Symptomatic Pulmonary Embolism Research Articles

Approach to: Venous Thromboembolism

Venous thromboembolisms can manifest as a spectrum of diseases and complications, such as deep vein thrombosis (DVT) and pulmonary embolism (PE), as a consequence of hypercoagulability, endothelial damage and/or venous stasis. DVT can present as localized pain or heaviness, unilateral edema, dilatation of superficial nonvaricose veins, a palpable cord or Homans’s sign. Symptoms of PE include acute or worsening shortness of breath and pleuritic chest pain while physical examination may be remarkable for tachycardia and tachypnea. However, given their non-specificity, using these signs and symptoms alone allows for poor differentiation between VTE and other entities. This review will focus on a multi-step diagnostic tree allowing for evidence-based interpretation of tests following a determined pre-test probability (PTP), as per Thrombosis Canada recommendations and ASH clinical guidelines. An introduction to VTE in Pediatrics and pregnancy will also be discussed.

Signs of chronic thromboembolic pulmonary hypertension in acute pulmonary embolism: results from the FOCUS study

Abstract Background/Introduction Chronic thromboembolic pulmonary hypertension (CTEPH) is considered to be a late complication of acute pulmonary embolism (PE). However, up to one third of CTEPH patients do not report prior symptomatic venous thromboembolism (VTE). Furthermore, a substantial proportion of patients presenting with an acute PE event may exhibit radiological signs of chronicity at baseline computed tomography pulmonary angiography (CTPA). Purpose To determine the prevalence of baseline radiological parameters indicating chronic thrombosis or pulmonary hypertension, and ultimately pre-existing CTEPH, among patients with acute PE enrolled in the prospective multicentre Follow-Up after Acute Pulmonary Embolism (FOCUS) cohort study. Methods Patients with acute symptomatic PE and absence of a known history of CTEPH, enrolled at two large FOCUS centres, were included. The assessment of index CTPA scans was conducted by two independent expert radiologists who were unaware of the clinical characteristics and the follow-up data of the patients. CTPA parameters indicating chronicity were prespecified on the basis of recently proposed criteria in the literature. A third independent expert radiologist provided an assessment in case of disagreement between the first two. Baseline radiological data were prospectively validated with the aid of two-year prospective clinical follow-up data focusing on CTEPH and the post-PE syndrome (co-primary outcomes of the FOCUS study). Results A total of 303 patients (median age: 63 years, 44.6% women) were included. In >95% of the patients, the expert radiologists could confirm signs of acute PE at baseline CTPA. Radiological signs of chronic thrombi or pulmonary hypertension at baseline were detected in 46 (15.2%) patients. In 8 patients, the expert radiologists agreed on the presence of pre-existing CTEPH based on their interpretation of the overall radiological pattern. During follow-up, five (1.7%; 95% CI 0.7–3.8%) of 303 patients were diagnosed with CTEPH, over a median time of 95 days after baseline. Four of them were among the 8 patients in whom the radiological experts suspected pre-existing CTEPH at baseline, and among the 46 patients in whom CTPA findings suggesting chronic thrombi or chronic pulmonary hypertension were present at baseline. The use of the predefined individual parameters of chronicity from the literature also helped identifying patients with chronic disease, and could be used as a tool for screening acute PE patients for pre-existing CTEPH. Conclusion A substantial proportion of patients who are diagnosed with CTEPH during follow-up after acute PE may already have pre-existing CTEPH at the time of the index event. An intensified follow-up programme and focussed screening for CTEPH should be considered in patients with signs of chronicity at baseline CTPA. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): Bayer Health Care

OUTCOMES FROM CATHETER-DIRECTED EMBOLECTOMY FOR INTERMEDIATE-RISK AND HIGH-RISK PULMONARY EMBOLISM

OUTCOMES FROM CATHETER-DIRECTED EMBOLECTOMY FOR INTERMEDIATE-RISK AND HIGH-RISK PULMONARY EMBOLISM

Extended Thromboprophylaxis in Hospitalized Patients with Heart Failure: A Post Hoc Analysis of the MAGELLAN Study.

This post hoc subgroup analysis examined efficacy and safety outcomes with extended thromboprophylaxis rivaroxaban compared with in-hospital enoxaparin in 2,078 patients from the MAGELLAN study who had a hospitalization for heart failure or a history of heart failure and a lower risk of bleeding. A significant 36% reduction in the composite endpoint of asymptomatic proximal deep vein thrombosis (DVT) in the lower extremity, symptomatic DVT in the lower extremity (proximal or distal), symptomatic nonfatal pulmonary embolism, and venous thromboembolism-related death was observed with rivaroxaban. Major bleeding was low in both groups and not significantly increased with rivaroxaban.

Clinical and imaging outcomes of OptionELITE vena cava filter placement procedures

ObjectiveWe sought to determine the clinical and imaging outcomes after placement of the OptionELITE inferior vena cava (IVC) filter (Argon Medical Devices, Plano, TX). MethodsThe clinical characteristics and imaging findings of patients who had undergone OptionELITE filter placement at six affiliated hospitals between January 1, 2013 and April 19, 2019, were analyzed. Data were obtained from the Radiology Information System, imaging database, and electronic medical records. The patients were followed up until 1 month after filter removal, death, or the first clinic visit and imaging study after June 1, 2019. ResultsA total of 603 filter placement procedures in 594 patients were evaluated. Of the 603 procedures, 602 were technically successful (99.8%). Of the 594 patients, 356 had presented with acute pulmonary embolism and/or deep vein thrombosis. A total of 189 filters were retrieved from the 191 patients for whom retrieval had been attempted at 4.3 ± 6.3 months (median, 2.5 months) after placement. The 414 filters without removal procedures had been followed up for 14.8 ± 17.7 months (median, 6.9 months). During the follow-up period, 57 patients (9.5%) had developed new or worsening deep vein thrombosis caudal to the filter and 19 (3.2%) had experienced new symptomatic nonfatal pulmonary embolism after filter placement. One filter had migrated and fractured, and another filter had fractured and a strut was lost. Perforation was demonstrated equivocally in 12 (3%) and definitely in 17 (4.3%) of 399 patients with adequate imaging studies available, with penetration into surrounding structures in 13 patients (3.3%). Of 332 patients with adequate imaging studies, 12 (3.6%) had developed substantial IVC thrombosis and 4 (1.2%) had developed IVC occlusion. ConclusionsThe rates of symptomatic pulmonary embolism and filter-related complications were low after OptionELITE IVC filter placement, and filter retrieval, when attempted, was 99% successful.

Pulmonary Embolism in the Cancer Associated Thrombosis Landscape.

In cancer patients, pulmonary embolism (PE) is the second leading cause of death after the cancer itself, most likely because of difficulties in diagnosing the disease due to its nonclassical presentation. The risk of PE recurrence and possibly the case-fatality rate depends on whether the patient presents a symptomatic PE, an unsuspected PE, a subsegmental PE, or a catheter-related PE. Choosing the best therapeutic option is challenging and should consider the risk of both the recurrence of thrombosis and the occurrence of bleeding. The purpose of this review is to provide an overview of the clinical characteristics and the treatment of cancer-associated PE, which could benefit clinicians to better manage the deadliest form of thrombosis associated with cancer. After a brief presentation of the epidemiological data, we will present the current attitude towards the diagnosis and the management of cancer patients with PE. Finally, we will discuss the perspectives of how the medical community can improve the management of this severe medical condition.

Pharmacomechanical Catheter-Directed Thrombolysis With the Bashir Endovascular Catheter for Acute Pulmonary Embolism: The RESCUE Study

BackgroundCatheter-directed thrombolysis (CDT) has been associated with rapid recovery of right ventricular (RV) function. The Bashir catheter was developed for enhanced thrombolysis in large vessels such as the pulmonary arteries (PAs) with lower doses of tissue plasminogen activator (tPA). ObjectivesThe aim of this study was to evaluate the efficacy and safety of tPA infused using a pharmacomechanical (PM) CDT device called the Bashir endovascular catheter in patients with intermediate-risk acute pulmonary embolism (PE). MethodsPatients with symptoms of acute PE with computed tomographic evidence of RV dilatation were enrolled. The Bashir catheter was used to deliver 7 mg tPA into each PA over 5 hours. The primary efficacy endpoint was the core laboratory–assessed change in computed tomographic angiography–derived RV/left ventricular (LV) diameter ratio at 48 hours, and the primary safety endpoint was serious adverse events (SAEs) including major bleeding at 72 hours. ResultsAt 18 U.S. sites, 109 patients were enrolled. The median device placement time was 15 minutes. At 48 hours after PM-CDT, the RV/LV diameter ratio decreased by 0.56 (33.3%; P < 0.0001). PA obstruction as measured by the refined modified Miller index was reduced by 35.9% (P < 0.0001). One patient (0.92%) had 2 SAEs: a retroperitoneal bleed (procedure related) and iliac vein thrombosis (device related). Two other procedure-related SAEs were epistaxis and non–access site hematoma with anemia. ConclusionsPM-CDT with the Bashir endovascular catheter is associated with a significant reduction in RV/LV diameter ratio and a very low rate of adverse events or major bleeding in patients with intermediate-risk acute PE. The notable finding was a significant reduction in PA obstruction with low-dose tPA. (Recombinant tPA by Endovascular Administration for the Treatment of Submassive PE Using CDT for the Reduction of Thrombus Burden [RESCUE]; NCT04248868)

Construction and verification of a nomogram predicting the risk of preoperative deep vein thrombosis progression after elective spine surgery

ObjectiveThis study aimed to construct and verify a useful nomogram that predicts the risk of preoperative deep vein thrombosis (DVT) progression after elective spine surgery. MethodsData of patients were collected from 366 patients with preoperative DVT who underwent elective spine surgery at our hospital between July 2017 and May 2022. The least absolute shrinkage and selection operator method combined with multivariable logistic regression analysis were applied to select features for the preoperative DVT progression risk model. The model's capability was evaluated using the concordance index (C-index), calibration curve, and receiver operating characteristic (ROC) curve. The decision curve and bootstrapping were used to analyze the clinical value of the nomogram. ResultA total of 366 DVT patients were enrolled in this study. Preoperative DVT progression after elective spine surgery was 24.04% (88 cases). Among these patients, 86 patients had thrombosis extending into a proximal vein or appearing in a different branch of the vein, either ipsilateral or contralateral, and two had a symptomatic pulmonary embolism. D-dimer, lower extremity varicosities, hyperlipidemia, lower limb paralysis, and operation time were among the predictors in the nomogram. Furthermore, the C-index of the prediction nomogram was 0.805 (95％ CI: 0.754–0.856), with an interval bootstrapping validation of 0.786 and an area under the ROC curve value of 0.800. According to the calibration curves and decision curve analysis, the nomogram could accurately predict the probability of preoperative DVT progression after elective spine surgery. ConclusionThe advantages of the nomogram included the unique discrimination capability, clinical utility, and predictive accuracy, which was beneficial for clinicians to distinguish high-risk groups of DVT progression after elective spine surgery and formulate relevant prevention measures.

Case report: Bi-atrial thrombus after occlusion of atrial septal defect with acute cerebral infarction and pulmonary embolism

A 49-year-old man presented to the hospital with symptoms of acute cerebral infarction and pulmonary embolism who underwent transcatheter closure of atrial septal defect a year before. Transthoracic echocardiography showed a 13 × 9 mm hypoechoic mass attached to the left-atrial side of the device, which was suspected to be a neoplasm or thrombus. The patient was indicated for surgery after multidisciplinary discussion due to ineffective medical therapy and typical stroke and pulmonary embolism symptoms. Three-dimensional transesophageal echocardiography (3D-TEE) revealed left-atrial vegetation (21 × 16 mm) and right-atrial vegetation (8 × 6 mm) attached to the device, which was confirmed as thrombus by surgical separation and laboratory examination. This case highlights the importance of 3D-TEE and a multidisciplinary team in the diagnosis and therapy of device-related thrombus.

342.8: Postoperative Statin Therapy Is Not Associated With Reduced Incidence of Venous Thromboembolic Events Following Kidney Transplantation

Background: Deep vein thrombosis (DVT) and pulmonary embolism (PE), collectively venous thromboembolism (VTE), are common sources of morbidity and mortality following solid organ transplantation. The pleiotropic effects of statin therapy on inflammation and coagulation may reduce the risk of venous thromboembolism. This study evaluated whether statin therapy is associated with decreased venous thromboembolic (VTE) events following kidney transplantation. Methods: We performed a retrospective analysis of all primary kidney transplants performed between January 2014 and December 2019 at Mayo Clinic Arizona. Patients were divided into two groups depending on sustained statin therapy during the first year following transplantation. Statin exposure was defined as any statin prescribed on admission for KT or upon discharge from KT plus continous treatment for one year. Recipient and donor clinical and demographic data were collected. The primary outcome was admission for symptomatic VTE events (deep vein thrombosis (DVT) or pulmonary embolism (PE)). Cox regression was used to model overall survival and VTE event-free survival. Fine and Gray’s regression was used to model outcome for VTE while treating death as a competing risk event. Results: Sustained statin therapy in the first year following transplant was observed in 16.1% (n=223) of 1384 kidney transplants included in the study cohort. The control group of 1161 patients had no statin exposure during the first year following KT. Demographic and perioperative characteristics are presented in Table 1. The overall incidence of VTE events in the year following kidney transplant was 3.8%. VTE occurred in 4.1% of recipients treated with statins and 3.8% of the controls – (hazard ratio [HR] 0.96, 95% confidence interval [95% CI] 0.43, 2.14, P = 0.93) (Table 2). However, there were significant differences between the groups in terms of age, gender and body mass index. Following sensitivity analysis in which cohort matching was performed to account for these differences, there was no difference in VTE event-free survival (HR 0.85, 95% CI 0.43, 1.68, P=0.65) or overall survival (HR 0.54, 95%CI 0.15, 1.94, P= 0.35) between patients treated with statins compared to controls (Figure 3). Conclusion: In this single center, retrospective investigation, statin therapy in the year following successful kidney transplant was not associated with a reduction in risk of VTE. Although previous investigations have demonstrated ameliorative effects of statin therapy on rejection, VTE, cancer recurrence and vasculopathy following liver, heart and lung transplantation, the current study and others have failed to confirm any such benefit in the kidney transplant population.

Long-term outcomes after using retrievable vena cava filters in major trauma patients with contraindications to prophylactic anticoagulation

PurposeTo investigate the long-term outcomes of using vena cava filters to prevent symptomatic pulmonary embolism (PE) in major trauma patients who have contraindications to prophylactic anticoagulation.MethodsThis was an a priori sub-study of a randomized controlled trial (RCT) involving long-term outcome data of 223 patients who were enrolled in Western Australia. State-wide clinical information system, radiology database and death registry were used to assess long-term outcomes, including incidences of venous thromboembolism, venous injury and mortality beyond day-90 follow-up.ResultsThe median follow-up time of 198 patients (89%) who survived beyond 90 days was 65 months (interquartile range 59–73). Ten patients (5.1%) died after day-90 follow-up; and four patients developed venous thromboembolism, including two with symptomatic PE, all allocated to the control group (0 vs 4%, p = 0.043). Inferior vena cava injuries were not recorded in any patients. The mean total hospitalization cost, including the costs of the filter and its insertion and removal, to prevent one short- or long-term symptomatic PE was A$284,820 (€193,678) when all enrolled patients were considered. The number of patients needed to treat (NNT = 5) and total hospitalization cost to prevent one symptomatic PE (A$1,205 or €820) were, however, substantially lower when the filter was used only for patients who could not be anticoagulated within seven days of injury.ConclusionLong-term complications related to retrievable filters were rare, and the cost of using filters to prevent symptomatic PE was acceptable when restricted to those who could not be anticoagulated within seven days of severe injury.

Diagnosis, Diagnostic Tools, and Risk Stratification for Contemporary Treatment of Pulmonary Embolism.

Pulmonary embolism (PE) is quite common and is associated with significant morbidity and mortality. It is estimated that it is the cause of approximately 100,000 annual deaths in the United States. With great variability in presenting symptoms of PE, poor recognition of PE can be fatal. As such, many risk scores have been created to identify the sickest patients. Choosing the appropriate imaging modality is also critical. Invasive pulmonary angiography was once the gold standard to establish the diagnosis. With the advent of nuclear imaging, V/Q scans, invasive angiography has been phased out for diagnosing acute PE. At present, the standard for diagnosis of acute PE is computed tomography pulmonary angiography. In select patient cohorts, nuclear studies remain the modality of choice. Once the diagnosis of acute PE is established, there is a broad spectrum of severity in outcome which has led to substantial focus and development of risk stratification prediction models. We will discuss making the proper diagnosis with contemporary diagnostic tools and risk stratifying patients with PE to receive the correct treatment.

Outcomes After Transcatheter Aortic Valve Implantation in Men Versus Women

Gender-based differences in outcomes after successful transcatheter aortic valve implantation (TAVI) in patients without an indication for oral anticoagulation have not been well studied. We aim to evaluate gender-based differences in clinical outcomes after TAVI. In the present analysis of the GALILEO (Global study comparing a rivaroxaban-based antithrombotic strategy to an antiplatelet-based strategy after transcatheter aortic valve replacement to optimize clinical outcomes) trial, patients with symptomatic severe aortic stenosis and who underwent successful TAVI were stratified by gender. The primary outcome was major adverse cardiac and cerebrovascular events (MACCEs), a composite of all-cause mortality or thromboembolic events (including any stroke, myocardial infarction, symptomatic valve thrombosis, systemic embolism, deep-vein thrombosis, or pulmonary embolism). Major bleeding was defined as a composite of major, life-threatening, or disabling Valve Academic Research Consortium-2 bleeding. Of 1,644 patients, 813 were female, and 831 were male. At baseline, female patients were older and at higher surgical risk (Society of Thoracic Surgeons risk score: 4.7 ± 3.6 versus 3.6 ± 3.0, p &lt;0.0001) than male patients. After adjustment for differences in baseline clinical and procedural parameters, female patients had lower rates of MACCE (hazard ratio [HR] 0.69, 95% confidence interval [CI] 0.49 to 0.96), all-cause mortality (HR 0.54, 95% CI 0.34 to 0.87), and noncardiovascular mortality (HR 0.33, 95% CI 0.15 to 0.75) at a median of 17 months of follow-up. By landmark analyses, these differences appeared to emerge with a longer follow-up time. No significant differences in major, life-threatening, or disabling bleeding, cardiovascular mortality, and stroke were noted. In conclusion, compared with male patients, female patients with severe symptomatic aortic stenosis had a lower risk of MACCE and mortality but a similar risk of bleeding events after TAVI.

Left iliac vein involvement is a protective factor against symptomatic pulmonary embolism in lower left extremity deep vein thrombosis

ObjectiveLeft iliac vein compression is associated with left iliac vein thrombosis (IVT), potentially limiting the migration of the thrombus from this stenotic segment to the pulmonary arteries. We sought to investigate the differences in clinical characteristics and risk factors of symptomatic pulmonary embolism (SPE) in patients with deep vein thrombosis (DVT) in different limbs and anatomical locations. MethodsA retrospective analysis was conducted of 1476 patients with acute unilateral lower extremity DVT. Differences of clinical characteristics and risk factors between left-sided and right-sided DVT, IVT, and non-IVT, cases with SPE and cases without SPE were compared. Risk factors for SPE were investigated using logistic regression analysis. ResultsSPE was more common in patients with right-sided DVT than patients with left-sided DVT (13.8% vs 7.0%; P < .001). SPE incidence in left IVT (5.4%) was lower than that in left non-IVT, right IVT, and right non-IVT (12.8%, 10.1%, 16.6%, respectively; P < .001). There was no difference in SPE incidence among patients with left non-IVT, right IVT and right non-IVT (P > .05). In patients with left-sided DVT, male sex was associated with an increased odds of SPE (odds ratio [OR], 1.77; 95% confidence interval [CI], 1.10-2.85; P = .02). IVT, surgery, and immobilization were associated with a decreased odds of SPE (OR, 0.46 [95% CI, 0.28-0.76; P < .01]; OR, 0.55 [95% CI, 0.32-0.95; P = .03]; and OR, 0.53 [95% CI, 0.32-0.86; P = .01]). In patients with right-sided DVT, provoked DVT was associated with a decreased odds of SPE (OR, 0.50; 95% CI, 0.27-0.93; P = .03). ConclusionsLeft IVT is associated with a lower SPE incidence than right-sided DVT. Left IVT and may be a relative protective factor against SPE.

D-dimer and reduced-dose apixaban for extended treatment after unprovoked venous thromboembolism: the Apidulcis study

AbstractD-dimer assay is used to stratify patients with unprovoked venous thromboembolism (VTE) for the risk of recurrence. However, this approach was never evaluated since direct oral anticoagulants are available. With this multicenter, prospective cohort study, we aimed to assess the value of an algorithm incorporating serial D-dimer testing and administration of reduced-dose apixaban (2.5 mg twice daily) only to patients with a positive test. A total of 732 outpatients aged 18 to 74 years, anticoagulated for ≥12 months after a first unprovoked VTE, were included. Patients underwent D-dimer testing with commercial assays and preestablished cutoffs. If the baseline D-dimer during anticoagulation was negative, anticoagulation was stopped and testing repeated after 15, 30, and 60 days. Patients with serially negative results (286 [39.1%]) were left without anticoagulation. At the first positive result, the remaining 446 patients (60.9%) were given apixaban for 18 months. All patients underwent follow-up planned for 18 months. The study was interrupted after a planned interim analysis for the high rate of primary outcomes (7.3%; 95% confidence interval [CI], 4.5-11.2), including symptomatic proximal deep vein thrombosis (DVT) or pulmonary embolism (PE) recurrence, death for VTE, and major bleeding occurring in patients off anticoagulation vs that in those receiving apixaban (1.1%; 95% CI, 0.4-2.6; adjusted hazard ratio [HR], 8.2; 95% CI, 3.2-25.3). In conclusion, in patients anticoagulated for ≥1 year after a first unprovoked VTE, the decision to further extend anticoagulation should not be based on D-dimer testing. The results confirmed the high efficacy and safety of reduced-dose apixaban against recurrences. This trial was registered at www.clinicaltrials.gov as #NCT03678506.

Statin use and 30‐day mortality in patients with acute symptomatic pulmonary embolism

BackgroundStatins possess antithrombotic and profibrinolytic properties. The association between statin use and short‐term outcomes in patients with acute pulmonary embolism (PE) remains unknown. MethodsWe used the data from the Registro Informatizado de Pacientes con Enfermedad TromboEmbólica registry to compare the 30‐day all‐cause mortality in patients with acute PE according to the use of statins. Secondary outcome was fatal PE. We used cancer‐related mortality as a falsification endpoint. ResultsFrom January 2009 to April 2021, 31 169 patients with PE were recruited. Of these, 5520 (18%) were using statins at baseline: low intensity: 829, moderate: 3636, high intensity: 1055. Statin users were older and had a higher frequency of diabetes, hypertension, or atherosclerotic disease than non‐users (P <0.001 for all comparisons). During the first 30 days, 1475 patients died (fatal PE, 255). On multivariable analysis, statin users had a lower risk of all‐cause death (odds ratio [OR]: 0.65; 95% confidence interval [CI]: 0.56–0.76) and fatal PE (OR: 0.42; 95% CI: 0.28–0.62) than non‐users. The risk for death was lower in patients using either low‐ (OR: 0.51; 95% CI: 0.34–0.77), moderate‐ (OR: 0.68; 95% CI: 0.57–0.81), or high‐intensity statins (OR: 0.68; 95% CI: 0.51–0.92). Results did not change in mixed effects logistic regression models with hospitals as a random effect. Statins were not associated with a significant chance in cancer mortality (falsification endpoint). ConclusionsPE patients using statins at baseline had a significantly lower risk of dying within the first 30 days than non‐users. Randomized trials are needed to confirm these data.

Acute on Chronic Thromboembolic Pulmonary Hypertension: Case Series and Review of Management.

Chronic thromboembolic pulmonary hypertension (CTEPH) is a distinct form of precapillary pulmonary hypertension classified as group 4 by the World Symposium on Pulmonary Hypertension (WSPH) and should be excluded during an episode of acute pulmonary embolism (PE). Patients presenting to emergency departments with sudden onset of signs and symptoms of acute PE may already have a pre-existing CTEPH condition decompensated by the new PE episode. Identifying an underlying and undiagnosed CTEPH during acute PE, while challenging, is an important consideration as it will alter the patients’ acute and long-term management. Differential diagnosis and evaluation require an interdisciplinary expert team. Analysis of the clinical condition, the CT angiogram, and the hemodynamic situation are important considerations; patients with CTEPH usually have significantly higher sPAP at the time of index PE, which is unusual and unattainable in the context of acute PE and a naïve right ventricle. The imaging may reveal signs of chronic disease such as right ventricle hypertrophy bronchial collaterals and atypical morphology of the thrombus. There is no standard for the management of acute on chronic CTEPH. Herein, we provide a diagnostic and management algorithm informed by several case descriptions and a review of the literature.

Clinical Outcome of Different Post-operative Prophylactic Strategies on Symptomatic Venous Thromboembolism after Total Knee Arthroplasty

IntroductionThe objective of this study was to evaluate the use of different post-operative prophylactic strategies on the rates of symptomatic venous thromboembolic events (VTE) incidence after primary total knee arthroplasty (TKA).MethodsA retrospective study of patients who underwent primary TKA procedure was performed from January 2015 through July 2020. Outcomes examined prophylaxis medication used during inpatient and outpatient care, amount of medication, length of medication, complications occurring within 90 days post-operatively, including symptomatic VTE (deep venous thrombosis (DVT), and pulmonary embolism (PE)), gastrointestinal (GI) bleeding requiring medical attention, change in management protocols after post-operative complications, and mortality.ResultsIn total, 5,663 cases were included (mean age 66 ± 10 years, mean BMI 34.1 ± 7.1kg/m2). The overall post-operative complication rate was 0.9% (DVT: 0.5%, PE: 0.3%, VTE: 0.04%, and GI bleeding: 0.09%). Enoxaparin use as inpatient anticoagulation medication was reduced significantly (67% vs. 13%, p < 0.001), and apixaban was increased significantly (6% vs. 49%, p < 0.001). Average hospital stays were reduced significantly among the years (3 ± 2 days vs. 2 ± 1 days, p < 0.001), and complication rates were not significantly different between the five years (~1%, p < 0.001). Most post-operative complications occurred on either aspirin 325 mg (36%) or apixaban (26%). However, the relative risk ratio results indicating that utilization of warfarin, rivaroxaban, and aspirin 81 mg as outpatient anticoagulation medication were more likely to increase the risk of symptomatic VTE incidence compared to other anticoagulants. The average time of complication detected was 21 ± 21 days (range: 1 – 87 days). More than 54% of complication events occurred after the patient had completed their medication (enoxaparin, rivaroxaban, and apixaban).ConclusionsThe observed incidence of symptomatic VTE in this study was similar to previous studies regardless of the type of post-operative inpatient or outpatient prophylaxis prescribed. The ultimate choice of prophylaxis should remain with the treating physician and their knowledge of a particular patient’s medical history.

Prevention of Deep Vein Thrombosis by Panax Notoginseng Saponins Combined with Low-Molecular-Weight Heparin in Surgical Patients.

To evaluate the efficacy of deep vein thrombosis (DVT) prevention among real-world surgical inpatients who received panax notoginseng saponins (PNS) combined with low-molecular-weight heparin (LMWH). A prospective cohort study was conducted among surgical patients between January 2016 and November 2018 in Xuanwu Hospital, Capital Medical University, Beijing, China. Participants received LMWH alone or PNS combined with LMWH for preventing DVT. The primary outcome was incidence of lower extremity DVT, which was screened once a week. Participants in the LMWH group were given LMWH (enoxaparin) via hypodermic injection, 4000-8000 AxalU once daily. Participants in the exposure group received PNS (Xuesaitong oral tablets, 100 mg, 3 times daily) combined with LMWH given the same as LMWH group. Of the 325 patients screened for the study, 281 participants were included in the final analysis. The cohort was divided into PNS + LMWH group and LMWH group with 134 and 147 participants, respectively. There was a significant difference of DVT incidence between two groups (P=0.01), with 21 (15.7%) incident DVT in the PNS + LMWH group, and 41 (27.9%) incident DVT in the LMWH group. Compared with participants without DVT, the participants diagnosed with DVT were older and had higher D-dimer level. The multivariate logistic regression model showed a significant lower risk of incident DVT among participants in the PNS + LMWH group compared with the LMWH group (odds ratio 0.46, 95% confidence interval, 0.25-0.86). There were no significant differences in thromboelaslography values (including R, K, Angle, and MA) and differences in severe bleeding between two groups. No symptomatic pulmonary embolism occurred during the study. Combined application of PNS and LMWH can effectively reduce the incidence of DVT among surgical inpatients compared with LMWH monotherapy, without increased risk of bleeding.

Saddle Pulmonary Embolism in Patients with Cancer in the Era of Incidental Events: Clinical Findings and Outcomes in a Single Centre Cohort.

Background There is scarce information regarding the prevalence and clinical impact of saddle pulmonary embolism (PE) in patients with cancer. Objectives This study aimed to assess the prevalence, clinical findings, and short-term outcomes of patients with cancer-related saddle PE including acute symptomatic and unsuspected events. Patients/Methods Consecutive patients with cancer-related PE (March 1, 2006–October 31, 2014) were retrospectively reviewed by a chest radiologist to assess PE burden and signs of right ventricular (RV) overload. The clinical outcomes within 30 days were evaluated according to saddle versus nonsaddle PE. Results Thirty-six (12%) out of 289 patients with newly diagnosed cancer-related PE presented with saddle PE. Saddle PE was found in 21 cases (58%) with acute symptomatic PE and the remaining 15 cases (42%) were found as unsuspected findings. Patients with saddle PE had more frequently experienced a previous thrombotic event (31 vs. 13%; p =0.008), and it occurred more frequently as an acute symptomatic event (58 vs. 39%; p =0.025) compared with those with nonsaddle PE. Signs of RV overload including RV/left ventricle ratio ≥1 (22 vs. 4%; p <0.001) and interventricular septum displacement (53 vs. 20%; p <0.001) were also more common in patients with saddle PE compared with nonsaddle PE. Overall, PE-related mortality, venous thromboembolism recurrence, and major bleeding within 30 days were found to be similar according to saddle versus nonsaddle PE. Conclusion Saddle PE is not uncommon in patients with cancer-related PE including in those with unsuspected PE. Similar 30-day outcomes were found according to saddle versus nonsaddle PE in our cohort.