Prior History Of Deep Vein Thrombosis Research Articles

Method of venous thromboembolism prophylaxis is not a predictor of pulmonary embolus following elective bariatric surgery: a retrospective cohort study of 135,409 patients.

Patients with obesity are at increased risk of pulmonary embolus (PE), a risk that increases perioperatively and is challenging to manage. An analysis of the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) database was performed to determine predictors of PE in patients undergoing elective bariatric surgery. North American accredited bariatric surgery institutions included in the MBSAQIP database from 2020-2021. We extracted data from the MBSAQIP database (2020-2021) on patients who underwent elective Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG). Data were extracted on patient co-morbidities, race, prior history of deep vein thrombosis (DVT), and type of DVT prophylaxis. A multivariate logistic regression model was developed to determine predictors of PE and impact of PE on 30-day serious complications and mortality. In the MBSAQIP database, a total of 135,409 patients underwent SG or RYGB from 2020 to 2021. PE was reported in 194 patients (.14%). Prior history of DVT (odds ratio [OR] = 3.28; 95% confidence interval [CI]: 1.85-5.83; P < .0001), Black race (OR = 3.03; 95% CI: 2.22-4.13; P<.0001), gastroesophageal reflux disease (OR = 1.51; 95% CI: 1.11-2.04; P = .008), higher body mass index (OR = 1.11; 95% CI: 1.01-1.20; P = .023), male sex (OR = 1.76; 95% CI: 1.26-2.45; P = .001), and older age (OR = 1.27; 95% CI: 1.10-1.46; P = .001) were associated with increased odds of PE. Chronic obstructive pulmonary disease, sleep apnea, and hypertension were not significant predictors of PE (P > .05). Neither combined mechanical and pharmacologic DVT prophylaxis nor pharmacologic prophylaxis alone was a significant predictor of PE (P > .05). Prior history of DVT is the strongest predictor of PE after bariatric surgery. African American race, male sex, and gastroesophageal reflux disease are additional risk factors. Method of venous thromboembolism prophylaxis was not identified as significant predictor of PE. Further, studies on the evaluation and optimization of venous thromboembolism prophylaxis are required.

Risk of Postoperative Thromboembolism in Men Undergoing Urological Prosthetic Surgery: An Assessment of 21,413 Men.

We assessed venous thromboembolism (VTE) and associated risk factors following artificial urinary sphincter (AUS) and inflatable penile prosthesis (IPP) surgery. Using IBM® MarketScan, a commercial claims database, patients undergoing AUS and IPP surgery were identified using CPT® and ICD (International Classification of Diseases)-10 procedure codes between 2008 and 2017. ICD-9 and -10 codes were used to identify health care visits associated with lower extremity deep vein thrombosis (DVT) and pulmonary embolism (PE) within 90 days of surgery. Covariates were assessed using a multivariable model to determine association with outcome of DVT and/or PE. A total of 21,413 men underwent AUS (4,870) or IPP (16,543) surgery between 2008 and 2017 with a median age of 62 years and 68 years, respectively. DVT and PE events following AUS and IPP surgery occurred in 1.54% and 1.04%, respectively. A history of varicose veins (HR 2.76; 95% CI 1.11-6.79), prior history of DVT (HR 13.65; 95% CI 7.4-25.19), or PE (HR 7.65; 95% CI 4.01-14.6) in those undergoing AUS surgery was highly associated with development of postoperative VTE. Likewise, prior history of DVT (HR 12.6; 95% CI 7.99-19.93) and PE (HR 8.9; 95% CI 5.6-14.13) was strongly associated with a VTE event following IPP surgery. In a large cohort of men undergoing AUS and IPP surgery, 1.54% and 1.04% of men experienced a VTE event within 90 days of surgery, respectively. Prior history of varicose veins, DVT, and PE was associated with an increased likelihood of developing a postoperative DVT or PE.

ADALIMUMAB (HUMIRA) AND THE RISK OF RECURRENT VENOUS THROMBOEMBOLISM

SESSION TITLE: Monday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/21/2019 02:30 PM - 03:15 PM INTRODUCTION: Anti-TNF alpha agents have increasingly been used to treat several types of auto-immune diseases, including rheumatoid arthritis and Crohn’s disease. Deep vein thrombosis is an uncommon but important side effect of this medication. Optimum duration of anticoagulation therapy is unknown due to lack of large data studies or guidelines.. In this case, we discuss the possible necessity of indefinite anticoagulation for patients taking adalimumab after having a venous thrombotic event. CASE PRESENTATION: A 54 year old African American female with past medical history significant for obesity, uveitis, retinal detachment and rheumatoid arthritis, presented to the ED with generalized fatigue, dizziness, and shortness of breath. She had no other significant cardiac history. She did not have any history of prior deep vein thrombosis or family history of a hyper-coagulable disorder. She had started Adalimumab 4-5 months prior to this visit. Notable vitals included heart rate of 140 and EKG showing atrial fibrillation with no changes indicating ischemia. CXR showed mild pulmonary vascular congestion. She was given diltiazem 20mg IV in the ED and started on diltiazem 30mg PO every 6 hours. CT angiography of the chest revealed bilateral main pulmonary artery emboli, segmental, and subsegmental pulmonary emboli. She was started on tPA via catheter directed thrombolysis for 24 hours and heparin drip. Ultrasound of BLE was significant for non-occlusive deep vein thrombosis (DVT) in right popliteal vein. Patient was discharged on apixaban 10mg BID for 6 days to switch to 5mg BID for 6 months. After 6 months, apixaban was discontinued. Two months after discontinuation of apixaban, she presented to the ED with left calf pain. LLE Venous Duplex was performed and revealed left popliteal DVT. Anticoagulation therapy with apixaban was reinstituted. DISCUSSION: Adalimumab is associated with increased risk of DVT. Since our patient did not have a prior history of DVT, we believed the use of Adalimumab resulted in a hyper-coagulable state. Despite causing a lupus-like syndrome, the true mechanism is unknown. Previous studies discussed that patients with Adalimumab antibodies may have an increased risk of thromboembolic events compared to those without. A subsequent larger study refuted this association. The temporality of events, including recurrence of DVT after discontinuation of anticoagulation therapy strongly suggests possibility of ongoing risk of thromboembolism and need of continued anticoagulation therapy, similar to the patients with other chronic hyper-coagulable states and certain types of cancer. CONCLUSIONS: This case demonstrates the need for evaluation of anticoagulation guidelines in patients taking Adalimumab due to the persistence of hyper-coagulable state after previous thromboembolic events. Reference #1: Korswagen, L. A., Bartelds, G. M., Krieckaert, C. L., Turkstra, F. , Nurmohamed, M. T., van Schaardenburg, D. , Wijbrandts, C. A., Tak, P. P., Lems, W. F., Dijkmans, B. A., van Vugt, R. M. and Wolbink, G. J. (2011), Venous and arterial thromboembolic events in adalimumab-treated patients with antiadalimumab antibodies: A case series and cohort study. Arthritis & Rheumatism, 63: 877-883. https://doi.org/10.1002/art.30209 DISCLOSURES: No relevant relationships by Chinmaya Sharma, source=Web Response

High Altitude Is an Independent Risk Factor for Developing a Pulmonary Embolism, but Not a Deep Vein Thrombosis Following a 1- to 2-Level Lumbar Fusion.

Study Design:Retrospective study.Objective:To identify if a 1- to 2-level posterior lumbar fusion at higher altitude is an independent risk factor for postoperative deep vein thrombosis (DVT) and pulmonary embolism (PE).Methods:A national Medicare database was queried for all patients undergoing 1- to 2-level lumbar fusions from 2005 to 2014. Those with a prior history of DVT, PE, coagulopathy, or peripheral vascular complications were excluded to better isolate altitude as the dependent variable. The groups were matched 1:1 based on age, gender, and comorbidities to limit potential cofounders. Using ZIP codes of the hospitals where the procedure occurred, we separated our patients into high (>4000 feet) and low (<100 feet) altitudes to investigate postoperative rates of DVTs and PEs at 90 days.Results:Compared with lumbar fusions performed at low-altitude centers, patients undergoing the same procedure at high altitude had significantly higher PE rates (P = .010) at 90 days postoperatively, and similar rates of 90-day postoperative DVTs (P = .078). There were no significant differences in age or comorbidities between these cohorts due to our strict matching process (P = 1.00).Conclusion:Spinal fusions performed at altitudes >4000 feet incurred higher PE rates in the first 90 days compared with patients receiving the same surgery at <100 feet but did not incur higher rates of postoperative DVTs.

Long-Term Antithrombotic Therapy after Venous Stent Placement

IntroductionChronic deep venous insufficiency (CVI) is a common disorder of the venous valves which can cause many debilitating symptoms including edema, pain, and skin changes. CVI may result from a primary non-thrombotic cause, such as May-Thurner syndrome (MTS) or extrinsic compression from a pelvic mass, or as the sequelae of an acute deep vein thrombosis (DVT). Endovascular interventions, including percutaneous transluminal angioplasty and venous stent placement, have been increasingly utilized as a minimally-invasive treatment option for CVI. In patients treated via endovascular therapy, stent restenosis is a significant area of clinical concern. However, there is a paucity of data on the optimal preventative long-term antithrombotic strategy. Current practice is highly variable and employs a combination of anticoagulation and antiplatelet agents, which borrows heavily from experience with venous thromboembolism and arterial stent management, respectively. This study examines the prescribing patterns and outcomes of various antithrombotic regimens after venous stent placement at a large academic medical center.MethodsPatients who received venous stents at our institution between January 1st, 2010 and December 31st, 2015 were eligible for the study. A retrospective review was performed to determine the antithrombotic regimens and the rates of stent restenosis and major bleeding within two years of stent placement. The relationship between these outcomes and antithrombotic regimens was analyzed via logistic regression. Additional logistic regression and linear regression models were used to evaluate the impact of indications and hypercoagulable risk factors on the selection of antithrombotic agents.ResultsA total of 151 patients were included in the study (Table 1). Antithrombotic regimens were variable: 58 patients (38%) received triple therapy (i.e., anticoagulation plus dual antiplatelet therapy), 25 (17%) received anticoagulation only, 21 (14%) received anticoagulation plus a single antiplatelet agent, 15 (10%) received dual antiplatelet therapy only, 10 (7%) received a single antiplatelet, and 22 (15%) received no antithrombotic therapy (Figure 1). Patients with acute DVTs with or without MTS were more frequently given multiple antithrombotic agents compared to those with extrinsic compression. The duration of antithrombotic therapy was also variable. When anticoagulation was prescribed (n = 104), 31% received indefinite therapy, followed by 22% for 6 months and 12% for 3 months. Patients with a history of prior DVTs or thrombophilia were more likely to be prescribed indefinite anticoagulation. Aspirin was most commonly prescribed for an indefinite duration (62 of 88 patients) while clopidogrel was most commonly prescribed for just 3 months (60 of 89 patients).Twenty-three patients (15%) developed stent restenosis. Triple antithrombotic therapy had significantly lower rates of stent restenosis compared to no antithrombotic therapy (OR = 0.05, p < 0.01), and was associated with lower rates of restenosis compared to anticoagulation alone (OR = 0.19, p = 0.07) and dual antiplatelet therapy (OR = 0.25, p = 0.09). Anticoagulation with a single antiplatelet agent also led to lower rates of stent restenosis when compared to no antithrombotic therapy (OR = 0.08, p = 0.04). Medication non-compliance and antiphospholipid antibody syndrome were identified as independent predictors of stent restenosis (OR = 8.84, p = 0.01 and OR = 7.11, p = 0.03, respectively). Major bleeding was observed in 11 patients (7%). Of note, there were no major bleeding events observed in the dual antiplatelet or single antiplatelet groups, which were thus excluded from the regression model. Among the remaining treatment groups, there was no significant difference in major bleeding rates.ConclusionsThis study emphasizes the considerable variability in the prescribing patterns of long-term antithrombotic therapy after venous stent placement. There appears to be benefit to antithrombotic therapy in preventing stent restenosis, particularly when anticoagulation is combined with antiplatelet agents. However, this may be counterbalanced by an increased risk of bleeding. Larger prospective trials are needed to evaluate the relative risks and benefits of each antithrombotic regimen, and ultimately determine the optimal management strategy, following venous stent placement. [Display omitted] DisclosuresDesai:Philips/Spectranetics: Other: consulting; Cook Medical: Other: consulting, Speakers Bureau; Boston Scientific: Other: consulting, Speakers Bureau; AngioDynamics: Other: consulting, Speakers Bureau; OptiMed: Other: consulting.

Prevalence and Predictors of Deep Vein Thrombosis in Critically Ill Medical Patients Who Underwent Diagnostic Duplex Ultrasonography.

Deep vein thrombosis (DVT) is a recognized but preventable cause of morbidity and mortality in the medical intensive care unit (MICU). We examined the prevalence and risk factors for DVT in MICU patients who underwent diagnostic venous duplex ultrasonography (DUS) and the potential effect on clinical outcomes. This is a retrospective study examining prevalence of DVT in 678 consecutive patients admitted to a tertiary care level academic MICU from July 2014 to 2015. Patients who underwent diagnostic DUS were included. Potential conditions of interest were mechanical ventilation, hemodialysis, sepsis, Sequential Organ Failure Assessment (SOFA) scores, central venous catheters, prior DVT, and malignancy. Primary outcomes were pulmonary embolism, ICU length of stay, and mortality. Additionally, means of thromboprophylaxis was compared between the groups. Multivariable logistic regression analysis was utilized to determine predictors of DVT occurrence. Of the 678 patients, 243 (36%) patients underwent DUS to evaluate for DVT. The prevalence of DVT was 16% (38) among tested patients, and a prior history of DVT was associated with DVT prevalence (P < .01). Between cases and controls, there were no significant differences in central venous catheters, mechanical ventilation, hemodialysis, sepsis, SOFA scores, malignancy, and recent surgery. Patients receiving chemical prophylaxis had fewer DVTs compared to persons with no prophylaxis (14% vs 29%; P = .01) and persons with dual chemical and mechanical prophylaxis (P = 0.1). Fourteen percent of patients tested had documented DVT while on chemoprophylaxis. There were no significant differences in ICU length of stay (P = .35) or mortality (P = .34). Despite the appropriate use of universal thromboprophylaxis, critically ill nonsurgical patients still demonstrated high rates of DVT. A history of DVT was the sole predictor for development of proximal DVT on DUS testing. Dual chemical and mechanical prophylaxis does not appear to be superior to single-chemical prophylaxis in DVT prevention in this population.

Venous Thromboembolism After Adult Lung Transplantation: A Frequent Event Associated With Lower Survival.

The incidence of venous thromboembolism (VTE) after lung transplantation (LTX) varies significantly across studies. Two studies have suggested that these thrombotic events are associated with a lower posttransplant survival. Herein, we sought to determine the incidence, predictors, and impact of VTE on survival after LTX at a quaternary referral center. This was a large cohort study of LTX recipients. Key outcome parameters were time to VTE after transplant and survival. Deep vein thrombosis (DVT) diagnosis required a positive ultrasound. Pulmonary embolism diagnosis required either a positive chest computed tomography angiogram or a high-probability ventilation/perfusion scan. The overall incidence of VTE among 701 LTX recipients was 43.8%, of which 97.7% were DVT episodes, of which 71.3% were in the upper extremities. Predictors of VTE were prior history of DVT (hazard ratio [HR], 2.82; 95% confidence interval [CI], 1.49-5.37), days in intensive care (HR, 1.01; 95% CI, 1.01-1.02), and the use of extracorporeal membrane oxygenation (HR, 2.22; 95% CI, 1.43-3.45). Importantly, VTE predicted a lower posttransplant survival (HR, 1.70; 95% CI, 1.28-2.26), when occurring within or after the first 30 days. The location of the DVT, either upper extremity or below the knee, also predicted a poor survival. VTE was frequent in LTX recipients and predicted a poor survival even when located in the upper extremities or below the knee. These data suggest that aggressive VTE screening/treatment protocols be implemented in post-LTX population.

A Phase II LYSA Study of Obinutuzumab Combined with Lenalidomide for Relapsed or Refractory Aggressive B-Cell Lymphoma

A Phase II LYSA Study of Obinutuzumab Combined with Lenalidomide for Relapsed or Refractory Aggressive B-Cell Lymphoma

A Phase Ib Study of Obinutuzumab Combined with Lenalidomide for Relapsed/Refractory Follicular B-Cell Lymphoma

BACKGROUND:Lenalidomide exerts anti-proliferative activity on lymphoma cells, enhances T- and NK-cell function, and improves ADCC. The combination of lenalidomide and rituximab (R2) has been shown to be synergistic in pre-clinical models and in patients with relapsed and first-line follicular lymphoma (FL). Obinutuzumab, a unique type II glycoengineered monoclonal anti-CD20 antibody with increased ADCC and increased direct cell death induction compared to rituximab, has shown promising efficacy in NHL. Combining obinutuzumab with lenalidomide might be even more efficient than R2 combination. In 2012, we started a phase Ib/II study to assess the safety and efficacy of this combination (ClinicalTrials.gov: NCT01582776, GALEN) for relapsed/refractory lymphoma patients. Here, we report the phase Ib part whose primary objective was to determine the maximum tolerated dose (MTD) of lenalidomide in combination with a fixed dose of obinutuzumab.METHODS:To identify the MTD of lenalidomide, four patient cohorts received escalating doses (10, 15, 20, and 25 mg) of daily oral lenalidomide on days 1-21 of a 28-day cycle for the first cycle and on days 2-22 of a 28-day cycle from cycles 2 to 6. Intravenous infusions of obinutuzumab at a flat dose of 1000mg were given on Days 8, 15, and 22 of the first cycle and at D1 of cycles 2 to 6 (total of 8 infusions). Steroid premedication was mandatory before first obinutuzumab infusion. All subjects were required to take daily aspirin (100 mg) for deep vein thrombosis (DVT) prophylaxis during study period. Subjects who were unable to tolerate aspirin and subjects with prior history of DVT or at high risk received low molecular weight heparin therapy or warfarin (coumadin) treatment. Dose was escalated in a 3+3 design based on dose limiting toxicity (DLT) assessment during cycle 1RESULTS:20 patients with FL ([10 mg: 7; 15 mg: 3; 20 mg: 6, 25 mg: 4] QD) were enrolled between Oct 2012 and Feb 2014 at 7 centers, 10 men/10 women, median age 64 (range, 39–80) years, 15 with Ann Arbor stage IV, median number of prior systemic therapies 2 (range, 1–5) and 8 were rituximab refractory. One patient was withdrawn before receiving any treatment due to neutropenia occurring at baseline screening. Median number of cycles was 6 (range, 1–6). We observed 163 AEs (87 grade 1; 53 grade 2; 21 grade 3; one grade 4 and one grade 5). The most common AEs (All grades, ≥20% patients) were neutropenia (10/19; 53%), constipation (10/19; 53%) asthenia (7/19; 37%), upper respiratory tract infection (7/19; 37%), rash/cutaneous eruption (5/19; 26%), cough (5/19; 26%), diarrhea (4/19 ; 26%) and fever (4/19, 21%). Grade (G) 3/4 AEs occurring in ≥2 patients only consisted in neutropenia (8/19; 42%). Infusion related reactions occurred in 3 patients and did not exceed grade 2. Four DLTs have occurred in 2 patients: one unexplained death (G5) at 10 mg in the setting of G3 worsening pleural effusion; another patient treated at 20 mg had G3 pulmonary infection with G3 hypokalemia, both deemed unrelated to study treatment. The MTD was not reached. Among 19 evaluable patients, 13 (68%) had an overall response according to Cheson 1999 criteria: 7 achieved CR, 3 CRu and 3 PR.CONCLUSION:Oral lenalidomide plus obinutuzumab is well tolerated and effective in patients with relapsed or refractory FL. Recommended dose of lenalidomide was established at 20mg based on the increased incidence of grade 3/4 neutropenia between cycle 2 and 6 at 25mg. The Phase II partis currently assessing theefficacy of lenalidomide (at 20 mg) in combination with obinutuzumab in 2 separate populations of patients: relapsed/refractory follicular lymphoma in one cohort and relapsed/refractory aggressive lymphoma (diffuse large B-cell lymphoma and mantle cell lymphoma) in another cohort. DisclosuresMorschhauser:Celgene: advisory boards, advisory boards Other, Honoraria; Genentech/roche: Honoraria, travel grants Other. Off Label Use: obinutuzumab and lenlidomide in relapsed follicular lymphoma. Salles:celgene: Honoraria, Membership on an entity’s Board of Directors or advisory committees; roche: advisory boards, advisory boards Other, Honoraria, Research Funding. Le Gouill:Roche: Consultancy. Tilly:Roche/Genetech: advisory boards, advisory boards Other, Honoraria; Celgene: advisory boards Other, Honoraria. Cartron:roche: Consultancy, Honoraria; celgene: Honoraria.

Researcher Overcomes Recession Hurdles

Researcher Overcomes Recession Hurdles

Post-thrombotic syndrome after total hip arthroplasty is uncommon

Background Deep vein thrombosis (DVT), usually asymptomatic, is common after total hip arthroplasty (THA). Post-thrombotic syndrome (PTS) is a potential late complication of DVT, but there is limited data on its occurrence.Patients and methods This was a prospective cohort study of subjects at one hospital who had participated in a trial of thromboprophylaxis for THA and who had postoperative venography. Data were collected at baseline and 2–4 years later to ascertain symptoms of PTS using a modification of a validated scoring system. Outcomes were collected without knowledge of baseline characteristics or venogram results. Potential predictors of PTS were explored using exact logistic regression analyses.Results The cohort (n=188) had a mean age of 63 years, 51% were male, 35% had a BMI of>30, and 4% had a prior history of DVT. 25 patients (13%) had DVTs on venography. 12 patients (6%, 95% CI: 3–11) subsequently developed symptoms consistent with PTS, 7 with bilateral symptoms. Most affected limbs (15 of 19) had no postoperative DVT. No statistically significant predictors of PTS were found.Interpretation Symptoms of PTS are infrequent after THA in patients who receive some form of thromboprophylaxis. Our findings, which are consistent with the existing literature, suggest that there is a potential benefit to giving thromboprophylaxis for reduction of symptomatic PTS.

The Use of a Clinical Prediction Model and D-Dimer (DD) Testing in the Diagnosis of Deep Vein Thrombosis (DVT): A Systematic Review.

Background: The diagnosis of DVT can be made by determining pretest probability of disease and using this information in combination with DD testing and ultrasound imaging. A number of studies have evaluated the use of clinical probability but this literature has not been summarized.Purpose: To systematically review trials that evaluated DVT prevalence using clinical prediction rules either with or without DD for the diagnosis of DVT.Data Sources: English and French language studies were identified from a MEDLINE search from 1990 to March 2004 and were supplemented by a review of all relevant bibliographies.Study Selection: Prospective management studies of symptomatic outpatients with suspected DVT in which patients were followed for a minimum of 3 months were selected. Clinical prediction rules had to be employed prior to DD and diagnostic tests. Studies were excluded if patients with a history of prior DVT were enrolled or if insufficient information was presented to calculate the prevalence of DVT for each of the 3 clinical probability estimates (low, moderate and high risk).Data Extraction: Two reviewers assessed each study for inclusion/exclusion criteria and collected data on prevalence and on sensitivity, specificity and likelihood ratios of DD in each of the 3 clinical probability estimates (low, moderate and high risk).Data Synthesis: 14 management studies involving a clinical prediction model in the diagnosis of DVT in over 8000 patients were included, of which 11 utilized DD in the diagnostic algorithm. All studies employed the same clinical prediction rule. The inverse variance weighted average prevalence of DVT in the low, moderate and high probability subgroups were 4.9% (95% CI= 4.2% to 5.7%), 17.4% (95% CI= 16.2% to 18.8%), and 53.6% (95% CI= 51.1% to 56.2%), respectively. The overall weighted prevalence was 18.3% (95% CI= 17.4% to 19.2%). The sensitivity of DD for the diagnosis of DVT in the low, moderate and high probability subgroups were 90.4% (95% CI= 84.7% to 94.2%), 92.0 % (95% CI= 89.1% to 94.2%), 93.6% (95% CI= 91.2% to 94.3%); and the specificities were 69.9% (95% CI= 68.0% to 71.8%), 52.4% (95% CI= 49.8% to 55.0%), and 43.2% (95% CI= 38.8% to 47.6%), respectively. The Mantel-Haenszel pooled estimates for diagnostic odds ratios (DOR) were 17.4 (95%CI=10.4–29.1), 10.2 (95% CI=7.1–14.6), and 10.1 (95% CI=6.9–14.9) in low, moderate and high groups respectively.Conclusion: Accurate estimates of the prevalence of DVT can be achieved using the same clinical prediction rule. Using this rule, it is unlikely that low probability patients have a DVT probability of more than 5%. Specificity of the DD seems to have clinically relevant differences depending on pretest probability but the DORs (which incorporate sensitivity and specificity) are similar. The data suggest that DVT can be excluded if patients are low probability even when DDs of lower sensitivity are employed and that DD testing has lower utility in high probability patients since false positives are common.

Prevention of Deep Vein Thrombosis and Pulmonary Embolism

Venous thromboembolism comprises deep vein thrombosis (DVT) and pulmonary embolism (PE) and strikes more than 1 in 1000 adults per year, causing discomfort, suffering, and occasionally death. DVT is defined as blood clots in the pelvic, leg, or major upper-extremity veins. These clots can break off from the veins, travel through the heart, and lodge in the lung arteries, causing potentially deadly PE. Although about 300 000 new cases are diagnosed yearly in the United States, probably 3 to 4 times as many cases occur without obvious symptoms and are never detected. This illness is often “silent” and can mimic other common conditions such as heart attack, pneumonia, and anxiety. Its aftermath spans a wide spectrum, from inconsequential to fatal. Awareness of DVT and PE is the best way to prevent this condition. Medical professionals have recognized DVT for almost 2 centuries, but until recently, only about half of Americans were informed about the disease. Without knowledge of DVT as a medical problem, the public could not engage healthcare providers to discuss lifestyle changes and more intensive measures that usually succeed in preventing this illness. Historically, many prominent public figures have been afflicted with DVT but received little attention. However, …