Validation Of Risk Assessment Model Research Articles

External validation of a bleeding risk assessment model developed with natural language processing and machine learning (PREDICT-AI study) in patients with anticoagulated cancer with venous thromboembolism in the TESEO international prospective registry.

e24123 Background: The risk factors for bleeding during anticoagulation in patients with cancer-associated thrombosis (CAT) remain largely unexplored. The recently developed PredictAI model ( Muñoz Martín AJ et al. JCO 40, e18744-e18744(2022) was aimed to predict major bleeding (MB) in anticoagulant-treated cancer patients within the first 6 months following venous thromboembolism (VTE) diagnosis. The goal was to validate the PredictAI model using an independent cohort of patients from the TESEO international, observational, prospective registry. Methods: The performance of the three predictive models developed in PredictAI were assessed in terms of accuracy, precision, recall, F1-score, and the receiver operating characteristic (ROC) area under the curve (AUC): PredictAI decision tree classifier ROC-AUC 0.66 (confidence interval 95% [CI 95%], 0.63-0.69; P < .0001), random forest classifier ROC-AUC 0.61 (CI 95%, 0.58-0.64; P < .0001), and logistic regression ROC-AUC 0.70 (CI 95%, 0.67-0.73; P < .0001). The outcome was MB within 6 months following VTE diagnosis, whereas the analyzed predictors for MB at baseline comprised those from PredictAI, namely patient’s age, presence of metastasis, hemoglobin levels, platelet count, leukocyte count, and serum creatinine levels. Results: The TESEO cohort used for the external validation comprised 2,179 patients (51.9% male, mean age = 64.72 ± 11.34 years) with active cancer and VTE under anticoagulant treatment. The median (Q1, Q3) follow-up duration across patients was 6 (2, 14) months. Considering the ROC-AUC values for the three tested models (table 1), the results confirm a statistically significant validation and best performance of the logistic regression (ROC-AUC = 0.59; 95% CI = 0.53, 0.65; P = .002) approach. Conclusions: Our results support the first external validation of a risk assessment model of bleeding specifically developed for CAT. This model may guide objective decisions regarding the extension and dosing of anticoagulant therapy in this population. Future steps should involve further validation of the present model in other patient cohorts and the generation of a clinical tool to facilitate its use in healthcare settings. [Table: see text]

Overuse and underuse of thromboprophylaxis in medical inpatients

BackgroundThromboprophylaxis (TPX) prescription is recommended in medical inpatients categorized as high risk of venous thromboembolism (VTE) by validated risk assessment models (RAMs), but how various RAMs differ in categorizing patients in risk groups, and whether the choice of RAM influences estimates of appropriate TPX use is unknown. ObjectivesTo determine the proportion of medical inpatients categorized as high or low risk according to validated RAMs, and to investigate the appropriateness of TPX prescription. MethodsThis is a prospective cohort study of acutely ill medical inpatients from 3 Swiss university hospitals. Participants were categorized as high or low risk of VTE by validated RAMs (ie, the Padua, the International Medical Prevention Registry on Venous Thromboembolism, simplified, and original Geneva scores). We assessed prescription of any TPX at baseline. We considered TPX prescription in high-risk and no TPX prescription in low-risk patients as appropriate. ResultsAmong 1352 medical inpatients, the proportion categorized as high risk ranged from 29.8% with the International Medical Prevention Registry on Venous Thromboembolism score to 66.1% with the original Geneva score. Overall, 24.6% were consistently categorized as high risk, and 26.3% as low risk by all 4 RAMs. Depending on the RAM used, TPX prescription was appropriate in 58.7% to 63.3% of high-risk (ie, 36.7%-41.3% underuse) and 52.4% to 62.8% of low-risk patients (ie, 37.2%-47.6% overuse). ConclusionThe proportion of medical inpatients considered as high or low VTE risk varied widely according to different RAMs. Only half of patients were consistently categorized in the same risk group by all RAMs. While TPX remains underused in high-risk patients, overuse in low-risk patients is even more pronounced.

Evaluating the impact of nurse navigation on high-risk breast clinic appointment uptake in a cancer risk assessment program.

e13510 Background: Patients in the breast imaging center are offered comprehensive cancer risk assessment (CRA) using validated risk assessment models (Tyrer-Cuzick 8, GAIL, and NCCN guidelines for genetic testing) at the time of screening mammography. All patients who receive a high-risk breast cancer score are recommended to follow-up at the high-risk breast clinic (HRBC) to determine a personalized management plan including MRI screening, genetic testing, and treatment options. Insufficient communication and patient education regarding breast cancer screening contributes to low HRBC appointment uptake. Nurse navigation (NN) was used to increase the HRBC appointment completion rate. This project aims to assess the effect of NN on HRBC appointment uptake in patients with a high-risk of breast cancer. Methods: Data regarding NN and HRBC appointment uptake for all women at a breast imaging center with a high-risk breast cancer score between July 2021 and January 2022 was extracted from the EMR and grouped into cohorts to assess the impact of NN on HRBC appointment completion. Family history of breast cancer, breast cancer risk model type, and insurance status were also extracted to analyze their relationships with HRBC appointment uptake. A chi-squared analysis was performed to assess the significance of the results. Results: NN contact and HRBC appointment completion of 4090 patients were analyzed. Of the 4090 patients, 1787 (43.7%) were successfully contacted by a nurse navigator. Patients with a family history of breast cancer were more likely to have contact with the nurse navigator (p = 0.022) and complete HRBC appointment (p = 0.017). The distribution of breast cancer risk model and distribution of insurance type were different for patients who completed HRBC appointments and those who did not, (p = 0.0012) and (p = 0.0027), respectively. Of the 4090 total patients, 122 (3.0%) attended the HRBC. Of the 1787 patients contacted by a nurse navigator, 80 (4.5%) completed HRBC appointments (p < 0.0001). Conclusions: Coupling NN with a CRA program at the breast imaging center increased the number of qualified patients who completed HRBC appointments who would not have been identified prior to this program. Patients with a family history of breast cancer, certain types of breast cancer risk model, and certain types of insurance were found to have increased uptake of HRBC appointments. As a result, more patients will receive recommended supplemental screenings and management from a multidisciplinary care team.[Table: see text]

Development and Internal Validation of Risk Assessment Models for Chronic Obstructive Pulmonary Disease in Coal Workers.

Coal workers are more likely to develop chronic obstructive pulmonary disease due to exposure to occupational hazards such as dust. In this study, a risk scoring system is constructed according to the optimal model to provide feasible suggestions for the prevention of chronic obstructive pulmonary disease in coal workers. Using 3955 coal workers who participated in occupational health check-ups at Gequan mine and Dongpang mine of Hebei Jizhong Energy from July 2018 to August 2018 as the study subjects, random forest, logistic regression, and convolutional neural network models are established, and model performance is evaluated to select the optimal model, and finally a risk scoring system is constructed according to the optimal model to achieve model visualization. The training set results show that the logistic, random forest, and CNN models have sensitivities of 78.55%, 86.89%, and 77.18%; specificities of 85.23%, 92.32%, and 87.61%; accuracies of 81.21%, 85.40%, and 83.02%; Brier scores of 0.14, 0.10, and 0.14; and AUCs of 0.76, 0.88, and 0.78, respectively, and similar results are obtained for the test set and validation set, with the random forest model outperforming the other two models. The risk scoring system constructed according to the importance ranking of random forest predictor variables has an AUC of 0.842; the evaluation results of the risk scoring system shows that its accuracy rate is 83.7% and the AUC is 0.827, and the established risk scoring system has good discriminatory ability. The random forest model outperforms the CNN and logistic regression models. The chronic obstructive pulmonary disease risk scoring system constructed based on the random forest model has good discriminatory power.

Unmet definitions in thromboprophylaxis for hospitalized medical patients: An appraisal for the need of recommendation

Up to about 60% of venous thromboembolic events in a community are associated with hospitalization, and most can be prevented by appropriate thromboprophylaxis. Several randomized clinical trials and guidelines have addressed the issue of thromboprophylaxis in hospitalized patients and recommended strategies to assess patients' risk and thromboprophylaxis. Simple and validated risk assessment models are available to assist physicians in selecting patients who are at high risk for VTE, in whom thromboprophylaxis should be used. However, some concepts employed are imprecise or not appropriately defined. Indeed, there has been wide variation in the onset, duration, and adequacy of thromboprophylaxis, as well as in the definition of some risk factors. Inarticle, we highlight these issues and the unmet definitions in thromboprophylaxis in hospitalized patients mainly by addressing selected randomized clinical trials and guidelines.

Current practices in pediatric hospital‐acquired thromboembolism: Survey of the Children's Hospital Acquired Thrombosis (CHAT) Consortium

BackgroundA rise in hospital‐acquired venous thromboembolism (HA‐VTE) in children has led to increased awareness regarding VTE prophylaxis and risk assessment. Despite no consensus exists regarding these practices in pediatrics. ObjectiveTo describe common practices in VTE prophylaxis, VTE risk assessment models, and anticoagulation dosing strategies in pediatric hospitals that are members of the Children's Hospital Acquired Thrombosis (CHAT) Consortium. MethodsAn electronic survey of 44 questions evaluating practices surrounding pediatric HA‐VTE risk assessment and prevention was distributed between August 9, 2021, and August 30, 2021, to the primary investigators from the 32 institutions within the CHAT Consortium. ResultsThe survey response rate was 100% (n = 32). In total, 85% (n = 27) of the institutions assess HA‐VTE, but only 63% (n = 20) have formal hospital guidelines. Within the institutions with formal guidelines, 100% (n = 20) include acute systemic inflammation or infection and presence of a central venous catheter (CVC) as risk factors for VTE. Pharmacologic prophylaxis is prescribed at 87% (28) of institutions, with enoxaparin being the most frequent (96%, n = 27). Variability in responses persisted regarding risk factors, risk assessment, thromboprophylaxis, dosing of prophylactic anticoagulation or anticoagulant drug monitoring. A majority of providers were comfortable providing thromboprophylaxis across all age groups. In addition, the global coronavirus disease 2019 increased the providers' use of prophylactic anticoagulation 78% (n = 25). ConclusionPractices among institutions are variable in regard to use of HA‐VTE prophylaxis, risk assessment, or guideline implementation, highlighting the need for further research and a validated risk assessment model through groups like the CHAT Consortium.

Cancer-associated coagulation disorders

Diagnosis and treatment of paraneoplastic coagulation disorders are achallenge in daily practice. While prophylactic anticoagulation to prevent venous thromboembolism (VTE) is standard of care in all surgical and acutely ill medical cancer patients, particularly careful evaluation of risks and benefits using validated risk assessment models is required during outpatient chemotherapy. Low-molecular-weight heparin and direct oral factor Xa inhibitors are available to treat established cancer-associated VTE, adhering to algorithms for bleeding risk stratification. In patients with overt disseminated intravascular coagulation, therapeutic measures should strictly follow clinical symptoms. An acquired von Willebrand syndrome may evoke asevere bleeding tendency in patients with myeloproliferative neoplasms or plasma cell dyscrasias. In 15% of cases, acquired hemophiliaA, due to the formation of inhibitory autoantibodies against coagulation factor VIII, is associated with malignancy.

Cancer risk assessment models versus National Comprehensive Cancer Network guidelines: What is the most comprehensive method to assess cancer risk and triage for genetic testing? (373)

Cancer risk assessment models versus National Comprehensive Cancer Network guidelines: What is the most comprehensive method to assess cancer risk and triage for genetic testing? (373)

Health information technology to improve referral to genetic testing for high-risk patients in a gynecologic oncology clinic (102)

<b>Objectives:</b> Our previously presented pilot study evaluated a web-based tool to collect family cancer history (FCH). It demonstrated that this tool resulted in significantly higher quality FCH compared to standard of care face-to-face physician interviews. However, the true value of FCH requires translation into the utilization of genetic services. Here, we aimed to evaluate referral rates and completion of genetic services for patients completing the web-based tool versus standard of care. <b>Methods:</b> Patients scheduled for a gynecologic oncology new patient visit between September 2019 and September 2021 were eligible for enrollment in this institutional review board-approved prospective trial. The trial had three arms: <i>1)</i> Standard of care (FCH collection by physicians) <i>2)</i> Web-based tool administered by email prior to the visit, <i>3)</i> Web-based tool administered in the office prior to the visit (this arm closed early due to COVID-19 restrictions). Individuals were identified as high-risk for familial cancer if they met National Comprehensive Cancer Network (NCCN) guidelines in the standard of care arm, or if the validated cancer risk models embedded in the web-based tool returned a lifetime cancer risk >20% or mutation risk >2.5% in the web-based tool arms. Validated risk assessment models included breast and ovarian BRCAPRO, Claus, Tyrer-Cuzick, Gail, colorectal and endometrial MMRPRO, MELAPRO, PANCPRO, and PREMM. The primary endpoint was the percentage of high-risk patients referred for genetic counseling/testing. Secondary endpoints included the completion of genetic counseling and genetic testing. <b>Results:</b> Two hundred and fifty patients were enrolled (Arm 1: 110; Arm 2: 105; Arm 3: 35). Among patients randomized to the web-based tool, 88 (63%) completed the tool. In the control arm, 31 patients (28%) met the criteria for referral to genetics, among which 18 (58%) had previously completed genetic testing. In the web-based tool arm, 26 patients (30%) met the criteria, among which 12 (46%) had previously completed genetic testing, and one was deceased soon after her visit. In the control arm, 54% of high-risk patients were referred to genetic counseling, 23% completed genetic counseling, and 23% completed genetic testing. In the web-based tool arm, 100% of high-risk patients were referred to genetic counseling, 54% completed genetic counseling, and 38% completed genetic testing (Table 1). <b>Conclusions:</b> When successfully completed, the use of a web-based tool for FCH collection facilitated the process of referral to genetics, resulting in significantly higher referral rates to genetic counseling than the standard of care physician interviews (100% vs 54%, p=0.01). However, 37% of patients could not complete the web-based tool. Our findings demonstrate the potential power of health information technology to identify millions of individuals unknowingly carrying familial cancer syndromes and highlight those tools must be designed in a way to maximize patient participation.Fig. 1

Update on Guidelines for the Prevention of Cancer-Associated Thrombosis.

Patients with cancer are at high risk of developing arterial and venous thromboembolism (VTE). They constitute 15% to 20% of the patients diagnosed with VTE. Depending on the type of tumor, cancer therapy, and presence of other risk factors, 1% to 25% of patients with cancer will develop thrombosis. The decision to start patients with cancer on primary thromboprophylaxis depends on patient preference, balancing risk of bleeding versus risk of thrombosis, cost, and adequate organ function. Currently, guidelines recommend against the use of routine primary thromboprophylaxis in unselected ambulatory patients with cancer. Validated risk assessment models can accurately identify patients at highest risk for cancer-associated thrombosis (CAT). This review summarizes the recently updated NCCN Guidelines for CAT primary prophylaxis, with a primarily focus on VTE prevention. Two main clinical questions that providers commonly encounter will also be addressed: which patients with cancer should receive primary thromboprophylaxis (both surgical and medical oncology patients) and how to safely choose between different anticoagulation agents.

P25: CARFILZOMIB-BASED TREATMENTS COULD BE ADDED TO IMPEDE-VTE SCORE TO BETTER PREDICT VENOUS THROMBOEMBOLIC RISK IN MM PATIENTS

Introduction: Venous thromboembolic (VTE) risk in Multiple Myeloma (MM) patients treated with novel agents can be very high, particularly with lenalidomide combined with high dose steroid. Guidelines do not recommend a validated Risk Assessment Model (RAM) to precisely identify patients with high VTE risk, in order to personalize the thromboprophylactic strategy. The IMWG score, that is widely used, is not actually performing well, as VTE events continue to occur in about 15% of MM patients. We aim to test IMPEDE-VTE score, which seems to be the most effective RAM in MM, in our real life MM population, trying to eventually implement it with emergent new risk factors. Patients and methods: In our database, we prospectively collected data from 393 MM patients, treated from 2010 to 2021. One-hundred-thirteen (29%) patients were >75 years old, 45% were frail according to simplified Frailty Score, 17% had abnormal LDH level, 19% had renal failure and 4% had a BMI ≥35. ISS stage 3 was scored in 27% of patients and 31% of patients had high-risk cytogenetics. Sixty-six percent of patients received Immunomodulatory (IMIDs)-based therapy (lenalidomide in 32% of patients). Monoclonal antibodies (MoAbs) were used in 8% of patients (MoAbs associated to lenalidomide in 75%) and carfilzomib in 10% of patients (carfilzomib associated to lenalidomide in 51%). Patients were stratified per IMPEDE-VTE score: high, intermediate and low risk were formed by 10%, 41% and 49% of patients, respectively. Eleven percent of patients had a central venous catheter (CVC), and thromboprophylaxis was chosen according to the IMWG criteria (ASA or none 74%, anticoagulants 26%). We have finally analysed the impact of therapeutic risk factors on thromboembolic events’ incidence. Results: VTE events’ rate in our MM population was 16%, the majority of them occurring during the first three months from the starting of therapy. None of patient-related risk factors (age, CCI, Frailty Score, LDH value), nor disease-related risk factors (ISS, cytogenetics, renal failure), except for bone disease, was significant in univariate analysis for increasing VTE risk. On the contrary, CVC, IMPEDE-VTE score, lenalidomide and carfilzomib treatments retained statistical significance. Analysing therapy-related risk factors for VTE risk, we have found only a trend between the group treated with IMIDs-based (thalidomide, lenalidomide, pomalidomide) and that with non-IMIDs-based therapy (p=0.095). Nevertheless, patients treated with lenalidomide had higher VTE risk compared with patients treated without lenalidomide (13% vs 7% at 6 months; p<0.001). MoAbs-based therapy concurred to increase VTE risk, but only when associated to lenalidomide (p<0.001). On the contrary, carfilzomib monotherapy significantly increased VTE risk (p<0.001), regardless the association with lenalidomide. Stepwise Cox regression analysis selected IMPEDE-VTE score (LR-IR vs HR: 7% vs 16% at 6 months; p=0.032) and carfilzomib treatment (24% vs 7% at 6 months; p< 0.001) as independent significant risk factors for VTE. Conclusions: Despite our analysis being retrospective, we confirmed IMPEDE-VTE as a predictive score of VTE risk in a real life MM population. However, our analysis found carfilzomib-based therapy an independent risk factor from IMPEDE-VTE score. We attempt to prospectively study the “carfilzomib-based therapy” parameter in order to implement IMPEDE-VTE score, aiming to better stratify VTE risk in MM patients.

External validation of the HIGH-2-LOW model: A predictive score for venous thromboembolism after allogeneic transplant.

In patients undergoing hematopoietic cell transplantation (HCT), venous thromboembolism (VTE) remains a serious complication that lacks validated risk assessment models (RAMs) to guide thromboprophylaxis. To address this dilemma, we performed a temporal and external validation study of the recently derived HIGH-2-LOW RAM. We selected adult patients undergoing allogeneic HCT from Fred Hutchinson Cancer Research Center (FHCRC) and MD Anderson Cancer Center (MDACC). Patients who died, received anticoagulation, or did not engraft platelets by day 30 were excluded. Primary outcomes were defined as overall VTE and pulmonary embolism ± lower-extremity deep venous thromboembolism (PE/LE-DVT) by day 180. Covariates were weighted according to the original model, except that grade 2-4 GVHD was substituted for grade 3-4. Discrimination and calibration were assessed. A total of 765 patients from FHCRC and 954 patients from MDACC were included. Incident VTE by day 180 was 5.1% at FHCRC and 6.8% at MDACC. The HIGH-2-LOW score had a c-statistic of 0.67 (0.59-0.75) for VTE and 0.75 (0.64-0.81) for PE/LE-DVT at FHCRC and 0.62 (0.55-0.70) for VTE and 0.70 (0.56-0.83) for PE/LE-DVT at MDACC. Twenty-five percent and 23% of patients were classified as high risk (2+ points) in the two cohorts, respectively. High versus low-risk was associated with odds ratio (OR) of 2.80 (1.46-5.38) for VTE and 4.21 (1.82-9.77) for PE/LE-DVT at FHCRC and OR of 3.54 (2.12-5.91) for VTE and 6.82 (2.30-20.16) for PE-LE-DVT at MDACC. The HIGH-2-LOW RAM identified allogeneic HCT recipients at high risk for VTE in both validation cohorts. It can improve evidence-based decision-making for thromboprophylaxis post-transplant.

Validation of Risk Assessment Models Predicting Venous Thromboembolism in Inpatients with Acute Exacerbation Of Chronic Obstructive Pulmonary Disease: A Multicenter Cohort Study in China

Inpatients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) are at increased risk for venous thromboembolism (VTE); however, the prophylaxis for VTE is largely underused in China. Identifying high-risk patients requiring thromboprophylaxis is critical to reduce the mortality and morbidity associated with VTE. This study aimed to evaluate and compare the validities of the Padua Prediction Score and Caprini risk assessment model (RAM) in predicting the risk of VTE in inpatients with AECOPD in China. The inpatients with AECOPD were prospectively enrolled from seven medical centers of China between September 2017 and January 2020. Caprini and Padua scores were calculated on admission, and the incidence of 3-month VTE was investigated. Among the 3,277 eligible patients with AECOPD, 128 patients (3.9%) developed VTE within 3 months after admission. The distribution of the study population by the Caprini risk level was as follows: high, 53.6%; moderate, 43.0%; and low, 3.5%. The incidence of VTE increased by risk level as high, 6.1%; moderate, 1.5%; and low, 0%. According to the Padua RAM, only 10.9% of the study population was classified as high risk and 89.1% as low risk, with the corresponding incidence of VTE of 7.9 and 3.4%, respectively. The Caprini RAM had higher area under curve compared with the Padua RAM (0.713 ± 0.021 vs. 0.644 ± 0.023, p = 0.029). The Caprini RAM was superior to the Padua RAM in predicting the risk of VTE in inpatients with AECOPD and might better guide thromboprophylaxis in these patients.

Protocol for prophylaxis of venous thromboembolism in varicose vein surgery of the lower limbs.

Pulmonary embolism is the most feared complication of venous thromboembolism (VTE) and the third leading cause of cardiovascular mortality in the world, after acute myocardial infarction and stroke. The risk of VTE is virtually universal in hospitalized patients, especially those with reduced mobility. Although variable in incidence between clinical and surgical patients, up to 66.6% of events related to hospitalizations can occur after discharge, with this risk remaining for up to 90 days. Despite all the investment made in VTE prophylaxis in recent decades, there is still no consensus or specific guidelines for its prevention in patients undergoing conventional surgery for varicose veins of lower limbs. The adoption of a validated risk assessment model for VTE prophylaxis, based on the current literature, may help in the implementation and standardization of VTE prophylaxis in conventional lower limb varicose vein surgery, in addition to this benefit, it may lead to a reduction in the length of hospital stay and the number of readmissions.

Internal and External Validation of the High-2-Low Model: A Predictive Score for Venous Thromboembolism after Allogeneic Transplant

Introduction: In patients undergoing allogeneic hematopoietic cell transplantation (HCT), venous thromboembolism (VTE) remains a serious complication that lacks validated risk assessment models to guide optimal timing and implementation of thromboprophylaxis. We recently derived the HIGH-2-LOW score that incorporated 7 simple clinical predictors assessed at day 30 post-transplant (Table 1, PMID 33570631). In this present study, we performed validation in two independent datasets.Methods: We selected consecutive patients undergoing first allogeneic HCT from Fred Hutchinson Cancer Research Center (FHCRC, 2015-2019) and MD Anderson Cancer Center (MDACC, 2016-2020). Patients who died, received therapeutic anticoagulation, or did not engraft platelets at day 30 were excluded (Table 2). Day 30 was chosen as the index date because most patients would be transfusion-dependent before that time. We used a combination of ICD9/10 codes and natural language processing (NLP) algorithms to identify possible cases of VTE, followed by confirmation via individual chart review. VTE was defined as radiology-confirmed pulmonary embolism (PE), lower-extremity deep venous thromboembolism (LE-DVT), or catheter-related DVT (CR-DVT). Covariates were captured and weighted according to the original model, except that grade 2-4 was used instead of grade 3-4 GVHD. Discrimination was assessed in each cohort by fitting logistic regression models with VTE and PE/LE-DVT outcomes at 100 days to estimate the c statistic, where a higher c statistic is desirable. Both continuous scores and categorical models were assessed. Kaplan Meier failure curves were plotted to compare the final risk stratification with high- vs. low/intermediate-risk groups.Results: The two cohorts (n=772 in FHCRC, n=1109 in MDACC) had similar characteristics in age, sex, race, weight, disease, and conditioning intensity. Key differences between the two cohorts included a higher number of umbilical cord transplants at FHCRC (vs. haploidentical at MDACC), higher numbers of acute GVHD at FHCRC (due to differences in grading criteria), fewer historical CR-DVT at FHCRC (4.0% vs. 6.8%), and more anticoagulation treatment at day 30 at FHCRC (9.0% vs. 3.5% - excluded). Incident VTE was 2.5% by 100 days and 7.8% by 365 days at FHCRC; incident VTE was 5.4% by 100 days and 9.4% by 365 days at MDACC (Table 2). Incident PE or LE-DVTs were similar in the two cohorts.When treated as a continuous score, every 1-point increase in the HIGH-2-LOW score was associated with odds ratio (OR) of 1.55 for VTE (1.06-2.27, c=0.64) and 2.50 (1.40-4.44, c=0.84) for PE/LE-DVT in the FHCRC cohort. The same increase was associated with OR of 1.93 (1.55-2.39, c=0.64) for VTE and 2.46 (1.61-3.76, c=0.79) for PE/LE-DVT in the MDACC cohort (Table 3). A total of 24% and 19% of patients were classified as high-risk (2+ points), respectively. High vs. low/intermediate-risk was associated with OR of 2.99 (1.20-7.49, c=0.62) for VTE and 19.93 (2.38-166.67, c=0.81) for PE/LE-DVT in the internal validation cohort. High vs. low/intermediate-risk was associated with OR of 4.58 (2.69-7.79, c=0.66) for VTE and 12.05 (3.17-45.81, c=0.77) for PE-LE-DVT in the external validation cohort. The VTE risk stratification separated early and persisted beyond 100 days (Figure 1).Conclusion: Despite differences in HCT and patient characteristics, the HIGH-2-LOW score identified ~20% of allogeneic HCT recipients at high-risk for VTE, particularly that of PE or LE-DVT, in both independent validation cohorts. The lower-than-expected absolute VTE incidence in the FHCRC cohort was likely driven by the increasing use of anticoagulation immediately post-transplant (exclusion criteria); however, the model retained similar OR with modest discrimination in both cohorts. In patients with prior history of PE/LE-DVT off anticoagulation, or those with prolonged admission and at least 1 additional risk factors from the HIGH-2-LOW score (2+ points), VTE prophylaxis should be considered upon platelet engraftment. [Display omitted] DisclosuresLee: Kadmon: Research Funding; Syndax: Research Funding; Takeda: Research Funding; Pfizer: Research Funding; Novartis: Other: clinical trials, Research Funding; JANSSEN: Other; Incyte: Research Funding; AstraZeneca: Research Funding; Amgen: Research Funding; National Marrow Donor Program: Membership on an entity's Board of Directors or advisory committees. Shpall: Bayer HealthCare Pharmaceuticals: Honoraria; Novartis: Consultancy; Takeda: Patents & Royalties; Affimed: Patents & Royalties; Magenta: Honoraria; Magenta: Consultancy; Navan: Consultancy; Novartis: Honoraria; Axio: Consultancy; Adaptimmune: Consultancy.

Validation of risk assessment models for venous thromboembolism and bleeding in critically ill adolescents

ObjectiveTo determine the performance of risk assessment models that were developed for adults, in predicting venous thromboembolism (VTE) and bleeding in critically ill adolescents. Study designWe conducted a retrospective cohort study of adolescents 12 to 17 years old admitted to the pediatric intensive care unit who received cardiopulmonary support but did not have VTE on admission nor received anticoagulation. Discrimination, using areas under the receiver operating characteristic (AUROC) and precision-recall (AUPRC) curves, and calibration, using Hosmer-Lemeshow test, of the Geneva, Padua, IMPROVE VTE and IMPROVE Bleed models were calculated. ResultsOf 536 adolescents analyzed, 7 (1.3%) developed VTE and 13 (2.4%) bled. AUROCs of the Geneva, Padua and IMPROVE VTE models ranged from 0.46 to 0.59, with 95% confidence intervals (CI) including 0.5. AUPRCs ranged from 0.011 to 0.017, with 95% CIs including 0.013. Only IMPROVE VTE model had non-statistically significant Hosmer-Lemeshow test. IMPROVE Bleed model had AUROC and AUPRC of 0.75 and 0.062, with 95% CIs excluding 0.5 and 0.024, respectively. Hosmer-Lemeshow test was not statistically significant. ConclusionDespite similarities in coagulation between adolescents and adults, risk assessment models for VTE in adults should not be used for critically ill adolescents. The model for bleeding may be useful.

Venous thromboembolism prophylaxis in plastic surgery: state of the art and our approach.

The issue of prevention of thromboembolism in plastic surgery is a rather controversial subject. The actual frequency of VTE among plastic surgery patients is probably higher than we know. Although several studies have shown that chemoprophylaxis likely increases rates of re-operative hematoma by less than one percent, surgeons are strongly resistant to adopting chemoprophylaxis due to the fear of increased bleeding and its complications. A literature review was conducted. The 2012 ACCP guidelines suggest the use of the 2005 Caprini score as the most widely used and well-validated individualized risk-stratification tool. We propose a modified 2005 Caprini score, with specific changes pertaining to plastic surgery, in which we combine a patient risk stratification model and a procedure-driven approach explicitly indicating what procedures have to be considered at high or low risk. The risk of venous thromboembolism in plastic surgery cannot be disregarded. However, the plastic surgery literature still lacks high-level evidence for appropriate means of VTE prophylaxis, although an increasing amount of attention has been paid to the topic. We suggest the development of an international guideline, based on plastic surgical data, using a validated risk assessment model, which combines the surgical risk with the patient-related risk. Determining the proper venous thromboembolism prophylaxis is a clinical decision that should be made on a patient-to-patient basis. The algorithm presented in this article is meant to simplify this complex problem and to help expedite and clarify the decision-making process.

A Review of Current and Future Antithrombotic Strategies in Surgical Patients-Leaving the Graduated Compression Stockings Behind?

Venous thromboembolism (VTE) remains an important consideration within surgery, with recent evidence looking to refine clinical guidance. This review provides a contemporary update of existing clinical evidence for antithrombotic regimens for surgical patients, providing future directions for prophylaxis regimens and research. For moderate to high VTE risk patients, existing evidence supports the use of heparins for prophylaxis. Direct oral anticoagulants (DOACs) have been validated within orthopaedic surgery, although there remain few completed randomised controlled trials in other surgical specialties. Recent trials have also cast doubt on the efficacy of mechanical prophylaxis, especially when adjuvant to pharmacological prophylaxis. Despite the ongoing uncertainty in higher VTE risk patients, there remains a lack of evidence for mechanical prophylaxis in low VTE risk patients, with a recent systematic search failing to identify high-quality evidence. Future research on rigorously developed and validated risk assessment models will allow the better stratification of patients for clinical and academic use. Mechanical prophylaxis’ role in modern practice remains uncertain, requiring high-quality trials to investigate select populations in which it may hold benefit and to explore whether intermittent pneumatic compression is more effective. The validation of DOACs and aspirin in wider specialties may permit pharmacological thromboprophylactic regimens that are easier to administer.

Evaluating post-operative venous thromboembolism risk in urology patients using a validated risk assessment model

BackgroundVenous thromboembolism (VTE) is an important cause of post-surgical morbidity and mortality. This study aimed to apply a validated risk assessment model to evaluate the risk of post-operative VTE in urology patients.MethodsThis prospective descriptive observational study used the Caprini risk assessment model to evaluate VTE risk in patients planned for elective urology surgery at a tertiary Johannesburg hospital from January to June 2020.ResultsTwo hundred and twenty-six patients with a mean age of 52 years were evaluated for post-operative VTE risk. The population was generally overweight, with a mean BMI of 26.3 kg/m2. The mean Caprini score was 4.42, reflecting a population at high risk for post-operative VTE. There was no statistically significant difference between males and females in this regard. On average, participants had three risk factors for post-operative VTE. Fifteen per cent of all patients were at low risk for VTE, while 40.3% of participants were categorised as moderate risk. The category with the highest percentage of participants (44.7%) was the high-risk category (Caprini score ≥ 5). High-risk patients undergoing oncology surgery comprised 16.8% of the population, and these patients may require extended duration pharmacological thromboprophylaxis to prevent VTE. The most clinically significant risk factors for post-operative VTE included age, obesity, malignancy and HIV infection.ConclusionVenous thromboembolism may be difficult to diagnose, and clinicians may underestimate the risk for it to develop. Risk assessment models, such as the Caprini score, are objective and a practical tool to guide the application of thromboprophylaxis. The application of the Caprini RAM in the elective urological surgery population at Chris Hani Baragwanath Academic Hospital yields similar results to studies performed elsewhere on similar surgical populations. Further research is required to evaluate whether the actual incidence of VTE correlates with the risk assessment in this population. Clinician compliance with the use of RAMs as well as the corresponding recommendations for prophylaxis may need to be evaluated. A validated risk assessment model which accounts for procedure-specific risks in urology may be useful.

Clinical Risk Factors Associated with Recurrent Venous Thromboembolism and Major Bleeding in Gastrointestinal Cancer Patients Receiving Doacs for Secondary Thromboprophylaxis

IntroductionCancer associated venous thromboembolism (VTE) is associated with a significant morbidity and mortality burden in cancer care, and anticoagulation offers a survival benefit. Recurrent VTE and major bleeding complications due to secondary prophylaxis remain a salient issue in treating patients with cancer associated-VTE, regardless of validated risk assessment models. Gastrointestinal (GI) cancers confer an increased risk for recurrent VTE and bleeding. We evaluated our current institutional utilization of Direct Oral Anticoagulants (DOACs) in patients with active GI malignancies addressing both efficacy and safety profiles with these agents. We estimated the association strength between each risk factor and the outcomes to further contribute in future risk assessment tools.MethodsThis is a retrospective chart review of patients receiving DOACs with histologically proven GI malignancy and a symptomatic or incidental VTE treated at the University of Arizona Cancer Center from November 2013 to February 2017. Patients were excluded if DOACs were prescribed for any other reason not related to VTE: VTE was determined to be in the context of a non-GI malignancy or when anticoagulation was contraindicated. The primary efficacy outcome was defined as documented recurrent deep vein thrombosis (DVT), nonfatal pulmonary embolism (PE), or fatal PE before and after 6 months of DOAC therapy. The secondary safety outcome was defined as documented major bleeding (hemoglobin reduction of ≥2 g/dL, requirement of transfusion of ≥2 units of Packed Red Blood Cells, bleeding in a critical site, or bleeding contributing to death) before and after 6 months of therapy. Descriptive statistical analyses were utilized. The t- test was performed to compare continuous variables. Fisher exact test is used for testing the difference in categorical variables. Odds ratios were used to compare the relative odds of the occurrence of the outcome given exposure to the risk factor. The 95% confidence interval (CI) was used to estimate the precision of the OR. Results were determined to be ‘statistically significant’ when this value was less than or equal to 0.05.ResultsOur review included 62 patients with balanced baseline characteristics whom were prescribed apixaban (n=28) and rivaroxaban (n=34) [Table 1]. Primary outcome events at 6 months were 4.8% in total (2 DVT & 1 PE); 7.4% (2 DVT) for patients on apixaban and 2.9% (1 PE) for those taking rivaroxaban. Beyond 6 months on DOACs therapy, 6.4% of patients experienced recurrent VTE (1 DVT event in the apixiban subgroup). Secondary outcome events at 6 months were 11.2% total (7 major bleeds), 7.1% (n=2) and 14.7% (n=5) for apixaban and rivaroxaban respectively. There were 2 bleeds contributing to death (hemopericardium and upper GI bleed) and 2 other bleed in critical sites (subarachnoid hemorrhage and retroperitoneal) in the rivaroxaban group, with all other adverse outcomes being upper or lower GI bleeds. Including those events beyond 6 months, 17.7% of patients had recorded bleeding events (2 additional major bleeds for each therapy). Significant predictors of a primary or secondary outcome were pancreatic cancer (OR, 9.6, 95% CI, 1.48 to 62.16, p =0.017), stage IV disease (OR, 15, 95% CI, 7.55 to 297.63, p = 0.0075) and high Khorana Score [≥3] (OR, 7.5, 95% CI, 1.3 to 43.92, p= 0.0238). Those who suffered a primary or secondary outcome were 67 times more likely to die within a month period, compared to those who completed their therapy (CI, 5.33 to 854.82, p = 0.0011).ConclusionsCancer associated VTE remains a challenging clinical scenario with a lack of data for utilization of DOACs in the setting of secondary prophylaxis. The utilization of DOACs in cancer patients provides another therapy for VTE secondary prophylaxis treatment, which must be weighed, based on safety profiles in our study population. The utilization of rivaroxaban led to a higher bleeding rate in patients, with both apixaban and rivaroxaban showing similar efficacy for prophylaxis. This study warrants further exploration of DOACs in the setting of VTE treatment for patients on active chemotherapy who are at high risk of recurrent VTE. In addition, further evaluation of clinical predictors that may influence the risk of VTE recurrence and major bleeding is warranted. Wide confidence intervals reflect of our sample size and future studies may benefit from multi-center participation to maximize sample size. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.