Research Forum Abstracts Of 112 (98.2%) receiving at least 1 dose of study drug, 99 (86.8%) completed the study. There were 15 (13.2%) discontinuations; 7 (6.1%) lost to follow-up, 4 (3.5%) adverse events, and 2 (1.8%) consent withdrawal. Median (IQR) therapy duration was 91 (89, 94), and 89 (85, 93) days for rivaroxaban vs SOC. The intent to treat primary endpoint was 4.6 hours for rivaroxaban vs 33.4 hours for SOC (mean difference -1.20 days, 95% CI -1.773, -0.630). Mean total hospital days (for any reason) at 90 days after randomization were significantly shorter for rivaroxaban than SOC; 0.8 vs. 1.8 days (mean difference between groups was -0.8 days; 95% CI: -0.963, -0.605). At 90 days follow-up there were no ISTH bleeding events, recurrent VTE, or deaths. Unplanned VTE and bleeding related hospital or doctor visits within 90 days were numerically lower with rivaroxaban; 2 (3.9%) vs. 4 (6.3%); difference in proportions -0.02 (95% CI: -0.21 to 0.16). The composite safety endpoint was similar in both groups; difference in proportions 0.005 (95% CI: -0.181 to 0.191). There were numerically more adverse events (AEs) with rivaroxaban than SOC, 59.2% vs. 39.7%, however, the overall rate of serious AEs, AEs leading to hospitalization, and AEs leading to study drug discontinuation were similar between cohorts (p>0.05). Conclusions: In this prospective, open label, randomized standard-therapy controlled trial, low risk ED PE patients discharged on rivaroxaban had similar outcomes as SOC but spent fewer total days in the hospital in the month following their ED discharge.
71
PERC Rule to Exclude the Diagnosis of Pulmonary Embolism in Low-Risk Emergency Patients: A Noninferiority Randomized Controlled Trial
Freund Y, Bokobza J, Cachanado M, Aubry A, Aufredou F-P, Raynal P-A, Simon T, Riou B/Hopital Pitié-Salpêtrière, Paris, France; Hôpital Cochin, Paris, France; Hopital Saint-Antoine, Paris, France; Hopital Avicenne, Paris, France
Study Objectives: As physicians may fear missing a pulmonary embolism (PE), some reports suggest that this diagnosis may be over-investigated, if not overdiagnosed, in emergency departments (ED). The Pulmonary Embolism Rule-out Criteria (PERC), an 8-item block of clinical criteria, has been derived and validated to select patients that should not undergo any investigation for PE. However, this rule has never been prospectively validated in an interventional study, and controversies on its safety limit its application in Europe. We tested the hypothesis that among patients with a low clinical probability of PE and a PERC score of zero, PE can be safely ruled out. Methods: This was a cluster cross-over noninferiority randomized controlled trial (N¼14 centers) in France. Each center was randomized for the study period: six months control period (routine care) followed by six months intervention period (PERC-based strategy), or in reverse. The two periods were separated by a two month wash-out period. We included all adult patients with a suspicion of PE and low gestalt clinical probability. In the intervention period, if the PERC score was zero, PE was ruled out with no other test. During routine care, all included patients underwent D-dimer testing. The primary outcome was the percentage of failure resulting from each diagnostic strategy, defined as venous thromboembolic events diagnosed at three-month follow-up among patients for whom PE was initially ruled out. Secondary endpoints included computed tomography of pulmonary artery (CTPA) performed, time spent in the ED, and initiation of anticoagulation therapy. The delta was fixed at 1.5%, power at 80%, one-sided alpha at 5% and a cluster design effect at 1.12; therefore, we needed to recruit 1920 patients. Results: We included 1916 patients in the study: 962 in the PERC group and 954 in the control group. Mean age was 44 years (+/- 17). In the PERC group, 462 (48%) patients had a PERC score of 0. A total of 39 PEs (2%) were diagnosed at the index visit: 14 (1.5%) in the PERC group vs 25 (2.6%) in the control group (relative risk reduction RRR 45%, 95% confidence interval CI [-6%; 71%], p¼0.07). Among outpatients for whom PE was ruled out, there were no venous thromboembolic events diagnosed after three months: primary outcome at 0 (0%) in both groups. We observed a reduction of CTPA performance in the PERC group: 129 (13%) vs 220 (23%), RRR 42% (95% CI 29% to 52%, p<0.001). We also observed a reduction in median length of ED stay: 4h36 (interquartile range IQR 3h16 – 6:22) vs 5h14 (IQR 3h50 – 7:19), p<0.001. There was no significant reduction in initiation of anticoagulation [21 (2%) vs 33 (3.5%), p¼0.09].
S30 Annals of Emergency Medicine
The per-protocol analysis of 1856 patients (56 patients lost to follow up and 4 patients in the PERC group that were investigated for PE despite a PERC¼0) found similar results. Conclusions: The implementation of the PERC strategy for patients with a low gestalt clinical probability of PE in the ED was safe and reduced length of stay and rate of unnecessary testing in the ED.
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Predictors of Serious Outcomes After Syncope: A Systematic Review and Meta-Analysis
Sun B, Gibson T, Weiss R/Oregon Health and Science University, Portland, OR; UCLA, Los Angeles, CA; UCLA, Los Angeles, CA
Study Objectives: The emergency department (ED) evaluation of syncope is associated with high rates of testing and admissions with scant evidence of benefit. Objective risk prediction is foundational for creating high-value management algorithms for syncope; however, existing prediction instruments are no better than clinical judgment. We perform a systematic review and meta-analysis to identify predictors of adverse outcome after an ED visit for syncope. Methods: We performed a Pubmed search of all observational syncope risk prediction studies that enrolled patients from ED settings from 1990 to 2017. We also manually reviewed the reference lists of relevant studies. Serious outcomes included death, arrhythmias, structural or ischemic heart disease, pulmonary embolism, stroke, and severe anemia. Papers were included in a meta-analysis if they provided either univariate or multivariate information for potential predictors stratified by the presence of adverse outcomes. We analyzed all variables for which at least two papers provided information. We created summary estimates of association on a variable-by-variable basis using a Bayesian randomeffects model. Results: We screened 3,158 potentially eligible studies. We included 14 studies representing 71,234 patients. There were 50 candidate predictors of adverse outcomes reported in these studies. The Figure illustrates univariate odds ratios for the 30 candidate predictors that were reported by at least two papers. The top five risk factors included advanced age, abnormal ECG, a prior history of congestive heart failure, myocardial infarction, or arrhythmia. Conclusions: We establish baseline effect estimates for a large number of potential risk predictors. We intend to use these estimates to inform “priors” in the development of a novel Bayesian risk prediction model.
Volume 70, no. 4s : October 2017