Recurrent venous thromboembolism after surgery-provoked versus unprovoked thromboembolism

Optimizing emergency department imaging utilization for pulmonary emboli: A study on the effects of IV contrast rationing

PURPOSE

To study the impact of a contrast mitigation protocol on imaging utilization for pulmonary embolism (PE) in the emergency department (ED).

MATERIAL AND METHODS

Medical records of ED patients with suspected PE who underwent CT pulmonary angiography (CTPA) or ventilation-perfusion (VQ) scans were analyzed in control (3/15/22-4/15/22) and test (5/15/22-6/15/22) periods. The test period included a contrast mitigation protocol due to a global iodinated contrast shortage (05/2022-06/2022). Out of 610 scans, 28 were excluded for non-PE indications. Patient demographics, time metrics, and imaging reports were recorded.

RESULTS

Among 11,019 ED visits, there were 582 imaging events for suspected PE. The test period exhibited a significantly lower imaging rate of 4.16 % compared to 6.54 % in the control period (p < 0.001). CTPA usage decreased by 47.73 %, while VQ scan usage increased by 775.00 % during the test period. Test period positivity rate was 0.82 %, with CTPA at 0.58 % (1/173) and VQ scan at 1.43 % (1/70). In the control period, the positivity rate was 0.29 %, with CTPA at 0.30 % (1/331) and VQ scan at 0.00 % (0/8). Previous hospitalization history was significantly higher in the test period (70/243 vs. 39/339, p < 0.001). The positivity rates between the two periods showed no significant difference (p = 0.57). There were no significant differences in ED length of stay and image acquisition times.

CONCLUSION

The contrast mitigation protocol reduced CTPA use, increased VQ scans, and maintained positivity rates and image acquisition times. However, concerns persist about unnecessary imaging and low positivity rates, necessitating further research to optimize PE diagnostic algorithms.

Who should get long-term anticoagulant therapy for venous thromboembolism and with what?

After an initial 3 to 6 months of anticoagulation for venous thromboembolism (VTE), clinicians and patients face an important question: "Do we stop anticoagulants or continue them indefinitely?" The decision is easy in some scenarios (eg, stop in VTE provoked by major surgery). In most scenarios, which are faced on a day-to-day basis in routine practice, it is a challenging decision because of uncertainty in estimates in the long-term risks (principally major bleeding) and benefits (reducing recurrent VTE) and the tight trade-offs between them. Once the decision is made to continue, the next question to tackle is "Which anticoagulant?" Here again, it is a difficult decision because of the uncertainty with regard to estimates of efficacy and the safety of anticoagulant options and the tight trade-offs between choices. We conclude with the approach that we take in our clinical practice.

Evaluation of the predictive value of the bleeding prediction score VTE-BLEED for recurrent venous thromboembolism

INTRODUCTION

VTE-BLEED is a validated score for identification of patients at increased risk of major bleeding during extended anticoagulation for venous thromboembolism (VTE). It is unknown whether VTE-BLEED high-risk patients also have an increased risk for recurrent VTE, which would limit the potential usefulness of the score.

METHODS

This was a post hoc analysis of the randomized, double-blind, placebo-controlled PADIS-PE trial that randomized patients with a first unprovoked pulmonary embolism (PE) initially treated during 6 months to receive an additional 18-month of warfarin vs. placebo. The primary outcome of this analysis was recurrent VTE during 2-year follow-up after anticoagulant discontinuation, that is, after the initial 6-month treatment in the placebo arm and after 24 months of anticoagulation in the active treatment arm. This rate, adjusted for study treatment allocation, was compared between patients in the high- vs. low-risk VTE-BLEED group.

RESULTS

In complete case analysis (n = 308; 82.4% of total population), 89 (28.9%) patients were classified as high risk; 44 VTE events occurred after anticoagulant discontinuation during 668 patient-years. The cumulative incidence of recurrent VTE was 16.4% (95% confidence interval [CI], 10.0%-26.1%; 14 events) and 14.6% (95% CI, 10.4%-20.3%; 30 events) in the high-risk and low-risk VTE-BLEED groups, respectively, for an adjusted hazard ratio of 1.16 (95% CI, 0.62-2.19).

CONCLUSION

In this study, patients with unprovoked PE classified at high risk of major bleeding by VTE-BLEED did not have a higher incidence of recurrent VTE after cessation of anticoagulant therapy, supporting the potential yield of the score for making management decisions on the optimal duration of anticoagulant therapy.

Clinical Characteristics and Outcomes of Venous Thromboembolisms According to an Out-of-Hospital vs. In-Hospital Onset - From the COMMAND VTE Registry

BACKGROUND

Differences in the clinical characteristics and outcomes of venous thromboembolisms (VTEs) based on different clinical situations surrounding the onset might be important for directing appropriate treatment strategies, but have not yet been appropriately evaluated. Methods and Results: The COMMAND VTE Registry is a multicenter registry enrolling 3,027 consecutive patients with acute symptomatic VTEs in Japan between January 2010 and August 2014. We divided the study population into 3 groups: Out-of-hospital onset (n=2,308), In-hospital onset with recent surgery (n=310), and In-hospital onset without recent surgery (n=374). Active cancer was most prevalent in the In-hospital onset without recent surgery group, and least in the Out-of-hospital onset group (Out-of-hospital onset group: 20%, In-hospital onset with recent surgery group: 26%, and In-hospital onset without recent surgery group: 38%, P<0.001). The cumulative 5-year incidence of recurrent VTEs did not significantly differ across the 3 groups (11.4%, 5.8%, and 8.7%, respectively; P=0.11). The cumulative 5-year incidences of major bleeding and all-cause death were highest in the In-hospital onset without recent surgery group (11.1%, 8.5%, and 23.3%, P<0.001; 26.8%, 24.9%, and 48.4%, P<0.001, respectively).

CONCLUSIONS

In the real-world VTE registry, the clinical characteristics and long-term outcomes substantially differed according to the clinical situation of VTE onset, suggesting the need for different treatment strategies for VTEs in different clinical settings.

Biologic roles of the ABH and Lewis histo-blood group antigens part II: thrombosis, cardiovascular disease and metabolism

The ABH and Lewis antigens were among the first of the human red blood cell polymorphisms to be identified and, in the case of the former, play a dominant role in transfusion and transplantation. But these two therapies are largely twentieth-century innovations, and the ABH and related carbohydrate antigens are not only expressed on a very wide range of human tissues, but were present in primates long before modern humans evolved. Although we have learned a great deal about the biochemistry and genetics of these structures, the biological roles that they play in human health and disease are incompletely understood. This review and its companion, which appeared in a previous issue of Vox Sanguinis, will focus on a few of the biologic and pathologic processes which appear to be affected by histo-blood group phenotype. The first of the two reviews explored the interactions of two bacteria with the ABH and Lewis glycoconjugates of their human host cells, and described the possible connections between the immune response of the human host to infection and the development of the AB-isoagglutinins. This second review will describe the relationship between ABO phenotype and thromboembolic disease, cardiovascular disease states, and general metabolism.

The epidemiology of venous thromboembolism

Venous thromboembolism (VTE) is categorized by the U.S. Surgeon General as a major public health problem. VTE is relatively common and associated with reduced survival and substantial health-care costs, and recurs frequently. VTE is a complex (multifactorial) disease, involving interactions between acquired or inherited predispositions to thrombosis and VTE risk factors, including increasing patient age and obesity, hospitalization for surgery or acute illness, nursing-home confinement, active cancer, trauma or fracture, immobility or leg paresis, superficial vein thrombosis, and, in women, pregnancy and puerperium, oral contraception, and hormone therapy. Although independent VTE risk factors and predictors of VTE recurrence have been identified, and effective primary and secondary prophylaxis is available, the occurrence of VTE seems to be relatively constant, or even increasing.

Assessing the risk of recurrent venous thromboembolism--a practical approach

Recurrent venous thromboembolism (VTE) is associated with increased morbidity and mortality. This risk is lowered by anticoagulation, with a large effect in the initial phase following the venous thromboembolic event, and with a smaller effect in terms of secondary prevention of recurrence when extended anticoagulation is performed. On the other hand, extended anticoagulation is associated with an increased risk of major bleeding and thus leads to morbidity and mortality. Therefore, it is necessary to assess the risk of recurrence for VTE on an individual basis, and a recommendation for secondary prophylaxis should be specifically based on risk calculation of recurrence of VTE and bleeding. In this review, we provide a comprehensive summary of relevant risk factors for recurrent VTE and a practical approach for assessing the risk of recurrence in daily practice.

Epidemiology of venous thromboembolism

Thrombosis can affect any venous circulation. Venous thromboembolism (VTE) includes deep-vein thrombosis of the leg or pelvis, and its complication, pulmonary embolism. VTE is a fairly common disease, particularly in older age, and is associated with reduced survival, substantial health-care costs, and a high rate of recurrence. VTE is a complex (multifactorial) disease, involving interactions between acquired or inherited predispositions to thrombosis and various risk factors. Major risk factors for incident VTE include hospitalization for surgery or acute illness, active cancer, neurological disease with leg paresis, nursing-home confinement, trauma or fracture, superficial vein thrombosis, and-in women-pregnancy and puerperium, oral contraception, and hormone therapy. Although independent risk factors for incident VTE and predictors of VTE recurrence have been identified, and effective primary and secondary prophylaxis is available, the occurrence of VTE seems to be fairly constant, or even increasing.

Predicting the risk of venous thromboembolism recurrence

Venous thromboembolism (VTE) is a chronic disease with a 30% ten-year recurrence rate. The highest incidence of recurrence is in the first 6 months. Active cancer significantly increases the hazard of early recurrence, and the proportions of time on standard heparin with an APTT ≥ 0.2 anti-X(a) U/mL, and on warfarin with an INR ≥ 2.0, significantly reduce the hazard. The acute treatment duration does not affect recurrence risk after treatment is stopped. Independent predictors of late recurrence include increasing patient age and body mass index, leg paresis, active cancer and other persistent VTE risk factors, idiopathic VTE, antiphospholipid antibody syndrome, antithrombin, protein C or protein S deficiency, hyperhomocysteinemia and a persistently increased plasma fibrin D-dimer. A recommendation for secondary prophylaxis should be individualized based on the risk for recurrent VTE (especially fatal pulmonary embolism) and bleeding. The appropriateness of secondary prophylaxis should be continuously reevaluated, and the prophylaxis stopped if the benefit no longer exceeds the risk.