Multicenter Trial of Rivaroxaban for Early Discharge of Pulmonary Embolism From the Emergency Department (MERCURY PE): Rationale and Design

Outpatient versus inpatient treatment for acute pulmonary embolism

BACKGROUND

Pulmonary embolism (PE) is a common life-threatening cardiovascular condition, with an incidence of 23 to 69 new cases per 100,000 people each year. For selected low-risk patients with acute PE, outpatient treatment might provide several advantages over traditional inpatient treatment, such as reduction of hospitalisations, substantial cost savings, and improvements in health-related quality of life. This is an update of an earlier Cochrane Review.

OBJECTIVES

To assess the effects of outpatient versus inpatient treatment in low-risk patients with acute PE.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 31 May 2021.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of outpatient versus inpatient treatment of adults (aged 18 years and over) diagnosed with low-risk acute PE.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were short- and long-term all-cause mortality. Secondary outcomes were bleeding, adverse effects, recurrence of PE, and patient satisfaction. We used GRADE to assess certainty of evidence for each outcome.

MAIN RESULTS

We did not identify any new studies for this update. We included a total of two RCTs involving 453 participants. Both trials discharged participants randomised to the outpatient group within 36 hours of initial triage, and both followed participants for 90 days. One study compared the same treatment regimens in both outpatient and inpatient groups, and the other study used different treatment regimens. There was no clear difference in treatment effect for the outcomes of mortality at 30 days (risk ratio (RR) 0.33, 95% confidence interval (CI) 0.01 to 7.98; 2 studies, 453 participants; low-certainty evidence), mortality at 90 days (RR 0.98, 95% CI 0.06 to 15.58; 2 studies, 451 participants; low-certainty evidence), major bleeding at 14 days (RR 4.91, 95% CI 0.24 to 101.57; 2 studies, 445 participants; low-certainty evidence) and at 90 days (RR 6.88, 95% CI 0.36 to 132.14; 2 studies, 445 participants; low-certainty evidence), minor bleeding (RR 1.08, 95% CI 0.07 to 16.79; 1 study, 106 participants; low-certainty evidence), recurrent PE within 90 days (RR 2.95, 95% CI 0.12 to 71.85; 2 studies, 445 participants; low-certainty evidence), and patient satisfaction (RR 0.97, 95% CI 0.90 to 1.04; 2 studies, 444 participants; moderate-certainty evidence). We downgraded the certainty of the evidence because the CIs were wide and included treatment effects in both directions, the sample sizes and numbers of events were small, and it was not possible to determine the effect of missing data or the presence of publication bias. The included studies did not assess PE-related mortality or adverse effects, such as haemodynamic instability, or adherence to treatment.

AUTHORS' CONCLUSIONS

Currently, only low-certainty evidence is available from two published randomised controlled trials on outpatient versus inpatient treatment in low-risk patients with acute PE. The studies did not provide evidence of any clear difference between the interventions in overall mortality, bleeding, or recurrence of PE.

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."

Anticoagulation Strategies in the Management of Lemierre Syndrome: A Systematic Review of the Literature

OBJECTIVE

To determine the optimal anticoagulation strategy in patients diagnosed with Lemierre Syndrome (LS).

DATA SOURCES

A systematic review in accordance with PRISMA guidelines was conducted using PubMed, MEDLINE, Scopus, ProQuest, and CINAHL from January to April 2020. Search terms included "Lemierre Syndrome" AND "anticoagulation" NOT "prophylaxis" OR "atrial fibrillation," in addition to a list of parenteral and oral anticoagulants. Adult patients who developed a clot and required systemic anticoagulation as a result of LS were included in this review.

STUDY SELECTION AND DATA EXTRACTION

A total of 4180 records were initially identified, though following the removal of duplicates and nonrelevant entries, 216 full-text articles were reviewed for inclusion; 13 articles were ultimately included.

DATA SYNTHESIS

The majority (11/14) of patients developed thromboses of the internal jugular veins, which corresponds to the pathophysiology of LS. Anticoagulation strategies were varied in the included literature, though 12/14 patients initially received a parenteral product. Two patients received a direct-acting oral anticoagulant (DOAC) following either intravenous heparin or subcutaneous enoxaparin and had outcomes similar to patients transitioned to warfarin.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Anticoagulation in LS is a clinical controversy because the thromboembolic events have rarely led to significant complications; thrombi typically resolve independently, and concerns for bleeding risks are well founded; however, this review indicates both the efficacy and safety of anticoagulation.

CONCLUSIONS

Anticoagulation is both efficacious and safe in LS, including treatment using a DOAC. Although further studies are needed, clinicians should consider a duration of anticoagulation of 6 to 12 weeks.

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.

Outpatient versus inpatient treatment for acute pulmonary embolism

BACKGROUND

Pulmonary embolism (PE) is a common life-threatening cardiovascular condition, with an incidence of 23 to 69 new cases per 100,000 people each year. For selected low-risk patients with acute PE, outpatient treatment might provide several advantages over traditional inpatient treatment, such as reduction of hospitalisations, substantial cost savings, and improvements in health-related quality of life. This is an update of the review first published in 2014.

OBJECTIVES

To compare the efficacy and safety of outpatient versus inpatient treatment in low-risk patients with acute PE for the outcomes of all-cause and PE-related mortality; bleeding; adverse events such as haemodynamic instability; recurrence of PE; and patients' satisfaction.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL and AMED databases, and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers, to 26 March 2018. We also undertook reference checking to identify additional studies.

SELECTION CRITERIA

We included randomised controlled trials of outpatient versus inpatient treatment of adults (aged 18 years and over) diagnosed with low-risk acute PE.

DATA COLLECTION AND ANALYSIS

Two review authors selected relevant trials, assessed methodological quality, and extracted and analysed data. We calculated effect estimates using risk ratio (RR) with 95% confidence intervals (CIs), or mean differences (MDs) with 95% CIs. We used standardised mean differences (SMDs) to combine trials that measured the same outcome but used different methods. We assessed the quality of the evidence using GRADE criteria.

MAIN RESULTS

One new study was identified for this 2018 update, bringing the total number of included studies to two and the total number of participants to 451. Both trials discharged patients randomised to the outpatient group within 36 hours of initial triage and both followed participants for 90 days. One study compared the same treatment regimens in both outpatient and inpatient groups, and the other study used different treatment regimes. There was no clear difference in treatment effect for the outcomes of short-term mortality (30 days) (RR 0.33, 95% CI 0.01 to 7.98, P = 0.49; low-quality evidence), long-term mortality (90 days) (RR 0.98, 95% CI 0.06 to 15.58, P = 0.99, low-quality evidence), major bleeding at 14 days (RR 4.91, 95% CI 0.24 to 101.57, P = 0.30; low-quality evidence) and at 90 days (RR 6.88, 95% CI 0.36 to 132.14, P = 0.20; low-quality evidence), minor bleeding (RR 1.08, 95% CI 0.07 to 16.79; P = 0.96, low-quality evidence), recurrent PE within 90 days (RR 2.95, 95% CI 0.12 to 71.85, P = 0.51, low-quality evidence), and participant satisfaction (RR 0.97, 95% CI 0.90 to 1.04, P = 0.39; moderate-quality evidence). We downgraded the quality of the evidence because the CIs were wide and included treatment effects in both directions, the sample sizes and numbers of events were small, and because the effect of missing data and the absence of publication bias could not be verified. PE-related mortality, and adverse effects such as haemodynamic instability and compliance, were not assessed by the included studies.

AUTHORS' CONCLUSIONS

Currently, only low-quality evidence is available from two published randomised controlled trials on outpatient versus inpatient treatment in low-risk patients with acute PE. The studies did not provide evidence of any clear difference between the interventions in overall mortality, bleeding and recurrence of PE.

Clinical and Economic Outcomes in Low-risk Pulmonary Embolism Patients Treated with Rivaroxaban versus Standard of Care

BACKGROUND

Rivaroxaban, a fixed-dose oral direct factor Xa inhibitor, does not require continuous monitoring and thus reduces the hospital stay and economic burden in low-risk pulmonary embolism (LRPE) patients. Study Question: What is the effectiveness of rivaroxaban versus the standard of care (SOC; low-molecular-weight heparin, unfractionated heparin, warfarin) among LRPE patients in the Veterans Health Administration?

STUDY DESIGN

Adult patients with continuous health plan enrollment for ≥12 months pre- and 3 months post-inpatient PE diagnosis (index date=discharge date) between October 1, 2011-June 30, 2015 and an anticoagulant claim during the index hospitalization were included.

MEASURES AND OUTCOMES

Patients scoring 0 points on the simplified Pulmonary Embolism Stratification Index were considered low-risk and were stratified into SOC and rivaroxaban cohorts. Propensity score matching (PSM) was used to compare hospital-acquired complications (HACs), PE-related outcomes (recurrent venous thromboembolism, major bleeding, and death), and healthcare utilization and costs between the rivaroxaban and SOC cohorts.

RESULTS

Among 6746 PE patients, 1918 were low-risk; of these, 73 were prescribed rivaroxaban, 1546 were prescribed SOC, and 299 were prescribed other anticoagulants during the index hospitalization. After 1:3 PSM, 64 rivaroxaban and 192 SOC patients were included. During the index hospitalization, rivaroxaban users (versus SOC) had similar inpatient length of stay (LOS; 7.0 vs 6.7 days, standardized difference [STD]=1.8) but fewer HACs (4.7% vs 10.4%; STD: 21.7). In the 90-day post-discharge period, PE-related outcome rates were similar between the cohorts (all p>0.05). However, rivaroxaban users had fewer outpatient (15.9 vs 20.4; p=0.0002) visits per patient as well as lower inpatient ($765 vs $2,655; p<0.0001), pharmacy ($711 vs $1,086; p=0.0033), and total costs ($6,270 vs $9,671; p=0.0027).

CONCLUSIONS

LRPE patients prescribed rivaroxaban had similar index LOS and PE-related outcomes, but fewer HACs, and lower total costs than those prescribed SOC.

Emergency Department Discharge of Pulmonary Embolus Patients

Background

Hospitalization for low‐risk pulmonary embolism (PE) is common, expensive, and of questionable benefit.

Objective

The objective was to determine if low‐risk PE patients discharged from the emergency department (ED) on rivaroxaban require fewer hospital days compared to standard of care (SOC).

Methods

Multicenter, open‐label randomized trial in low‐risk PE defined by Hestia criteria. Adult subjects were randomized to early ED discharge on rivaroxaban or SOC. Primary outcome was total number of initial hospital hours, plus hours of hospitalization for bleeding or venous thromboembolism (VTE), 30 days after randomization. A 90‐day composite safety endpoint was defined as major bleeding, clinically relevant nonmajor bleeding, and mortality.

Results

Of 114 randomized subjects, 51 were early discharge and 63 were SOC. Of 112 (98.2%) receiving at least one dose of study drug, 99 (86.8%) completed the study. Initial hospital LOS was 4.8 hours versus 33.6 hours, with a mean difference of –28.8 hours (95% confidence interval [CI] = –42.55 to –15.12 hours) for early discharge versus SOC, respectively. At 90 days, mean total hospital days (for any reason) were less for early discharge than SOC, 19.2 hours versus 43.2 hours, with a mean difference of 26.4 hours (95% CI = –46.97 to –3.34 hours). At 90 days, there were no bleeding events, recurrent VTE, or deaths. The composite safety endpoint was similar in both groups, with a difference in proportions of 0.005 (95% CI = –0.18 to 0.19). Total costs were $1,496 for early discharge and $4,234 for SOC, with a median difference of $2,496 (95% CI = –$2,999 to –$2,151).

Conclusions

Low‐risk ED PE patients receiving early discharge on rivaroxaban have similar outcomes to SOC, but fewer total hospital days and lower costs over 30 days.

Direct oral anticoagulants in the treatment of pulmonary embolism

OBJECTIVE

The objective of this review is to examine the management strategies for pulmonary embolism (PE) with an emphasis of the role of direct oral anticoagulants (DOACs).

METHODS

PubMed was searched to identify relevant journal articles published through April 2017. Additional references were obtained from articles discovered during the database search.

RESULTS

Initial heparinization followed by long-term anticoagulation with vitamin K antagonists has been considered the mainstay for the treatment of PE. However, DOACs now offer comparably effective and potentially safer alternatives for both acute and long-term treatment of PE using a monotherapy approach without the need for initial heparinization for rivaroxaban or apixaban. Advantages to using DOACs include oral availability, rapid onset of action, minimal drug and food interactions, predictable pharmacokinetics, and lack of need for routine monitoring. Limitations of using these agents include a limited availability of assays to quickly and efficiently measure their anticoagulant effects and the lack of widely available reversal agents for the direct oral factor Xa inhibitors; although idarucizumab has recently been approved for the reversal of dabigatran's anticoagulant effects.

CONCLUSIONS

Advantages to using DOACs render them an attractive alternative to conventional therapy in PE treatment that may simplify acute and long-term treatment paradigms, improve patient outcomes, and increase patient compliance. However, questions remain pertaining to the use of DOACs in PE patients with high-risk features and in cancer patients and fragile populations. Clinical studies are under way to address many of these issues.

Cardiovascular Conditions in the Observation Unit: Beyond Chest Pain

The first emergency department observation units (EDOUs) focused on chest pain and potential acute coronary syndromes. However, most EDOUs now cover multiple other conditions that lend themselves to protocolized, aggressive diagnostic and therapeutic regimens. In this article, the authors discuss the management of 4 cardiovascular conditions that have been successfully deployed in EDOUs around the country.

Discharge or admit? Emergency department management of incidental pulmonary embolism in patients with cancer: a retrospective study

BACKGROUND

Hospitalization and early anticoagulation therapy remain standard care for patients who present to the emergency department (ED) with pulmonary embolism (PE). For PEs discovered incidentally, however, optimal therapeutic strategies are less clear-and all the more so when the patient has cancer, which is associated with a hypercoagulable state that exacerbates the threat of PE.

METHODS

We conducted a retrospective review of a historical cohort of patients with cancer and incidental PE who were referred for assessment to the ED in an institution whose standard of care is outpatient treatment of selected patients and use of low-molecular-weight heparin for anticoagulation. Eligible patients had received a diagnosis of incidental PE upon routine contrast enhanced chest CT for cancer staging. Survival data was collected at 30 days and 90 days from the date of ED presentation and at the end of the study.

RESULTS

We identified 193 patients, 135 (70%) of whom were discharged and 58 (30%) of whom were admitted to the hospital. The 30-day survival rate was 92% overall, 99% for the discharged patients and 76% for admitted patients. Almost all (189 patients, 98%) commenced anticoagulation therapy in the ED; 170 (90%) of these received low-molecular-weight heparin. Patients with saddle pulmonary artery incidental PEs were more likely to die within 30 days (43%) than were those with main or lobar (11%), segmental (6%), or subsegmental (5%) incidental PEs. In multivariate analysis, Charlson comorbidity index (age unadjusted), hypoxemia, and incidental PE location (P = 0.004, relative risk 33.5 (95% CI 3.1-357.4, comparing saddle versus subsegmental PE) were significantly associated with 30-day survival. Age, comorbidity, race, cancer stage, tachycardia, hypoxemia, and incidental PE location were significantly associated with hospital admission.

CONCLUSIONS

Selected cancer patients presenting to the ED with incidental PE can be treated with low-molecular-weight heparin anticoagulation and safely discharged. Avoidance of unnecessary hospitalization may decrease in-hospital infections and death, reduce healthcare costs, and improve patient quality of life. Because the natural history and optimal management of this condition is not well described, information supporting the creation of straightforward evidence-based practice guidelines for ED teams treating this specialized patient population is needed.