Low left ventricular outflow tract velocity time integral predicts normotensive shock in patients with acute pulmonary embolism.

In this study, we found that a low LVOT VTI (<15 cm), a simple bedside point-of-care measurement, predicts normotensive shock in patients with acute intermediate-risk PE.

Catheter-based therapy for intermediate or high-risk pulmonary embolism is associated with lower in-hospital mortality in patients with cancer: Insights from the National Inpatient Sample.

BACKGROUND: Pulmonary embolism (PE) is a common complication among patients with cancer and is a significant contributor to morbidity and mortality. Catheter-based therapies (CBT), including catheter-directed thrombolysis (CDT) and mechanical thrombectomy, have been developed and are used in patients with intermediate or high-risk PE. However, there is a paucity of data on outcomes in patients with cancer as most clinical studies exclude this group of patients. AIMS: To characterize outcomes of patients with cancer admitted with intermediate or high-risk PE treated with CBT compared with no CBT. METHODS: Patients with an admission diagnosis of intermediate or high-risk PE and a history of cancer from October 2015 to December 2018 were identified using the National Inpatient Sample. Outcomes of interest were in-hospital death or cardiac arrest (CA) and major bleeding. Inverse probability treatment weighting (IPTW) was utilized to compare outcomes between patients treated with and without CBT. Variables that remained unbalanced after IPTW were adjusted using multivariable logistic regression. RESULTS: A total of 2084 unweighted admissions (10,420 weighted) for intermediate or high-risk PE and cancer were included, of which 136 (6.5%) were treated with CBT. After IPTW, CBT was associated with lower death or CA (aOR 0.54, 95% CI 0.46-0.64) but higher major bleeding (aOR 1.41, 95% CI 1.21-1.65). After stratifying by PE risk type, patients treated with CBT had lower risk of death or CA in both intermediate (aOR 0.52, 95% CI 0.36-0.75) and high-risk PE (aOR 0.48, 95% CI 0.33-0.53). However, patients with CBT were associated with increased risk of major bleeding in intermediate-risk PE (aOR 2.12, 95% CI 1.67-2.69) but not in those with high-risk PE (aOR 0.84, 95% CI 0.66-1.07). CONCLUSIONS: Among patients with cancer hospitalized with intermediate or high-risk PE, treatment with CBT was associated with lower risk of in-hospital death or CA but higher risk of bleeding. Prospective studies and inclusion of patients with cancer in randomized trials are warranted to confirm our findings.

Percutaneous mechanical thrombectomy in acute pulmonary embolism: Outcomes from a safety-net hospital.

BACKGROUND: Our study aims to present clinical outcomes of mechanical thrombectomy (MT) in a safety-net hospital. METHODS: This is a retrospective study of intermediate or high-risk pulmonary embolism (PE) patients who underwent MT between October 2020 and May 2023. The primary outcome was 30-day mortality. RESULTS: Among 61 patients (mean age 57.6 years, 47% women, 57% Black) analyzed, 12 (19.7%) were classified as high-risk PE, and 49 (80.3%) were intermediate-risk PE. Of these patients, 62.3% had Medicaid or were uninsured, 50.8% lived in a high poverty zip code. The prevalence of normotensive shock in intermediate-risk PE patients was 62%. Immediate hemodynamic improvements included 7.4 mmHg mean drop in mean pulmonary artery pressure (-21.7%, p < 0.001) and 93% had normalization of their cardiac index postprocedure. Thirty-day mortality for the entire cohort was 5% (3 patients) and 0% when restricted to the intermediate-risk group. All 3 patients who died at 30 days presented with cardiac arrest. There were no differences in short-term mortality based on race, insurance type, citizenship status, or socioeconomic status. All-cause mortality at most recent follow up was 13.1% (mean follow up time of 13.4 ± 8.5 months). CONCLUSION: We extend the findings from prior studies that MT demonstrates a favorable safety profile with immediate improvement in hemodynamics and a low 30-day mortality in patients with acute PE, holding true even with relatively higher risk and more vulnerable population within a safety-net hospital.

Medical and Mechanical Circulatory Support of the Failing Right Ventricle.

PURPOSE OF REVIEW: To describe medical therapies and mechanical circulatory support devices used in the treatment of acute right ventricular failure. RECENT FINDINGS: Experts have proposed several algorithms providing a stepwise approach to medical optimization of acute right ventricular failure including tailored volume administration, ideal vasopressor selection to support coronary perfusion, inotropes to restore contractility, and pulmonary vasodilators to improve afterload. Studies have investigated various percutaneous and surgically implanted right ventricular assist devices in several clinical settings. The initial management of acute right ventricular failure is often guided by invasive hemodynamic data tracking parameters of circulatory function with the use of pharmacologic therapies. Percutaneous microaxial and centrifugal extracorporeal pumps bypass the failing RV and support circulatory function in severe cases of right ventricular failure.

Chronic thromboembolic pulmonary hypertension and the post-pulmonary embolism (PE) syndrome.

Over a third of patients surviving acute pulmonary embolism (PE) will experience long-term cardiopulmonary limitations. Persistent thrombi, impaired gas exchange, and altered hemodynamics account for aspects of the postpulmonary embolism syndrome that spans mild functional limitations to debilitating chronic thromboembolic pulmonary hypertension (CTEPH), the most worrisome long-term consequence. Though pulmonary endarterectomy is potentially curative for the latter, less is understood surrounding chronic thromboembolic disease (CTED) and post-PE dyspnea. Advances in pulmonary vasodilator therapies and growing expertise in balloon pulmonary angioplasty provide options for a large group of patients ineligible for surgery, or those with persistent postoperative pulmonary hypertension. In this clinical review, we discuss epidemiology and pathophysiology as well as advances in diagnostics and therapeutics surrounding the spectrum of disease that may follow months after acute PE.

Real world prescribing practices of apixaban or rivaroxaban lead-in doses for the treatment of venous thromboembolism in hospitalized patients.

The oral factor Xa inhibitors (OFXAi) apixaban and rivaroxaban are increasingly utilized for the treatment of venous thromboembolism (VTE) with recommended initial higher dose 7- and 21-day lead-in regimens, respectively. In patients receiving initial parenteral anticoagulation, it remains unknown if the full recommended higher dose OFXAi lead-in regimens are warranted, or if days can be subtracted. We aimed to describe when clinicians may deviate from recommended lead-in durations and evaluate clinical outcomes in these scenarios. This is a retrospective, observational study of patients 18 years or older who were treated with rivaroxaban or apixaban for acute pulmonary embolism (PE) or symptomatic proximal deep vein thrombosis (DVT) that received parenteral anticoagulation for at least 24 h before transitioning to the OFXAi. Among our cohort of 171 patients with acute VTE who received parenteral anticoagulation for a median of 48 h, 134 (78%) were prescribed a full OFXAi lead-in and 37 (22%) were prescribed a reduced lead-in. Patients in the reduced lead-in group were older with more cardiac comorbidities and antiplatelet use. There were four recurrent thromboembolic events within 3 months, two in the reduced lead-in group and two in the full lead-in group (5% vs. 2%, p = 0.206). Bleeding within 3 months occurred in 9 (5%) patients, with 6 events occurring in the reduced lead-in group and 3 events in the full lead-in group (16% vs. 2%, p = 0.004). Prescribing patterns of OFXAi lead-in therapy duration are variable in patients receiving initial parenteral anticoagulation. Larger cohorts are needed to better define the safety and efficacy of lead-in reduction.

High incidence of patients lost to follow-up after venous thromboembolism diagnosis - Identifying an unmet need for targeted transition of care.

OBJECTIVES: Venous thromboembolism, including deep venous thrombosis and pulmonary embolism, is a major source of morbidity, mortality, and healthcare utilization. Given the prevalence of venous thromboembolism and its associated mortality, our study sought to identify factors associated with loss to follow-up in venous thromboembolism patients. METHODS: This is a single-center retrospective study of all consecutive admitted (inpatient) and emergency department patients diagnosed with acute venous thromboembolism via venous duplex examination and/or chest computed tomography from January 2018 to March 2019. Patients with chronic deep venous thrombosis and those diagnosed in the outpatient setting were excluded. Lost to venous thromboembolism-specific follow-up (LTFU) was defined as patients who did not follow up with vascular, cardiology, hematology, oncology, pulmonology, or primary care clinic for venous thromboembolism management at our institution within three months of initial discharge. Patients discharged to hospice or dead within 30 days of initial discharge were excluded from LTFU analysis. Statistical analysis was performed using STATA 16 (College Station, TX: StataCorp LLC) with a p-value of <0.05 set for significance. RESULTS: During the study period, 291 isolated deep venous thrombosis, 25 isolated pulmonary embolism, and 54 pulmonary embolism with associated deep venous thrombosis were identified in 370 patients. Of these patients, 129 (35%) were diagnosed in the emergency department and 241 (65%) in the inpatient setting. At discharge, 289 (78%) were on anticoagulation, 66 (18%) were not, and 15 (4%) were deceased. At the conclusion of the study, 120 patients (38%) had been LTFU, 85% of whom were discharged on anticoagulation. There was no statistically significant difference between those LTFU and those with follow-up with respect to age, gender, diagnosis time of day, venous thromboembolism anatomic location, discharge unit location, or anticoagulation choice at discharge. There was a non-significant trend toward longer inpatient length of stay among patients LTFU (16.2 days vs. 12.3 days, p = 0.07), and a significant increase in the proportion of LTFU patients discharged to a facility rather than home (p = 0.02). On multivariate analysis, we found a 95% increase in the odds of being lost to venous thromboembolism-specific follow-up if discharged to a facility (OR 1.95, CI 1.1-3.6, p = 0.03) as opposed to home. CONCLUSIONS: Our study demonstrates that over one-third of patients diagnosed with venous thromboembolism at our institution are lost to venous thromboembolism-specific follow-up, particularly those discharged to a facility. Our work suggests that significant improvement could be achieved by establishing a pathway for the targeted transition of care to a venous thromboembolism-specific follow-up clinic.

Thrombosis in hospitalized patients with viral respiratory infections versus COVID-19.

We evaluated the incidence of thrombosis in patients hospitalized with non-COVID-19 acute viral respiratory illnesses nationwide from 2012 to 2014 and compared this to the incidence among patients hospitalized with COVID-19 at a large health system in New York. Non-COVID-19 viral respiratory illness was complicated by acute MI in 2.8% of hospitalizations, VTE in 1.6%, ischemic stroke in 0.7%, and other systemic embolism in 0.1%. The proportion of hospitalizations complicated by thrombosis was lower in patients with viral respiratory illness in 2002-2014 than in COVID-19 (5% vs 16%; P< .001). BACKGROUND: Thrombosis is a prominent feature of the novel Coronavirus disease 2019 (COVID-19). The incidence of thrombosis during hospitalization for non-COVID-19 viral respiratory infections is uncertain. We evaluated the incidence of thrombosis in patients hospitalized with non-COVID-19 acute viral respiratory illnesses compared to COVID-19. METHODS: Adults age >18 years hospitalized with a non-COVID-19 viral respiratory illness between 2002 and 2014 were identified. The primary study outcome was a composite of venous and arterial thrombotic events, including myocardial infarction (MI), acute ischemic stroke, and venous thromboembolism (VTE), as defined by ICD-9 codes. The incidence of thrombosis in non-COVID-19 viral respiratory illnesses was compared to the recently published incidence of thrombosis in COVID-19 from 3,334 patients hospitalized in New York in 2020. RESULTS: Among 954,521 hospitalizations with viral pneumonia from 2002 to 2014 (mean age 62.3 years, 57.1% female), the combined incidence of arterial and venous thrombosis was 5.0%. Acute MI occurred in 2.8% of hospitalizations, VTE in 1.6%, ischemic stroke in 0.7%, and other systemic embolism in 0.1%. Patients with thrombosis had higher in-hospital mortality (14.9% vs 3.3%, P< .001) than those without thrombosis. The proportion of hospitalizations complicated by thrombosis was lower in patients with viral respiratory illness in 2002-2014 than in COVID-19 (median age 64; 39.6% female) in 2020 (5% vs 16%; P< .001) CONCLUSION: In a nationwide analysis of hospitalizations for viral pneumonias, thrombosis risk was lower than that observed in patients with COVID-19. Investigations into mechanisms of thrombosis and risk reduction strategies in COVID-19 and other viral respiratory infections are necessary.

A Systematic Review of the Incidence and Outcomes of In-Hospital Cardiac Arrests in Patients With Coronavirus Disease 2019.

OBJECTIVES: To investigate the incidence, characteristics, and outcomes of in-hospital cardiac arrest in patients with coronavirus disease 2019 and to describe the characteristics and outcomes for patients with in-hospital cardiac arrest within the ICU, compared with non-ICU patients with in-hospital cardiac arrest. Finally, we evaluated outcomes stratified by age. DATA SOURCES: A systematic review of PubMed, EMBASE, and preprint websites was conducted between January 1, 2020, and December 10, 2020. Prospective Register of Systematic Reviews identification: CRD42020203369. STUDY SELECTION: Studies reporting on consecutive in-hospital cardiac arrest with a resuscitation attempt among patients with coronavirus disease 2019. DATA EXTRACTION: Two authors independently performed study selection and data extraction. Study quality was assessed with the Newcastle-Ottawa Scale. Data were synthesized according to the Preferred Reporting Items for Systematic Reviews guidelines. Discrepancies were resolved by consensus or through an independent third reviewer. DATA SYNTHESIS: Eight studies reporting on 847 in-hospital cardiac arrest were included. In-hospital cardiac arrest incidence varied between 1.5% and 5.8% among hospitalized patients and 8.0-11.4% among patients in ICU. In-hospital cardiac arrest occurred more commonly in older male patients. Most initial rhythms were nonshockable (83.9%, [asystole = 36.4% and pulseless electrical activity = 47.6%]). Return of spontaneous circulation occurred in 33.3%, with a 91.7% in-hospital mortality. In-hospital cardiac arrest events in ICU had higher incidence of return of spontaneous circulation (36.6% vs 18.7%; p < 0.001) and relatively lower mortality (88.7% vs 98.1%; p < 0.001) compared with in-hospital cardiac arrest in non-ICU locations. Patients greater than or equal to 60 years old had significantly higher in-hospital mortality than those less than 60 years (93.1% vs 87.9%; p = 0.019). CONCLUSIONS: Approximately, one in 20 patients hospitalized with coronavirus disease 2019 received resuscitation for an in-hospital cardiac arrest. Hospital survival after in-hospital cardiac arrest within the ICU was higher than non-ICU locations and seems comparable with prepandemic survival for nonshockable rhythms. Although the data provide guidance surrounding prognosis after in-hospital cardiac arrest, it should be interpreted cautiously given the paucity of information surrounding treatment limitations and resource constraints during the pandemic. Further research is into actual causative mechanisms is needed.

Prevalence and Outcomes of D-Dimer Elevation in Hospitalized Patients With COVID-19.

OBJECTIVE: To determine the prevalence of D-dimer elevation in coronavirus disease 2019 (COVID-19) hospitalization, trajectory of D-dimer levels during hospitalization, and its association with clinical outcomes. Approach and Results: Consecutive adults admitted to a large New York City hospital system with a positive polymerase chain reaction test for SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) between March 1, 2020 and April 8, 2020 were identified. Elevated D-dimer was defined by the laboratory-specific upper limit of normal (>230 ng/mL). Outcomes included critical illness (intensive care, mechanical ventilation, discharge to hospice, or death), thrombotic events, acute kidney injury, and death during admission. Among 2377 adults hospitalized with COVID-19 and ≥1 D-dimer measurement, 1823 (76%) had elevated D-dimer at presentation. Patients with elevated presenting baseline D-dimer were more likely than those with normal D-dimer to have critical illness (43.9% versus 18.5%; adjusted odds ratio, 2.4 [95% CI, 1.9-3.1]; P<0.001), any thrombotic event (19.4% versus 10.2%; adjusted odds ratio, 1.9 [95% CI, 1.4-2.6]; P<0.001), acute kidney injury (42.4% versus 19.0%; adjusted odds ratio, 2.4 [95% CI, 1.9-3.1]; P<0.001), and death (29.9% versus 10.8%; adjusted odds ratio, 2.1 [95% CI, 1.6-2.9]; P<0.001). Rates of adverse events increased with the magnitude of D-dimer elevation; individuals with presenting D-dimer >2000 ng/mL had the highest risk of critical illness (66%), thrombotic event (37.8%), acute kidney injury (58.3%), and death (47%). CONCLUSIONS: Abnormal D-dimer was frequently observed at admission with COVID-19 and was associated with higher incidence of critical illness, thrombotic events, acute kidney injury, and death. The optimal management of patients with elevated D-dimer in COVID-19 requires further study.

Pulmonary Embolism Response Team activation during the COVID-19 pandemic in a New York City Academic Hospital: a retrospective cohort analysis.

Coronavirus disease 2019 (COVID-19) is associated with increased rates of deep vein thrombosis (DVT) and pulmonary embolism (PE). Pulmonary Embolism Response Teams (PERT) have previously been associated with improved outcomes. We aimed to investigate whether PERT utilization, recommendations, and outcomes for patients diagnosed with acute PE changed during the COVID-19 pandemic. This is a retrospective cohort study of all adult patients with acute PE who received care at an academic hospital system in New York City between March 1st and April 30th, 2020. These patients were compared against historic controls between March 1st and April 30th, 2019. PE severity, PERT utilization, initial management, PERT recommendations, and outcomes were compared. There were more cases of PE during the pandemic (82 vs. 59), but less PERT activations (26.8% vs. 64.4%, p < 0.001) despite similar markers of PE severity. PERT recommendations were similar before and during the pandemic; anticoagulation was most recommended (89.5% vs. 86.4%, p = 0.70). During the pandemic, those with PERT activations were more likely to be female (63.6% vs. 31.7%, p = 0.01), have a history of DVT/PE (22.7% vs. 1.7%, p = 0.01), and to be SARS-CoV-2 PCR negative (68.2% vs. 38.3% p = 0.02). PERT activation during the pandemic is associated with decreased length of stay (7.7 ± 7.7 vs. 13.2 ± 12.7 days, p = 0.02). PERT utilization decreased during the COVID-19 pandemic and its activation was associated with different biases. PERT recommendations and outcomes were similar before and during the pandemic, and led to decreased length of stay during the pandemic.

Point-of-care ultrasound during the COVID-19 pandemic: A multidisciplinary approach between intensivists and echocardiographers.

PURPOSE: The coronavirus disease-2019 (COVID-19) led to a large influx of critically ill patients and altered echocardiography laboratory workflow. We developed a point-of-care ultrasound (POCUS) first approach to patients requiring echocardiography and describe our workflow and findings. METHODS: We performed a single-center retrospective analysis of all POCUS studies performed on critically ill patients with COVID-19. Sonography was performed by intensivists, uploaded and archived, and rapidly reviewed by echocardiographers. We evaluated each study based on the number of views obtained. Additionally, we provide a description of the workflow during the COVID-19 surge at a tertiary care hospital in New York City. RESULTS: Fifty patients had POCUS studies performed by intensivists and reviewed by echocardiographers obviating the need for sonographer-performed studies. Of the 48 cardiac POCUS studies, 17% of patients had 4 of 4 standard views available while 53% had 3 of 4 standard views. The parasternal long-axis view was obtained on 81%, subxiphoid view on 79%, apical 4-chamber view on 71%, and parasternal short-axis view on 63% of patients. CONCLUSIONS: Our POCUS workflow allowed intensivists to perform cardiac sonography for rapid bedside diagnosis of pathology with immediate interpretation performed by echocardiographers. At least 3 views were obtained in the majority of cases.

Thromboelastography Profiles of Critically Ill Patients With Coronavirus Disease 2019.

OBJECTIVES: The rate of thromboembolic events among patients with coronavirus disease 2019 is high; however, there is no robust method to identify those at greatest risk. We reviewed thromboelastography studies in critically ill patients with coronavirus disease 2019 to characterize their coagulation states. DESIGN: Retrospective. SETTING: Tertiary ICU in New York City. PATIENTS: Sixty-four patients with coronavirus disease 2019 admitted to the ICU with thromboelastography performed. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Fifty percent of patients had a clotting index in the hypercoagulable range (clotting index > 3) (median 3.05). Reaction time and K values were below the lower limit of normal in 43.8% of the population consistent with a hypercoagulable profile. The median α angle and maximum amplitude (75.8° and 72.8 mm, respectively) were in the hypercoagulable range. The α angle was above reference range in 70.3% of patients indicative of rapid clot formation. Maximum amplitude, a factor of fibrinogen and platelet count and function, and a measure of clot strength was above reference range in 60.1% of patients. Thirty-one percent had thromboembolic events; thromboelastography parameters did not correlate with events in our cohort. Those with D-dimer values greater than 2,000 were more likely to have shorter reaction times compared with those with D-dimer levels less than or equal to 2,000 (4.8 vs 5.6 min; p = 0.001). CONCLUSIONS: A large proportion of critically ill patients with coronavirus disease 2019 have hypercoagulable thromboelastography profiles with additional derangements related to fibrinogen and platelet function. As the majority of patients have an elevated thromboelastography maximum amplitude, a follow-up study evaluating platelet aggregation would be instructive.

Low left ventricular outflow tract velocity time integral is associated with poor outcomes in acute pulmonary embolism.

The left ventricular outflow tract (LVOT) velocity time integral (VTI) is an easily measured echocardiographic stroke volume index analog. Low values predict adverse outcomes in left ventricular failure. We postulate the left ventricular VTI may be a signal of right ventricular dysfunction in acute pulmonary embolism, and therefore a predictor of poor outcomes. We retrospectively reviewed echocardiograms on all Pulmonary Embolism Response Team activations at our institution at the time of pulmonary embolism diagnosis. Low LVOT VTI was defined as ⩽ 15 cm. We examined two composite outcomes: (1) in-hospital death or cardiac arrest; and (2) shock or need for primary reperfusion therapies. Sixty-one of 188 patients (32%) had a LVOT VTI of ⩽ 15 cm. Low VTI was associated with in-hospital death or cardiac arrest (odds ratio (OR) 6, 95% CI 2, 17.9; p = 0.0014) and shock or need for reperfusion (OR 23.3, 95% CI 6.6, 82.1; p < 0.0001). In a multivariable model, LVOT VTI ⩽ 15 remained significant for death or cardiac arrest (OR 3.48, 95% CI 1.02, 11.9; p = 0.047) and for shock or need for reperfusion (OR 8.12, 95% CI 1.62, 40.66; p = 0.011). Among intermediate-high-risk patients, low VTI was the only variable associated with the composite outcome of death, cardiac arrest, shock, or need for reperfusion (OR 14, 95% CI 1.7, 118.4; p = 0.015). LVOT VTI is associated with adverse short-term outcomes in acute pulmonary embolism. The VTI may help risk stratify patients with intermediate-high-risk pulmonary embolism.

The physiology of cardiac tamponade and implications for patient management.

Exceeding the limit of pericardial stretch, intrapericardial collections exert compression on the right heart and decrease preload. Compensatory mechanisms ensue to maintain hemodynamics in the face of a depressed stroke volume but are outstripped as disease progresses. When constrained within a pressurized pericardial space, the right and left ventricles exhibit differential filling mediated by changes in intrathoracic pressure. Invasive hemodynamics and echocardiographic findings inform on the physiologic effects. In this review, we describe tamponade physiology and implications for supportive care and effusion drainage.

Physiology-Guided Resuscitation: Monitoring and Augmenting Perfusion during Cardiopulmonary Arrest.

Given the high morbidity and mortality associated with cardiopulmonary arrest, there have been multiple trials aimed at better monitoring and augmenting coronary, cerebral, and systemic perfusion. This article aims to elucidate these interventions, first by detailing the physiology of cardiopulmonary resuscitation and the available tools for managing cardiopulmonary arrest, followed by an in-depth examination of the newest advances in the monitoring and delivery of advanced cardiac life support.

Anti-factor Xa as the preferred assay to monitor heparin for the treatment of pulmonary embolism.

INTRODUCTION: The mainstay of acute pulmonary embolism (PE) treatment is anticoagulation. Timely anticoagulation correlates with decreased PE-associated mortality, but the ability to achieve a therapeutic activated partial thromboplastin time (aPTT) with unfractionated heparin (UFH) remains limited. Although some institutions have switched to a more accurate and reproducible test to assess for heparin's effectiveness, the anti-factor Xa (antiXa) assay, data correlating a timely therapeutic antiXa to PE-associated clinical outcomes remains scarce. We evaluated time to a therapeutic antiXa using intravenous heparin after PE response team (PERT) activation and assessed clinical outcomes including bleeding and recurrent thromboembolic events. METHODS: This was a retrospective cohort study at NYU Langone Health. All adult patients ≥18 years with a confirmed PE started on IV UFH with >2 antiXa levels were included. Patients were excluded if they received thrombolysis or alternative anticoagulation. The primary endpoint was the time to a therapeutic antiXa level of 0.3-0.7 units/mL. Secondary outcomes included recurrent thromboembolism, bleeding and PE-associated mortality within 3 months. RESULTS: A total of 330 patients with a PERT consult were identified with 192 patients included. The majority of PEs were classified as sub massive (64.6%) with 87% of patients receiving a bolus of 80 units/kg of UFH prior to starting an infusion at 18 units/kg/hour. The median time to the first therapeutic antiXa was 9.13 hours with 93% of the cohort sustaining therapeutic anticoagulation at 48 hours. Recurrent thromboembolism, bleeding and mortality occurred in 1%, 5% and 6.2%, respectively. Upon univariate analysis, a first antiXa <0.3 units/ml was associated with an increased risk of mortality [27.78% (5/18) vs 8.05% (14/174), p = 0.021]. CONCLUSION: We observed a low incidence of recurrent thromboembolism or PE-associated mortality utilizing an antiXa titrated UFH protocol. The use of an antiXa based heparin assay to guide heparin dosing and monitoring allows for timely and sustained therapeutic anticoagulation for treatment of PE.