The changing pattern of venous thromboembolic disease

Association Between Asymptomatic Proximal Deep Vein Thrombosis and Mortality in Acutely Ill Medical Patients

Background Asymptomatic proximal deep vein thrombosis (DVT) is an end point frequently used to evaluate the efficacy of anticoagulant thromboprophylaxis in medical patients. Recently, the clinical relevance of asymptomatic DVT has been challenged. Methods and Results The objective of this study was to evaluate the relationship between asymptomatic proximal DVT and all-cause mortality (ACM) using a cohort analysis of a randomized trial for the prevention of venous thromboembolism (VTE) in acutely ill medical patients. Patients who received at least 1 dose of study drug and had an adequate compression ultrasound examination of the legs on either day 10 or day 35 were categorized into 1 of 3 cohorts: no VTE, asymptomatic proximal DVT, or symptomatic DVT. Cox proportional hazards model, with adjustment for significant independent predictors of mortality, were used to compare the incidences of ACM. Of the 7036 patients, 6776 had no VTE, 236 had asymptomatic DVT, and 24 had symptomatic VTE. The incidence of ACM was 4.8% in patients without VTE. Both asymptomatic proximal DVT (mortality, 11.4%; hazard ratio [HR], 2.31; 95% CI, 1.52-3.51; P<0.0001) and symptomatic VTE (mortality, 29.2%; HR, 9.42; 95% CI, 4.18-21.20; P<0.0001) were independently associated with significant increases in ACM. The analysis was post hoc, and ultrasound results were not available for all patients. Adjustment for baseline variables significantly associated with ACM may not fully compensate for differences. Conclusions Asymptomatic proximal DVT is associated with higher ACM than no VTE and remains a relevant end point to evaluate the efficacy of anticoagulant thromboprophylaxis in medical patients. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT00571649.

Recommendations for VTE Prophylaxis in Medically Ill Patients

Venous thromboembolism (VTE) remains highly prevalent in medically ill patients, and often leads to increased mortality and cost burden during hospitalization and post-discharge. Nearly half of all VTEs occur during or after hospitalization, with pulmonary embolism accounting for 10% of inpatient mortality. Appropriate prophylaxis in high-risk medically ill patients has been shown to reduce risk of VTE and related mortality. Despite current evidence-based guidelines, VTE prophylaxis has been under-used. This owes greatly to ambiguity and concerns related to appropriate patient and prophylactic agent selection, and duration of prophylaxis. Because many acutely ill medical patients have multiple comorbidities, the risk of major bleeding must be considered when choosing to implement pharmacological VTE prophylaxis. Multiple risk assessment models have been developed and validated to help estimate VTE and bleeding risks in this population. While studies have shown that the risk for VTE often extends far beyond hospital discharge, there is no evidence to support extending prophylaxis after hospital discharge. The appropriate selection of VTE prophylaxis requires consideration for cost, availability, patient preference, compliance, and underlying comorbidities. Our paper reviews the current evidence and reasoning for appropriate selection of VTE prophylaxis in acutely medical ill patients, and highlights our own approach and recommendations.

Acute Pulmonary Embolism: Focus on the Clinical Picture

Acute pulmonary embolism (APE) is characterized by numerous clinical manifestations which are the result of a complex interplay between different organs; the symptoms are therefore various and part of a complex clinical picture. For this reason, it may not be easy to make an immediate diagnosis. This is a comprehensive review of the literature on all the various clinical pictures in order to help physicians to promptly recognize this clinical condition, remembering that our leading role as cardiologists depends on and is influenced by our knowledge and working methods.

Venous thromboembolism risks and prophylaxis in King Fahad Hospital, Madinah, Saudi Arabia

OBJECTIVE

To evaluate the risk factors, physician's compliance, and implementation of the American College of Chest Physicians (ACCP) guidelines for venous thromboembolism (VTE) prophylaxis at our hospital.

METHODS

A retrospective cohort study was conducted in King Fahad Hospital, Madinah, Saudi Arabia, from July 2015 to September 2015. We used the ACCP 2012 guidelines to assess the VTE risk and to determine whether patients had received the recommended prophylaxis. All hospital inpatients aged 14years or older were assessed for risk of VTE by reviewing the hospital chart. The primary endpoint was the rate of appropriate thromboprophylaxis.

RESULTS

A total of 414 patients were studied. Their mean age was 47.74±20.4years, and 208 (50.2%) were female. There were 292 (70.5%) patients at high risk and 73 (17.6%) at moderate risk. As per the ACCP criteria, 375 (90.5%) patients were at risk for VTE and qualified for prophylaxis. Although 227 (60.5%) received some form of prophylaxis, only 144 (38.4%) of them received ACCP-recommended VTE prophylaxis.

CONCLUSION

In our hospital, most of the patients are at high risk for developing VTE. The VTE prophylaxis guideline is not properly implemented and is underutilized. Strategies should be developed and implemented to ensure patient safety.

Incidences and variations of hospital acquired venous thromboembolism in Australian hospitals: a population-based study

BACKGROUND

Data on hospital-acquired venous thromboembolism (HA-VTE) incidence, case fatality rate and variation amongst patient groups and health providers is lacking. We aim to explore HA-VTE incidences, associated mortality, trends and variations across all acute hospitals in New South Wales (NSW)-Australia.

METHODS

A population-based study using all admitted patients (aged 18-90 with a length of stay of at least two days and not transferred to another acute care facility) in 104 NSW acute public and private hospitals during 2002-2009. Poisson mixed models were used to derive adjusted rate ratios (IRR) in presence of patient and hospital characteristics.

RESULTS

Amongst, 3,331,677 patients, the incidence of HA-VTE was 11.45 per 1000 patients and one in ten who developed HA-VTE died in hospital. HA-VTE incidence, initially rose, but subsequently declined, whereas case fatality rate consistently declined by 22 % over the study period. Surgical patients were 128 % (IRR = 2.28, 95 % CI: 2.19-2.38) more likely to develop HA-VTE, but had similar case fatality rates compared to medical patients. Private hospitals, in comparison to public hospitals had a higher incidence of HA-VTE (IRR = 1.76; 95 % CI: 1.42-2.18) for medical patients. However, they had a similar incidence (IRR = 0.91; 95 % CI: 0.75-1.11), but a lower mortality (IRR = 0.59; 95 % CI: 0.47-0.75) amongst surgical patients. Smaller public hospitals had a lower HA-VTE incidence rate compared to larger hospitals (IRR < 0.68) but a higher case fatality rate (IRR > 1.71). Hospitals with a lower reported HA-VTE incidence tended to have a higher HA-VTE case fatality rate.

CONCLUSION

Despite the decline in HA-VTE incidence and case fatality, there were large variations in incidents between medical and surgical patients, public and private hospitals, and different hospital groups. The causes of such differences warrant further investigation and may provide potential for targeted interventions and quality improvement initiatives.

Impact of the national venous thromboembolism risk assessment tool in secondary care in England: retrospective population-based database study

Venous thromboembolism (VTE) is a common and important cause of death in hospital patients. We therefore investigated possible associations between the introduction of the compulsory national VTE risk assessment tool in England in 2010 and patient outcomes. A retrospective database study, using data from the Health and Social Care Information Centre and Office of National Statistics, was undertaken. The main outcome measures were VTE-related secondary diagnosis rates, 30-day and 90-day readmission rates and mortality rates. The observed mean VTE-related secondary diagnosis rate for 2011–2012 was 91% of the rate estimated from a linear regression model of the data for 2006–2007 to 2010–2011 (P = 0.001). Similarly, the observed mean 30-day VTE-related readmission rate for 2011 was 96% of the estimated rate (P = 0.067) and the observed mean 90-day VTE-related readmission rate for 2011 was 96% of the estimated rate (P = 0.022). The observed annual VTE-related national mortality rate was 91% of the estimated rate for 2011 and 92% of the estimated rate for 2012. This study shows a reduction in VTE-related secondary diagnoses and readmissions among adults admitted to hospital, and a reduction in VTE-related population mortality, since the introduction of a national VTE risk assessment screening tool in England. Despite some study limitations, this suggests that the concerted effort made by NHS England to improve prevention of hospital-acquired VTE has been successful.

Heparin for the prevention of venous thromboembolism in acutely ill medical patients (excluding stroke and myocardial infarction)

BACKGROUND

Venous thromboembolic disease has been extensively studied in surgical patients. The benefit of thromboprophylaxis is now generally accepted, but it is medical patients who make up the greater proportion of the hospital population. Medical patients differ from surgical patients with regard to their health and the pathogenesis of thromboembolism and the impact that preventative measures can have. The extensive experience from thromboprophylaxis studies in surgical patients is therefore not necessarily applicable to non-surgical patients. This is an update of a review first published in 2009.

OBJECTIVES

To determine the effectiveness and safety of heparin (unfractionated heparin or low molecular weight heparin) thromboprophylaxis in acutely ill medical patients admitted to hospital, excluding those admitted to hospital with an acute myocardial infarction or stroke (ischaemic or haemorrhagic) or those requiring admission to an intensive care unit.

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched November 2013) and CENTRAL (2013, Issue 10).

SELECTION CRITERIA

Randomised controlled trials comparing unfractionated heparin (UFH) or low molecular weight heparin (LMWH) with placebo or no treatment, or comparing UFH with LMWH.

DATA COLLECTION AND ANALYSIS

One review author identified possible trials and a second review author confirmed their eligibility for inclusion in the review. Two review authors extracted the data. Disagreements were resolved by discussion. We performed the meta-analysis using a fixed-effect model with the results expressed as odds ratios (ORs) with 95% confidence intervals (CIs).

MAIN RESULTS

Sixteen studies with a combined total of 34,369 participants with an acute medical illness were included in this review. We identified 10 studies comparing heparin with placebo or no treatment and six studies comparing LMWH to UFH. Just under half of the studies had an open-label design, putting them at a risk of performance bias. Descriptions of random sequence generation and allocation concealment were missing in most of the studies. Heparin reduced the odds of deep vein thrombosis (DVT) (OR 0.38; 95% CI 0.29 to 0.51; P < 0.00001). The estimated reductions in symptomatic non-fatal pulmonary embolism (PE) (OR 0.46; 95% CI 0.19 to 1.10; P = 0.08), fatal PE (OR 0.71; 95% CI 0.43 to 1.15; P = 0.16) and in combined non-fatal PE and fatal PE (OR 0.65; 95% CI 0.42 to 1.00; P = 0.05) associated with heparin were imprecise. Heparin resulted in an increase in major haemorrhage (OR 1.81; 95% CI 1.10 to 2.98; P = 0.02). There was no clear evidence that heparin had an effect on all-cause mortality and thrombocytopaenia. Compared with UFH, LMWH reduced the risk of DVT (OR 0.77; 95% CI 0.62 to 0.96; P = 0.02) and major bleeding (OR 0.43; 95% CI 0.22 to 0.83; P = 0.01). There was no clear evidence that the effects of LMWH and UFH differed for the PE outcomes, all-cause mortality and thrombocytopaenia.

AUTHORS' CONCLUSIONS

The data from this review describe a reduction in the risk of DVT in patients presenting with an acute medical illness who receive heparin thromboprophylaxis. This needs to be balanced against an increase in the risk of bleeding associated with thromboprophylaxis. The analysis favoured LMWH compared with UFH, with a reduced risk of both DVT and bleeding.

A cohort study on the incidence and outcome of pulmonary embolism in trauma and orthopedic patients

BACKGROUND

This study aims to determine the incidence of pulmonary embolism (PE) in trauma and orthopedic patients within a regional tertiary referral center and its association with the pattern of injury, type of treatment, co-morbidities, thromboprophylaxis and mortality.

METHODS

All patients admitted to our institution between January 2010 and December 2011, for acute trauma or elective orthopedic procedures, were eligible to participate in this study. Our cohort was formed by identifying all patients with clinical features of PE who underwent Computed Tomography-Pulmonary Angiogram (CT-PA) to confirm or exclude the clinical suspicion of PE, within six months after the injury or the surgical procedure.Case notes and electronic databases were reviewed retrospectively to identify each patient's venous thromboembolism (VTE) risk factors, type of treatment, thromboprophylaxis and mortality.

RESULTS

Out of 18,151 patients admitted during the study period only 85 (0.47%) patients developed PE (positive CT-PA) (24 underwent elective surgery and 61 sustained acute trauma). Of these, only 76% of the patients received thromboprophylaxis. Hypertension, obesity and cardiovascular disease were the most commonly identifiable risk factors. In 39% of the cases, PE was diagnosed during the in-hospital stay. The median time of PE diagnosis, from the date of injury or the surgical intervention was 23 days (range 1 to 312). The overall mortality rate was 0.07% (13/18,151), but for those who developed PE it was 15.29% (13/85). Concomitant deep venous thrombosis (DVT) was identified in 33.3% of patients. The presence of two or more co-morbidities was significantly associated with the incidence of mortality (unadjusted odds ratio (OR) = 3.52, 95% confidence interval (CI) (1.34, 18.99), P = 0.034). Although there was also a similar clinical effect size for polytrauma injury on mortality (unadjusted OR = 1.90 (0.38, 9.54), P = 0.218), evidence was not statistically significant for this factor.

CONCLUSIONS

The incidence of VTE was comparable to previously reported rates, whereas the mortality rate was lower. Our local protocols that comply with the National Institute for Health and Clinical Excellence (NICE) guidelines in the UK appear to be effective in preventing VTE and reducing mortality in trauma and orthopedic patients.

Mortality from pulmonary embolism is decreasing in hospital patients

OBJECTIVES

Pulmonary embolism is believed to be a common cause of death of hospital inpatients. The aims of this study were to estimate the number of deaths caused by pulmonary embolism and the potential to reduce this by the use of caval filters according to accepted indications.

DESIGN

Review of autopsy reports and death notification records from 2007 and 2008. When pulmonary embolism was given as cause of death (in the autopsy report or in section 1 a-c or part 2 of the Medical Certificate of the Cause of Death), hospital records were reviewed for evidence of pre-mortem diagnosis of pulmonary embolism or deep vein thrombosis (DVT) and for evidence of accepted indications for caval filter placement.

SETTING

Large UK teaching hospital.

PARTICIPANTS

Hospital inpatients whose deaths were attributed to pulmonary embolism.

MAIN OUTCOME MEASURES

Proportion of deaths adjudged at autopsy to be due to pulmonary embolism; evidence of pre-mortem diagnosis of DVT or pulmonary embolism; total number of hospital admission and deaths.

RESULTS

From a total of 186,517 adult inpatient admissions there were 2583 (1.4%) adult inpatient deaths of which 696 (27%) underwent autopsy. Of those undergoing autopsy, 14 (2.0%, 95% CI 1.2-3.3%) deaths were caused by pulmonary embolism. Pulmonary embolism was recorded as a cause of death in a further 12 (0.7%) of 1773 patients who did not undergo autopsy. Of these, five had a pre-mortem diagnosis of DVT or pulmonary embolism.

CONCLUSIONS

The proportion of deaths caused by pulmonary embolism appears to be considerably lower than the widely published rate, and of this small number, few have a pre-mortem diagnosis of DVT or pulmonary embolism. There is little scope for further reduction of pulmonary embolism mortality through use of caval filters according to guidelines. Current policy on pulmonary embolism risk prevention appears to be based on an over-estimate of the level of risk.

Prophylaxis for venous thromboembolism: guidelines translated for the clinician

Venous thromboembolism is a major cause of morbidity and mortality worldwide and most often affects hospitalized postoperative surgical and medical patients. Venous thromboembolism prophylaxis undoubtedly improves the care of these patients, as demonstrated by the current literature and guidelines. Failure to prescribe prophylaxis when indicated, however, remains a vital health care concern. The American College of Chest Physicians (ACCP) published their most recent guidelines regarding venous thromboembolism prophylaxis in 2008. In this review, we aim to summarize the most recent ACCP prophylaxis guidelines with practical application and interpretation for the practicing physician. Here we present the most practical information from these guidelines and summarize essential recommendations in key tables. We will briefly review the grading system used in the guidelines for the level of evidence and the strength of the recommendation. We will then discuss the recommendations for prophylaxis in the various patient populations described in these guidelines including general and orthopedic surgery, gynecologic surgery, urologic surgery, thoracic surgery, neurosurgery, trauma, medical conditions, cancer patients, and critical care. In addition, we will discuss recent clinical trials regarding novel anticoagulants for venous thromboembolism prophylaxis and share some conclusions.

[Risk of venous thromboembolic disease in general surgery]

Despite preventive efforts, venous thromboembolic disease (VTED) is still a major problem for surgeons due to its frequency and the morbidity, mortality and enormous resource consumption caused by this entity. However, the most important feature of VTED is that it is one of the most easily preventable complications and causes of death. To take appropriate prophylactic decisions (indication, method, initiation, duration, etc.), familiarity with the epidemiology of VTED in general surgery and some of its most significant populations (oncologic, laparoscopic, bariatric, ambulatory and short-stay) is essential. These factors must also be known to determine the distinct risk factors in these settings with a view to stratifying preoperative risk.

Prevention of venous thromboembolism in medical patients and outpatients

The majority of fatal cases of pulmonary embolism in hospitalized patients occur in acutely ill, medically treated patients. Current guidelines, based on a large number of prospective, randomized, controlled trials evaluating the safety and efficacy of pharmacologic venous thromboembolism (VTE) prophylaxis in medical patients, now recommend using VTE prophylaxis in this population. Unfortunately, prophylaxis rates in medical patients are unacceptably low, despite efforts to develop strategies for improving implementation of prophylaxis regimens. Studies indicate that a substantial proportion of patients with VTE present after hospital discharge, but no clinical trials evaluating VTE prophylaxis for medical outpatients have yet been published. In this Review, we examine the literature on VTE prophylaxis in hospitalized medical patients, and evaluate the available data for the outpatient setting.

Prevention of venous thromboembolism in medically ill patients: a clinical update

The risk of venous thromboembolism (VTE) in hospitalised medically ill patients is often underestimated, despite the fact that it remains a major cause of preventable morbidity and mortality in this group. It is not well recognised that the risk of VTE in many hospitalised medically ill patients is at least as high as in populations after surgery. This may partly be attributed to the clinically silent nature of VTE in many patients, and the difficulty in predicting which patients might develop symptoms or fatal pulmonary embolism. Two large studies, Prospective Evaluation of Dalteparin Efficacy for Prevention of VTE in Immobilized Patients Trial and prophylaxis in MEDical patients with ENOXaparin, have shown that low-molecular-weight heparins provide effective thromboprophylaxis in medically ill patients, without increasing bleeding risk. Recent guidelines from the American College of Chest Physicians recommend that acutely medically ill patients admitted with congestive heart failure or severe respiratory disease, or those who are confined to bed and have at least one additional risk factor for VTE, should receive thromboprophylaxis.

Efficacy and safety of fondaparinux for the prevention of venous thromboembolism in older acute medical patients: randomised placebo controlled trial

OBJECTIVE

To determine the efficacy and safety of the anticoagulant fondaparinux in older acute medical inpatients at moderate to high risk of venous thromboembolism.

DESIGN

Double blind randomised placebo controlled trial.

SETTING

35 centres in eight countries.

PARTICIPANTS

849 medical patients aged 60 or more admitted to hospital for congestive heart failure, acute respiratory illness in the presence of chronic lung disease, or acute infectious or inflammatory disease and expected to remain in bed for at least four days.

INTERVENTIONS

2.5 mg fondaparinux or placebo subcutaneously once daily for six to 14 days.

OUTCOME MEASURE

The primary efficacy outcome was venous thromboembolism detected by routine bilateral venography along with symptomatic venous thromboembolism up to day 15. Secondary outcomes were bleeding and death. Patients were followed up at one month.

RESULTS

425 patients in the fondaparinux group and 414 patients in the placebo group were evaluable for safety analysis (10 were not treated). 644 patients (75.9%) were available for the primary efficacy analysis. Venous thrombembolism was detected in 5.6% (18/321) of patients treated with fondaparinux and 10.5% (34/323) of patients given placebo, a relative risk reduction of 46.7% (95% confidence interval 7.7% to 69.3%). Symptomatic venous thromboembolism occurred in five patients in the placebo group and none in the fondaparinux group (P = 0.029). Major bleeding occurred in one patient (0.2%) in each group. At the end of follow-up, 14 patients in the fondaparinux group (3.3%) and 25 in the placebo group (6.0%) had died.

CONCLUSION

Fondaparinux is effective in the prevention of asymptomatic and symptomatic venous thromboembolic events in older acute medical patients. The frequency of major bleeding was similar for both fondaparinux and placebo treated patients.

Fatal pulmonary embolism in hospitalised patients: a necropsy review

AIMS

To carry out a retrospective review of all postmortem reports during the period 1991 to 2000 at King's College Hospital, London, as an extension of a previous analysis performed for the period 1965 to 1990.

METHODS

The number of deaths resulting from necropsy confirmed fatal pulmonary embolism in hospitalised patients was determined, and a limited analysis of the clinical characteristics of those patients who died was performed.

RESULTS

During the 10 year period, 16 104 deaths occurred and 6833 (42.4%) necropsies were performed. The outcome measure, fatal pulmonary embolism, was recorded as cause of death in 265 cases (3.9% of all necropsies; 5.2% of adult cases). No deaths from pulmonary embolism occurred in patients under 18 years of age; 80.0% occurred in patients older than 60 years. Of the fatal emboli, 214 of 265 (80.8%) occurred in patients who had not undergone recent surgery. Of these patients, 110 (51.4%) had suffered an acute medical illness in the six weeks before death, most often an acute infectious episode (26 cases).

CONCLUSIONS

Thromboembolic events remain a relatively common cause of death in hospitalised patients and appear to occur more frequently in non-surgical than in surgical patients.

Acp. Best practice no 155. Pathological investigation of deaths following surgery, anaesthesia, and medical procedures

The pathological investigation of deaths following surgery, anaesthesia, and medical procedures is discussed. The definition of "postoperative death" is examined and the classification of deaths following procedures detailed. The review of individual cases is described and the overall approach to necropsy and interpretation considered. There are specific sections dealing with the cardiovascular system (including air embolism, perioperative myocardial infarction, cardiac pacemakers, central venous catheters, cardiac surgery, heart valve replacement, angioplasty, and vascular surgery); respiratory system (postoperative pneumonia, pulmonary embolism, pneumothorax); central nervous system (dissection of cervical spinal cord), hepatobiliary and gastrointestinal system; musculoskeletal system; and head and neck region. Deaths associated with anaesthesia are classified and the specific problems of epidural anaesthesia and malignant hyperthermia discussed. The article concludes with a section on the recording of necropsy findings and their communication to clinicians and medicolegal authorities.

Rational antithrombotic therapy and prophylaxis in elderly, immobile patients

The aging process is associated with increased coagulation and fibrinolysis parameters, resulting in an overall 'prethrombotic state'. This probably explains the increased baseline susceptibility of elderly patients to the development of thromboembolic disease. Additional factors such as major surgery or malignant disease multiply the risk of thromboembolism in this population. Even when adequate antithrombotic therapy is instituted, the mortality associated with thromboembolic disease remains considerable; this underlines the importance of adequate thromboembolic prophylaxis. At present, the use of low molecular weight heparins (LMWHs) in elderly immobile patients appears to be the most effective approach to prophylaxis. The use of compression stockings seems to be effective in the prevention of venous thrombosis, at least in moderate risk surgical patients. In patients undergoing orthopaedic surgery, additional prophylaxis (e.g. with an LMWH) is necessary. In the management of venous thrombosis, patients can initially be treated with a bodyweight-adjusted dosage of an LMWH. In patients with deep vein leg thrombosis or pulmonary embolism, oral anticoagulant therapy should be started as soon as possible, and should be continued for 6 months. However, before starting prophylaxis or therapy, an individual risk assessment should be performed in which the benefits and disadvantages are balanced. Most of the large trials that have studied the effects of thromboembolic prophylaxis have focused on postsurgical patients. However, it will be of great interest to develop more specific prophylactic and therapeutic regimens for different nonsurgical high risk subgroups of patients, particularly the elderly.