Outpatient Management of Emergency Department Patients With Acute Pulmonary Embolism: Variation, Patient Characteristics, and Outcomes

Selection of Home Treatment and Identification of Low-Risk Patients With Pulmonary Embolism Based on Simplified Pulmonary Embolism Severity Index Score in the Era of Direct Oral Anticoagulants

BACKGROUND

The simplified Pulmonary Embolism Severity Index (sPESI) score could help identify low-risk patients with pulmonary embolism for home treatment. However, the application of the sPESI score and selection for home treatment have not been fully evaluated in the direct oral anticoagulants era.

METHODS AND RESULTS

The COMMAND VTE (Contemporary Management and Outcomes in Patients With Venous Thromboembolism) Registry-2 is a multicenter registry enrolling consecutive patients with acute symptomatic venous thromboembolism. The current study population consists of 2496 patients with hemodynamically stable pulmonary embolism (2100 patients [84%] treated with direct oral anticoagulants), who were divided into 2 groups: sPESI scores of 0 and ≥1. We investigated the 30-day mortality, home treatment prevalence, and factors predisposing to home treatment using the Kaplan-Meier method and logistic regression model. Patients with an sPESI score of 0 accounted for 612 (25%) patients, and only 17% among 532 patients with out-of-hospital pulmonary embolism were treated at home. The cumulative 30-day mortality was lower in patients with an sPESI score of 0 than the score of ≥1 (0% and 4.8%, log-rank P<0.001). There was no patient with 30-day mortality with an sPESI score of 0. Independent factors for home treatment among out-of-hospital pulmonary embolism patients with an sPESI score of 0 were no transient risk factors for venous thromboembolism, no cardiac biomarker elevation, and direct oral anticoagulants use in the acute phase.

CONCLUSIONS

The 30-day mortality rate was notably low in an sPESI score of 0. Nevertheless, only a minority of patients with an sPESI score of 0 were treated at home between 2015 and 2020 after the introduction of direct oral anticoagulants for venous thromboembolismin Japan.

Implementation of a transition of care pathway for low-risk patients presenting to the emergency department with venous thromboembolism

Inpatient management of low-risk patients with venous thromboembolism (VTE) places a large resource burden on the healthcare system. Adult patients diagnosed with deep vein thrombosis (DVT) or pulmonary embolism (PE) in the emergency department (ED) have historically been hospitalized and treated with therapeutic anticoagulation. However, over the last two decades, outpatient treatment of patients with acute DVT and low risk PE has become increasingly accepted as an effective and safe option for patients given the low risk of short-term clinical deterioration. The purpose of this project was to establish a transition of care (TCM) program for patients with acute VTE presenting to the ED. The primary goals for the project included better quality patient follow-up in the Vascular Medicine Nurse Practitioner (NP) within one week and medication adherence. The second goal was increasing appropriate ED discharges for patients with low-risk VTE. Outcome metrics include the rate of early discharge of low-risk patients with VTE, follow-up in the Vascular Medicine NP clinic, and anticoagulant adherence.

Choice and Duration of Anticoagulation for Venous Thromboembolism

Venous thromboembolism (VTE) is a prevalent medical condition with high morbidity, mortality, and associated costs. Anticoagulation remains the main treatment for VTE, though the decision on when, how, and for how long to administer anticoagulants is increasingly complex. This review highlights the different phases of VTE management, with special circumstances for consideration such as antiphospholipid syndrome, coronary artery disease, cancer-associated thrombus, COVID-19, and future anticoagulation options. Anticoagulation management will continue to be a complex decision, applying evidence-based medicine to individual patients with the hope of maximizing effectiveness while minimizing risks.

Early discharge and home treatment of patients with acute pulmonary embolism in the tertiary care setting

Acute pulmonary embolism (PE) is a potentially life-threatening disease. Current guidelines suggest risk-adapted management. Hospitalization is required for intermediate- and high-risk patients. Early discharge and home treatment are considered safe in the majority of low-risk patients. In this study, we describe characteristics, discharge, and outcome of outpatients diagnosed with acute PE at a tertiary care center. All outpatients undergoing computed tomography pulmonary angiography or ventilation/perfusion lung scan between 01.01.2016 and 31.12.2019 at the University Hospital Vienna, Austria, were screened for a PE diagnosis. Electronic patient charts were used to extract characteristics, clinical course, and outcomes. Within the 4-year period, 709 outpatients (median age: 62 years, 50% women) were diagnosed with PE. Thirty-three (5%) patients were classified as high-risk, 159 (22%) as intermediate-high, 332 (47%) as intermediate-low, and 185 (26%) as low-risk PE according to the European Society of Cardiology risk stratification. In total, 156 (22%) patients (47% with low-risk and 20% with intermediate-low-risk PE) were discharged as outpatients and received home treatment. Rates for home treatment increased 2.4-fold during the study period. Thirty-day mortality in the entire population was 4.9%. All low-risk patients and all but one patient with home treatment survived the first 30 days. Home treatment significantly increased over time and seems to be safe in routine clinical practice. Notably, one in five intermediate-low-risk patients was discharged immediately, suggesting that a subpopulation of intermediate-low-risk patients may also be eligible for home treatment.

Disposition of emergency department patients with acute pulmonary embolism after ambulance arrival

Objective

Most outpatients with pulmonary embolism (PE) are diagnosed in the emergency department (ED). The relationship between means of arrival, site of diagnosis, and disposition in ED patients with PE is unknown. We compared discharge home between patients arriving by emergency medical services (EMS) and those arriving by other means. Within the EMS cohort, we compared those with a recent PE diagnosis in the outpatient clinic setting to those who were diagnosed with PE in the ED.

Methods

This study was a secondary analysis of a retrospective cohort that included all adult, non-pregnant ED patients treated for acute PE across 21 community EDs from January 2013 to April 2015. The primary outcome was discharge home within 24 h of ED registration; we also examined mortality. We described associations with patient arrival method and other patient characteristics.

Results

Among 2996 ED patient encounters with acute PE, 644 (21.5%) arrived by EMS. This group had a lower frequency of discharge (9.2% vs 26.4%) and higher 30-day all-cause mortality (8.7% vs 3.1%) than their counterparts (p < 0.001 for both). These associations remained after adjusting for confounding variables. Among the EMS cohort, 14 patients (2.2%) arrived with a PE diagnosis recently made in the outpatient setting.

Conclusion

Patients with PE who arrived at the ED by EMS were less likely to be discharged home within 24 h and more likely to die within 30 days than those who arrived by other means. Less than 3% of the EMS group had been diagnosed with PE before ED arrival.

Impact of an Institutional Clinical Pathway on Emergency Physicians' Stated Preferences in Treating Patients with Low-Risk Pulmonary Embolism

BACKGROUND

Evidence continues to accumulate that select patients with acute low-risk pulmonary embolism (PE) can be safely discharged from the emergency department. Despite this, outpatient management continues to be uncommon. We report changes in emergency providers' stated preferences on low-risk acute PE management before and after the development and implementation of an institutional clinical pathway and decision tool.

METHODS

We performed an observational analysis of attending emergency physicians' stated preferences towards the management of low-risk acute PE using survey results before and after the development and implementation of an electronic health record-embedded institutional low-risk acute PE pathway.

RESULTS

Attending emergency medicine providers reported feeling more comfortable using PE risk stratification scores to identify dischargeable low-risk PE patients and also reported that they would be more likely to discharge a hypothetical patient with low-risk acute PE.

CONCLUSION

Our results suggest that the implementation of an institutional clinical pathway with integration into the electronic health record was associated with a change in emergency physicians' stated preferences for managing patients with acute low-risk PE in the emergency department. Implementation of an evidence-based standard pathway was associated with increased comfort and familiarity with PE risk stratification, and an increased comfort with and preference for early outpatient management of low-risk PE.

Bilateral Emboli and Highest Heart Rate Predict Hospitalization of Emergency Department Patients With Acute, Low-Risk Pulmonary Embolism

STUDY OBJECTIVE

Some patients with acute pulmonary embolism (PE) will suffer adverse clinical outcomes despite being low risk by clinical decision rules. Emergency physician decisionmaking processes regarding which low-risk patients require hospitalization are unclear. Higher heart rate (HR) or embolic burden may increase short-term mortality risk, and we hypothesized that these variables would be associated with an increased likelihood of hospitalization for patients designated as low risk by the PE Severity Index.

METHODS

This was a retrospective cohort study of 461 adult emergency department (ED) patients with a PE Severity Index score of fewer than 86 points. Primary exposures were the highest observed ED HR, most proximal embolus location (proximal vs distal), and embolism laterality (bilateral vs unilateral PE). The primary outcome was hospitalization.

RESULTS

Of 461 patients meeting inclusion criteria, most (57.5%) were hospitalized, 2 patients (0.4%) died within 30 days, and 142 (30.8%) patients were at elevated risk by other criteria (Hestia criteria or biochemical/radiographic right ventricular dysfunction). Variablesassociated with an increased likelihood of admission were highest observed ED HR of ≥110 beats/minute (vs HR <90 beats/min) (adjusted odds ratio [aOR] 3.11; 95% confidence interval [CI] 1.07 to 9.57), highest ED HR 90 to 109 (aOR 2.03; 95% CI 1.18-3.50) and bilateral PE (aOR 1.92; 95% CI 1.13 to 3.27). Proximal embolus location was not associated with the likelihood of hospitalization (aOR 1.19; 95% CI 0.71 to 2.00).

CONCLUSIONS

Most patients were hospitalized, often with recognizable high-risk characteristics not accounted for by the PE Severity Index. Highest ED HR of ≥90 beats/min and bilateral PE were associated with a physician's decision for hospitalization.

Quality of life 1 month after acute pulmonary embolism in emergency department patients

OBJECTIVE

The Pulmonary Embolism Quality-of-Life (PEmb-QoL) questionnaire assesses quality of life (QoL) after pulmonary embolism (PE). We aimed to determine whether any clinical or pathophysiologic features of PE were associated with worse PEmb-QoL scores 1 month after PE.

METHODS

In this prospective multicenter registry, we conducted PEmb-QoL questionnaires. We determined differences in QoL domain scores for four primary variables: clinical deterioration (death, cardiac arrest, respiratory failure, hypotension requiring fluid bolus, catecholamine support, or new dysrhythmia), right ventricular dysfunction (RVD), PE risk stratification, and subsequent rehospitalization. For overall QoL score, we fit a multivariable regression model that included these four primary variables as independent variables.

RESULTS

Of 788 PE patients participating in QoL assessments, 156 (19.8%) had a clinical deterioration event, 236 (30.7%) had RVD of which 38 (16.1%) had escalated interventions. For those without and with clinical deterioration, social limitations had mean (±SD) scores of 2.07 (±1.27) and 2.36 (±1.47), respectively (p = 0.027). For intensity of complaints, mean (±SD) scores for patients without RVD (4.32 ± 2.69) were significantly higher than for those with RVD with or without reperfusion interventions (3.82 ± 1.81 and 3.83 ± 2.11, respectively; p = 0.043). There were no domain score differences between PE risk stratification groups. All domain scores were worse for patients with rehospitalization versus without. By multivariable analysis, worse total PEmb-QoL scores with effect sizes were subsequent rehospitalization 11.29 (6.68-15.89), chronic obstructive pulmonary disease (COPD) 8.17 (3.91-12.43), and longer index hospital length of stay 0.06 (0.03-0.08).

CONCLUSIONS

Acute clinical deterioration, RVD, and PE severity were not predictors of QoL at 1 month post-PE. Independent predictors of worsened QoL were rehospitalization, COPD, and index hospital length of stay.

Clinical decision support to Optimize Care of patients with Atrial Fibrillation or flutter in the Emergency department: protocol of a stepped-wedge cluster randomized pragmatic trial (O'CAFÉ trial)

BACKGROUND

Management of adults with atrial fibrillation (AF) or atrial flutter in the emergency department (ED) includes rate reduction, cardioversion, and stroke prevention. Different approaches to these components of care may lead to variation in frequency of hospitalization and stroke prevention actions, with significant implications for patient experience, cost of care, and risk of complications. Standardization using evidence-based recommendations could reduce variation in management, preventable hospitalizations, and stroke risk.

METHODS

We describe the rationale for our ED-based AF treatment recommendations. We also describe the development of an electronic clinical decision support system (CDSS) to deliver these recommendations to emergency physicians at the point of care. We implemented the CDSS at three pilot sites to assess feasibility and solicit user feedback. We will evaluate the impact of the CDSS on hospitalization and stroke prevention actions using a stepped-wedge cluster randomized pragmatic clinical trial across 13 community EDs in Northern California.

DISCUSSION

We hypothesize that the CDSS intervention will reduce hospitalization of adults with isolated AF or atrial flutter presenting to the ED and increase anticoagulation prescription in eligible patients at the time of ED discharge and within 30 days. If our hypotheses are confirmed, the treatment protocol and CDSS could be recommended to other EDs to improve management of adults with AF or atrial flutter.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05009225 .  Registered on 17 August 2021.

CTEPH: A Kaiser Permanente Northern California Experience

INTRODUCTION

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare and life-threatening form of pulmonary hypertension and the only potentially curable form of the World Health Organization Pulmonary Hypertension classes. Thus, the prompt and accurate diagnosis of this condition is imperative. Despite widespread chronic symptoms following acute pulmonary embolism (PE), the condition is rarely considered, and an externally validated inexpensive diagnostic algorithm is lacking.

METHODS

A long-term, retrospective cohort study was conducted to assess the incidence of CTEPH following acute PE in a real-world study population. Additional data were collected regarding the practice patterns of diagnostic testing and imaging, particularly in patients with persistent or recurrent symptoms. Amongst diagnosed CTEPH patients, previously established risk factors were evaluated for degree of risk and commonly used diagnostic tests (electrocardiogram [ECG] right ventricular hypertrophy [RVH] pattern, B-type natriuretic peptide [BNP] elevations) employed during this period were evaluated and assessed for feasibility as screening tests. The study population was obtained from the MAPLE study cohort, comprised of patients presenting with acute PE in 21 community medical centers across the Kaiser Permanente Northern California system from January 2013 to April 2015. Diagnosis of CTEPH was confirmed via pulmonary vascular imaging (ventilation/perfusion [V/Q] scanning, computed tomography angiography, pulmonary angiography) and diagnostic right heart catheterization (RHC). Probable diagnoses were defined as a combination of suggestive echocardiographic and RHC findings. Additional inclusion criteria included age (≥18 years) with at least 2 years follow up and no previous diagnosis of CTEPH or PE during the prior 30 days.

RESULTS

There were 1973 patients who met inclusion criteria (mean age 62.4 years). Despite 75 % of patients developing symptoms consistent with CTEPH >3 months following acute PE, only 5.6 % of these symptomatic patients underwent V/Q scanning. There was overall a very low cumulative incidence of CTEPH (2.3 %), which was significantly higher amongst patients with symptoms compared to those without symptoms. When controlled for confounding in the multivariate analysis, only recurrent PE (HR 19.3, P < 0.001) and pulmonary artery systolic pressure >50 mmHg (HR 10.4, P < 0.001) were statistically significant predictors of CTEPH. Of the non-invasive diagnostic tests, ECG criteria for RVH were found to be poorly sensitive (2.6 %), but very specific (98.8 %) for CTEPH. Elevated levels of BNP alone were more sensitive than RVH ECG criteria (76.3 %) but poorly specific (44.4 %).

CONCLUSIONS

The diagnosis of CTEPH is uncommonly made following acute PE. Despite the frequency of persistent symptoms consistent with CTEPH following acute PE, the appropriate diagnostic work-up is rarely undertaken as evidenced in this cohort. This suggests that CTEPH is underappreciated and rarely considered, likely underestimating the true incidence in this cohort. Future studies are needed to elucidate the true prevalence of CTEPH and further investigate both the optimal diagnostic tools and timing of appropriate screening. These discoveries may help guide future development of diagnostic algorithms that can effectively rule out and accurately identify this potentially curable disease in a timely manner.

Accuracy of Medical Student Measurements of CT Right-to-Left Ventricular Diameter in Patients with Acute Pulmonary Embolism

Objectives: Acute pulmonary embolism (PE) is a common disease, necessitating risk stratification to determine management. A right ventricle (RV) to left ventricle (LV) diameter ratio ≥1.0 on computed tomography pulmonary angiography (CTPA) suggests RV strain, which may indicate a worse prognosis. Two prior studies showed that residents with brief training by a radiologist could accurately measure RV/LV ratio. We assessed whether medical students could accurately measure RV dilatation. Methods: We conducted a post hoc analysis of a retrospective cohort study of adults undergoing management for acute PE at 21 community emergency departments across Kaiser Permanente Northern California from 2013 to 2015. We created a sample, stratified to contain an equal number of patients from each of the 5 PE Severity Index classes. Four medical students measured RV and LV diameter on CTPA after training from an emergency medicine physician and an interventional radiologist. We used Cohen's kappa statistics, Bland-Altman plots, and Pearson correlation coefficients to assess interrater reliability. Results: Of the 108 CTPAs reviewed, 79 (73%) showed RV dilatation and 29 (27%) did not. The kappa statistic for the presence of RV dilatation of the medical students compared to the radiologist showed moderate agreement for 3 medical students (kappa (95% CI): 0.46 (0.21-0.70), 0.49 (0.31-0.68), 0.50 (0.32-0.68)) and fair agreement for 1 medical student (kappa (95% CI): 0.29 (0.10-0.47)). The average interrater differences in RV/LV ratio between a radiologist and each of the 4 medical students were -0.04, -0.05, 0.04, and 0.24. Pearson correlation coefficients were 0.87, 0.80, 0.74, and 0.78, respectively, indicating moderate correlation (P < .001 for all). Conclusion: Medical students were able to identify RV dilatation on CTPA in moderate agreement with that of a radiologist. Further study is needed to determine whether medical student accuracy could improve with additional training.

Management and Outcomes of Adults Diagnosed with Acute Pulmonary Embolism in Primary Care: Community-Based Retrospective Cohort Study

BACKGROUND

The management and outcomes of patients diagnosed with acute pulmonary embolism in primary care have not been characterized.

OBJECTIVE

To describe 30-day outcomes stratified by initial site-of-care decisions DESIGN: Multicenter retrospective cohort study PARTICIPANTS: Adults diagnosed with acute pulmonary embolism in primary care in a large, diverse community-based US health system (2013-2019) MAIN MEASURES: The primary outcome was a composite of 30-day serious adverse events (recurrent venous thromboembolism, major bleeding, and all-cause mortality). The secondary outcome was 7-day pulmonary embolism-related hospitalization, either initial or delayed.

KEY RESULTS

Among 652 patient encounters (from 646 patients), median age was 64 years; 51.5% were male and 70.7% identified as non-Hispanic white. Overall, 134 cases (20.6%) were sent home from primary care and 518 cases (79.4%) were initially referred to the emergency department (ED) or hospital. Among the referred, 196 (37.8%) were discharged home from the ED without events. Eight patients (1.2%; 95% CI 0.5-2.4%) experienced a 30-day serious adverse event: 4 venous thromboemboli (0.6%), 1 major bleed (0.2%), and 3 deaths (0.5%). Seven of these patients were initially hospitalized, and 1 had been sent home from primary care. All 3 deaths occurred in patients with known metastatic cancer initially referred to the ED, hospitalized, then enrolled in hospice following discharge. Overall, 328 patients (50.3%) were hospitalized within 7 days: 322 at the time of the index diagnosis and 6 following initial outpatient management (4 clinic-only and 2 clinic-plus-ED patients).

CONCLUSIONS

Patients diagnosed with acute pulmonary embolism in this primary care setting uncommonly experienced 30-day adverse events, regardless of initial site-of-care decisions. Over 20% were managed comprehensively by primary care. Delayed 7-day pulmonary embolism-related hospitalization was rare among the 51% treated as outpatients. Primary care management of acute pulmonary embolism appears to be safe and could have implications for cost-effectiveness and patient care experience.

Sustainability of a Clinical Decision Support Intervention for Outpatient Care for Emergency Department Patients With Acute Pulmonary Embolism

IMPORTANCE

Physicians commonly hospitalize patients presenting to the emergency department (ED) with acute pulmonary embolism (PE), despite eligibility for safe outpatient management. Risk stratification using electronic health record-embedded clinical decision support systems can aid physician site-of-care decision-making and increase safe outpatient management. The long-term sustainability of early improvements after the cessation of trial-based, champion-led promotion is uncertain.

OBJECTIVE

To evaluate the sustainability of recommended site-of-care decision-making support 4 years after initial physician champion-led interventions to increase outpatient management for patients with acute PE.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study was conducted in 21 US community hospitals in an integrated health system. Participants included adult patients presenting to the ED with acute PE. Study sites had participated in an original decision-support intervention trial 4 years prior to the current study period: 10 sites were intervention sites, 11 sites were controls. In that trial, decision support with champion promotion resulted in significantly higher outpatient management at intervention sites compared with controls. After trial completion, all study sites were given continued access to a modified decision-support tool without further champion-led outreach. Data were analyzed from January 2019 to February 2020.

EXPOSURES

ED treatment with a modified clinical decision support tool.

MAIN OUTCOMES AND MEASURES

The main outcome was frequency of outpatient management, defined as discharge home directly from the ED, stratified by the PE Severity Index. The safety measure of outpatient care was 7-day PE-related hospitalization.

RESULTS

This study included 1039 patients, including 533 (51.3%) women, with a median (IQR) age of 65 (52-74) years. Nearly half (474 patients [45.6%]) were rated lower risk on the PE Severity Index. Overall, 278 patients (26.8%) were treated as outpatients, with only four 7-day PE-related hospitalizations (1.4%; 95% CI, 0.4%-3.6%). The practice gap in outpatient management created by the earlier trial persisted in the outpatient management for patients with lower risk: 109 of 236 patients (46.2%) at former intervention sites vs 81 of 238 patients (34.0%) at former control sites (difference, 12.2; [95% CI, 3.4-20.9] percentage points; P = .007), with wide interfacility variation (range, 7.1%-47.1%).

CONCLUSIONS AND RELEVANCE

In this cohort study, a champion-led, decision-support intervention to increase outpatient management for patients presenting to the ED with acute pulmonary embolism was associated with sustained higher rates of outpatient management 4 years later. The application of our findings to improving sustainability of practice change for other clinical conditions warrants further study.

Can right ventricular assessments improve triaging of low risk pulmonary embolism?

OBJECTIVES

Identifying right ventricle (RV) abnormalities is important to stratifying pulmonary embolism (PE) severity. Disposition decisions are influenced by concerns about early deterioration. Triaging strategies, like the Simplified Pulmonary Embolism Severity Index (sPESI), do not include RV assessments as predictors or early deterioration as outcome(s). We aimed to (1) determine if RV assessment variables add prognostic accuracy for 5-day clinical deterioration in patients classified low risk by sPESI, and (2) determine the prognostic importance of RV assessments compared to other variables and to each other.

METHODS

We identified low risk sPESI patients (sPESI = 0) from a prospective PE registry. From a large field of candidate variables, we developed, and compared prognostic accuracy of, full and reduced random forest models (with and without RV assessment variables, respectively) on a validation database. We reported variable importance plots from full random forest and provided odds ratios for statistical inference of importance from multivariable logistic regression. Outcomes were death, cardiac arrest, hypotension, dysrhythmia, or respiratory failure within 5 days of PE.

RESULTS

Of 1736 patients, 610 (35.1%) were low risk by sPESI and 72 (11.8%) experienced early deterioration. Of the 610, RV abnormality was present in 157 (25.7%) by CT, 121 (19.8%) by echocardiography, 132 (21.6%) by natriuretic peptide, and 107 (17.5%) by troponin. For deterioration, the receiver operating characteristics for full and reduced random forest prognostic models were 0.80 (0.77-0.82) and 0.71 (0.68-0.73), respectively. RV assessments were the top four in the variable importance plot for the random forest model. Echocardiography and CT significantly increased predicted probability of 5-day clinical deterioration by the multivariable logistic regression.

CONCLUSIONS

A PE triaging strategy with RV imaging assessments had superior prognostic performance at classifying low risk for 5-day clinical deterioration versus one without.

A clinical decision framework to guide the outpatient treatment of emergency department patients diagnosed with acute pulmonary embolism or deep vein thrombosis: Results from a multidisciplinary consensus panel

The outpatient treatment of select emergency department patients with acute pulmonary embolism (PE) or deep vein thrombosis (DVT) has been shown to be safe, cost effective and associated with high patient satisfaction. Despite this, outpatient PE and DVT treatment remains uncommon. To address this, the American College of Emergency Physicians assembled a multidisciplinary team of content experts to provide evidence-based recommendations and practical advice to help clinicians safely treat patients with low-risk PE and DVT without hospitalization. The emergency clinician must stratify the patient's risk of clinical decompensation due to their PE or DVT as well as their risk of bleeding due to anticoagulation. The clinician must also select and start an anticoagulant and ensure that the patient has access to the medication in a timely manner. Reliable follow-up is critical, and the patient must also be educated about signs or symptoms that should prompt a return to the emergency department. To facilitate access to these recommendations, the consensus panel also created 2 web-based "point-of-care tools."

Right ventricle assessment in patients with pulmonary embolism at low risk for death based on clinical models: an individual patient data meta-analysis

AIMS

Patients with acute pulmonary embolism (PE) at low risk for short-term death are candidates for home treatment or short-hospital stay. We aimed at determining whether the assessment of right ventricle dysfunction (RVD) or elevated troponin improves identification of low-risk patients over clinical models alone.

METHODS AND RESULTS

Individual patient data meta-analysis of studies assessing the relationship between RVD or elevated troponin and short-term mortality in patients with acute PE at low risk for death based on clinical models (Pulmonary Embolism Severity Index, simplified Pulmonary Embolism Severity Index or Hestia). The primary study outcome was short-term death defined as death occurring in hospital or within 30 days. Individual data of 5010 low-risk patients from 18 studies were pooled. Short-term mortality was 0.7% [95% confidence interval (CI) 0.4-1.3]. RVD at echocardiography, computed tomography or B-type natriuretic peptide (BNP)/N-terminal pro BNP (NT-proBNP) was associated with increased risk for short-term death (1.5 vs. 0.3%; OR 4.81, 95% CI 1.98-11.68), death within 3 months (1.6 vs. 0.4%; OR 4.03, 95% CI 2.01-8.08), and PE-related death (1.1 vs. 0.04%; OR 22.9, 95% CI 2.89-181). Elevated troponin was associated with short-term death (OR 2.78, 95% CI 1.06-7.26) and death within 3 months (OR 3.68, 95% CI 1.75-7.74).

CONCLUSION

RVD assessed by echocardiography, computed tomography, or elevated BNP/NT-proBNP levels and increased troponin are associated with short-term death in patients with acute PE at low risk based on clinical models. RVD assessment, mainly by BNP/NT-proBNP or echocardiography, should be considered to improve identification of low-risk patients that may be candidates for outpatient management or short hospital stay.

Outpatient treatment of emergency department patients diagnosed with venous thromboembolism

Venous thromboembolism (VTE) includes the diagnosis of either deep venous thrombosis (DVT) and/or pulmonary embolism (PE). This review discusses an evidence-based approach to the outpatient treatment of VTE in the emergency care setting. Main findings: The majority of patients diagnosed with VTE in the acute care setting are at low risk for an adverse event. Outpatient treatment for patients deemed low-risk by validated clinical decision tools leads to safe, efficacious, patient-centered, and cost-effective care. From a patient perspective, outpatient treatment of VTE can been simplified by the use of direct oral anticoagulant (DOACs) medications, and is supported by clinical trial evidence, and clinical practice guidelines from international societies. Outpatient treatment of patients with DVT has been more widely accepted as a best practice, while adoption of outpatient treatment of low-risk patients with acute PE has lagged. Many acute care clinicians remain wary of discharging patients with PE, concerned about drug access, adherence, and follow-up. Patients with VTE should be risk stratified identically as emerging evidence has demonstrated efficacy and safety in the interdependence of acute care protocols for the outpatient treatment of low-risk DVT and PE. Clinicians who practice in the acute care setting should be comfortable with risk stratification, anticoagulation, and discharge of low-risk VTE.

Outpatient Management of Patients Following Diagnosis of Acute Pulmonary Embolism

OBJECTIVE

While guidelines recommend outpatient management of patients with low-risk pulmonary embolism (PE), little is known about the disposition of patients with PE diagnosed in United States emergency departments (EDs). We sought to determine disposition practices and subsequent health care utilization in patients with acute PE in U.S. EDs.

METHODS

This was a retrospective cohort study of adult ED patients with a new diagnosis of acute PE treated at 740 U.S. acute care hospitals from July 1, 2016, through June 30, 2018. The primary outcome was the initial disposition following an ED visit for acute PE. Additional measures included hospital cost and 30-day revisit rate to the ED.

RESULTS

A total of 61,070 cases were included in the overall cohort, of which 4.1% of new cases of PE were discharged from the ED. The median hospital-specific proportion of patients discharged was 3.1% (interquartile range = 0.8%-6.8%). The median odds ratio, representing the importance of the hospital in initial disposition decisions, was 2.21 (95% confidence interval = 2.05 to 2.37), which was greater than any patient-level factor with the exception of concurrent ED diagnosis of hypoxemia/respiratory failure, shock, or hypotension. Within 30 days of discharge, 17.9% of discharged cases had an ED return visit to the ED only and 10.3% of patients were hospitalized. Of the 30-day ED return visits in patients initially managed as outpatients, 1.3% had a bleeding-associated diagnosis.

CONCLUSION

Despite guidelines promoting outpatient management, few patients are currently discharged home in the United States; however, practice varies widely across hospitals. Return visit rates were high but most did not result in hospitalization.

Text message alerts to emergency physicians identifying potential study candidates increase clinical trial enrollment

Prospective enrollment of research subjects in the fast-paced emergency department (ED) is challenging. We sought to develop a software application to increase real-time clinical trial enrollment during an ED visit. The Prospective Intelligence System for Clinical Emergency Services (PISCES) scans the electronic health record during ED encounters for preselected clinical characteristics of potentially eligible study participants and notifies the treating physician via mobile phone text alerts. PISCES alerts began 3 months into a cluster randomized trial of an electronic health record-based risk stratification tool for pediatric abdominal pain in 11 Northern California EDs. We compared aggregate enrollment before (2577 eligible patients, October 2016 to December 2016) and after (12 049 eligible patients, January 2017 to January 2018) PISCES implementation. Enrollment increased from 10.8% to 21.1% following PISCES implementations (P < .001). PISCES significantly increased study enrollment and can serve as a valuable tool to assist prospective research enrollment in the ED.

Outpatient management of patients presenting with venous thromboembolism: Retrospective cohort study at 11 community hospitals

A gap exists between clinical practice guidelines and real-world practice. We aim to investigate hospital admissions among patients presenting to emergency departments of 11 hospitals with venous thromboembolism (VTE). Eligible patients’ first emergency department VTE visit were retrospectively collected between 2013 and 2018 from electronic medical records (EMR). Patients were categorized at low risk of VTE complications if they were diagnosed with deep vein thrombosis (DVT) of the leg or if they were diagnosed with pulmonary embolism (PE) and had a PE score index < 85. Multivariable logistic regression models were constructed to measure the adjusted odds ratios (OR) and 95% confidence intervals (CI) of hospital admissions before and after clinical practice guidelines were updated to recommend outpatient management of DVT and PE with low risk of complications. A total of 13,677 patients were included in the analysis, of which 55% were diagnosed with DVT. Mean age was 65  ±  17 years, 54% were females, and 62% were Caucasian. Overall, 9281 patients were categorized at low risk VTE complications, of whom 77% were admitted for in-hospital management. The rate of in-hospital management declined from 81% in 2013 to 73% in 2018. Patients visiting emergency departments between 2016 and 2018 (post-guidelines) were equally likely to be admitted compared to patients visiting the emergency departments between 2013 and 2015 (pre-guidelines; OR = 0.99; 95% CI: 0.88, 1.11). Results from this real-world study indicate that most low-risk VTE patients are admitted for in-hospital management, despite recommendations in clinical practice guidelines.

Outpatient treatment of pulmonary embolism: A single center 4-year experience

BACKGROUND

Pulmonary embolus (PE) is associated with significant utilization of health resources. As patients can be risk-stratified, there is an opportunity for a subset of patients to be safely treated without hospitalization, thus reducing the associated costs of treatment. Our aim was to describe the population, treatment strategies, complications, and outcomes associated with outpatient management of PE following treatment in the ED.

METHODS

This retrospective health records survey investigated a 4-year cohort of patients presenting with PE who were discharged to home.

RESULTS

Data from 151 patients demonstrated that 78% (118/151) of patients were discharged directly home; 19% (28/151) were discharged following ED clinical decision unit observation. Treatment with a novel oral anticoagulant was provided in 40% of cases (61/151). Six patients (4%) experienced a medication-related complication; 26 (17%) had a return visit within 30 days.

CONCLUSION

In this cohort of patients with PE, outpatient management was safe and effective for the large majority. Immediate and 30-day complications were few.

Diagnostic Performance of Emergency Physician Gestalt for Predicting Acute Appendicitis in Patients Age 5 to 20 Years

OBJECTIVES

Pediatric appendicitis remains a challenging diagnosis in the emergency department (ED). Available risk prediction algorithms may contribute to excessive ED imaging studies. Incorporation of physician gestalt assessment could help refine predictive tools and improve diagnostic imaging decisions.

METHODS

This study was a subanalysis of a parent study that prospectively enrolled patients ages 5 to 20.9 years with a chief complaint of abdominal pain presenting to 11 community EDs within an integrated delivery system between October 1, 2016, and September 30, 2018. Prior to diagnostic imaging, attending emergency physicians enrolled patients with ≤5 days of right-sided or diffuse abdominal pain using a Web-based application embedded in the electronic health record. Predicted risk (gestalt) of acute appendicitis was prospectively entered using a sliding scale from 1% to 100%. As a planned secondary analysis, we assessed the performance of gestalt via c-statistics of receiver operating characteristic (ROC) curves; tested associations between gestalt performance and patient, physician, and facility characteristics; and examined clinical characteristics affecting gestalt estimates.

RESULTS

Of 3,426 patients, 334 (9.8%) had confirmed appendicitis. Physician gestalt had excellent ROC curve characteristics (c-statistic = 0.83, 95% confidence interval = 0.81 to 0.85), performing particularly well in the low-risk strata (appendicitis rate = 1.1% in gestalt 1%-10% range, negative predictive value of 98.9% for appendicitis diagnosis). Physicians with ≥5 years since medical school graduation demonstrated improved gestalt performance over those with less experience (p = 0.007). All clinical characteristics tested, except pain <24 hours, were significantly associated with physician gestalt value (p < 0.05).

CONCLUSION

Physician gestalt for acute appendicitis diagnosis performed well, especially in low-risk patients and when employed by experienced physicians.

Hospitalization Is Less Common in Ambulatory Patients With Acute Pulmonary Embolism Diagnosed Before Emergency Department Referral Than After Arrival

BACKGROUND

Emergency department (ED) patients with acute pulmonary embolism (PE) may undergo diagnostic pulmonary imaging as an outpatient before referral to the ED for definitive management. This population has not been well characterized.

METHODS

This retrospective cohort study included ambulatory adults with acute objectively confirmed PE across 21 EDs in an integrated health care system from January 1, 2013, through April 30, 2015. We excluded patients arriving by ambulance. We compared outpatients with diagnostic pulmonary imaging in the 12 hours prior to ED arrival (the clinic-based cohort) with those receiving imaging for PE only after ED arrival. We reported adjusted odds ratio (aOR) with 95% confidence intervals (CIs) for hospitalization, adjusted for race, presyncope or syncope, proximal clot location, and PE Severity Index class.

RESULTS

Among 2,352 eligible ED patients with acute PE, 344 (14.6%) had a clinic-based diagnosis. This cohort had lower PE Severity Index classification and were less likely to be hospitalized than their counterparts with an ED-based diagnosis: 80.8% vs. 92.0% (p < 0.0001). The inverse association with hospitalization persisted after adjusting for the above patient characteristics with aOR of 0.36 (95% CI = 0.26 to 0.50).

CONCLUSION

In the study setting, ambulatory outpatients with acute PE are commonly diagnosed before ED arrival. A clinic-based diagnosis of PE identifies ED patients less likely to be hospitalized. Research is needed to identify which patients with a clinic-based PE diagnosis may not require transfer to the ED before home discharge.

Presyncope Is Associated with Intensive Care Unit Admission in Emergency Department Patients with Acute Pulmonary Embolism

INTRODUCTION

Syncope is common among emergency department (ED) patients with acute pulmonary embolism (PE) and indicates a higher acuity and worse prognosis than in patients without syncope. Whether presyncope carries the same prognostic implications has not been established. We compared incidence of intensive care unit (ICU) admission in three groups of ED PE patients: those with presyncope; syncope; and neither.

METHODS

This retrospective cohort study included all adults with acute, objectively confirmed PE in 21 community EDs from January 2013-April 2015. We combined electronic health record extraction with manual chart abstraction. We used chi-square test for univariate comparisons and performed multivariate analysis to evaluate associations between presyncope or syncope and ICU admission from the ED, reported as adjusted odds ratios (aOR) with 95% confidence intervals (CI).

RESULTS

Among 2996 PE patients, 82 (2.7%) had presyncope and 109 (3.6%) had syncope. ICU admission was similar between groups (presyncope 18.3% vs syncope 25.7%) and different than their non-syncope counterparts (either 22.5% vs neither 4.7%; p<0.0001). On multivariate analysis, both presyncope and syncope were independently associated with ICU admission, controlling for demographics, higher-risk PE Severity Index (PESI) class, ventilatory support, proximal clot location, and submassive and massive PE classification: presyncope, aOR 2.79 (95% CI, 1.40, 5.56); syncope, aOR 4.44 (95% CI 2.52, 7.80). These associations were only minimally affected when excluding massive PE from the model. There was no significant interaction between either syncope or presyncope and PESI, submassive or massive classification in predicting ICU admission.

CONCLUSION

Presyncope appears to carry similar strength of association with ICU admission as syncope in ED patients with acute PE. If this is confirmed, clinicians evaluating patients with acute PE may benefit from including presyncope in their calculus of risk assessment and site-of-care decision-making.

Comprehensive Outpatient Management of Low-Risk Pulmonary Embolism: Can Primary Care Do This? A Narrative Review

INTRODUCTION

The evidence for outpatient management of hemodynamically stable, low-risk patients with acute symptomatic pulmonary embolism (PE) is mounting. Guidance in identifying patients who are eligible for outpatient (ambulatory) care is available in the literature and society guidelines. Less is known about who can identify patients eligible for outpatient management and in what clinical practice settings.

OBJECTIVE

To answer the question, "Can primary care do this?" (provide comprehensive outpatient management of low-risk PE).

METHODS

We undertook a narrative review of the literature on the outpatient management of acute PE focusing on site of care. We searched the English-language literature in PubMed and Embase from January 1, 1950, through July 15, 2019.

RESULTS

We identified 26 eligible studies. We found no studies that evaluated comprehensive PE management in a primary care clinic or general practice setting. In 19 studies, the site-of-care decision making occurred in the Emergency Department (or after a short period of supplemental observation) and in 7 studies the decision occurred in a specialty clinic. We discuss the components of care involved in the diagnosis, outpatient eligibility assessment, treatment, and follow-up of ambulatory patients with acute PE.

DISCUSSION

We see no formal reason why a trained primary care physician could not provide comprehensive care for select patients with low-risk PE. Leading obstacles include lack of ready access to advanced pulmonary imaging and the time constraints of a busy outpatient clinic.

CONCLUSION

Until studies establish safe parameters of such a practice, the question "Can primary care do this?" must remain open.

Home vs hospital treatment of low-risk venous thromboembolism: a systematic review and meta-analysis

Increasing evidence supports the safety and effectiveness of managing low-risk deep vein thrombosis (DVT) or pulmonary embolism (PE) in outpatient settings. We performed a systematic review to assess safety and effectiveness of managing patients with DVT or PE at home compared with the hospital. Medline, Embase, and Cochrane databases were searched up to July 2019 for relevant randomized clinical trials (RCTs), and prospective cohort studies. Two investigators independently screened titles and abstracts of identified citations and extracted data from relevant full-text papers. Risk ratios (RRs) were calculated, and certainty of evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE). Seven RCTs (1922 patients) were included in meta-analyses on managing patients with DVT. Pooled estimates indicated decreased risk of PE (RR = 0.64; 95% confidence interval [CI], 0.44-0.93) and recurrent DVT (RR = 0.61; 95% CI, 0.42-0.90) for home management, both with moderate certainty of the evidence. Reductions in mortality and major bleeding were not significant, both with low certainty of the evidence. Two RCTs (445 patients) were included in meta-analyses on home management of low-risk patients with PE. Pooled estimates indicated no significant difference in all-cause mortality, recurrent PE, and major bleeding, all with low certainty of the evidence. Results of pooled estimates from 3 prospective cohort studies (234 patients) on home management of PE showed similar results. Our findings indicate that low-risk DVT patients had similar or lower risk of patient-important outcomes with home treatment compared with hospital treatment. In patients with low-risk PE, there was important uncertainty about a difference between home and hospital treatment.

Age-Stratified National Trends in Pulmonary Embolism Admissions

BACKGROUND

Pulmonary embolism (PE) is one of the leading causes of death in hospitalized patients. Treatment patterns and patient demographics for PE are changing; therefore, we sought to evaluate national trends in admission rate, discharge disposition, and length of stay (LOS) in patients hospitalized with PE.

METHODS

The National Inpatient Sample database was used to collect data for hospitalizations of patients ≥ 20 years old with primary diagnosis of PE between January 2000 and September 2015. Patient demographics and hospital characteristics, stratified by patient age, were reported. Trends in rates of hospitalizations for PE, LOS, discharge disposition, and hospital charges were assessed across age groups.

RESULTS

There were an estimated 2,159,568 hospitalizations with primary diagnosis of PE. The rate of PE per 100,000 persons increased by > 100%, and was highest among elderly patients. Increased age and comorbidity burden were independently associated with poor outcomes. Inpatient mortality and LOS decreased across all age groups, but was highest in the elderly. Home health utilization increased in patients ≥ 55 years old. Average hospital charges increased across all age groups, despite shorter length of stay, with patients ≥ 85 experiencing $13,000 average increase.

CONCLUSIONS

Between 2000 and 2015, the rate of hospitalization for PE increased across all age groups. Despite improvements in average LOS and inpatient mortality, hospitalizations became more expensive, and patients required more resources (ie, home health) on discharge. This increased resource utilization was most apparent in elderly patients. This suggests that targeted clinical trials designed to improve outcomes in all age brackets are needed.

Reducing the hospital burden associated with the treatment of pulmonary embolism

Pulmonary embolism (PE) is the most feared clinical presentation of venous thromboembolism (VTE). Patients with PE have traditionally been treated in hospital; however, many are at low risk of adverse outcomes and current guidelines suggest outpatient treatment as an option. Outpatient treatment of PE offers several advantages, including reduced risk of hospital-acquired conditions and potential cost savings. Despite this, patients with low-risk PE are still frequently hospitalized for treatment. This narrative review summarizes current guideline recommendations for the identification of patients with low-risk PE who are potentially suitable for outpatient treatment, using prognostic assessment tools (e.g. the Pulmonary Embolism Severity Index [PESI] and simplified PESI) and clinical exclusion criteria (e.g. Hestia criteria) alone or in combination with additional cardiac assessments. Treatment options are discussed along with recommendations for the follow-up of patients managed in the non-hospital environment. The available data on outpatient treatment of PE are summarized, including details on patient selection, anticoagulant choice, and short-term outcomes in each study. Accumulating evidence suggests that outcomes in patients with low-risk PE treated as outpatients are at least as good as, if not better than, those of patients treated in the hospital. With mounting pressures on health care systems worldwide, increasing the proportion of patients with PE treated as outpatients has the potential to reduce health care burdens associated with VTE.

Increasing Safe Outpatient Management of Emergency Department Patients With Pulmonary Embolism: A Controlled Pragmatic Trial

BACKGROUND

Many low-risk patients with acute pulmonary embolism (PE) in the emergency department (ED) are eligible for outpatient care but are hospitalized nonetheless. One impediment to home discharge is the difficulty of identifying which patients can safely forgo hospitalization.

OBJECTIVE

To evaluate the effect of an integrated electronic clinical decision support system (CDSS) to facilitate risk stratification and decision making at the site of care for patients with acute PE.

DESIGN

Controlled pragmatic trial. (ClinicalTrials.gov: NCT03601676).

SETTING

All 21 community EDs of an integrated health care delivery system (Kaiser Permanente Northern California).

PATIENTS

Adult ED patients with acute PE.

INTERVENTION

Ten intervention sites selected by convenience received a multidimensional technology and education intervention at month 9 of a 16-month study period (January 2014 to April 2015); the remaining 11 sites served as concurrent controls.

MEASUREMENTS

The primary outcome was discharge to home from either the ED or a short-term (<24-hour) outpatient observation unit based in the ED. Adverse outcomes included return visits for PE-related symptoms within 5 days and recurrent venous thromboembolism, major hemorrhage, and all-cause mortality within 30 days. A difference-in-differences approach was used to compare pre-post changes at intervention versus control sites, with adjustment for demographic and clinical characteristics.

RESULTS

Among 881 eligible patients diagnosed with PE at intervention sites and 822 at control sites, adjusted home discharge increased at intervention sites (17.4% pre- to 28.0% postintervention) without a concurrent increase at control sites (15.1% pre- and 14.5% postintervention). The difference-in-differences comparison was 11.3 percentage points (95% CI, 3.0 to 19.5 percentage points; P = 0.007). No increases were seen in 5-day return visits related to PE or in 30-day major adverse outcomes associated with CDSS implementation.

LIMITATION

Lack of random allocation.

CONCLUSION

Implementation and structured promotion of a CDSS to aid physicians in site-of-care decision making for ED patients with acute PE safely increased outpatient management.

PRIMARY FUNDING SOURCE

Garfield Memorial National Research Fund and The Permanente Medical Group Delivery Science and Physician Researcher Programs.

Emergency Department Patient Satisfaction with Treatment of Low-risk Pulmonary Embolism

Introduction

Many emergency department (ED) patients with acute pulmonary embolism (PE) who meet low-risk criteria may be eligible for a short length of stay (LOS) (<24 hours), with expedited discharge home either directly from the ED or after a brief observation or hospitalization. We describe the association between expedited discharge and site of discharge on care satisfaction and quality of life (QOL) among patients with low-risk PE (PE Severity Index [PESI] Classes I-III).

Methods

This phone survey was conducted from September 2014 through April 2015 as part of a retrospective cohort study across 21 community EDs in Northern California. We surveyed low-risk patients with acute PE, treated predominantly with enoxaparin bridging and warfarin. All eligible patients were called 2-8 weeks after their index ED visit. PE-specific, patient-satisfaction questions addressed overall care, discharge instruction clarity, and LOS. We scored physical and mental QOL using a modified version of the validated Short Form Health Survey. Satisfaction and QOL were compared by LOS. For those with expedited discharge, we compared responses by site of discharge: ED vs. hospital, which included ED-based observation units. We used chi-square and Wilcoxon rank-sum tests as indicated.

Results

Survey response rate was 82.3% (424 of 515 eligible patients). Median age of respondents was 64 years; 47.4% were male. Of the 145 patients (34.2%) with a LOS<24 hours, 65 (44.8%) were discharged home from the ED. Of all patients, 89.6% were satisfied with their overall care and 94.1% found instructions clear. Sixty-six percent were satisfied with their LOS, whereas 17.5% would have preferred a shorter LOS and 16.5% a longer LOS. There were no significant differences in satisfaction between patients with LOS<24 hours vs. ≥24 hours (p>0.13 for all). Physical QOL scores were significantly higher for expedited-discharge patients (p=0.01). Patients with expedited discharge home from the ED vs. the hospital had no significant difference in satisfaction (p>0.20 for all) or QOL (p>0.19 for all).

Conclusion

ED patients with low-risk PE reported high satisfaction with their care in follow-up surveys. Expedited discharge (<24 hours) and site of discharge were not associated with differences in patient satisfaction.

Acute Pulmonary Embolism in Emergency Department Patients Despite Therapeutic Anticoagulation

Introduction

Emergency department (ED) patients with acute pulmonary embolism (PE) despite therapeutic anticoagulation at the time of diagnosis are uncommonly encountered and present a diagnostic and management challenge. Their characterization and outcomes are poorly described. We sought to describe the prevalence and characteristics of therapeutically anticoagulated patients among a population of patients with acute PE in a community setting and to describe treatment changes and 30-day outcomes.

Methods

From a large retrospective cohort of adults with acute, objectively-confirmed PE across 21 EDs between 01/2013 and 04/2015, we identified patients who arrived on direct oral or injectable anticoagulants, or warfarin with an initial ED international normalized ratio (INR) value ≥2.0. Patients were excluded from the larger cohort if they had received a diagnosis of venous thromboembolism (VTE) in the prior 30 days. We gathered demographic and clinical variables from electronic health records and structured manual chart review. We report discharge anticoagulation regimens and major 30-day adverse outcomes.

Results

Among 2,996 PE patients, 36 (1.2%) met study criteria. Mean age was 63 years. Eleven patients (31%) had active cancer and 25 (69%) were high risk on the PE Severity Index (Classes III–V), comparable to the larger cohort (p>0.1). Reasons for pre-arrival anticoagulation were VTE treatment or prevention (n=21), and atrial fibrillation or flutter (n=15). All patients arrived on warfarin and one was also on enoxaparin: 32 had a therapeutic INR (2.0–3.0) and four had a supratherapeutic INR (>3.0). Fifteen patients (42%) had at least one subtherapeutic INR (<2.0) in the 14 days preceding their diagnostic visit. Two patients died during hospitalization. Of the 34 ultimately discharged, 22 underwent a change in anticoagulation drug or dosing, 19 of whom received injectables, either to replace or to supplement warfarin. Four patients also received inferior vena cava filters. Thirty-day outcomes included one major hemorrhage and one additional death. No patients experienced recurrent or worsening VTE.

Conclusion

We found a low prevalence of therapeutic anticoagulation at the time of acute PE diagnosis. Most patients with breakthrough PE underwent a change in therapy, though management varied widely. Subtherapeutic anticoagulation levels in the preceding weeks were common and support the importance of anticoagulation adherence.