Treatment Of Pulmonary Embolism Research Articles

Abstract 18303: Characteristics of Clinical Studies Evaluating Thrombolysis and Novel Catheter-Based Interventions for Pulmonary Embolism

Introduction: Novel treatment approaches for pulmonary embolism (PE) including catheter directed thrombolysis (CDT), percutaneous thrombectomy (PT), and systemic thrombolysis (ST) are under investigation. However, characteristics of studies of these interventions are not well described. We sought to evaluate the state of studies pertaining to advanced PE therapies. Methods: The ClinicalTrials.gov (CTG) database was queried using search terms specific to advanced therapies and PE between January 1, 2000, and June 30, 2022, with unrelated, withdrawn, and terminated studies excluded. Advanced therapies were defined as studies evaluating either systemic thrombolysis, CDT, and/or PT. Geographic data from enrollment was gathered using zip codes of study sites. Descriptive characteristics related to studies were explored, and ANOVA was used to compare mean trial enrollment between interventions. Results: Of 700 total results, our search yielded 56 eligible studies (8.0%) investigating advanced PE therapies, among which 39.3% studies evaluated CDT, 32.1% evaluated ST, and 28.6% evaluated MT. Most studies were interventional (76.7%) rather than observational (23.3%). The primary study endpoint was most commonly a surrogate endpoint (60.7%), with mortality (5.4%) or a composite including mortality (21.4%), or other endpoints (12.5%) were less frequent (Figure). Mean enrollment was 206.4 in ST, 101.5 in CDT, and 103.7 in PT studies, with no significant difference in study size between intervention type (p=0.207). The USA was the most frequent trial sponsor (41.1%), and within the USA, trial sites were most commonly in large, urban areas and demonstrated geographic variation. Conclusion In conclusion, there is a paucity of studies evaluating advanced therapies for PE with substantial heterogeneity in design and geography. These data highlight the need for further high-quality studies to inform clinical decision making for the treatment of PE.

Abstract 13715: Catheter-Based Therapies in High-Risk Pulmonary Embolism: Outcomes From a Tertiary Referral Center

Introduction: Prompt and effective treatment of pulmonary embolism (PE) is essential to prevent morbidity and mortality. We aim to evaluate and compare the effectiveness of two FDA-approved catheter-based therapies (CBT) for acute high-risk PE: ultrasound-assisted catheter-directed thrombolysis EKOS (EKOS Corporation, Bothell, WA) and Penumbra Indigo aspiration thrombectomy (Penumbra Inc., Alameda, CA, USA). Methods: Patients with acute high-risk submassive or massive PE who underwent CBTs between 09/2014 and 08/2022 at our institution were identified. The primary efficacy outcome was the change in the echocardiographic RV/LV diameter ratio within 48 to 72h of procedure. Results: A total of 189 patients underwent EKOS (n=119) or Penumbra (n=70) for submassive (n=175) and massive (n=14) PE (Table). Both groups had similar demographics and clinical characteristics except for prior DVT. Mean age was 60.6±14.3 years old and 55.6% were male. The RV/LV ratio showed significant improvement post intervention, with 21.2% decrease in the EKOS group (EG) and 35.6% in the Penumbra group (PG). The PG had a greater decrease in RV/LV (median change 0.396 (IQR, 0.347) vs. 0.207 (IQR, 0.306), p<0.001). In the cohort, 25 adverse events were reported (13.2%). The rate of complications did not differ between the 2 groups, with 15.1% in EG and 10% in PG. In terms of bleeding complications, GUSTO moderate bleeding was observed in 8 cases (5 in EG and 3 in PG), while severe bleeding was observed in 3 (2 in EG and 1 in PG), including 1 intracranial hemorrhage in the PG. ICU admissions were higher in the PG (p<0.001), but median hospital and ICU stays were comparable. No significant difference was found in the rate of in-hospital mortality (2.5% in EG, 4.3% in PG, p=0.672). Conclusion: Both CBT options are promising for treating submassive PE, with efficacy outcomes favoring Penumbra thrombectomy. Longer follow-up and randomized controlled trials are needed for definitive conclusions.

Cancer-Associated Abdominal Vein Thrombosis.

Cancer is associated with an increased risk of developing venous thromboembolism, due to its direct influence on the three pillars of Virchow's triad (e.g., compression on the blood vessels by the tumour, blood vessels invasion, and cytokine release), together with the effect of exogenous factors (such as chemotherapy, radiotherapy, surgery). In cancer patients, the risk of thrombosis at unusual sites, such as splanchnic, ovarian and renal vein thrombosis, is also increased. Abdominal vein thromboses are frequently incidental findings on abdominal imaging performed as part of the diagnostic/staging workup or the follow-up care of malignancies. There is little evidence on the management of unusual site venous thromboembolism in cancer patients since there are only a few specific recommendations; thus, the management follows the general principles of the treatment of cancer-associated deep vein thrombosis and pulmonary embolism. This narrative review summarises the latest evidence on cancer-associated abdominal vein thrombosis, i.e., thrombosis of the splanchnic, ovarian and renal veins.

Survival Outcomes in Patients with Intermediate and High-Risk Pulmonary Embolism Treated with Low Molecular Weight or Unfractionated Heparin: Time to Start of Anticoagulant Therapy

Introduction Venous Thromboembolism (VTE), including pulmonary embolism (PE), is the third most common cause of vascular disease related death in the United States. If left untreated, the mortality of PE is as high as 30%. The main-stay of treatment for PE involves anticoagulant therapy (AT), commonly with low molecular weight heparin (LMWH), or unfractionated heparin (UFH). Prior data has demonstrated a reduction in mortality with anticoagulant timing. In one study, 30-day all-cause mortality was lower in patients who achieved therapeutic AT, as defined by activated partial thromboplastin time (aPTT), within 24 hours of ER presentation. However, recent data demonstrated low numbers of patients with therapeutic range aPTT at 24 hours (< 30%). Thus, we aimed to assess the association between time to anticoagulant therapy from emergency room (ER) presentation and 30-day PE-associated mortality. Methods We performed a retrospective cohort study of patients at Barnes Jewish Hospital between January 2021 and April 2023 for which the Pulmonary Embolism Response Team (PERT) was activated. Patients with intermediate-low, intermediate-high, or massive (high-risk) PE who presented to the emergency department or urgent care facility with signs/symptoms concerning for PE were included. PE was objectively confirmed on imaging studies (CT or VQ Scan). Only patients initiated on UFH or LMWH were included. Patient demographic and hemodynamic data were collected on presentation. Those with low-risk PE, those started on an AT other than UFH/LMWH, and those who died prior to the start of AT were excluded. Time from ER presentation (as estimated by triage vital signs) to start of AT was calculated based on review of the Electronic Medical Record. The primary outcome was PE-associated mortality within 30 days. PE-associated mortality was defined as: deaths directly caused by PE, deaths caused by the treatment of PE, and multifactorial deaths with PE as a contributing illness. Using logistic regression, we calculated the association between each doubling of the time until AT was given and PE-associated mortality. Results A total of 184 patients met inclusion criteria, 138 patients with intermediate-risk PE and 46 with massive PE. 81% of patients received UFH (n = 149) and 19% received LMWH (n = 35). PE-associated mortality occurred in 5.1% (n = 7) of patients in the intermediate-risk group and 32.6% (n = 15) in the high-risk group. The average time from ER triage to start of AT was 5 hours in intermediate-risk patients who survived versus 8.1 hours in those who died. The average time from ER triage to start of AT was 5.3 hours in massive PE patients who survived versus 5.4 hours in those who died. After adjusting for massive PE classification and sPESI score, each doubling of time in delay of AT from ER presentation was associated with 1.27 increased odds of PE-associated death (odds ratio (OR) 1.27, 95% confidence interval (CI) 0.85, 1.89) (Table 1). The discrimination of the model was very good with a c-statistic of 0.83 for prediction of PE-associated 30-day mortality. When only analyzing patients with intermediate-risk PE, each doubling of time in delay of AT from ER presentation was associated with 2.72 increased odds of PE-associated death (OR 2.72, 95% CI 1.11, 6.78) (Table 1). Conclusions In patients with intermediate-risk or massive PE, each doubling of the time from patient presentation to the ER to start of anticoagulant therapy was associated with 1.27 increased odds in the risk of PE-associated 30-day mortality. This association was more pronounced in patients with intermediate-risk PE. Future efforts should be aimed at decreasing time from ER presentation to start of anticoagulant therapy in patients with PE such as through quality improvement projects and/or triage protocolization.

Can GRACE Risk Score Predict Mortality and the Need for Thrombolytic Treatment in Acute Pulmonary Embolism?

Acute coronary syndrome and pulmonary embolism (PE) are clinical entities sharing similar presentation and risk factors. Risk scores and indexes help to identify disease severity in both diseases. In this study, we aimed to evaluate if the Global Registry of Acute Coronary Events (GRACE) risk score could predict 30-day mortality and the need for thrombolytic treatment in patients with acute PE. Patients hospitalized with a diagnosis of PE in our tertiary center between January 2018 and May 2022 were included in this retrospective study. Pulmonary Embolism Severity Index (PESI) and GRACE risk scores on admission were calculated using clinical, electrocardiographic, and laboratory parameters for each patient. A total of 197 patients were included. The 30-day mortality rate was 28.4% whereas 32.5% of the patients required thrombolytic treatment. GRACE and PESI scores were found independent risk factors associated with 30-day mortality and the need for thrombolytic treatment. A cut-off value of 160.5 for GRACE score was associated with 88.5% sensitivity and 89.4% specificity in prediction of 30-day mortality. In contrast, GRACE score had 61.0% sensitivity and 60.0% specificity in the prediction of the need for thrombolytic treatment when the cut-off value was 147. In conclusion, GRACE risk score has an effective discriminating power in determining the early mortality of patients with acute PE. The incidence of short-term PE-related mortality was significantly increased in patients with high GRACE risk scores. Concomitant use of GRACE and PESI risk scores may aid in defining patients with high-risk PE and help predict poor prognosis with high specificity and probability.

FlowTriever System for Pulmonary Embolism: A Review of Clinical Evidence.

Pulmonary embolism (PE) is a significant cause of cardiovascular mortality, and its incidence has been increasing due to the growing aging population. Systemic or catheter-directed thrombolytic treatment for PE has an increased risk of bleeding that may offset the benefit in some patients. Mechanical thrombectomy devices such as the FlowTriever System are designed to resolve vascular occlusion and correct ventilation-perfusion mismatch without the need for thrombolytic drugs. This review covers the FlowTriever system, clinical data from the FlowTriever Pulmonary Embolectomy Clinical Study, FlowTriever for Acute Massive Pulmonary Embolism, and FlowTriever All-comer Registry for Patient Safety and Hemodynamics trials, and real-world experiences, demonstrating its safety and effectiveness in treating intermediate-risk and high-risk PE. Additionally, we explore off-label uses of the FlowTriever System for various large vessel thromboses.

A comparison of the efficacy and safety between anticoagulation alone and combined with catheter-directed thrombolysis for treatment of pulmonary embolism on outcome: A systematic review and meta-analysis.

Catheter-directed thrombolysis (CDT) is one of the newest treatment options for submassive pulmonary embolism (sPE). This study will compare the efficacy and safety of catheter-directed thrombolysis (CDT) combine with anticoagulation versus anticoagulation alone (AC) in patients with PE. A database search was conducted using PubMed, EMBASE, Cochrane Library, and Clinicaltrials.gov for trials that compared CDT with AC in patients with pulmonary embolism. The primary outcomes was1-year mortality. The secondary outcomes were in-hospital, 30days, 90days mortality, in-hospital major and minor bleeding (Thrombolysis in Myocardial Infarction (TIMI) classification), length of hospital stay (LOS), reduction of pulmonary arterial systolic pressure (PASP) and RV/LV diameter ratio. A total of 16 articles (3 RCTs and 13 non-RCTs) and 10595 patients were included in this study. 2237 patients were in the CDT group and 8358 patients were in the AC group. CDT group was associated with significantly lower in-hospital mortality (2.1% vs 6.2%,OR:0.36, 95%CI:0.26-0.51, p < .00001,I2 = 0%), 30days mortality (3.1% vs 8.6%,OR:0.39,95%CI:0.23-0.66, p = .0005, I2 = 0%), 90days mortality (3.8% vs 7.7%,OR:0.49,95%CI:0.29-0.80,p = .005,I2 = 7%), 1-year mortality (6.1% vs 11%, OR:0.51, 95%CI:0.35-0.76, p = .0008,I2 = 36%) compared to AC group, especially in ultrasound-assisted thrombolysis (USAT) subgroup. There were no differences on major bleeding between two groups (1.8% vs 2.2%, OR:1.10, 95%CI:0.61-1.98, p = .75, I2 = 0%). Minor bleeding was significantly higher in CDT group than AC group (6.2% vs 3.8%, OR:1.93,95%CI:1.27-2.94.66, p = .002, I2 = 1%). CDT group significantly reduced PASP (WMD:11.90,95%CI:6.45-17.35, p < .0001, I2 = 72%) and RV/LV (WMD:0.17,95%CI:0.04-0.30, p = .009, I2 = 69%) rapidly than AC group after treatment. LOS was similar between two groups (WMD:0.02,95%CI: -0.68-0.73, p = .95, I2 = 51%). Results thus confirmed that CDT reduced in-hospital, 30days, 90days and 1-year all-cause mortality in patients with sPE compared to AC, particularly in USAT subgroup. Nonetheless, CDT group was associated with a higher risk of minor bleeding.

Primary Care in Management of Pulmonary Embolism in Prolonged Recumbences

A frequent and possibly fatal kind of venous thromboembolic illness is pulmonary embolism (PE). It is a significant issue for public health. A typical diagnosis as a primary care in an emergency room is pulmonary embolism (PE). Additionally, it makes up a sizable portion of the patients admitted to hospital wards. In selected low-risk individuals with acute PE, there is mounting evidence that outpatient therapy, or treatment without hospitalization, is practical, safe, and efficient. PE patients may be risk-classified and given an early release from the emergency department. As a result, there are more hospital beds available for other patients, which lowers treatment expenses for the healthcare system. There is growing support for the outpatient care of low-risk, hemo-dynamically stable patients with acute symptomatic pulmonary embolism (PE). There is assistance in identifying patients who are eligible for outpatient (primary) care. This move has been made easier by the accessibility and simplicity of direct oral anticoagulants. Acute PE is currently mostly treated with direct, non-vitamin K-dependent oral anticoagulants. In comparison to vitamin K antagonists, they have been demonstrated to simplify initial and prolonged anticoagulation regimes while lowering the risk of bleeding. In this consensus practice document, we present a thorough analysis of primary care in the diagnosis, treatment, and follow-up of acute PE.

Healthcare utilization during the COVID-19 pandemic: changes, potential causes. A Swiss cohort study

Abstract Background The COVID-19 pandemic led to a decrease in the provision and use of healthcare. Few studies reported reasons for these changes. We aimed to (i) describe the frequency of changes in healthcare utilization in those requiring ongoing treatment, and possible reasons thereof, and (ii) assess characteristics associated with change, during the second wave of the pandemic. Methods Participants from the Corona Immunitas e-cohort study (age ≥20 years) completed monthly questionnaires between September 2020 and February 2021. We used descriptive and bivariate statistics, to compare participants reporting a change in healthcare utilization with those who reported no change. We used negative binomial regression to explore characteristics associated with the number of changes. Results In total, 3190 adults from nine research sites participated in this study. One-fifth (N = 658, 21%) reported the need for regular treatment. About 14% of them reported a change in healthcare utilization, defined as events in which participants reported that they changed their ongoing treatment, irrespective of the reason. Reported reasons for change were medication changes and side-effects, specifically for hypertension, or pulmonary embolism treatment. Females were more likely to report changes in healthcare utilization (Incidence Rate Ratio (IRR)=1.69, p = 0.030), and those with hypertension were least likely to report changes (IRR=0.45, p = 0.092). Conclusions Among those who needed regular treatment, few reported changes in healthcare utilization. The importance of continuity of care for females and chronic diseases other than hypertension must be emphasized. This calls for tailored measures considering gender disparities. Key messages • Changes in healthcare utilization were more pronounced in women than men during the Covid-19 pandemic. • Tailored disease surveillance is necessary considering gender disparities and chronic diseases other than hypertension.

Modern Treatment of Pulmonary Embolism (USCDT vs MT): Results From a Real-World, Big Data Analysis (REAL-PE)

BackgroundAdvanced therapies are increasingly utilized to treat pulmonary embolism (PE). A unique data platform allows access to electronic health record data for comparison of the safety of PE therapies. MethodsAll data from Truveta (Truveta, Inc) were analyzed (16 systems, 83,612,413 patients, 535,567 with PE). All patients treated with ultrasound-assisted catheter-directed thrombolysis (USCDT) (Boston Scientific) or mechanical thrombectomy (MT) (Inari Medical) for PE were identified. The primary analysis was based on index procedures performed from January 2009 to May 2023, and contemporary analysis on those performed from January 2018 to May 2023. Bleeding was assessed via direct laboratory analysis and transfusion administration documentation. International Society for Thrombosis and Hemostasis (ISTH) and Bleeding Academic Research Consortium (BARC) 3b definitions were recreated. Multiple logistic regression analysis of major bleeding was performed. In-hospital death and median length of stay were measured. ResultsFor the primary analysis, 2259 patients (N = 1577 USCDT, N = 682 MT) and for the contemporary analysis 1798 patients (N = 1137 USCDT, N = 661 MT) met the criteria. Incidence of hemoglobin reduction (>2 and >5 g/dL) and transfusions received were significantly higher among MT-treated patients in both analyses, as was ISTH and BARC 3b major bleeding (primary: ISTH MT 17.3% vs USCDT 12.4% P = .002; BARC 3b MT 15.4% vs USCDT 11.8% P = .019) (contemporary: ISTH MT 17.2% vs USCDT 11.0% P = .0002; BARC 3b MT 15.4% vs USCDT 10.6% P = .002). Regression analysis demonstrated that MT is associated with major bleeding. Median length of stay, all-cause 30-day readmission and in-hospital mortality were similar between groups. Intracranial hemorrhage was more common with MT. ConclusionsMajor bleeding derived from direct laboratory and transfusion data occurred more frequently with MT vs USCDT. Intracranial hemorrhage was more common among MT-treated patients. In the absence of randomized data, these results provide guidance regarding the bleeding risk and safety of strategies for advanced PE therapy.

Pulmonary Embolism Treatment Evolution: A Comparative Analysis of Pulmonary Embolism Response Team Management at a Single Institution

Pulmonary Embolism Treatment Evolution: A Comparative Analysis of Pulmonary Embolism Response Team Management at a Single Institution

Intensify Standardized Anticoagulation for Cancer-associated Pulmonary Embolism: From Single-center Real-world Data

Pulmonary embolism (PE) is a significant contributor to mortality in patients with cancer. Although anticoagulation serves as the cornerstone of treatment for cancer-associated PE, it has not been emphasized in real-world settings. The aim of this study was to examine the impact of suboptimal anticoagulant treatment on the prognosis of cancer-associated PE. A cohort of 356 individuals newly diagnosed with acute PE were enrolled. The primary outcome of the study was recurrent venous thromboembolism (VTE), and the secondary outcomes were all-cause mortality and major bleeding (consisting of a reduction in the hemoglobin level by at least 20 g/L, transfusion of at least 2 units of blood, or symptomatic bleeding in a critical area or organ or fatal bleeding). Of the total participants, 156 (43.8%) were diagnosed with cancer. A comparison between the cancer and noncancer groups revealed that patients with cancer were more frequently asymptomatic (41.0% vs 4.5%; P < 0.001), less likely to have right ventricular dysfunction (4.5% vs 14.0%; P=0.001), received less anticoagulant treatment during hospitalization (85.3% vs 98.5%; P < 0.001), and had a shorter duration of anticoagulation (5.02 [7.40] months vs 14.19 [10.65] months; P < 0.001). In addition, patients with cancer were found to be at a higher risk of recurrent VTE (17.3% vs 4.0%; P < 0.001) and all-cause mortality (23.7% vs 10.5%; P=0.001). Multiple Cox regression analysis indicated that discontinuation of anticoagulation at 3 months was a significant risk factor for recurrent VTE in the cancer group (HR, 15.815; 95% CI, 3.047-82.079; P=0.001). The brief duration of anticoagulation therapy and elevated likelihood of recurrent VTE serve as cautionary indicators for the need to enhance awareness of standardized anticoagulant treatment for cancer-associated PE. The ultimate goal is to enhance patient prognosis and quality of life.

Treatment of acute sub-massive pulmonary embolism with balloon angioplasty and thrombolysis simultaneously

Background: Acute sub-massive pulmonary embolism is a common clinical condition, and it is associated with high mortality and morbidity. This condition is commonly associated with various co-morbidities and clinical circumstances. Methods: This is a case report series of 4 patients, wherein the thrombolysis and balloon angioplasty was performed simultaneously using a Cordis 6F diagnostic catheter and later exchanged with a 6F guide catheter in the respective pulmonary artery when a larger balloon was required. Results: All these four patients achieved successful revascularization of the respective pulmonary artery. One patient expired 30 hours after the procedure with a significant reduction in the symptoms suddenly, which was likely a second episode of pulmonary embolism. No bleeding manifestations were observed in any of the patients. The other three patients are on follow-up. Conclusion: Simultaneous coronary balloon dilatation and thrombolysis is a useful method in the treatment of sub-massive acute pulmonary embolism. If needed, higher caliber balloons can be used for the same technique using guide catheters.

Efficacy and safety of catheter-directed treatment in intermediate-risk pulmonary embolism: a single-centre experience in Singapore.

Efficacy and safety of catheter-directed treatment in intermediate-risk pulmonary embolism: a single-centre experience in Singapore.

Advances in the treatment of pulmonary embolism at University Hospital Centre Rijeka

Advances in the treatment of pulmonary embolism at University Hospital Centre Rijeka

OC 40.2 Outcomes of Home Treatment of Acute Pulmonary Embolism in Clinically Relevant Patient Subgroups: A Systematic Review and Individual-Patient Data Meta-Analysis

OC 40.2 Outcomes of Home Treatment of Acute Pulmonary Embolism in Clinically Relevant Patient Subgroups: A Systematic Review and Individual-Patient Data Meta-Analysis

Catheter-directed interventions in acute pulmonary embolism treatment

Abstract: Catheter-based interventions for acute pulmonary embolism (PE) have evolved over the past decades to achieve the benefits of systemic thrombolysis, avoiding though its systemic complications and offering a therapeutic option to a wider spectrum of PE patients who may be contraindicated for thrombolytics. Although numerous observational, retrospective, or small prospective studies have been performed to evaluate the myriad devices used in the preceding years, few are of adequate quality to support widespread use. However, we were seeing an increasing use of catheter thrombolytic and aspiration thrombectomy procedures in both US and Europe. Evidence is building up through several industry trials, and more recently, the PE-Thrombus Removal with Adjunctive Catheter-directed Therapy randomized National Institutes of Health-funded trial was approved to evaluate their benefit over anticoagulation alone in intermediate risk patients. The current evolution of these techniques and existing evidence for their use are summarized.

Initial results of investigator initiated international database on catheter directed therapy of acute pulmonary embolism.

Catheter directed therapies (CDT) are widely used in the treatment of acute pulmonary embolism (PE). A multicenter registry was organized to evaluate their application in real life and to determine efficacy and safety of these procedures. Local experience of participating centers in percutaneous techniques for PE treatment was assessed. An internet-based registry was designed to collect clinical, echocardiographic and laboratory data of consecutive PE patients treated with CDT in participating centers between 2017 and 2022. Under analysis were 145 consecutive patients with acute PE, aged 61 ± 15 years, treated with CDT in 7 centers: 50 (34.5%) patients with high-risk PE (HRPE), and 95 (65.5%) patients with intermediate-high risk PE (IHRPE). 100 (69%) patients were treated with dedicated devices, in 45 (31%) subjects a pigtail catheter was used. Total PE or CDT related in-hospital mortality in HRPE reached 14% (7 patients), while in IHRPE 3.2% (3 patients) (p = 0.032). 50% of PE or CDT related deaths occurred in patients treated with a pigtail catheter. All-cause mortality in 145 patients was 9.7%, and it was higher in HRPE than in IHRPE (18% vs. 5.3%, p = 0.019). The use of pigtail catheters compared to dedicated systems was associated with higher mortality (20% vs. 5%, p = 0.01). Catheter directed therapies is a real option of treating PE. It was used as primary therapy also in patients without contraindication for thrombolysis suggesting that clinical practice does not always follow current PE guidelines. Patients treated with dedicated CDT systems had a higher survival rate than subjects treated with pigtail catheters.

Clinical implications of thrombolytic therapy for patients with acute intermediate-high risk pulmonary embolism in Tibet plateau, China

At present, clinical studies and case reports of systemic thrombolytic therapy for patients with acute pulmonary embolism in Tibet Plateau are very rare. There is little understanding of the risk factors, clinical characteristics, and thrombolytic therapy for patients with acute pulmonary embolism at intermediate-high risk in Tibet Plateau. In this paper, we reported the data of 4 patients with acute intermediate-high risk pulmonary embolism treated with thrombolytic therapy in Lhasa People's Hospital. The demographic characteristics, clinical manifestations, treatment, and outcomes were analyzed. We summarized the clinical features and raised scientific issues. We aimed to provide basic data to improve the standardized diagnosis and treatment of acute pulmonary embolism in plateau, and to point out the direction of future clinical research in this field.

Advanced Treatment of Hemodynamically Unstable Acute Pulmonary Embolism and Clinical Follow-up.

High-risk acute pulmonary embolism (PE), defined as acute PE associated with hemodynamic instability, remains a significant contributor to cardiovascular morbidity and mortality in the United States and worldwide. Historically, anticoagulant therapy in addition to systemic thrombolysis has been the mainstays of medical therapy for the majority of patients with high-risk PE. In efforts to reduce the morbidity and mortality, a wide array of interventional and surgical therapies has been developed and employed in the management of these patients. However, the most recent guidelines for the management of PE have reserved the use of these advanced therapies in scenarios where thrombolytic therapy plus anticoagulation are unsuccessful. This is due largely to the lack of prospective, randomized studies in this population. Stemming from this, the approach to treatment of these patients varies widely depending on institutional experience and resources. Furthermore, morbidity and mortality remain unacceptably high in this population, with estimated 30-day mortality of at least 30%. As such, development of a standardized approach to treatment of these patients is paramount to improving outcomes. Early and accurate risk stratification in conjunction with a multidisciplinary team approach in the form of a PE response team is crucial. With the advent of novel therapies for the treatment of acute PE, in addition to the growing availability of and familiarity with mechanical circulatory support systems, such a standardized approach may now be within reach.