Venous thromboembolism in Asia and worldwide: Emerging insights from GARFIELD-VTE

Monocyte/macrophage-mediated venous thrombus resolution

Venous thromboembolism (VTE) poses a notable risk of morbidity and mortality. The natural resolution of the venous thrombus might be a potential alternative treatment strategy for VTE. Monocytes/macrophages merge as pivotal cell types in the gradual resolution of the thrombus. In this review, the vital role of macrophages in inducing inflammatory response, augmenting neovascularization, and facilitating the degradation of fibrin and collagen during thrombus resolution was described. The two phenotypes of macrophages involved in thrombus resolution and their dual functions were discussed. Macrophages expressing various factors, including cytokines and their receptors, adhesion molecules, chemokine receptors, vascular endothelial growth factor receptors, profibrinolytic- or antifibrinolytic-related enzymes, and other elements, are explored for their potential to promote or attenuate thrombus resolution. Furthermore, this review provides a comprehensive summary of new and promising therapeutic candidate drugs associated with monocytes/macrophages that have been demonstrated to promote or impair thrombus resolution. However, further clinical trials are essential to validate their efficacy in VTE therapy.

Risk of recurrent venous thromboembolism and major bleeding according to risk factor profiles in Asian patients: a subgroup analysis EINSTEIN-Extension and EINSTEIN-CHOICE

BACKGROUND

Risks of recurrence and major bleeding with extended anticoagulation in Asian patients with venous thromboembolism (VTE) are similar to those in non-Asian patients but risks according to baseline risk factor profiles is not well documented.

METHODS

Subgroup analysis of two randomized trials, which compared once-daily rivaroxaban (20 mg or 10 mg) with placebo or aspirin (100 mg) for extended treatment in Asian patients with VTE who had completed 6-12 months of anticoagulation. Index events were classified as unprovoked, provoked by major persistent risk factors, minor persistent risk factors, minor transient risk factors, or major transient risk factors. One-year cumulative risks of recurrent VTE were calculated for these risk factor profiles.

RESULTS

367 patients received rivaroxaban, 159 aspirin, and 48 placebo. For patients with unprovoked VTE, one-year cumulative incidences of recurrence in the 202 patients given rivaroxaban, the 89 given aspirin and the 28 given placebo were 1.6%, 5.8%, and 14.8%, respectively. For patients with VTE provoked by minor persistent risk factors, these incidences were 0% in the 74 patients given rivaroxaban, 9.3% in the 36 given aspirin, and 0% in the 12 given placebo. No recurrent VTE occurred in patients with VTE provoked by major persistent or transient risk factors or minor transient risk factors. Rivaroxaban was not associated with a significant increase in major bleeding.

CONCLUSIONS

Rivaroxaban seems to be an effective and safe option for extended treatment in Asian patients, especially those presenting with unprovoked VTE. Subgroups of patients with provoked risk factors were too small to draw meaningful conclusions.

TRIAL REGISTRATION

NCT00439725 and NCT02064439.

Nomogram for hospital-acquired venous thromboembolism among patients with cardiovascular diseases

BACKGROUND

Identifying venous thromboembolism (VTE) is challenging for patients with cardiovascular diseases due to similar clinical presentation. Most hospital-acquired VTE events are preventable, whereas the implementation of VTE prophylaxis in clinical practice is far from sufficient. There is a lack of hospital-acquired VTE prediction models tailored specifically designed for patients with cardiovascular diseases. We aimed to develop a nomogram predicting hospital-acquired VTE specifically for patients with cardiovascular diseases.

MATERIAL AND METHODS

Consecutive patients with cardiovascular diseases admitted to internal medicine of Fuwai hospital between September 2020 and August 2021 were included. Univariable and multivariable logistic regression were applied to identify risk factors of hospital-acquired VTE. A nomogram was constructed according to multivariable logistic regression, and internally validated by bootstrapping.

RESULTS

A total of 27,235 patients were included. During a median hospitalization of four days, 154 (0.57%) patients developed hospital-acquired VTE. Multivariable logistic regression identified that female sex, age, infection, pulmonary hypertension, obstructive sleep apnea, acute coronary syndrome, cardiomyopathy, heart failure, immobility, central venous catheter, intra-aortic balloon pump and anticoagulation were independently associated with hospital-acquired VTE. The nomogram was constructed with high accuracy in both the training set and validation (concordance index 0.865 in the training set, and 0.864 in validation), which was further confirmed in calibration. Compared to Padua model, the Fuwai model demonstrated significantly better discrimination ability (area under curve 0.865 vs. 0.786, net reclassification index 0.052, 95% confidence interval 0.012-0.091, P = 0.009; integrated discrimination index 0.020, 95% confidence interval 0.001-0.039, P = 0.051).

CONCLUSION

The incidence of hospital-acquired VTE in patients with cardiovascular diseases is relatively low. The nomogram exhibits high accuracy in predicting hospital-acquired VTE in patients with cardiovascular diseases.

The Risk of Venous Thromboembolism in Korean Patients with Breast Cancer: A Single-Center Experience

The relationship between cancer and venous thromboembolism (VTE) has long been described. The risk of VTE in Asian patients with breast cancer remains largely unknown. This study described the incidence and risk factors of VTE in Korean patients with breast cancer. Data were collected from a retrospective database of patients who underwent breast cancer surgery between 2011 and 2020 at a single institution. The Cox proportional-hazards model was used to identify factors associated with VTE occurrences. Among the 2246 patients with breast cancer, 48 (2.1%) developed VTE during a median follow-up period of 53 months. The average incidence of VTE was 459 per 100,000 person-years. Age ≥ 60 years, male sex, chronic kidney disease, reconstructive procedures, and stage II or higher were independent predictive factors for VTE. VTE was associated with poor disease-free survival (hazard ratio (HR), 6.140; 95% confidence interval (CI), 3.480-10.835), and overall survival (HR, 8.842; 95% CI 4.386-17.824). Most VTE events were manageable with anticoagulation; three (6.3%) patients died of VTE, despite intensive care. The incidence of VTE was significantly elevated in Korean patients with breast cancer. Since VTE has a negative effect on oncologic outcomes of breast cancer, clinicians should manage its risk throughout their lifetime.

Mortality data from omission of early thromboprophylaxis in critically ill patients highlights the importance of an individualised diagnosis-related approach

BACKGROUND

Venous thromboembolism (VTE) prophylaxis is effective in reducing VTE events, however, its impact on mortality is unclear. We examined the association between omission of VTE prophylaxis within the first 24 h after intensive care unit (ICU) admission and hospital mortality.

METHODS

Retrospective analysis of prospectively collected data from the Australian New Zealand Intensive Care Society Adult Patient Database. Data were obtained for adult admissions between 2009 and 2020. Mixed effects logistic regression models were used to evaluate the association between omission of early VTE prophylaxis and hospital mortality.

RESULTS

Of the 1,465,020 ICU admissions, 107,486 (7.3%) did not receive any form of VTE prophylaxis within the first 24 h after ICU admission without documented contraindication. Omission of early VTE prophylaxis was independently associated with 35% increased odds of in-hospital mortality (odds ratios (OR): 1.35; 95% CI: 1.31-1.41). The associations between omission of early VTE prophylaxis and mortality varied by admission diagnosis. In patients diagnosed with stroke (OR: 1.26, 95% CI: 1.05-1.52), cardiac arrest (OR: 1.85, 95% CI: 1.65-2.07) or intracerebral haemorrhage (OR: 1.48, 95% CI: 1.19-1.84), omission of VTE prophylaxis was associated with increased risk of mortality, but not in patients diagnosed with subarachnoid haemorrhage or head injury.

CONCLUSIONS

Omission of VTE prophylaxis within the first 24 h after ICU admission was independently associated with increased risk of mortality that varied by admission diagnosis. Consideration of early thromboprophylaxis may be required for patients with stroke, cardiac arrest and intracerebral haemorrhage but not in those with subarachnoid haemorrhage or head injury. The findings highlight the importance of individualised diagnosis-related thromboprophylaxis benefit-harm assessments.

Thrombosis and anticoagulation: clinical issues of special importance to hematologists who practice in Asia

There are clinical issues of special importance and practice variation in the management of venous thromboembolism (VTE) and in the use of anticoagulants among hematologists who practice in Asia. In Asian-inherited thrombophilia, coagulation is disturbed due to loss-of-function mutations of protein S and protein C causing protein S and protein C deficiencies, whereas the gain-of-function factor V Leiden and prothrombin G20210A mutations are almost absent. Thrombophilia screening is not recommended in patients with VTE patients who have major provoking factors. However, it can be considered in unprovoked young patients with VTE who have a strong family history of VTE. Cancer is the most important acquired risk factor for VTE in Asians. Limited cancer screening at the initial presentation of unprovoked VTE is appropriate, especially in the elderly. Direct oral anticoagulants have been shown to have similar efficacy and reduce risk of major bleeding, including intracranial hemorrhage and bleeding requiring hospitalization, compared with warfarin. Most clinical trials evaluating therapies for treatment and prevention of VTE have included small numbers of Asian patients. Despite this lack of evidence, direct oral anticoagulants have been increasingly used in Asia for cancer-associated thrombosis. Individualized assessment of thrombotic and bleeding risks should be used for all hospitalized Asian patients when deciding on pharmacologic thromboprophylaxis. More research is needed to understand the factors that contribute to risks of VTE and anticoagulant-associated bleeding in Asian patients as these may differ from Western populations.

A Comparison among Nonvitamin K Antagonist Oral Anticoagulants in Asian Patients with Venous Thromboembolism: A Multi-Institutional Study

The comparison of clinical effectiveness and safety across different nonvitamin K antagonist direct oral anticoagulants (DOACs) in Asian patients with venous thromboembolism (VTE) remains unclear. Therefore, we assessed the real-world benefits of different DOACs in these patients. A cohort of 1480 patients with VTE were identified from the Chang Gung Research Database between 1 January 2012, and 31 December 2019. The composite outcomes of recurrent VTE and major bleeding were evaluated for four DOACs. The composite outcomes of recurrent VTE and major bleeding occurred in 9.06%, 9.80%, 8.61%, and 10.86% of the apixaban, dabigatran, edoxaban, and rivaroxaban groups, respectively, within 12 months of treatment initiation. The risk of the composite outcomes was similar in the rivaroxaban group and the apixaban, dabigatran, and edoxaban groups, with a subdistribution hazard ratio (SHR) of 0.80 (95% CI, 0.49-1.29), 0.81 (95% CI, 0.34-1.95), and 0.76 (95% CI, 0.42-1.39), respectively. No significant differences in the rates of recurrent VTE or major bleeding were observed between the rivaroxaban and other DOAC groups at the 12-month follow-up. According to real-world practice in Asian patients with VTE, the DOAC type was not associated with the differences in the risk of recurrent VTE or major bleeding within 12 months of treatment initiation.

Unfractionated heparin or low-molecular-weight heparin for venous thromboembolism prophylaxis after hepatic resection: A meta-analysis

BACKGROUND

Two systematic reviews summarized the efficacy and safety of pharmacological prophylaxis for venous thromboembolism (VTE) after hepatic resection, but both lacked a discussion of the differences in the pharmacological prophylaxis of VTE in different ethnicities. Therefore, we aimed to evaluate the efficacy and safety of low-molecular-weight heparin (LMWH) or unfractionated heparin (UFH) for VTE prophylaxis in Asian and Caucasian patients who have undergone hepatic resection.

METHODS

We searched PubMed, Web of Science, Embase, China National Knowledge Infrastructure, Wanfang Data, and VIP databases for studies reporting the primary outcomes of VTE incidence, bleeding events, and all-cause mortality from January 2000 to July 2022.

RESULTS

Ten studies involving 4318 participants who had undergone hepatic resection were included: 6 in Asians and 4 in Caucasians. A significant difference in VTE incidence was observed between the experimental and control groups (odds ratio [OR] = 0.39, 95% confidence interval [CI]: 0.20, 0.74, P = .004). No significant difference in bleeding events and all-cause mortality was observed (OR = 1.29, 95% CI: 0.80, 2.09, P = .30; OR = 0.71, 95% CI: 0.36, 1.42, P = .33, respectively). Subgroup analyses stratified by ethnicity showed a significant difference in the incidence of VTE in Asians (OR = 0.16, 95% CI: 0.06, 0.39, P < .0001), but not in Caucasians (OR = 0.69, 95% CI: 0.39, 1.23, P = .21). No significant differences in bleeding events were found between Asians (OR = 1.60, 95% CI: 0.48, 5.37, P = .45) and Caucasians (OR = 1.11, 95% CI: 0.58, 2.12, P = .75). The sensitivity analysis showed that Ejaz's study was the main source of heterogeneity, and when Ejaz's study was excluded, a significant difference in VTE incidence was found in Caucasians (OR = 0.58, 95% CI: 0.36, 0.93, P = .02).

CONCLUSION

This study's findings indicate that the application of UFH or LMWH for VTE prophylaxis after hepatic resection is efficacious and safe in Asians and Caucasians. It is necessary for Asians to receive drug prophylaxis for VTE after hepatic resection. This study can provide a reference for the development of guidelines in the future, especially regarding the pharmacological prevention of VTE in different ethnicities.

Impact of hereditary thrombophilia on cancer-associated thrombosis, tumour susceptibility and progression: A review of existing evidence

Venous thromboembolism (VTE) is a cardiovascular disorder frequently diagnosed among cancer patients. Aside from being common, VTE severely deteriorates the prognosis of these patients as they face a higher risk of morbidity and mortality, which makes clinical tools able to identify the patients more prompt to thrombogenesis very attractive. Over the years, several genetic polymorphisms have been linked with VTE susceptibility in the general population. However, their clinical usefulness as predictive biomarkers for cancer-related VTE is yet unclear. Furthermore, as a two-way association between cancer and VTE is well-recognized, with haemostatic components fuelling tumour progression, haemostatic gene polymorphisms constitute potential cancer predictive and/or prognostic biomarkers as well. Thus, in this article, we review the existing evidence on the role of these polymorphisms on cancer-related VTE and their impact on cancer onset and progression. Despite the promising findings, the existing studies had inconsistent results most likely due to their limited statistical power and population heterogeneity. Future studies are therefore required to clarify the role of these polymorphisms in setting of malignancy.

Characteristics and clinical outcomes of Japanese patients with venous thromboembolism receiving under-dose rivaroxaban: subanalysis of J'xactly

OBJECTIVE

Rivaroxaban is commonly prescribed to prevent venous thromboembolism (VTE). Although lower than standard dosages (under-dosing) may be administered in the real-world setting, data on subsequent clinical outcomes in Japanese patients are lacking.

METHODS

The prospective, multicenter, observational J'xactly study enrolled patients with acute symptomatic/asymptomatic deep vein thromboses (DVT), pulmonary embolism (PE), or both, who were prescribed rivaroxaban. This subanalysis investigated patient characteristics and outcomes associated with rivaroxaban under-dosing.

RESULTS

Among 1016 evaluable patients, 667 (65.6%) received an initial standard dosage of rivaroxaban (30 mg/day) and 349 (34.4%) received an initial under-dosage (20 mg/day, n = 22; 15 mg/day, n = 282; and 10 mg/day, n = 45). Those receiving an under-dose had significantly lower body weight and slower pulse rate compared with the standard-dose group regardless of DVT or PE status. Under-dosing was common for distal DVTs, but less frequent for massive/submassive PEs. There were no differences between under-dose and standard-dose groups in the incidences of recurring symptomatic VTEs (DVT: 1.77% vs. 3.35% per patient-year, p = .138; PE: 0.84% vs. 2.84% per patient-year, p = .208) or major bleeding (DVT: 3.55% vs. 3.41% per patient-year, p = .960; PE: not observed vs. 2.83% per patient-year, p = .132).

CONCLUSIONS

In the real-world setting, rivaroxaban under-dosing for patients with VTE occurred in those with lower body weight, slower pulse rate, distal DVT, or non-massive PEs. There were no statistically significant differences in the clinical outcomes for patients received under-dose of rivaroxaban at the discretion of the physicians in the clinical practice compared with those received standard dose of rivaroxaban.

Cost-Effectiveness Analysis of Direct Oral Anticoagulants Versus Vitamin K Antagonists for Venous Thromboembolism in China

Background: The drug therapy of venous thromboembolism (VTE) presents a significant economic burden to the health-care system in low- and middle-income countries. To understand which anticoagulation therapy is most cost-effective for clinical decision-making , the cost-effectiveness of apixaban (API) versus rivaroxaban (RIV), dabigatran (DAB), and low molecular weight heparin (LMWH), followed by vitamin K antagonist (VKA), in the treatment of VTE in China was assessed. Methods: To access the quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios (ICERs), a long-term cost-effectiveness analysis was constructed using a Markov model with 5 health states. The Markov model was developed using patient data collected from the Xijing Hospital from January 1, 2016 to January 1, 2021. The time horizon was set at 30 years, and a 6-month cycle length was used in the model. Costs and ICERs were reported in 2020 U.S. dollars. One-way sensitivity analysis and probabilistic sensitivity analysis (PSA) were used to test the uncertainties. A Chinese health-care system perspective was used. Results: In the base case, the data of 231 VTE patients were calculated in the base case analysis retrospectively. The RIV group resulted in a mean VTE attributable to 95% effective treatment. API, DAB, and VKA have a negative ICER (-187017.543, -284,674.922, and -9,283.339, respectively) and were absolutely dominated. The Markov model results confirmed this observation. The ICER of the API and RIV was negative (-216176.977), which belongs to the absolute inferiority scheme, and the ICER value of the DAB and VKA versus RIV was positive (110,577.872 and 836,846.343). Since the ICER of DAB and VKA exceeds the threshold, RIV therapy was likely to be the best choice for the treatment of VTE within the acceptable threshold range. The results of the sensitivity analysis revealed that the model output varied mostly with the cost in the DAB on-treatment therapy. In a probabilistic sensitivity analysis of 1,000 patients for 30 years, RIV has 100% probability of being cost-effective compared with other regimens when the WTP is $10973 per QALY. When WTP exceeded $148,000, DAB was more cost-effective than RIV. Conclusions: Compared with LMWH + VKA and API, the results proved that RIV may be the most cost-effective treatment for VTE patients in China. Our findings could be helpful for physicians in clinical decision-making to select the appropriate treatment option for VTE.