Natural History Of Venous Thromboembolism Research Articles

Risk factors for Venous Thromboembolism and clinical outcomes in adults with sickle cell disease

IntroductionThe natural history of venous thromboembolism (VTE) in sickle cell disease (SCD) is incompletely understood. We hypothesized that VTE recurrence is common in SCD and associated with increased disease severity. We sought to understand the short- and long-term clinical outcomes of VTE in SCD. MethodsWe conducted a single-center retrospective chart review study of patients with SCD 18 years and older at our institution between 2003 and 2018. Demographics, hemoglobin (Hb) genotype, medical history, and laboratory values were collected. We recorded VTE occurrence and potential provoking factors, duration of anti-coagulation and subsequent recurrence of VTE. We compared rates of emergency department (ED) visits, and hospitalizations for five years post-VTE to rates of ED visits and hospitalizations among those without VTE. ResultsFifty-five (23.6%) of 233 individuals with SCD in our cohort (69% HbSS/HbS-β0) had a VTE. Increased BMI, prior splenectomy, and white blood cell count were significantly associated with increased risk of VTE while Hb genotype, and severity of anemia were not. Recurrent VTE occurred in 27/55 (49%); 13 VTE recurrences occurred during active treatment with anticoagulants. Patients with a VTE had significantly higher rates of ED visits and hospital admissions than those without a VTE. ConclusionNearly a quarter of our single institution cohort had a VTE with a high recurrence rate even in those receiving anti-coagulation therapy. SCD patients had a higher rate of healthcare utilization after a VTE suggesting a link to disease severity.

Higher Rates of Death and Major Bleeding Highlight the Inequities That Exist in the Care of People with Venous Thromboembolism Who Experience Social Exclusion: Findings from a Prospective Registry of 79735 Patients (RIETE)

Background Social exclusion, experienced by vulnerable people at the margins of society, causes severe health inequity with dramatically increased risks of chronic disease and reductions in life-expectancy. Health services are not designed to meet the complex needs of socially excluded people (SEP). SEP are frequently unintentionally excluded from large observational studies such as household surveys and surveys requiring active participation (Levitas et al, 2007). This lack of data deepens inequity. Social exclusion in Ireland is strongly associated with injecting drug use, a strong risk factor for venous thromboembolism (VTE) (O'Reilly et al, 2015). Although an increased prevalence of VTE in lower socioeconomic groups has been described (Zoller et al, 2012), the impact of social exclusion and marginalisation on VTE has never been characterised in detail. The Registro Informatizado de Enfermedad TromboEmbólica (RIETE Registry) is the world's largest database on patients with VTE. It was commenced in 2001 and continues to collect prospective data on consecutive patients presenting to hospital with acute VTE events. Patients are followed longitudinally, for a minimum of three months (Bikdeli et al, 2018). One objective of the registry is to provide information on the natural history of VTE - particularly in subgroups of patients who would not usually be recruited to randomised clinical trials. Methods Our group has generated preliminary data (submitted separately to ASH 2019) which demonstrate that people with social exclusion can be identified from large national and international datasets using surrogate identifiers. The RIETE registry already collects several of these data elements that can be used to identify people who are socially excluded: HIV infection (which is strongly associated with injecting drug use), liver disease, chronic alcoholism and chronic psychiatric illness. We adapted the methodology developed in the Irish dataset and interrogated the RIETE registry utilising the available surrogate identifiers. We aimed to estimate the prevalence of social exclusion amongst patients with VTE, and to determine their clinical characteristics, treatment details and outcomes, with the ultimate goal of informing future service-planning and care-provision to this vulnerable group. Results At the time of interrogation of the RIETE registry, 79735 patients with VTE had been enrolled in 24 countries worldwide. Of these, 9211 (12%) met our criteria for SEP due to the presence of one or more of our surrogate identifiers. Of these, 60% presented with pulmonary embolism vs 52% in the non-SEP group (P<0.001), and SEP were more likely to have other medical co-morbidities. Major bleeding was more frequent in the SEP group (5.36 vs 3.55 events per 100 patient-years; HR 1.51 (1.35-1.69)), particularly in those with liver disease (8.70 events per 100 patient years) or psychiatric disorders (5.31 per 100 patient years). Death occurred more frequently in the SEP group (17.9 vs 12.0 events per 100 patient years; HR 1.49 (1.40-1.58)), and recurrent VTE occurred most frequently in those with HIV infection (4.31 events per 100 patient-years) and liver disease (4.46 events per 100 patient years, compared with 3.46 in the non-SEP group). Although Vitamin K Antagonists were used for longer term therapy in the majority of both patient groups (50% SEP, 63% non-SEP), the proportion who received low molecular weight heparin was higher in the SEP group (36% vs 26%). This was highest in the HIV infected subgroup, our identifier that best correlates with injecting drug use. Conclusions Social exclusion, as determined by the use of surrogate markers from a large prospective VTE registry, was associated with a higher overall incidence of death and major bleeding in patients treated for VTE. These data highlight the inequities experienced by this vulnerable patient group, demonstrating the need for increased funding for service planning and care provision to better prevent and manage VTE. This can lead to reductions in hospital admissions and costs, but ultimately to the provision of equitable healthcare for SEP. Disclosures Ewins: Bayer: Other: Conference Fees & Travel Expenses; Amgen: Other: Conference Fees & Travel Expenses. Ni Ainle:Daiichi Sankyo: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees, Research Funding; Leo Pharma: Research Funding; Boehringer: Membership on an entity's Board of Directors or advisory committees; Actelion: Research Funding. Ni Cheallaigh:MSD: Other: Travel Expenses; Pfizer: Research Funding.

Compression in acute stroke: nursing considerations

British Journal of Neuroscience NursingVol. 11, No. Sup2 CommentCompression in acute stroke: nursing considerationsEmma GeeEmma GeeSearch for more papers by this authorEmma GeePublished Online:27 Apr 2015https://doi.org/10.12968/bjnn.2015.11.Sup2.20AboutSectionsView articleView Full TextPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareShare onFacebookTwitterLinked InEmail View article References CLOTS trial collaboration (2009) Effectiveness of thigh-length graduated compression stockings to reduce the risk of deep vein thrombosis after stroke (CLOTS Trial 1): a multicentre, randomised controlled trial. Lancet 373(9679): 1958–65 Crossref, Google ScholarCLOTS trials collaboration (2010) Thigh-length versus below-knee stockings for DVT prophylaxis after stroke: a randomised trial. Ann Intern Med 153(9): 553–62 Crossref, Google ScholarCLOTS (Clots in Legs Or sTockings after Stroke) Trials Collaboration et al. (2013) Effectiveness of intermittent pneumatic compression in reduction of risk of deep vein thrombosis in patients who have had a stroke (CLOTS3): a multicentre randomised controlled trial. Lancet 382(9891): 516–24 Crossref, Google ScholarCLOTS (Clots in Legs Or sTockings after Stroke) Trials Collaboration (2014) Effect of intermittent pneumatic compression on disability, living circumstances, quality of life, and hospital costs after stroke: secondary analyses from CLOTS 3, a randomised trial. Lancet Neurol 13(12): 1186–92 Crossref, Google ScholarKearon C (2003) Natural History of Venous Thromboembolism. Circulation 107(23): 122–30 Google ScholarKelly J, Rudd A, Lewis RR, Coshall C et al. (2004) Venous Thromboembolism after acute ischaemic stroke; a prospective study using magnetic resonance direct thrombus imaging. Stroke 35: 2320–25 Crossref, Google ScholarKohro S, Yamakage M, Sato K et al. (2005) Intermittent pneumatic foot compression can activate blood fibrinolysis without changes in blood coagulability and platelet activation. Acta Anaesthesiologica Scandinavica 49: 660–4 Crossref, Google ScholarLankeit M, Konstantinides S (2011) Mortality risk assessment and the role of thrombolysis in pulmonary embolism. Critical Care Clinics 27(4): 953–67 Crossref, Google ScholarNational Institute for Health and Care Excellence (2010) NICE clinical guidance 92. Venous thromboembolism: reducing the risk: Reducing the risk of venous thromboembolism (deep vein thrombosis and pulmonary embolism) in patients admitted to hospital. https://www.nice.org.uk/guidance/cg92 (accessed 26 March 2015) Google ScholarNational Institute for Health and Care Excellence (2015) Addendum to NICE clinical guidance CG92. Reducing the risk of venous thromboembolism in patients admitted to hospital (Chapter 24-stroke patients). Draft for consultation. http://tinyurl.com/pdyk9xz (accessed 26 March 2015) Google ScholarStevens S, Woller S (2013) Intermittent pneumatic compression in patients with stroke. Lancet 382(9891): 484–6 Crossref, Google Scholar FiguresReferencesRelatedDetails 1 April 2015Volume 11Issue Sup2ISSN (print): 1747-0307ISSN (online): 2052-2800 Metrics History Published online 27 April 2015 Published in print 1 April 2015 Information© MA Healthcare LimitedPDF download

Ultrasound screening for deep venous thrombosis detection: a prospective evaluation of 200 plastic surgery outpatients.

Background:Our understanding of the pathophysiology of venous thromboembolism is largely based on the experience of orthopedic patients undergoing total joint replacement. Little is known regarding the natural history of venous thromboembolism in plastic surgery outpatients. Today, ultrasound screening, including compression and Doppler color flow imaging, represents the standard for detecting deep venous thromboses.Methods:Ultrasound screening was offered to 200 consecutive plastic surgery outpatients undergoing 205 operations. Patients were scanned before surgery, on the day after surgery, and approximately 1 week after surgery. No patient declined to participate (inclusion rate, 100%). Spontaneous breathing, Avoid gas, Face up, Extremities mobile anesthesia was used, with no chemoprophylaxis. Patient surveys were administered.Results:Six hundred ultrasound screening tests were performed. All scans performed the day after surgery were negative. Only one examination was positive, 8 days after a lipoabdominoplasty. Subsequent scans revealed complete resolution of the thrombosis with anticoagulation. Ninety percent of surveyed patients would choose to have ultrasound screening in the future.Conclusions:The natural history of thromboembolism in plastic surgery outpatients differs from orthopedic patients. The risk of a deep venous thrombosis in a patient treated with Spontaneous breathing, Avoid gas, Face up, Extremities mobile anesthesia is approximately 0.5%. Thromboses are unlikely to develop intraoperatively. In the single affected patient, the thrombosis was located distally, in a location that is less prone to embolism and highly susceptible to anticoagulation. Ultrasound screening is an effective and highly feasible method to identify affected patients for treatment.

VTE Registry: What Can Be Learned from RIETE?

The Registro Informatizado de Enfermedad TromboEmbólica (RIETE Registry) is an ongoing, international, prospective registry of consecutive patients with acute venous thromboembolism (VTE) designed to gather and analyze data on treatment patterns and outcomes in patients with acute VTE. It started in Spain in 2001, and 6 years later the database was translated into English with the aim to expand the Registry to other countries. In contrast to randomized controlled trials, there is no imposed experimental intervention: the management is determined solely by physicians. Thus, it provides data on patients with VTE in a real-world situation with an unselected patient population. Data from RIETE are hypothesis-generating and provide feedback from real-world clinical situations. So far, we learned about the natural history of VTE in patients with relative or absolute contraindications to anticoagulant therapy. We also learned interesting aspects on the natural history of VTE, and we built a number of prognostic scores to identify VTE patients at low, moderate, or high risk for adverse outcome.

Natural history of venous thromboembolism in patients from the Mediterranean region. A systematic review

Abstract Background Patients with cardiovascular diseases living in the Mediterranean area have a better outcome than those in other parts of the world, but it is not known whether these differences also occur with venous thromboembolism (VTE). Methods We searched the Medline and EMBASE databases to identify clinical trials and cohort studies of patients with VTE who had been treated with anticoagulant therapy for 3 months. Two reviewers independently extracted the data in a standardized manner. A total of 24 studies that included 7225 patients (2414 from the Mediterranean region and 4811 from other regions) were analyzed. Results The patients from the Mediterranean area were predominately women and older, and the idiopathic VTE was less frequent than in other regions. Compared with patients from other regions, patients from the Mediterranean region had an increased rate of recurrent deep vein thrombosis (4.35% vs. 2.68%; odds ratio [OR], 1.65; 95% confidence interval [95% CI] 1.27–2.15), fatal recurrent VTE (0.75% vs. 0.35%; OR, 2.11; 95% CI 1.09–4.12) and fatal bleeding (0.25% vs. 0.06%; odds ratio: 3.99; 95% CI 1.00–16.0). The case-fatality rate (CFR) for recurrent VTE was 12.8% (95% CI 7.99–19.1) in the Mediterranean region and 8.41% (5.15–12.9) in other areas. The CFR for major bleeding was 11.3% (95% CI 4.72–22.1) and 3.22% (95% CI 0.83–8.53), respectively. Conclusions Compared to other regions, patients with VTE from the Mediterranean region have greater mortality during the first 3 months of treatment due to a greater incidence of recurrent VTE and severe hemorrhaging.

P0170 Frequency, and effect on survival, of venous thrombosis in cancer patients: A single-centre experience

Background Venous thromboembolism (VTE) represents one of the most important causes of morbidity and mortality in cancer patients. We investigated the natural history of VTE in the oncology centre in a tertiary care hospital. Methods We did a retrospective study of cancer patients who presented to King Abdullah Medical City, a tertiary care hospital, from May 2011 to June 2013. The follow-up period was calculated from time of VTE diagnosis to the last clinical visit or to patient death. Findings Of 1678 cancer patients, 132 (7.87%) were diagnosed with VTE. Median patient age was 53.5 years, with a female-to-male ratio of 1.3/1. Thirty-one patients (23.5%) were diagnosed with VTE and cancer simultaneously, 74 patients (56.1%) were on chemotherapy and 28 (21.2%) were receiving best supportive care. VTE was symptomatic in 110 patients (83.3%) and asymptomatic in 22 (16.7%). Lower limbs were the most common site of VTE (42.4%), with the highest incidence in patients with advanced stage disease (93%). Forty-nine patients (37%) were receiving low-molecular-weight heparin as prophylaxis. Median survival for patients with VTE prophylaxis compared with those without prophylaxis was 12.6 months versus 6.3 months ( p = 0.102) and for those who were asymptomatic compared with those who were symptomatic was 9.8 months versus 12.4 months ( p = 0.885). Interpretation Thromboprophylaxis is underused in our region. Large prospective studies are needed to clarify the effect of VTE symptoms and presentation on patient’s survival.

Natural history of venous thromboembolism in gastrointestinal cancers.

593 Background: Venous thromboembolism (VTE) is a leading cause of mortality in patients with cancer. Characterisation of VTE in cancer will guide prophylactic anti-coagulation of high risk populations. Methods: We performed a retrospective analysis using electronic patient records, of 910 upper GI (UGI) cancer and 1,299 colorectal cancer (CRC) patients referred to a tertiary cancer centre to identify the incidence of VTE, its relationship to chemotherapy and impact on survival. VTE risk scores were calculated using the Khorana index (Khorana AA et al. Blood 2008 May 15;111(10):4902-7). Results: VTE were identified in 88/910 (9.7%) patients with UGI cancer (oesophageal 37%, gastro-oesophageal 24%, gastric 39%), comprising 50 deep vein thromboses (DVT) and 43 pulmonary emboli (PE). 52% were stage I-III and 48% stage IV. 56% of patients received chemotherapy up to 4 weeks before VTE. Median time to VTE from cancer diagnosis was 5.3 months (range -3 to 31.2). No difference in survival was seen for patients with VTE compared to a stage matched control group without VTE (median OS 12.5 v 9.4 months, log rank p=0.2). VTE (DVT:PE, 69:49) affected 115/1299 (8.9%) patients with CRC (25% stage I-III, 75% stage IV). Median time to VTE from CRC diagnosis was 5.4 months (range -4.3 to 54.5) for stage I-III and 8.6 months (range -4.3 to 77) for stage IV CRC. Chemotherapy was received by 41% (stage I-III) and 78% (stage IV) of patients within 4 weeks before VTE. Data to perform VTE risk score were available for 72/115 CRC patients with VTE, which classified 61.1% as low-risk (stage I-III 81.2% (13/16); stage IV 55.3% (31/56)). Again, no difference in survival was seen for patients with VTE compared to a control group without VTE matched for stage and performance status (median OS for stage I-III, 40 vs. 50.3 months p=0.41; stage IV, 20.7 vs. 18.8 months, p=0.52). Conclusions: VTE affects nearly 1 in 10 patients with GI cancer receiving chemotherapy. The peak incidence is in the first 6 months following diagnosis. Most patients have DVT and 36% are asymptomatic. No adverse impact on survival was seen for patients with VTE compared to stage matched controls implying VTE is not a prognosticator of poor outcomes in gastrointestinal cancers. Mature data will be presented at the meeting.

Venous thromboembolism in immobilized patients with dementia. Findings from the RIETE registry

BackgroundThe natural history of venous thromboembolism (VTE) in patients with dementia has not been thoroughly studied. MethodsWe used the RIETE Registry data to assess the clinical characteristics, treatment strategies and outcome during the first 3months after acute VTE in all immobilized patients with dementia. ResultsAs of August 2011, 37988 patients had been enrolled, of whom 1316 (3.5%) had dementia. Most patients in both subgroups were initially treated with low-molecular-weight heparin (LMWH). Then, 48% of patients with dementia and 25% of those without dementia received LMWH as long-term therapy. During the first 3months of anticoagulant therapy, patients with dementia had a higher incidence of fatal pulmonary embolism (PE): 4.0% vs. 1.2% (odds ratio: 3.3; 95% CI: 2.5-4.4) and fatal bleeding: 1.4% vs. 0.5% (odds ratio: 2.9; 95% CI: 1.8-4.6) than those without dementia. In demented patients initially presenting with PE, the incidence of fatal PE during the first week outweighed that of fatal bleeding (42 vs. 4 deaths), but from Day 8, the incidence of fatal PE was similar to the incidence of fatal bleeding. In patients initially presenting with deep vein thrombosis (DVT), there were 4 fatal PE and 8 fatal bleeding events. ConclusionsVTE patients with dementia had a high incidence of fatal PE and fatal bleeding. In those initially presenting with PE, the risk of dying of PE far outweighed that of fatal bleeding. In patients presenting with DVT alone, the risk of fatal PE was lower than that of fatal bleeding.

MOC-PS(SM) CME Article: Venous Thromboembolism Prophylaxis in Plastic Surgery Patients

After studying this article, the participant should be able to: 1. Understand and appreciate the incidence of venous thromboembolism in plastic surgery. 2. Understand and describe the cause and natural history of venous thromboembolism in the setting of plastic surgery. 3. Understand the important patient risk factors for venous thromboembolism and perform an individualized assignment of venous thromboembolism risk. 4. Select a method of venous thromboembolism prophylaxis based on a patient's venous thromboembolism risk assignment and the overall thromboprophylaxis guidelines by the American College of Chest Physicians. This Maintenance of Certification module reviews the incidence, cause, and natural history of venous thromboembolism in plastic surgery patients and highlights one algorithm for approaching venous thromboembolism risk assignment and choice of thromboprophylaxis.

Prevention of Pulmonary Embolism in General Surgery Patients

Case Presentation : A 29-year-old woman presented to the emergency department with complaints of pleuritic chest pain, fever, and left ankle swelling and tenderness. Cardiac examination was normal except for tachycardia. A chest computed tomography scan with contrast demonstrated extensive bilateral pulmonary emboli. Thirteen days previously, an intoxicated driver with multiple prior convictions for driving under the influence of alcohol crashed head-on into her car at a high speed. She was 8 months’ pregnant and suffered the loss of the child. She spent 7 days in the hospital and underwent cesarean section, exploratory laparotomy, and splenectomy. No preoperative pharmacological prophylaxis against venous thromboembolism (VTE) was administered. VTE, which includes deep vein thrombosis (DVT) and pulmonary embolism (PE), is an important and common complication of general surgery. A new era in the postoperative management of surgical patients began in 1975 when the effectiveness of low-dose heparin in preventing postoperative DVT and PE was established by the pivotal International Multicenter Trial.1 The dose was 5000 U subcutaneously every 8 hours, with the first injection administered 2 hours before the skin incision. Compared with control, the incidence of DVT in patients receiving heparin decreased from 24.6% to 7.7%. Similarly, the incidence of autopsy-proven PE was reduced 8-fold. The results of this trial introduced and validated the concept of using low-dose heparin to prevent postoperative VTE. This trial revolutionized surgical practice. By 1994, 90% of North American general surgeons reported the routine use of thromboprophylaxis.2 Most postoperative DVT originates in the deep calf veins, primarily within the valve cusps. Most thrombi remain confined to the calf. Propagation into the proximal veins increases the risk of PE. Symptoms and signs of postoperative VTE such as mild hypoxia or low-grade fever are frequently nonspecific. Moreover, clinical manifestations of postoperative VTE may not occur until …

The natural history of venous thrombo-embolism.

Journal Article The natural history of Venous Thrombo-Embolism Get access M G Walker M G Walker Aberdeen Royal Infirmary Search for other works by this author on: Oxford Academic Google Scholar British Journal of Surgery, Volume 59, Issue 10, October 1972, Pages 753–754, https://doi.org/10.1002/bjs.1800591003 Published: 07 December 2005

COST CONSEQUENCE ANALYSIS OF FONDAPARINUX VERSUS ENOXAPARIN IN THE PREVENTION OF VENOUS THROMBOEMBOLISM AFTER MAJOR ORTHOPAEDIC SURGERY IN BELGIUM

Fondaparinux, a selective inhibitor of activated factor X, has been shown to reduce further the risk of venous thromboembolism (VTE) in major orthopaedic surgery compared to the low molecular weight heparin enoxaparin, when both were applied for 7 days after surgery.To compare the expected costs and clinical outcomes of fondaparinux with enoxaparin applied for 7 days after surgery, we conducted a cost-consequence analysis in patients undergoing major orthopaedic surgery, i.e. total hip replacement, total knee replacement and hip fracture repair. Our decision model included endpoints relevant in routine clinical practice and the natural history of VTE over a long term period of 5 years. Costs for prevention, diagnosis and treatment of VTE and its complications were estimated from the Belgian health care payer perspective. Analyses were conducted for different time horizons and for the three indications, separately, and then combined.Overall, our results indicated that the initial investment in fondaparinux (cost per day: 10.39 € versus 3.74 € for enoxaparin) was soon compensated by savings due to avoided VTE events, with cost neutrality being achieved after 90 days and further savings being incurred over longer time periods mainly due to avoided post-thrombotic syndromes. These findings were most pronounced in patients undergoing hip fracture repair. Sensitivity analyses showed these findings to be robust for the three indications separately, and combined.We conclude that our analysis of health and economic consequences over a long term period, demonstrates the value for money of fondaparinux versus enoxaparin for the prevention of VTE events after total hip replacement, total knee replacement and hip fracture repair.

Natural History of Venous Thromboembolism

Development of venous thromboembolism involves many of the components of the circulatory system, including the blood veins and components carried in the blood. The development of a thrombosis, as described in Virchow’s triad, is a result of blood stasis, vessel wall damage, and/or hypercoagulability. The existence of any of these conditions can cause thrombosis formation. Recurrence of deep venous thrombosis or pulmonary embolism increases after the first venous thromboembolic incident. Deep venous thrombosis or pulmonary embolism can cause chronic health problems that require treatment for many years, including post-thrombotic syndrome and pulmonary hypertension.

Natural history of venous thromboembolism.

Most deep vein thromboses (DVTs) start in the calf, and most probably resolve spontaneously. Thrombi that remain confined to the calf rarely cause leg symptoms or symptomatic pulmonary embolism (PE). The probability that calf DVT will extend to involve the proximal veins and subsequently cause PE increases with the severity of the initiating prothrombotic stimulus. Although acute venous thromboembolism (VTE) usually presents with either leg or pulmonary symptoms, most patients have thrombosis at both sites at the time of diagnosis. Proximal DVTs resolve slowly during treatment with anticoagulants, and thrombi remain detectable in half of the patients after a year. Resolution of DVT is less likely in patients with a large initial thrombus or cancer. About 10% of patients with symptomatic DVTs develop severe post-thrombotic syndrome within 5 years, and recurrent ipsilateral DVT increases this risk. About 10% of PEs are rapidly fatal, and an additional 5% cause death later, despite diagnosis and treatment. About 50% of diagnosed PEs are associated with right ventricular dysfunction, which is associated with a approximately 5-fold greater in-hospital mortality. There is approximately 50% resolution of PE after 1 month of treatment, and perfusion eventually returns to normal in two thirds of patients. About 5% of treated patients with PE develop pulmonary hypertension as a result of poor resolution. After a course of treatment, the risk of recurrent thrombosis is higher (ie, approximately 10% per patient-year) in patients without reversible risk factors, in those with cancer, and in those with prothrombotic biochemical abnormalities such as antiphospholipid antibodies and homozygous factor V Leiden.

Current Monograph in Four Parts

HomeCirculationVol. 107, No. 23_suppl_1Current Monograph in Four Parts Free AccessEditorialPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessEditorialPDF/EPUBCurrent Monograph in Four Parts Clive Kearon, M.B., M.R.C.P.I., F.R.C.P.C., PhD Clive KearonClive Kearon Search for more papers by this author Originally published17 Jun 2003https://doi.org/10.1161/01.CIR.0000078462.30806.13Circulation. 2003;107:I-3The first issue of this series of supplements on venous thromboembolic disease is devoted to the epidemiology, risk factors, and natural history of venous thromboembolism (VTE). The monograph consists of four chapters. Epidemiology of VTE is described by Dr. Richard White of the University of California, Davis. He notes that the average population incidence of VTE is ≈1 per 1000 persons per year in North America but that this risk is greatly influenced by age and ethnicity. VTE is >100 times more common in the elderly than it is in children and, generally, the incidence doubles with each decade of age. Asians have a risk of VTE of about one fifth that of Caucasians and African-Americans. There is no convincing difference in the risk of VTE between men and women.Risk factors for VTE are described by Drs. Fredrick Anderson and Fredrick Spencer of the University of Massachusetts Medical School, Worcester. They note that about one half of VTE episodes are associated with hospital admission, the frequency in surgical and medical patients being similar. The risk of VTE differs markedly among hospitalized patients, and guidance is provided on how to identify those who are at moderate or high risk and should routinely receive prophylaxis. Hereditary and acquired biochemical states are associated with VTE in about one third of episodes; the prevalence and severity of these conditions as risk factors are described. It is noted that VTE risk is determined as much by the number of risk factors present in any one patient as it is by the strength of association of each factor.Cancer and VTE is described by Drs. Agnes Lee and Mark Levine of McMaster University, Hamilton. They describe the increase in VTE that is associated with different types and stages of cancer, and discuss how cancer treatments may further increase this risk. Among patients with an apparently unprovoked episode of VTE, cancer subsequently declares itself ≈5% of the time, often within 6 months of when VTE is diagnosed. As patients with occult cancers that are associated with VTE often have extensive disease, the authors suggest that broad screening for cancer in patients with unprovoked VTE is unlikely to result in improved outcomes and is generally not warranted.The natural history of VTE is described in my own chapter. It is noted that VTE usually starts in the calf veins, from where it may extend to involve the proximal veins before subsequently breaking free and causing pulmonary embolism. Progression of VTE through successive stages, each of which may or may not manifest symptoms, has important implications for prevention, diagnosis, and treatment of deep vein thrombosis and pulmonary embolism. Furthermore, treatment of VTE is designed to arrest or reverse this process.The goal of this issue is to provide clinicians with a quantitative understanding of the risks of deep vein thrombosis and pulmonary embolism in predefined populations and in individual patients. This knowledge is required for optimal management of persons at risk for, and those who develop, VTE. Consequently, this issue is intended to serve as a foundation for subsequent installments of this series on venous thromboembolic diseases. Previous Back to top Next FiguresReferencesRelatedDetails June 17, 2003Vol 107, Issue 23_suppl_1 Advertisement Article InformationMetrics https://doi.org/10.1161/01.CIR.0000078462.30806.13 Originally publishedJune 17, 2003 Keywordsthrombosisrisk factorsepidemiologyveinsembolismPDF download Advertisement

The work of D. Eugene Strandness, Jr., MD

D. Eugene Strandness, Jr., MD, died on January 7, 2002. At this 10th Congress of the WFUMB, it is appropriate to reflect on the many contributions Dr. Strandness made to the field of medical ultrasound. His initial work was based on the use of strain gauge plethysmography for the evaluation of arterial and venous disease, and it established physiologic testing as a valid and important clinical tool. The use of Doppler ultrasound for the transcutaneous assessment of vascular disease was pioneered by Dr. Strandness at the University of Washington in the 1960s. Based on this early work, the noninvasive vascular laboratory gradually became established as an indispensable resource for patient care and research. In the 1970s, Dr. Strandness and the bioengineering group at the University of Washington investigated the use of real-time B-mode scanning in the evaluation of the carotid artery bifurcation. An early case in which the internal carotid appeared patent on the B-mode image but occluded by arteriography led to the “duplex” concept of combining B-mode imaging and Doppler flow detection in a single instrument. The prototype duplex scanner built at the University of Washington gave rise to modern commercial duplex systems. Dr. Strandness also participated in the early efforts to credential vascular technologists and accredit vascular laboratories, which continue today. On the personal side, Dr. Strandness was both inspiring and challenging. He seemed to have an unlimited supply of enthusiasm and ideas. Those who worked closely with him will remember him as a strong friend and advocate, with a broad smile and a generous sense of humor. At the end of his life, Dr. Strandness was still actively engaged in his work and looking toward the future. Ongoing projects in his laboratory included the development of 3-dimensional ultrasound imaging, refining methods for vein graft surveillance, and the natural history of venous thromboembolism. In this era of large multicenter trials and program projects, it is exceedingly rare for one person to make a real difference in a medical field. Dr. Strandness is one of these rare people. His work will be remembered, and his presence among us will be missed.

The natural history of venous thromboembolism: Impact on ventilation/perfusion scan reporting

Deep vein thrombosis (DVT) and pulmonary embolism (PE) are separate but related aspects of the same dynamic disease process known as venous thromboembolism (VTE). Recent community studies have shown that VTE is a major health issue for the developed world, with at least 201,000 new cases each year in the United States, comprising 107,000 with DVT and 94,000 with PE. A quarter of PE cases die within 7 days, some so rapidly that treatment or intervention is impossible. Despite the availability of heparin prophylaxis, the annual incidence of VTE has remained constant at 1 event per 1,000 person-years since 1979 but reaches 1 event per 100 person-years for the over-85-year-olds. The most important risk factors for VTE are hemostatic and environmental. The recent discoveries of factor V Leiden, prothrombin 20210A, and high concentrations of factor VIII have highlighted the increasing importance of a genetic predisposition to thrombophilia. Acquired hemostatic factors include pregnancy and the puerperium, oral contraception, hormone-replacement therapy, malignant tumors, and antiphospholipid syndromes. Important environmental risk factors include hospitalization with previous surgery or trauma, confinement in a care facility, neurologic disease or paraplegia after stroke, current or recent central venous catheter or transvenous pacemaker, and long airplane flights. Internists may be confused about the risk of PE after ventilation/perfusion (VQ) imaging. This may well arise from their use of the relative risk of PE after a low-probability category scan rather than the absolute risk obtained by incorporating the PE prevalence for their particular patient in the risk analysis. Ideally, personal communication with an experienced referring physician provides this clinical information for nuclear medicine. Diagnostic tools or checklists can be used as an alternative. A general knowledge of the natural history of VTE will encourage the nuclear medicine physician to provide an appropriate clinical signal to complement VQ categorical analysis. Combination of these 2 dynamic elements of the art and science of VQ scan reporting-the clinical pretest probability of PE and lung scan category-will permit an accurate prediction of the absolute risk of PE posttest.

Natural history of venous thromboembolism.

Most deep vein thromboses (DVTs) start in the calf; however, thrombi that remain confined to the calf rarely cause leg symptoms or are associated with symptomatic pulmonary embolism (PE). The probability that calf DVT will extend to involve the proximal veins, and subsequently cause PE, increases with the severity of the initiating prothrombotic stimulus and if this stimulus persists. Although acute venous thromboembolism (VTE) usually presents with either leg or pulmonary symptoms, most patients have thrombosis at both sites at the time of diagnosis. Treated proximal DVTs resolve slowly, and half of patients still have detectable thrombi after a year. About 10% of patients with symptomatic DVT develop severe postthrombotic syndrome within 5 years. This is more likely to occur if there has been an ipsilateral recurrent DVT. About 10% of PEs are rapidly fatal. Of PEs that are diagnosed before death, about 50% are associated right ventricular dysfunction, a finding that is associated with a high short-term mortality. There is about 50% resolution of PE after 1 month of treatment, and perfusion eventually returns to normal in two thirds of patients. After a course of treatment, the risk of recurrent thrombosis is higher in patients without a reversible risk factor and in those with certain biochemical abnormalities, including antiphospholipid antibodies, hyperhomocysteinemia, and homozygous factor V Leiden.

Deep Vein Thrombosis and Pulmonary Embolism in the General Population

Deep vein thrombosis (DVT) and pulmonary embolism (PE) are common public health problems. Still, little is known about the epidemiology and the natural history of venous thromboembolism. In the Study of Men Born in 1913, 855 men were followed up prospectively from the age of 50 years to the age of 80 years. Several cross-sectional samples, also of men born in 1913, were studied at the ages of 50, 54, 60, 67, 75, and 80 years. Objective methods were used to ascertain a diagnosis of DVT or PE, and all were confirmed by hospital records or autopsy reports. The follow-up rate in the longitudinal study was 98.2%. In the longitudinal study, the incidence of DVT was 182 per 100,000 observation-years. Corresponding incidence rates were 98 for nonfatal PE, 107 for fatal PE, and 387 for all thromboembolic events. The cumulative probability for a venous thromboembolic event at different ages was estimated to be 0.5% by the age of 50 years and 10.7% by the age of 80 years. In the cross-sectional studies, a history of confirmed venous thromboembolism was found in 0.5% of the men at age 50 years, 0.9% at age 54 years, 1.3% at age 60 years, 2.0% at age 67 years, 4.5% at age 75 years, and 3.8% at age 80 years. The results indicate a high incidence of DVT and PE in the general population. The incidence of thromboembolic events increases with age. The rate of fatal PE seems to be higher than estimated before, and PE constitutes almost 5% of all deaths during follow-up.