Background:Venous thromboembolism (VTE) includes pulmonary embolism (PE), and deep vein thrombosis (DVT) and is a complication of total hip and knee (THR/TKR) joint replacement surgery. Guidelines historically recommended anticoagulation thromboprophylaxis for patients undergoing elective THR/TKR, and aspirin has emerged as an alternative for select patients. VTE risk stratification may identify patients who can safely receive aspirin. Limited evidence informs how to risk-stratify THR/TKR patients, then recommend risk-stratified thromboprophylaxis. Methods:We derived and implemented "Standardized Thromboembolism Prophylaxis in Orthopedic Patients to prevent Venous ThromboEmbolism (STOP-VTE)," an evidence-based electronic heath record embedded VTE risk assessment model in our 23-hospital-integrated health system. The model classified patients as at high or standard risk of VTE and recommended anticoagulation (mostly apixaban 2.5 mg twice daily for 28 days) or aspirin (81 mg twice daily) prophylaxis, respectively. The primary implementation outcome for this prospective management study was adherence to STOP-VTE guidance, and the primary clinical outcome was VTE. Among 38,207 consecutive patients, we recorded surgeon adherence to STOP-VTE guidance and outcome rates of 90-day VTE, PE, DVT, mortality, and rates of 30-day major bleeding, emergency department visits, and hospitalization. Outcomes were recorded for 2 years preceding implementation of STOP-VTE (baseline) and for 6.8 years after STOP-VTE implementation (intervention). Results:For the primary implementation outcome during the baseline period, 57.4% (1,467/2,554) received aspirin or anticoagulant prophylaxis consistent with risk classification, and during the intervention, this rate increased to 77.8% (27,744/35,653; p < 0.001). Clinical outcome rates at baseline vs. intervention were the following: for 90-day VTE, 0.9% vs. 0.65%; PE, 0.7% vs. 0.39%; DVT, 0.31% vs. 0.29%; and mortality, 0.16% vs. 016%. Thirty-day major bleeding was 0% vs. 0.04%; emergency department and rehospitalization rates were 6.97% vs. 5.31% and 2.45% vs. 1.71%, respectively. Pulmonary embolism, emergency department, and hospitalization visit rates significantly declined. Conclusion:STOP-VTE guidance was implemented and broadly adopted. Adherent chemoprophylaxis was associated with low rates of 90-day VTE, major bleeding, decrease in anticoagulant chemoprophylaxis, increase in aspirin chemoprophylaxis, and cost savings. Level of Evidence:Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Background: While established associations between air pollution and adverse cardiovascular outcomes are known, it remains uncertain whether short-term exposure to air pollution is a risk factor for venous thromboembolism (VTE). The risk of VTE associated with pollution seasonality (summer wildfire season vs winter inversion season) is not understood. Objectives: The aim of this study was to assess for an association between short-term exposure to air pollution and VTE. Methods: We queried the electronic data warehouse of an integrated healthcare system for VTE occurrence from January 1, 2008, to March 31, 2022, at 11 hospitals on Utah’s Wasatch Front. We described air pollution based on small particulate matter (PM2.5) and ozone exposures stratified by day and rolling multiday blocks. We described VTE outcomes in relation to wildfire season (June-October) and inversion season (November-March). We hypothesized that there would be no increased risk of VTE on high PM2.5 days and high ozone days compared with low PM2.5 days and low ozone days. Results: Among 25,083 VTE cases, no significant association was observed between short-term PM2.5 air pollution and VTE. Only lag 2-day ozone exposure was associated with an increased VTE risk (odds ratio [OR], 1.03 per +10 parts per billion; 95% CI, 1.01-1.06; P = .02). During the wildfire season, elevated ozone was associated with an increased odds of VTE at lag 1-day (OR, 1.05; 95% CI, 1.00-1.10; P = .0545), mean 3-day lagged average (OR, 1.06; 95% CI, 1.00-1.13; P = .05), and mean 7-day lagged average (OR, 1.09; 95% CI, 1.01-1.18; P = .037). Conclusion: We found little evidence that short-term air pollution exposure increases VTE risk. However, short-term PM2.5 and short-term ozone exposure may variably confer risk for VTE when stratified by wildfire and inversion seasons.

Background: Venous thromboembolism (VTE) is the third leading cause of preventable hospital-associated (HA) death. Most HA-VTE, including fatal pulmonary emboli, occur among medically ill patients. The rate of symptomatic VTE more than doubles over the first 21 days after hospital discharge. Trials have demonstrated that the burden of HA-VTE may be reduced with postdischarge thromboprophylaxis; however, few patients receive this therapy. We formerly validated the ability of eVTE (eVTE is the abbreviation for a risk assessment tool constituted by 2 calculations: one predicts 90-day VTE and the other predicts 30-day major bleeding derived from only elements of the complete blood count and basic metabolic panel and age) to identify medical patients being discharged with both an elevated risk of VTE and a low risk of bleeding. Objectives: Implement a cluster-randomized, stepped wedge, type II hybrid implementation/effectiveness trial generating an alert among select at-risk patients upon discharge for implementation of thrombosis chemoprophylaxis in a 23-hospital not-for-profit healthcare system. Methods: We use the Reach, Effectiveness, Adoption, Implementation, and Maintenance framework to guide implementation and outcomes reporting. Results: The primary outcome for aim 1 (implementation) is the prescription of rivaroxaban 10 mg daily for 30 days as postdischarge thromboprophylaxis among at-risk patients. The primary efficacy and safety outcomes (effectiveness) are the 90-day composite of symptomatic VTE, myocardial infartcion, nonhemorrhagic stroke, all-cause mortality, and 30-day major bleeding. Conclusion: The eVTE trial will provide high-quality, real-world evidence on the effectiveness and safety of a pragmatic intervention to implement targeted postdischarge thromboprophylaxis using decision support embedded in the electronic health record.

PURPOSE:Report the odds of short-term venous thromboembolism (VTE) risk related to air pollution defined as fine particulate matter (PM 2.5 ) and ozone exposure.METHODS: Air pollution measurement data including PM 2.5 and ozone levels were collected in metropolitan Salt Lake City (Wasatch Front) from fixed monitoring stations between 1 January 2008 and 31 March 2022.VTE events defined as deep vein thrombosis of the legs and pulmonary embolism among ambulatory patients were identified using validated natural language processing interrogation of the Intermountain HealthÒ electronic data repository that includes all patient demographics, laboratory results, and imaging reports from 11 hospitals and about 100 Wasatch Front clinics.A time-stratified case-crossover design matched exposures at the time of an event with $1 period when the event did not occur (referent periods) to estimate any potential excess risk using conditional Poisson regression.Referent periods were matched for day of the week in the same month and year as the event, resulting in up to 3 or 4 control periods per event date, therefore patients served as their own controls.Odds ratios associated with incremental increases in PM 2.5 concentration of each 10 mg/m 3 , and each 10 parts per billion ozone exposure were calculated.The primary outcome was the odds of VTE stratified by air pollution on the day of (D 0), or day before (D -1) the event, and the moving average (mAvg) during the preceding 3 (mAvg D -2-0) and 7 (mAvg D -6-0) days reported monthly, and by 'wildfire' (June-October) and 'inversion' (November-March) seasons. RESULTS:No significant increase in VTE odds existed for PM 2.5 exposure during D 0, D -1, mAvg D -2-0, or mAvg D -6-0 during wildfire or inversion seasons.VTE odds was significantly increased for ozone exposure during mAvg D -2-0 (OR¼1.062;95% CI 1.001-1.127,p¼0.047) and mAvg D -6-0 (OR¼1.090;95% CI 1.006-1.182,p¼0.037) during wildfire season and was reduced (OR¼0.949;95% CI 0.914-0.986;p¼0.007) during D 0 of inversion season.VTE odds calculated by month was not reliably increased for PM 2.5 however VTE odds was significantly increased for ozone exposure during September for mAvg D -2-0 (OR¼ 1.221; 95% CI 1.072-1.389,p¼0.0027) and mAvg D -6-0 (OR¼ 1.209; 95% CI 1.009-1.450,p¼0.041) and was reduced for D 0 (OR¼0.866,95% CI 0.777-0.964,p¼0.009) in November.CONCLUSIONS: Acute exposure to PM 2.5 does not appear to impact the odds of VTE.Exposure to elevated ozone especially during the antecedent 3 and 7 days, during wildfire season (and especially in the month of September), was associated with increased odds of VTE.CLINICAL IMPLICATIONS: Understanding the association of air pollution and VTE risk may heighted the clinical suspicion for VTE disease and inform policymaker efforts to advance air quality initiatives.

Severe acute respiratory distress syndrome coronavirus 2 (SARS-CoV-2) was first identified in December 2019 inWuhan, Hubei, China, to be the agent causing coronavirus disease (COVID19) (1). COVID-19 was officially classified as a pandemic by the World Health Organization onMarch 11, 2020. As of June 2021, theWorld Health Organization reported more than 174 million cases and more than 3.7 million deaths related to COVID-19 worldwide (2). Thrombosis has emerged as a potentially important feature of COVID-19. Abnormal markers of hypercoagulability have been reported, including elevated D-dimer, elevated fibrinogen concentrations, elevated factor VIII concentrations, elevated sepsisinduced coagulopathy scores, and thrombocytopenia (3). Early in the pandemic, multiple inpatient and autopsy studies suggested the possibility of an increased prevalence of venous thromboembolism (VTE) in patients with COVID-19 (4–7). A meta-analysis of VTE among inpatients with COVID-19 suggested an overall incidence of 17%, although comparative data are lacking (8). Multiple studies have identified infection as a risk factor for VTE in patients treated in both the inpatient and outpatient settings (9–11). A prospective study of 113 intensive care unit (ICU) patients determined the prevalence of VTE in ICU patients with sepsis to be 37% (12). Recently, infection was identified as being among the risk factors most predictive of VTE among hospitalized patients (13). Prior reports of VTE incidence in COVID-19 have not included appropriate comparison groups, limiting capacity to infer the presence of a distinctive thrombophilia associated with SARS-CoV-2 infection. In addition, failure to measure and adjust for rates of testing has limited the security of inferences regarding the incidence of VTE in COVID-19. The uncertainties regarding optimal clinical management and infection control, especially early in the pandemic, likely affected rates of clinical testing, thus underestimating the true incidence of VTE. To address these knowledge gaps, we compared the incidence of VTE among inpatients with COVID-19 with the incidence of VTE among patients with community-acquired pneumonia (CAP) admitted to the same hospitals. We also compared rates of testing for VTE among patients with COVID-19 and patients with CAP.

Objective To derive and validate a D-dimer cutoff for ruling out pulmonary embolism (PE) in COVID-19 patients presenting to the emergency department (ED). Methods A retrospective cohort study was performed in an integrated healthcare system including 22 adult ED's between March 1, 2020, and January 31, 2021. Results were validated among patients enrolled in the RECOVER Registry, representing data from 154 ED's from 26 US states. Consecutive ED patients with laboratory confirmed COVID-19, a D-dimer performed within 48 h of ED arrival, and with objectively confirmed PE were compared to those without PE. After identifying a D-dimer threshold at which the 95% confidence lower bound of the negative predictive value for PE was higher than 98% in the derivation cohort, it was validated using RECOVER registry data. Results Among 3978 patients with a D-dimer result, 3583 with confirmed COVID-19 infection were included in the derivation cohort. Overall, PE incidence was 4.1% and a D-dimer cutoff of <2 μ/mL (2000 ng/mL) was associated with a NPV of 98.5% (95% CI = 98.0%−98.9%). In the validation cohort of 13,091 patients with a D-dimer, 7748 had confirmed COVID-19 infection, and the PE incidence was 1.14%. A D-dimer cutoff of <2 μ/mL was associated with a NPV of 99.5% (95% CI = 99.3%−99.7%). Conclusion A D-dimer cutoff of <2 μ/ml was associated with a high negative predictive value for PE among patients with COVID-19. However, the resultant sensitivity for PE result at that threshold without pre-test probability assessment would be considered clinically unsafe.

Background:Structured reporting is an efficient and replicable method of presenting diagnostic results that eliminates variability inherent in narrative descriptive reporting and may improve clinical decisions. Synoptic element reporting can generate discrete coded data that then may inform clinical decision support and trigger downstream actions in computerized electronic health records. Objective:Limited evidence exists for use of synoptic reporting for computed tomography pulmonary arteriography (CTPA) among patients suspected of pulmonary embolism. We reported the accuracy of synoptic reporting for the outcome of pulmonary embolism among patients who presented to an integrated health care system with CTPA performed for suspected pulmonary embolism. Methods:Structured radiology reports with embedded synoptic elements were implemented for all CTPA examinations on March 1, 2018. Four hundred CTPA reports between January 4, 2019 and July 30, 2020 (200 reports each for which synoptic reporting recorded the presence or absence of pulmonary embolism [PE]) were selected at random. One non-diagnostic study was excluded from analysis. We then assessed the accuracy of synoptic reporting compared with the gold standard of manual chart review. Results:Synoptic reporting and manual review agreed in 99.2% of patients undergoing CTPA for suspected PE, agreed on the presence of PE in 196 of 199 (98.5%) cases, the absence of PE in 200 of 200 (100%) cases with a sensitivity of 87.6% (76.1-96.1) a specificity of 99.9% (99.7%-100%), a positive predictive value of 99.5% (98.1-100), and a negative predictive value of 98% (95.7%-99.5%). Conclusion:The overall rate of agreement was 99.2%, but we observed an unacceptable false-negative rate for clinical reliance on synoptic element reporting in isolation from dictated reports.

Background:Venous thromboembolism (VTE) risk is increased in patients with COVID-19 infection. Understanding which patients are likely to develop VTE may inform pharmacologic VTE prophylaxis decision making. The hospital-associated venous thromboembolism-Intermountain Risk Score (HA-VTE IMRS) and the hospital-associated major bleeding-Intermountain Risk Score (HA-MB IMRS) are risk scores predictive of VTE and bleeding that were derived from only patient age and data found in the complete blood count (CBC) and basic metabolic panel (BMP). Objectives:We assessed the HA-VTE IMRS and HA-MB IMRS for predictiveness of 90-day VTE and major bleeding, respectively, among patients diagnosed with COVID-19, and further investigated if adding D-dimer improved these predictions. We also reported 30-day outcomes. Patients/Methods:We identified 5047 sequential patients with a laboratory confirmed diagnosis of COVID-19 and a CBC and BMP between 2 days before and 7 days following the diagnosis of COVID-19 from March 12, 2020, to February 28, 2021. We calculated the HA-VTE IMRS and the HA-MB IMRS for all patients. We assessed the added predictiveness of D-dimer obtained within 48 hours of the COVID test. Results:The HA-VTE IMRS yielded a c-statistic of 0.70 for predicting 90-day VTE and adding D-dimer improved the c-statistic to 0.764 with the corollary sensitivity/specificity/positive/negative predictive values of 49.4%/75.7%/6.7%/97.7% and 58.8%/76.2%/10.9%/97.4%, respectively. Among hospitalized and ambulatory patients separately, the HA-VTE IMRS performed similarly. The HA-MB IMRS predictiveness for 90-day major bleeding yielded a c-statistic of 0.64. Conclusion:The HA-VTE IMRS and HA-MB IMRS predict 90- and 30-day VTE and major bleeding among COVID-19 patients. Adding D-dimer improved the predictiveness of the HA-VTE IMRS for VTE.

Introduction: Health, wellness, and healthcare are most effectively and efficiently managed when health status is quantitatively measured. The Intermountain Mortality Risk Score (IMRS) is a well-validated low-cost decision tool calculated from the complete blood count and basic metabolic profile that can be electronically deployed to inform clinician or patient actions. This study evaluated if 3 serial IMRS measurements improved mortality prediction. Methods: In 119,379 Intermountain Healthcare outpatients, inpatients, and emergency patients, baseline (BL) IMRS was calculated in 1999-2005. Of those, the following were excluded: 22,678 who died prior to having 3 IMRS measurements and 38,228 survivors who at 5 years (y) post-BL did not have 3 IMRS. In the study cohort of 58,473 patients, a 1 st follow-up (1F) IMRS was available 1.49±0.79 y post-BL (range 1-4 y), and a 2 nd follow-up (2F) IMRS at 3.75±0.80 y post-BL (range 2-5 y). Patients had 13.4±1.7 y of follow-up after 2F (range: 9.3-18.7 y), with total follow-up post-BL of 17.2±1.5 y (range: 14.3-20.7 y). Results: Overall, 26,693 patients died (45.7%) after 2F. In females, IMRS for decedents vs. survivors was, respectively, 11.3±3.9 vs 6.3±4.0 at BL, 11.1±3.9 vs 5.7±4.0 at 1F, and 12.2±4.2 vs 6.1±4.0 at 2F; differences in males were similar to those results (all p<0.001). Relative risks for IMRS categories are shown in the Table. C-statistics for females were c= 0.815, 0.834, 0.858 for BL, 1F, and 2F, with 0.872 for a sum of the 3 IMRS (results were similar for males, with absolute c 0.06-0.08 lower). Conclusions: IMRS predicted substantial risk differences at each of 3 timepoints, but the IMRS trajectory (including declines in IMRS) revealed by the sequence of IMRS measurements better personalized risk assessment. When risk level and direction are considered together, critical junctures in a person’s health journey may be revealed, empowering earlier or more intensive prevention, diagnostic testing, and interventions.

Thrombotic antiphospholipid syndrome (TAPS) is characterized by venous, arterial, or microvascular thrombosis. Patients with TAPS merit indefinite anticoagulation, and warfarin has historically been the standard treatment. Apixaban is an oral factor Xa inhibitor anticoagulant that requires no dose adjustment or monitoring. The efficacy and safety of apixaban compared with warfarin for TAPS patients remain unknown. This multicenter prospective randomized open-label blinded endpoint study assigned anticoagulated TAPS patients to apixaban or warfarin (target international normalized ratio 2-3) for 12 months. The primary efficacy outcome was clinically overt thrombosis and vascular death. Apixaban was first given at 2.5 mg twice daily. Two protocol changes were instituted based on recommendations from the data safety monitoring board. After the twenty-fifth patient was randomized, the apixaban dose was increased to 5 mg twice daily, and after the thirtieth patient was randomized, subjects with prior arterial thrombosis were excluded. Primary outcomes were adjudicated by independent experts blinded to treatment allocation. Patients randomized between 23 February 2015 and 7 March 2019 to apixaban (n = 23) or warfarin (n = 25) were similar. Among the components of the primary efficacy outcome, only stroke occurred in 6 of 23 patients randomized to apixaban compared with 0 of 25 patients randomized to warfarin. The study ended prematurely after the forty-eighth patient was enrolled. Conclusions from our study are limited due to protocol modifications and low patient accrual. Despite these limitations, our results suggest that apixaban may not be routinely substituted for warfarin to prevent recurrent thrombosis (especially strokes) among patients with TAPS. This trial was registered at www.clinicaltrials.gov as #NCT02295475.

Abstract Objective Multiple professional societies recommend pre‐test probability (PTP) assessment prior to imaging in the evaluation of patients with suspected pulmonary embolism (PE), however, PTP testing remains uncommon, with imaging occurring frequently and rates of confirmed PE remaining low. The goal of this study was to assess the impact of a clinical decision support tool embedded into the electronic health record to improve the diagnostic yield of computerized tomography pulmonary angiography (CTPA) in suspected patients with PE in the emergency department (ED). Methods Between July 24, 2014 and December 31, 2016, 4 hospitals from a healthcare system embedded an optional electronic clinical decision support system to assist in the diagnosis of pulmonary embolism (ePE). This system employs the Pulmonary Embolism Rule‐out Criteria (PERC) and revised Geneva Score (RGS) in series prior to CT imaging. We compared the diagnostic yield of CTPA) among patients for whom the physician opted to use ePE versus the diagnostic yield of CTPA when ePE was not used. Results During the 2.5‐year study period, 37,288 adult patients were eligible and included for study evaluation. Of eligible patients, 1949 of 37,288 (5.2%) were enrolled by activation of the tool. A total of 16,526 CTPAs were performed system‐wide. When ePE was not engaged, CTPA was positive for PE in 1556 of 15,546 scans for a positive yield of 10.0%. When ePE was used, CTPA identified PE in 211 of 980 scans (21.5% yield) (P < 0.001). Conclusions ePE significantly increased the diagnostic yield of CTPA without missing 30‐day clinically overt PE.

Background: Some hospitalized medical patients experience venous thromboembolism (VTE) following discharge. Prophylaxis extended beyond hospital discharge (extended duration thromboprophylaxis [EDT]) may reduce this risk. However, EDT is costly and can cause bleeding, so selecting appropriate patients is essential. We formerly reported the performance of a mortality risk prediction score (Intermountain Risk Score [IMRS]) that was minimally predictive of 90-day hospital-associated venous thromboembolism (HA-VIE) and major bleeding (HA-MB). We used the components of the IMRS to calculate de novo risk scores to predict 90-day HA-VTE (HA-VTE IMRS) and major bleeding (HA-MB IMRS). Methods: From 45 669 medical patients we randomly assigned 30 445 to derive the HA-VTE IMRS and the HA-MB IMRS. Backward stepwise regression and bootstrapping identified predictor covariates from the blood count and basic chemistry. These candidate variables were split into quintiles, and the referent quintile was that with the lowest event rate for HA-VTE and HA-MB; respectively. A clinically relevant rate of HA-VTE and HA-MB was used to inform outcome rates. Performance was assessed in the derivation set of 15 224 patients. Results: The HA-VTE IMRS and HA-MB IMRS area under the receiver operating curve (AUC) in the derivation set were 0.646, and 0.691, respectively. In the validation set, the HA-VIE IMRS and HA-MB IMRS AUCs were 0.60 and 0.643. Conclusions: Risk scores derived from components of routine labs ubiquitous in clinical care identify patients that are at risk for 90-day postdischarge HA-VTE and major bleeding. This may identify a subset of patients with high HA-VTE risk and low HA-MB risk who may benefit from EDT.

BACKGROUND:Although guidelines are established for the prevention and management of venous thromboembolism (VTE) in trauma, no consensus exists regarding protocols for the diagnostic approach. We hypothesized that at-risk trauma patients who undergo duplex ultrasound (DUS) surveillance for lower extremity deep venous thrombosis (DVT) will have a lower rate of symptomatic or fatal pulmonary embolism (PE) than those who do not undergo routine surveillance.METHODS:Prospective, randomized trial between March 2017 and September 2019 of trauma patients admitted to a single, level 1 trauma center, with a risk assessment profile score of ≥5. Patients were randomized to receive either bilateral lower extremity DUS surveillance on days 1, 3, and 7 and weekly during hospitalization ultrasound group (US) or no surveillance no ultrasound group (NoUS). Rates of in-hospital and 90-day DVT and PE were reported as was DVT propagation and all-cause mortality. Standard care for the prevention and management of VTE per established institutional protocols was provided to all patients.RESULTS:A total of 3,236 trauma service admissions were screened, and 1,989 moderate- and high-risk patients were randomized (US, 995; NoUS, 994). The mean ± SD age was 62 ± 20.1 years, Injury Severity Score was 14 ± 9.7, risk assessment profile was 7.1 ± 2.4, and 97% suffered blunt trauma. There was no difference in demographics or VTE risk factors between the groups. There were significantly fewer in-hospital PE in the US group than the NoUS group (1 [0.1%] vs. 9 [0.9%], p = 0.01). The US group experienced more in-hospital below-knee DVTs (124 [12.5%] vs. 8 [0.8%], p < 0.001) and above-knee DVTs (19 [1.9%] vs. 8 [0.8%], p = 0.05). There was no difference in 90-day PE or DVT, or overall mortality.CONCLUSION:The implementation of a selective routine DUS protocol was associated with significantly fewer in-hospital PE. More DVTs were identified with routine screening; however, surveillance bias appears to exist primarily with distal DVT. Larger trials are needed to further characterize the relationship between routine DUS screening and VTE outcomes in the high-risk trauma population.LEVEL OF EVIDENCE:Therapeutic/care management, level II.

Background The efficacy and safety of managing patients with low-risk pulmonary embolism (PE) without hospitalization requires objective data from US medical centers. We sought to determine the 90-day composite rate of recurrent symptomatic VTE, major bleeding events, and all-cause mortality among consecutive patients diagnosed with acute low-risk PE managed without inpatient hospitalization; and to measure patient satisfaction. Methods We performed a prospective cohort single-arm management study conducted from January 2013 to October 2016 in five EDs. We enrolled 200 consecutive adults diagnosed with objectively confirmed acute PE and assessed to have a low risk for mortality using the Pulmonary Embolism Severity Index (PESI) score (< 86), echocardiography, and whole-leg compression ultrasound (CUS). The primary intervention was observation in the ED or hospital (observation status) for > 12 to < 24 h, followed by outpatient management with Food and Drug Administration-approved therapeutic anticoagulation. Patients were excluded for a PESI ≥ 86, echocardiographic signs of right heart strain, DVT proximal to the popliteal vein, hypoxia, hypotension, hepatic or renal failure, contraindication to therapeutic anticoagulation, or another condition requiring hospital admission. The primary outcome was 90-day composite rate of all-cause mortality, recurrent symptomatic VTE, and major bleeding. Results The composite outcome occurred in one of 200 patients (90-day composite rate = 0.5%; 95% CI, 0.02%-2.36%). No patient suffered recurrent VTE or died during the 90-day follow-up period. A major bleed occurred in one patient. Patients indicated a high level of satisfaction with their care. Conclusions Treatment of carefully selected patients with acute PE and low risk by PESI < 86, echocardiography, and CUS without inpatient hospitalization is safe and acceptable to patients. Results must be viewed with caution because of the small sample size relative to the end point and the generalizability surrounding availability of emergent echocardiography. Trial Registry ClinicalTrials.gov; No.: NCT02355548; URL: www.clinicaltrials.gov

Discharged medical patients are at risk for venous thromboembolism (VTE). It is difficult to identify which discharged patients would benefit from extended duration thromboprophylaxis. The Intermountain Risk Score is a prediction score derived from discrete components of the complete blood cell count and basic metabolic panel and is highly predictive of 1‐year mortality. We sought to ascertain if the Intermountain Risk Score might also be predictive of 90‐day postdischarge hospital‐associated VTE (HA‐VTE).

SESSION TITLE: Late-breaking Abstracts SESSION TYPE: Original Investigations PRESENTED ON: October 18-21, 2020 PURPOSE: Identify hospitalized medical patients who at discharge have significant risk for hospital-associated venous thromboembolism (HA-VTE) or major bleeding (HA-MB) to inform extended-duration thromboprophylaxis (EDT) decision-making. METHODS: The Intermountain risk score (IMRS) is a highly predictive mortality risk estimation tool derived from components of the complete blood count (CBC) and basic metabolic panel (BMP). While minimally predictive for the outcome of 90-day HA-VTE [Snyder,L 2020] we hypothesized that IMRS components from the CBC and BMP could be re-weighted to be more predictive of HA-VTE and major bleeding (“HA-VTE IMRS” & “HA-MB IMRS”). To do so, a dataset of 45,669 medical patients who survived hospitalization in which 1038 (1.6%) VTE and 611 (1.3%) major bleeding events were recorded (as determined using validated natural language processing in EMR interrogation [Evans,RS 2010]) was split into a derivation (2/3) and validation (1/3) cohort. In the derivation set the CBC and BMP candidate variables were split into quintiles, and the referent quintile was determined as that with the lowest event rate. Backward stepwise regression in 500 bootstrapped samples was performed to identify predictors from the BMP and CBC candidate variables. A Cox model was fit in the derivation dataset with the variables included in 80%, 70%, 60%, and 50% of bootstrapped samples; these models were compared using likelihood ratio tests to determine if the additional variables included at each threshold significantly improved model fit. Coefficients from the Cox model were used to assign weights for the quintiles to generate the HA-VTE IMRS and HA-MB IMRS cutoff thresholds. Covariates selected for the final VTE model were: RDW, BUN, age, glucose, WBC, platelet count, RBC and sodium. Covariates selected for the final major bleeding model were: RDW, age, creatinine, MPV, Sodium, and RBC. RESULTS: In the derivation set 563/30,445 patients experienced HA-VTE and 399/30,445 experienced HA-MB. The HA-VTE IMRS ≥ 7 generated an AUC=0.603 and the HA-MB IMRS ≥ 8 generated an AUC=0.624. In the validation set 137/5242 had VTE in the HA-VTE IMRS ≥ 7 cohort vs. 160/9982 with a HA-VTE IMRS < 7 (2.6% vs 1.6%; HR=1.69; 95% CI 1.35-2.13; AUC=0.60). 135/7101 had MB in the HA-MB IMRS ≥ 8 cohort vs. 67/8123 with a HA-MB IMRS < 8 (1.9% vs. 0.8%; HR=2.35; 95% CI 1.75-3.16; AUC=0.64). CONCLUSIONS: HA-VTE and HA-MB risk may be estimated electronically at the time of hospital discharge based on components of the CBC and BMP. This information may inform decision-making regarding the prescription of EDT. CLINICAL IMPLICATIONS: If validated, this electronic program may be deployed in an EMR to calculate 90-day HA-VTE risk at the time of discharge with no additional time or expense based on laboratory values that are ubiquitously available and could inform decision-making regarding extended duration thromboprophylaxis for medical patients. DISCLOSURES: Consultant relationship with BD Please note: $5001 - $20000 Added 07/17/2020 by Joseph Bledsoe, source=Web Response, value=Consulting fee No relevant relationships by masarret fazili, source=Web Response PI of research grant relationship with AstraZeneca Please note: $20001 - $100000 Added 07/17/2020 by Benjamin Horne, source=Web Response, value=Grant/Research Support PI of research grant relationship with GlaxoSmithKline Please note: $1-$1000 Added 07/17/2020 by Benjamin Horne, source=Web Response, value=Grant/Research Support PI of research grant relationship with CareCentra Please note: $1-$1000 Added 07/17/2020 by Benjamin Horne, source=Web Response, value=Grant/Research Support Owner of intellectual property relationship with Alluceo Please note: $1-$1000 Added 07/17/2020 by Benjamin Horne, source=Web Response, value=IP was licensed Owner of intellectual property relationship with CareCentra Please note: $1-$1000 Added 07/17/2020 by Benjamin Horne, source=Web Response, value=IP was licensed No relevant relationships by James Lloyd, source=Web Response No relevant relationships by Gregory Snow, source=Web Response Research contract (no longer active) relationship with BMS/Pfizer Please note: $1-$1000 Added 07/17/2020 by Scott Stevens, source=Web Response, value=Grant/Research Support No relevant relationships by Scott Woller, source=Web Response

OBJECTIVE:Using augmented intelligence clinical decision tools and a risk score-guided multidisciplinary team-based care process (MTCP), this study evaluated the MTCP for heart failure (HF) patients' 30-day readmission and 30-day mortality across 20 Intermountain Healthcare hospitals. BACKGROUND:HF inpatient care and 30-day post-discharge management require quality improvement to impact patient health, optimize utilization, and avoid readmissions. METHODS:HF inpatients (N = 6182) were studied from January 2013 to November 2016. In February 2014, patients began receiving care via the MTCP based on a phased implementation in which the 8 largest Intermountain hospitals (accounting for 89.8% of HF inpatients) were crossed over sequentially in a stepped manner from control to MTCP over 2.5 years. After implementation, patient risk scores were calculated within 24 hours of admission and delivered electronically to clinicians. High-risk patients received MTCP care (n = 1221), while lower-risk patients received standard HF care (n = 1220). Controls had their readmission and mortality scores calculated retrospectively (high risk: n = 1791; lower risk: n = 1950). RESULTS:High-risk MTCP recipients had 21% lower 30-day readmission compared to high-risk controls (adjusted P = .013, HR = 0.79, CI = 0.66, 0.95) and 52% lower 30-day mortality (adjusted P < .001, HR = 0.48, CI = 0.33, 0.69). Lower-risk patients did not experience increased readmission (adjusted HR = 0.88, P = .19) or mortality (adjusted HR = 0.88, P = .61). Some utilization was higher, such as prescription of home health, for MTCP recipients, with no changes in length of stay or overall costs. CONCLUSIONS:A risk score-guided MTCP was associated with lower 30-day readmission and 30-day mortality in high-risk HF inpatients. Further evaluation of this clinical management approach is required.

BACKGROUND:Upper extremity deep vein thrombosis (UEDVT) constitutes approximately 10% of all deep vein thromboses (DVTs). The incidence of UEDVT is increasing in association with use of peripherally inserted central venous catheters. Treatment for UEDVT is derived largely from evidence for treatment of lower extremity DVT. Limited evidence exists for the use of a direct oral anticoagulant for the treatment of UEDVT. POPULATION:Sequential patients identified within the Intermountain Healthcare System and University of Utah Healthcare system with symptomatic UEDVT defined as the formation of thrombus within the internal jugular, subclavian, axillary, brachial, ulnar, or radial veins of the arm. INTERVENTION:Apixaban 10 mg PO twice daily for 7 days followed by apixaban 5 mg twice daily for 11 weeks. COMPARISON:The historical literature review rate of venous thrombosis reported for recurrent clinically overt objective venous thromboembolism (VTE) and VTE-related death. If the confidence interval for the observed rate excludes the threshold event rate of 4%, we will conclude that treatment with apixaban is noninferior and therefore a clinically valid approach to treat UEDVT. SAMPLE SIZE:We elected a sample size of 375 patients so that an exact 95% confidence interval would exclude an event rate of VTE in the observation cohort of 4%. OUTCOME:Ninety-day rate of new or recurrent objectively confirmed symptomatic venous thrombosis and VTE-related death. The primary safety outcome is the composite of major and clinically relevant nonmajor bleeding.

BACKGROUND:Guidelines suggest anticoagulation of patients with high pretest probability of pulmonary embolism (PE) while awaiting diagnostic test results (preemptive anticoagulation). Data relevant to the practice of preemptive anticoagulation are not available.METHODS:We reviewed 3,500 consecutive patients who underwent CT pulmonary angiography (CTPA) at two EDs. We classified the pretest probability for PE using the revised Geneva Score (RGS) as low (RGS 0-3), intermediate (RGS 4-10), or high (RGS 11-18). We classified patients with a high pretest probability of PE as receiving preemptive anticoagulation if therapeutic anticoagulation was given before CTPA completion. Patients with a high bleeding risk and those receiving treatment for DVT before CTPA were excluded from the preemptive anticoagulation analysis. We compared the time elapsed between ED registration and CTPA completion for patients with a low, intermediate, and high pretest probability for PE.RESULTS:We excluded three of 3,500 patients because CTPA preceded ED registration. Of the remaining 3,497 patients, 167 (4.8%) had a high pretest probability for PE. After excluding 29 patients for high bleeding risk and 21 patients who were treated for DVT prior to CTPA, only two of 117 patients (1.7%) with a high pretest probability for PE received preemptive anticoagulation. Furthermore, 37 of the remaining 115 patients (32%) with a high pretest probability for PE had a preexisting indication for anticoagulation but did not receive preemptive anticoagulation. The time from ED registration to CTPA completion did not differ based on the pretest probability of PE.CONCLUSIONS:Physicians rarely use preemptive anticoagulation in patients with a high pretest probability for PE. Clinicians do not expedite CTPA examinations for patients with a high pretest probability for PE.