The importance of appropriate prophylaxis for the prevention of venous thromboembolism in at-risk medical patients

Outcomes in patients discharged with extended venous thromboembolism prophylaxis after hospitalization with COVID-19

BACKGROUND

Venous thromboembolism (VTE) is a known complication of coronavirus disease (COVID-19) in patients requiring hospitalization and intensive care. We examined the association between extended pharmacological VTE prophylaxis and outcomes among patients hospitalized with COVID-19.

METHODS

This was a retrospective cohort study of patients with an index positive SARS-CoV-2 polymerase chain reaction (PCR) test at the time of, or during hospitalization. Patients who were prescribed extended pharmacological VTE prophylaxis were compared against patients who were not. Multivariable logistic regression was used to produce odds ratio (OR) estimates and Cox proportional hazard models for hazard ratios (HR) with 95% CI to examine the association between pharmacological VTE prophylaxis and outcomes of interest. Primary outcomes were 30- and 90-day VTE events. Secondary outcomes included 30- and 90-day mortality, 30-day superficial venous thrombosis (SVT), acute myocardial infarction (MI), acute ischemic stroke, critical limb ischemia, clinically significant bleeding, and inpatient readmissions.

RESULTS

A total of 1936 patients were included in the study. Among them, 731 (38%) were discharged on extended pharmacological VTE prophylaxis. No significant difference was found in 30- and 90-day VTE events among groups. Patients discharged on extended VTE prophylaxis showed improved survival at 30 (HR: 0.35; 95% CI: 0.21-0.59) and 90 days (HR: 0.36; 95% CI: 0.23-0.55) and reduced inpatient readmission at 30 days (OR: 0.12; 95% CI: 0.04-0.33) when compared to those without.

CONCLUSION

Patients discharged on extended VTE prophylaxis after hospitalization due to COVID-19 had similar thrombotic events on follow-up. However, use of extended VTE prophylaxis was associated with improved 30- and 90-day survival and reduced risk of 30-day inpatient readmission.

Risk and Management of Venous Thromboembolism in Patients with COVID-19

Background

One of the most pronounced and poorly understood pathological features of COVID-19 infection has been high risk for venous and arterial thromboembolic complications. An increasing number of thromboembolic events are being reported almost on a daily basis, and the medical community has struggled to predict and mitigate this risk. We aimed to review available literature on the risk and management of COVID-19 related venous thromboembolism (VTE), and provide evidence-based guidance to manage these events.

Methods

A literature review of VTE complications in patients with COVID-19 was performed, in addition to a summary of the societal guidelines and present pathways implemented at our institution for the management of both in- and outpatient COVID-19 related VTE.

Results

Although a significant VTE risk has been confirmed in patients with COVID-19, literature addressing best ways to mitigate this risk is lacking. Furthermore, there has been very limited guidance provided by societal guidelines to help prevent and manage VTE associated with the COVID-19 infection. In light of the available data, we advise that all patients admitted with suspected or confirmed COVID-19 receive pharmacological prophylaxis if bleeding risk is acceptable. For patients with COVID-19 who have been discharged from the emergency department or hospital, we suggest extended thromboprophylaxis (up to 39 days) as long as bleeding risk is low.

Conclusions

We believe that this literature summary along with our center recommendations and algorithms provide valuable guidance to providers caring for patients with COVID-19 related VTE. More research is needed to standardize prophylaxis and management protocols for these patients.

Coagulopathy, Venous Thromboembolism, and Anticoagulation in Patients with COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has led to a worldwide pandemic, and patients with the infection are referred to as having COVID‐19. Although COVID‐19 is commonly considered a respiratory disease, there is clearly a thrombotic potential that was not expected. The pathophysiology of the disease and subsequent coagulopathy produce an inflammatory, hypercoagulable, and hypofibrinolytic state. Several observational studies have demonstrated surprisingly high rates of venous thromboembolism (VTE) in both general ward and intensive care patients with COVID‐19. Many of these observational studies demonstrate high rates of VTE despite patients being on standard, or even higher intensity, pharmacologic VTE prophylaxis. Fibrinolytic therapy has also been used in patients with acute respiratory distress syndrome. Unfortunately, high quality randomized controlled trials are lacking. A literature search was performed to provide the most up‐to‐date information on the pathophysiology, coagulopathy, risk of VTE, and prevention and treatment of VTE in patients with COVID‐19. These topics are reviewed in detail, along with practical issues of anticoagulant selection and duration. Although many international organizations have produced guidelines or consensus statements, they do not all cover the same issues regarding anticoagulant therapy for patients with COVID‐19, and they do not all agree. These statements and the most recent literature are combined into a list of clinical considerations that clinicians can use for the prevention and treatment of VTE in patients with COVID‐19.

Call to Action to Prevent Venous Thromboembolism in Hospitalized Patients: A Policy Statement From the American Heart Association

Venous thromboembolism (VTE) is a major preventable disease that affects hospitalized inpatients. Risk stratification and prophylactic measures have good evidence supporting their use, but multiple reasons exist that prevent full adoption, compliance, and efficacy that may underlie the persistence of VTE over the past several decades. This policy statement provides a focused review of VTE, risk scoring systems, prophylaxis, and tracking methods. From this summary, 5 major areas of policy guidance are presented that the American Heart Association believes will lead to better implementation, tracking, and prevention of VTE events. They include performing VTE risk assessment and reporting the level of VTE risk in all hospitalized patients, integrating preventable VTE as a benchmark for hospital comparison and pay-for-performance programs, supporting appropriations to improve public awareness of VTE, tracking VTE nationwide with the use of standardized definitions, and developing a centralized data steward for data tracking on VTE risk assessment, prophylaxis, and rates.

Role of ambulation to prevent venous thromboembolism in medical patients: where do we stand?

Venous thromboembolism (VTE) encompasses the spectrum of manifestations of deep venous thrombosis and/or pulmonary embolism and is a common, serious, and preventable complication in hospitalized patients. Although immobility plays an important role in determining VTE risk in medical patients, no clear and uniform criteria exist to guide clinicians in assessing immobility. The variation in the descriptions that do exist makes it difficult to interpret and compare the results of randomized clinical trials with respect to the influence of different levels of immobility on the magnitude of VTE risk and the role that early ambulation as an isolated factor plays in prevention of such events. Understanding these limitations is a prerequisite for the proper use and interpretation of VTE risk assessment tools and for indicating the best strategy for preventing venous thrombosis in hospitalized medical patients. The objective of this study was to review the main evidence reported in the literature on the role of ambulation in prevention of VTE.

Effectiveness of interventions for the implementation of thromboprophylaxis in hospitalised patients at risk of venous thromboembolism: an updated abridged Cochrane systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

To assess the effectiveness of system-wide interventions designed to increase the implementation of thromboprophylaxis and decrease the incidence of venous thromboembolism (VTE) in hospitalised medical and surgical patients at risk of VTE.

DESIGN

Systematic review and meta-analysis of randomised controlled trials (RCTs).

DATA SOURCES

Medline, PubMed, Embase, BIOSIS, CINAHL, Web of Science, CENTRAL, DARE, EED, LILACS and clinicaltrials.gov without language restrictions from inception to 7 January 2017, as well as the reference lists of relevant review articles.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

RCTs that evaluated the effectiveness of system-wide interventions such as alerts, multifaceted, education, and preprinted orders when compared with no intervention, existing policy or another intervention.

RESULTS

We included 13 RCTs involving 35 997 participants. Eleven RCTs had data available for meta-analysis. Compared with control, we found absolute increase in the prescription of prophylaxis associated with alerts (21% increase, 95% CI [15% to 275%]) and multifaceted interventions (4% increase, 95% CI [3% to 11%]), absolute increase in the prescription of appropriate prophylaxis associated with alerts (16% increase, 95% CI [12% to 20%]) and relative risk reductions (risk ratio 64%, 95% CI [47% to 86%]) in the incidence of symptomatic VTE associated with alerts. Computer alerts were found to be more effective than human alerts, and multifaceted interventions with an alert component appeared to be more effective than multifaceted interventions without, although comparative pooled analyses were not feasible. The quality of evidence for improvement in outcomes was judged to be low to moderate certainty.

CONCLUSIONS

Alerts increased the proportion of patients who received prophylaxis and appropriate prophylaxis, and decreased the incidence of symptomatic VTE. Multifaceted interventions increased the proportion of patients who received prophylaxis but were found to be less effective than alerts interventions.

TRIAL REGISTRATION NUMBER

CD008201.

Interventions for implementation of thromboprophylaxis in hospitalized patients at risk for venous thromboembolism

BACKGROUND

Venous thromboembolism (VTE) is a leading cause of morbidity and mortality in hospitalized patients. While numerous randomized controlled trials (RCTs) have shown that the appropriate use of thromboprophylaxis in hospitalized patients at risk for VTE is safe, effective, and cost-effective, thromboprophylaxis remains underused or inappropriately used. Our previous review suggested that system-wide interventions, such as education, alerts, and multifaceted interventions were more effective at improving the prescribing of thromboprophylaxis than relying on individual providers' behaviors. However, 47 of the 55 included studies in our previous review were observational in design. Thus, an update to our systematic review, focused on the higher level of evidence of RCTs only, was warranted.

OBJECTIVES

To assess the effects of system-wide interventions designed to increase the implementation of thromboprophylaxis and decrease the incidence of VTE in hospitalized adult medical and surgical patients at risk for VTE, focusing on RCTs only.

SEARCH METHODS

Our research librarian conducted a systematic literature search of MEDLINE Ovid, and subsequently translated it to CENTRAL, PubMed, Embase Ovid, BIOSIS Previews Ovid, CINAHL, Web of Science, the Database of Abstracts of Reviews of Effects (DARE; in the Cochrane Library), NHS Economic Evaluation Database (EED; in the Cochrane Library), LILACS, and clinicaltrials.gov from inception to 7 January 2017. We also screened reference lists of relevant review articles. We identified 12,920 potentially relevant records.

SELECTION CRITERIA

We included all types of RCTs, with random or quasi-random methods of allocation of interventions, which either randomized individuals (e.g. parallel group, cross-over, or factorial design RCTs), or groups of individuals (cluster RCTs (CRTs)), which aimed to increase the use of prophylaxis or appropriate prophylaxis, or decrease the occurrence of VTE in hospitalized adult patients. We excluded observational studies, studies in which the intervention was simply distribution of published guidelines, and studies whose interventions were not clearly described. Studies could be in any language.

DATA COLLECTION AND ANALYSIS

We collected data on the following outcomes: the number of participants who received prophylaxis or appropriate prophylaxis (as defined by study authors), the occurrence of any VTE (symptomatic or asymptomatic), mortality, and safety outcomes, such as bleeding. We categorized the interventions into alerts (computer or human alerts), multifaceted interventions (combination of interventions that could include an alert component), educational interventions (e.g. grand rounds, courses), and preprinted orders (written predefined orders completed by the physician on paper or electronically). We meta-analyzed data across RCTs using a random-effects model. For CRTs, we pooled effect estimates (risk difference (RD) and risk ratio (RR), with 95% confidence interval (CI), adjusted for clustering, when possible. We pooled results if three or more trials were available for a particular intervention. We assessed the certainty of the evidence according to the GRADE approach.

MAIN RESULTS

From the 12,920 records identified by our search, we included 13 RCTs (N = 35,997 participants) in our qualitative analysis and 11 RCTs (N = 33,207 participants) in our meta-analyses.

PRIMARY OUTCOME

Alerts were associated with an increase in the proportion of participants who received prophylaxis (RD 21%, 95% CI 15% to 27%; three studies; 5057 participants; I² = 75%; low-certainty evidence). The substantial statistical heterogeneity may be in part explained by patient types, type of hospital, and type of alert. Subgroup analyses were not feasible due to the small number of studies included in the meta-analysis.Multifaceted interventions were associated with a small increase in the proportion of participants who received prophylaxis (cluster-adjusted RD 4%, 95% CI 2% to 6%; five studies; 9198 participants; I² = 0%; moderate-certainty evidence). Multifaceted interventions with an alert component were found to be more effective than multifaceted interventions that did not include an alert, although there were not enough studies to conduct a pooled analysis.

SECONDARY OUTCOMES

Alerts were associated with an increase in the proportion of participants who received appropriate prophylaxis (RD 16%, 95% CI 12% to 20%; three studies; 1820 participants; I² = 0; moderate-certainty evidence). Alerts were also associated with a reduction in the rate of symptomatic VTE at three months (RR 64%, 95% CI 47% to 86%; three studies; 5353 participants; I² = 15%; low-certainty evidence). Computer alerts were associated with a reduction in the rate of symptomatic VTE, although there were not enough studies to pool computer alerts and human alerts results separately.

AUTHORS' CONCLUSIONS

We reviewed RCTs that implemented a variety of system-wide strategies aimed at improving thromboprophylaxis in hospitalized patients. We found increased prescription of prophylaxis associated with alerts and multifaceted interventions, and increased prescription of appropriate prophylaxis associated with alerts. While multifaceted interventions were found to be less effective than alerts, a multifaceted intervention with an alert was more effective than one without an alert. Alerts, particularly computer alerts, were associated with a reduction in symptomatic VTE at three months, although there were not enough studies to pool computer alerts and human alerts results separately.Our analysis was underpowered to assess the effect on mortality and safety outcomes, such as bleeding.The incomplete reporting of relevant study design features did not allow complete assessment of the certainty of the evidence. However, the certainty of the evidence for improvement in outcomes was judged to be better than for our previous review (low- to moderate-certainty evidence, compared to very low-certainty evidence for most outcomes). The results of our updated review will help physicians, hospital administrators, and policy makers make practical decisions about adopting specific system-wide measures to improve prescription of thromboprophylaxis, and ultimately prevent VTE in hospitalized patients.

Variation in Definitions of Immobility in Pharmacological Thromboprophylaxis Clinical Trials in Medical Inpatients: A Systematic Review

BACKGROUND

Although immobility is a common risk factor for venous thromboembolism (VTE) in medical inpatients, lack of a consistent definition of this term may limit accurate assessment of VTE risk for thromboprophylaxis.

OBJECTIVE

To examine various definitions of immobility used in recent pharmacological thromboprophylaxis clinical trials.

DATA SOURCES

PubMed and relevant references from articles/reviews from 2008 to 2016 were searched. Randomized controlled trials (RCTs) and other clinical studies involving adult hospitalized medical patients in acute care hospital settings that used the term immobility were selected. Two investigators independently abstracted data in duplicate, and accuracy was checked by a third investigator.

RESULTS

Twenty-one clinical studies were included. There was heterogeneity among individual VTE risk factors, with respect to the definition of immobility in medical inpatients in these trials. Thirteen studies utilized objective criteria to define "immobility" including duration (12 studies) and distance or time walked (6 studies). In contrast, 7 studies focused principally on subjective definitions (ie, describing the nature of immobility rather than specifying its quantitative measurement). Three RCTs vaguely defined the level of patient's immobility after hospitalization.

CONCLUSION

Despite the well-known effectiveness of pharmacological thromboprophylaxis for the prevention of VTE in acutely ill medical patients, there is no current consensus on how to define immobility. The heterogeneous nature of definitions of immobility has led to uncertainty about the importance of immobility in VTE risk assessment models. Although clinical studies have incorporated varying definitions of immobility into their inclusion criteria, immobility as a specific VTE risk factor has not been clearly defined.

A risk-benefit analysis of factor V Leiden testing to improve pregnancy outcomes: a case study of the capabilities of decision modeling in genomics

PURPOSE

We sought to assess the benefits, risks, and personal utility of factor V Leiden mutation testing to improve pregnancy outcomes and to assess the utility of decision-analytic modeling for complex outcomes in genomics.

METHODS

We developed a model to evaluate factor V Leiden testing among women with a history of recurrent pregnancy loss, including heparin therapy during pregnancy in mutation-positive women. Outcomes included venous thromboembolism, major bleeds, pregnancy loss, maternal mortality, and quality-adjusted life-years.

RESULTS

Factor V Leiden testing in a hypothetical cohort of 10,000 women led to 7 fewer venous thromboembolic events, 90 fewer pregnancy losses, and an increase of 17 major bleeding events. Small improvements in quality-adjusted life-years were largely attributable to reduced mortality but also to improvements in health-related quality of life. However, sensitivity analyses indicate large variance in results due to data uncertainty. Furthermore, the complexity of outcomes limited our ability to fully capture the repercussions of testing in the quality-adjusted life-year measure.

CONCLUSION

Factor V Leiden testing involves tradeoffs between clinical and personal utility, and additional effectiveness data are needed for heparin use to prevent pregnancy loss. Decision-analytic methods offer somewhat limited value in assessing these tradeoffs, suggesting that evaluation of complex outcomes will require novel approaches to appropriately capture patient-centered outcomes.Genet Med 2013:15(5):374-381.

Novel oral anticoagulants and their role in clinical practice

The complexities of oral anticoagulation with warfarin have led to the search for more practical alternative agents. Novel direct factor IIa inhibitors and direct factor Xa inhibitors currently in development can be administered at a fixed dose and do not require routine coagulation monitoring and ongoing dosage adjustment to ensure their effectiveness and safety. A number of phase III trials of these agents for the prevention of venous thromboembolism associated with orthopedic surgery and acute medical illness, for the treatment of venous thromboembolism, and for stroke prevention in patients with atrial fibrillation have been completed, with almost universally positive results. If these novel agents are approved for use in the United States, the future of oral anticoagulant therapy will allow a more nuanced approach to drug selection than has been available in the past. Attention to drug interactions and renal function will be required, as methods to measure the presence of these agents are not precise, cannot quantify the degree of anticoagulant present, and are influenced by the changes in serum drug concentrations during the dosing interval. In the future, patient preferences and the pharmacokinetic and pharmacodynamic characteristics of individual drugs will be able to be matched to optimize therapy. These new agents represent a new paradigm for anticoagulation that promises to improve patient care in the long term.