adverse events. The most common adverse event associated with desirudin is hemorrhagic reactions. This observational study evaluated bleeding events and wound outcomes in patients receiving desirudin during the immediate postoperative period after total joint replacement surgery (hip and/or knee), followed by rivaroxaban for outpatient DVT prophylaxis.METHODS. Patients undergoing total hip (THR) and/or total knee (TKR) replacement were eligible to participate in the study. Inpatient DVT prophylaxis was initiated with desirudin 15 mg BID the evening following the completion of surgery. At the discretion of the treating physician, DVT prophylaxis continued with rivaroxaban 10 mg on an outpatient basis following hospital discharge. The primary endpoints were (1) fall in hemoglobin (g/dL) and (2) degree of wound discharge at release from hospital. Wound discharge was rated on a 5-point scale of bruising ranging from 0 (negligible bruising) to 4 (bright red blood). Secondary endpoints included degree of wound discharge at the first postoperative follow-up visit. Endpoint assessments were conducted at hospital discharge, at the first postoperative visit, and at the staple-removal visit. All patients were required to follow-up with their surgeons in the clinic or via telephone between postoperative day 7 and postoperative day 14.RESULTS. Patient demographic and baseline data are presented in Table 1. As shown, 151 patients participated in the study (THR, n=37; TKR, n=111; THR/TKR, n=2). Patients ranged between 37-98 years of age, with a mean age of 62 years. Almost 75% of the patients were female. It is also important to note that the overall patient population had a mean body mass index (BMI) of 35.9 kg/m2. Data for the primary endpoints (fall in hemoglobin and wound discharge at the time of release from the hospital) and the secondary endpoint of wound discharge at follow-up are shown in Table 2. There was a low incidence of wound discharge (score >0) at release (n=2; 1 patient had a score of 1, 1 patient had a score of 4); at follow-up, a higher incidence of wound discharge (score >0) was noted (n=44). There was also an average fall in hemoglobin in the range of approximately 3-4 g/dL across age, gender, type of surgery, and BMI.CONCLUSION. The demographic characteristics of patients in this study suggest a patient population with a relatively high risk of venous thromboembolism (VTE) due to age and obesity. These data suggest that the use of desirudin in patients who may be at a higher risk for VTE due to age or obesity is not associated with adverse wound outcomes or increased bleeding risk.TABLE 1Demographic or Baseline CharacteristicsPatients (N=151)Median age, years (range)62 (37-98)Mean weight, kg (SD)100.59 (25.16)Mean BMI, kg/m2 (SD)a35.96 (8.63)Age group, n (%)<65 years90 (59.6)≥65 years61 (40.4)Sex, n (%)bMale37 (24.5)Female112 (74.2)Race/ethnicity, n (%)cWhite86 (57)Black54 (35.8)Latin American and Mexican3 (2)Asian2 (1.3)Native American2 (1.3)Other1 (0.7)Surgery type, n (%)aTHR37 (24.5)TKR111 (73.5)THR/TKR2 (1.3)aData missing from 1 patientbData missing from 2 patientscData missing from 3 patientsTABLE 2PopulationWound Discharge at Release, Mean (SD)Wound Discharge at Follow-up, Mean (SD)Change in Hemoglobin, Mean (SD)Agea<65 (n=90)0.07 (0.48)0.43 (0.75)-4.13 (1.11)≥65 (n=61)0 (0)0.27 (0.71)-3.85 (1.52)GenderbMale (n=37)0.17 (0.75)0.42 (0.81)-4.24 (1.29)Female (n=112)0 (0)0.41 (0.72)-3.93 (1.29)Type of SurgerycTHR (n=37)0 (0)0.25 (0.73)-3.98 (1.36)TKR (n=111)0.06 (0.43)0.45 (0.74)-4.04 (1.27)THR + TKR (n=2)0 (0)0.50 (0.71)-3.05 (2.19)BMIc, kg/m2Nonobesed (n=40)0 (0)0.3 (0.64)-4.15 (1.49)Obesee (n=109)0.1 (0.44)0.4 (0.73)-3.97 (1.23)aData missing from 7 patientsbData missing from 2 patientscData missing from 1 patientdNonobese defined as BMI≤30eObese defined as BMI>30 DisclosuresMeyer:Marathon Pharma: Employment.

Variations in ultrasound scanning protocols in the UK for suspected deep vein thrombosis in outpatients

To assess current ultrasound scanning protocol in outpatients with suspected deep vein thrombosis (DVT), in particular whether practitioners routinely scanned calf veins. A standard questionnaire was sent out via post to all radiology departments in the United Kingdom (UK) and via the British Medical Ultrasound Society (BMUS) website in 2010. Responses were entered into Access® and database queries were run to analyse responses. Free-text comments were taken into account in our analysis. A total of 277 responses (50 through the BMUS website) were received (46% postal response rate). Of them, six were excluded as these were incomplete. Thus, 97 (36%) were consultants, 13 (5%) accredited vascular scientists (AVSs), 153 (56%) sonographers and six (2%) higher radiology trainees. All AVSs scanned the whole limb and used all three modalities of compression, colour and pulse wave Dopplers. Practice across other health-care professionals varied. In all, 120/176 (68%) of other health-care professionals trained in vascular ultrasound scanned the whole limb routinely and 82/120 of these used all three scanning modalities. Trained sonographers scanned the whole limb significantly more than the medical cohort (P = 0.017). The use of all three modalities varied significantly between AVS and the non-AVS trained professionals (P = 0.0194), the trained medical cohort of consultants and sonographers (P = 0.0001), and trained and non-trained respondents (P = 0.0113). The commonly chosen reason for not scanning the whole limb was that it had poor sensitivity for calf vein DVTs. Free-text reasons for not scanning the whole limb routinely included local protocols prohibiting it. There is a discrepancy between the scanning protocols of medically trained and allied health-care professionals, trained or otherwise in vascular ultrasound, and between these groups and AVSs. This is likely to have an impact on clinical governance.

Can foot compression under a plaster cast prevent deep-vein thrombosis during lower limb immobilisation?

We hypothesised that adjuvant intermittent pneumatic compression (IPC) beneath a plaster cast would reduce the risk of deep-vein thrombosis (DVT) during post-operative immobilisation of the lower limb. Of 87 patients with acute tendo Achillis (TA) rupture, 26 were prospectively randomised post-operatively after open TA repair. The treatment group (n = 14) received two weeks of IPC of the foot for at least six hours daily under a plaster cast. The control group (n = 12) had no additional treatment. At two weeks post-operatively all patients received an orthosis until follow-up at six weeks. At two and six weeks the incidence of DVT was assessed using colour duplex sonography by two ultrasonographers blinded to the treatment. Two patients withdrew from the study due to inability to tolerate IPC treatment. An interim analysis demonstrated a high incidence of DVT in both the IPC group (9 of 12, 75%) and the controls (6 of 12, 50%) (p = 0.18). No significant differences in incidence were detected at two (p = 0.33) or six weeks (p = 0.08) post-operatively. Malfunction of the IPC leading to a second plaster cast was found to correlate with an increased DVT risk at two weeks (ϕ = 0.71; p = 0.019), leading to a premature abandonment of the study. We cannot recommend adjuvant treatment with foot IPC under a plaster cast for outpatient DVT prevention during post-operative immobilisation, owing to a high incidence of DVT related to malfunctioning of this type of IPC application.

Abstract 52: Association of Heparin Lead-in Therapy and Recurrence in the Treatment of Venous Thromboembolism

Background: Venous thromboembolism (VTE) encompasses deep vein thrombosis (DVT) and pulmonary embolism (PE). Anticoagulant treatment significantly decreases the risk of recurrent VTE events and is typically initiated with the administration of a heparin therapy along with warfarin followed by warfarin treatment alone. The objective of this study was to assess the association between heparin lead-in therapy and VTE recurrence in patients receiving warfarin. Methods: Data from adult patients who had a VTE diagnosis in a large claims database (period 2005 - 2011), a warfarin claim within 30 days and continuous eligibility for at least 12 months pre/post first (index) diagnosis, were analyzed. Patients with atrial fibrillation, VTE, or treatment with warfarin therapy prior to the index date were excluded. Patients were classified into 4 cohorts: 1) Outpatient DVT; 2) Outpatient PE; 3) Inpatient DVT; 4) Inpatient PE. Inpatient cohort patients had an index inpatient VTE claim or had an inpatient VTE claim within 7 days of an index outpatient VTE claim. Outpatient cohort patients were required to have another outpatient VTE claim within 7 days of their index claim. Patients with both DVT and PE claims were included in the PE cohorts. Recurrent VTE was defined as the presence of an inpatient VTE claim within 365 days from the index date. Heparin use was identified by a UFH/LMWH pharmacy claim within 7 days of the outpatient index date or discharge from an inpatient VTE index event. Cox proportional hazard models adjusting for age, gender, health insurance type and baseline Elixhauser comorbidities were used. Results: A total of 39,424 patients met study criteria. Mean (SD) age was 59.8 (15.6) years and 50.6% (19,946/39,424) were female. Most patients (72.0%; 28,388/39,424) had an index inpatient event with a mean (SD) LOS=5.4 (4.1) days. Outpatient DVT/PE patients who used heparin had significantly lower rates of VTE recurrence vs. those who did not ( P &lt;0.05). Post-discharge heparin use was not associated with VTE recurrence rates within inpatient cohorts. Conclusion: The use of heparin lead-in therapy can significantly reduce VTE recurrence in the Outpatient VTE cohorts. Due to the lack of inpatient drug use data to identify heparin use in this claims database, additional studies are needed to confirm our Inpatient cohort results.

Comparison of five point‐of‐care D‐dimer assays with the standard laboratory method

D-dimer (DD) assays are effective for the exclusion of deep-vein thrombosis (DVT), but point-of-care (POC) DD assays have not been fully evaluated. We have compared five POC DD assays (Pathfast, Cardiac, Vidas, Stratus and NycoCard) with our routine DD method (Tinaquant), testing 60 samples from patients with suspected DVT. Using 0.5 μg/mL as a cut-off value, four samples tested negative with Tinaquant were positive with Pathfast. There were no Tinaquant-positive samples tested negative with Pathfast, while the overall agreement (k = 0.81) was very good. Four samples were discrepant between Tinaquant and Cardiac (cut-off, 0.4 μg/mL), while k = 0.72. One of two Tinaquant-negative samples was shown to be positive for either Vidas (cut-off, 0.5 μg/mL) or Stratus (cut-off, 0.4 μg/mL), respectively. The agreement with Tinaquant was excellent for both Vidas (k = 0.92) and Stratus (k = 0.94). Total CV was <10% for all four assays. Eight samples (of 27) were negative with NycoCard although they were positive with Tinaquant, while CV was 41%. Vidas cannot be considered a POC assay because the sample has to be centrifuged before testing. Our findings have also shown that the use of NycoCard is inappropriate. Stratus and Pathfast have a similar analytical profile in comparison with the Tinaquant method. Cardiac is potentially less sensitive but may still be acceptable for use. It seems that the employment of these three assays for rapid bed-side analysis offers a possibility to adequately rule out DVT in outpatients within minutes after admission.

Validation study for use of an algorithm for the diagnosis of deep vein thrombosis in out-patients

In a previous study we demonstrated that the use of an algorithm can decrease unnecessary emergency venous duplex evaluations (VDE) in out-patients and increase the percentage of positive yields. The present study was undertaken to validate the safety of following such an algorithm. During a six month period we suspended the application of the algorithm and performed VDE on all requests for out-patients. A total of 94 requests were received from the Emergency Department and all were honored. Of the 94 out-patients who underwent emergency VDE for deep vein thrombosis (DVT), eleven were positive for DVT (11.8%) and 83 were negative (88.2%). Had the algorithm been applied for patients screening, all the 11 positive studies would have gone to emergency VDE (100%). 10 patients had proximal DVT and 1 had isolated peroneal DVT. The application of an algorithm for inclusion/exclusion of out-patients for emergency VDE is a safe and effective means for limiting emergency access to the non-invasive vascular laboratory.