Effects of right ventricular remodeling in chronic thromboembolic pulmonary hypertension on the outcomes of balloon pulmonary angioplasty: a 2D-speckle tracking echocardiography study.

BACKGROUND: Balloon pulmonary angioplasty (BPA) improves the prognosis of chronic thromboembolic pulmonary hypertension (CTEPH). Right ventricle (RV) is an important predictor of prognosis in CTEPH patients. 2D-speckle tracking echocardiography (2D-STE) can evaluate RV function. This study aimed to evaluate the effectiveness of BPA in CTEPH patients and to assess the value of 2D-STE in predicting outcomes of BPA. METHODS: A total of 76 patients with CTEPH underwent 354 BPA sessions from January 2017 to October 2022. Responders were defined as those with mean pulmonary artery pressure (mPAP) ≤ 30 mmHg or those showing ≥ 30% decrease in pulmonary vascular resistance (PVR) after the last BPA session, compared to baseline. Logistic regression analysis was performed to identify predictors of BPA efficacy. RESULTS: BPA resulted in a significant decrease in mPAP (from 50.8 ± 10.4 mmHg to 35.5 ± 11.9 mmHg, p < 0.001), PVR (from 888.7 ± 363.5 dyn·s·cm-5 to 545.5 ± 383.8 dyn·s·cm-5, p < 0.001), and eccentricity index (from 1.3 to 1.1, p < 0.001), and a significant increase in RV free wall longitudinal strain (RVFWLS: from 15.7% to 21.0%, p < 0.001). Significant improvement was also observed in the 6-min walking distance (from 385.5 m to 454.5 m, p < 0.001). After adjusting for confounders, multivariate analysis showed that RVFWLS was the only independent predictor of BPA efficacy. The optimal RVFWLS cutoff value for predicting BPA responders was 12%. CONCLUSIONS: BPA was found to reduce pulmonary artery pressure, reverse RV remodeling, and improve exercise capacity. RVFWLS obtained by 2D-STE was an independent predictor of BPA outcomes. Our study may provide a meaningful reference for interventional therapy of CTEPH.

Early Mortality, Cardiovascular, and Renal Diseases in Women's Lives Following Hypertensive Disorders of Pregnancy: The Prospective Nationwide Study CONCEPTION.

BACKGROUND: We aimed to evaluate the impact of hypertensive disorders of pregnancy occurrence, recurrence, onset time, and severity on mortality and on a wide range of cardiovascular outcomes in France. METHODS AND RESULTS: CONCEPTION (Cohort of Cardiovascular Diseases in Pregnancy) is a French nationwide prospective cohort using data from the National Health Data System. We included all women in CONCEPTION with no history of a cardiovascular event who delivered in France for the first time between 2010 and 2018 (N=2 819 655). Hypertensive disorders of pregnancy and cardiovascular outcomes during the study follow-up were identified using algorithms combining International Classification of Diseases, Tenth Revision (ICD-10) coded diagnoses during hospitalization and purchases of medication between 2010 and 2021. We fitted Cox models with time-varying exposure to assess the associations of hypertensive disorders of pregnancy with mortality and cardiovascular events. Women with gestational hypertension had a 1.25- to 2-fold higher risk of stroke, acute coronary syndrome, peripheral arterial disease, pulmonary embolism, and chronic kidney disease, and a 2- to 4-fold higher risk of rhythm and conduction disorder and heart failure. Women with preeclampsia had a 1.35- to 2-fold higher risk of rhythm or conduction disorder and pulmonary embolism during follow-up; a 2- to 4-fold higher risk of stroke, acute coronary syndrome, and peripheral arterial disease; and a 7- to 9-fold higher risk of heart failure and chronic kidney disease. They were 1.8 times more likely to die and 4.4 times more likely to die of cardiovascular causes. CONCLUSIONS: Hypertensive disorders of pregnancy drastically increase the risk of mortality, cardiovascular, and renal events early after pregnancy. Recurrent, severe, and early-onset preeclampsia further increases this risk.

Angio-Jet Thrombolysis for Traumatic Inferior Vena Cava Thrombosis; Case Report and Review of Literature.

Background: Inferior vena cava thrombosis (IVC-Th) is a rare clinical entity after blunt abdominal trauma. It has both diagnostic and therapeutic dilemmas. Pulmonary embolism is the most dreadful complication and the leading cause of mortality after IVC-Th. Therefore, accurate prompt diagnosis is crucial. Objective: The aim of this article was to present a case of IVC-Th in a young male patient who had a blunt traumatic abdominal injury after a motor vehicle accident. Case presentation: The patient was brought to emergency department and was successfully managed by angio-jet thrombolysis. He developed a transient contrast nephropathy that was recovered after continuous renal replacement therapy. Several management options have been proposed in the literature, including conservative, endovascular and operative management. Conclusion: Angio-jet is a recent promising technique for managing of venous thrombosis. However, its use in cases of IVC-Th is not extensively discussed in the literature.

Venous thromboembolism chemical prophylaxis after skull base surgery.

PURPOSE: There is no guidance surrounding postoperative venous thromboembolism (VTE) prophylaxis using pharmacological agents (chemoprophylaxis) in patients undergoing skull base surgery. The aim of this study was to compare VTE and intracranial haematoma rates after skull base surgery in patients treated with/without chemoprophylaxis. METHODS: Review of prospective quaternary centre database including adults undergoing first-time skull base surgery (2009-2020). VTE was defined as deep vein thrombosis (DVT) and pulmonary embolism (PE) within 6 months of surgery. Multivariate logistic regression was used to determine factors predictive of postoperative intracranial haematoma/VTE. Propensity score matching (PSM) was used in group comparisons. RESULTS: One thousand five hundred fifty-one patients were included with a median age of 52 years (range 16-89 years) and female predominance (62%). Postoperative chemoprophylaxis was used in 81% of patients at a median of 1 day postoperatively. There were 12 VTE events (1.2%), and the use of chemoprophylaxis did not negate the risk of VTE entirely (p > 0.99) and was highest on/after postoperative day 6 (9/12 VTE events). There were 18 intracranial haematomas (0.8%), and after PSM, chemoprophylaxis did not significantly increase the risk of an intracranial haematoma (p > 0.99). Patients administered chemoprophylaxis from postoperative days 1 and 2 had similar rates of intracranial haematomas (p = 0.60) and VTE (p = 0.60), affirmed in PSM. CONCLUSION: Postoperative chemoprophylaxis represents a relatively safe strategy in patients undergoing skull base surgery. We advocate a personalised approach to chemoprophylaxis and recommend it on postoperative days 1 or 2 when indicated.

Biomarkers Profile in Provoked Versus Unprovoked Deep Venous Thrombosis.

Venous thromboembolism (VTE), including deep venous thrombosis (DVT) and pulmonary embolism (PE), represents a substantial healthcare challenge. Provoked and unprovoked DVT cases carry distinct risks and treatment considerations. Recognizing the limitations of this classification, molecular markers may enhance diagnostic precision and guide anticoagulation therapy duration relying on patient history and risk factors. This preliminary, open-label, prospective cohort study was conducted including 15 patients (10 provoked DVT and 5 unprovoked DVT) and a control group of healthy plasmatic subjects. Plasma levels of 9 biomarkers were measured at diagnosis (baseline, day 0, and D0) and after 30 days (day 30-D30). Patient demographics, clinical data, and biomarker concentrations were analyzed. Serum concentrations of D-dimer, von Willebrand factor, C-reactive protein, and Anti-Xa were elevated in DVT groups at D0 compared to controls. No significant differences were observed between the provoked and unprovoked groups on the day of diagnosis and 30 days later. Over 30 days, the provoked group exhibited significant biomarker changes related to temporal assessment. No significant differences were noted in the biomarker profile between provoked and unprovoked DVT groups. This study is indicative of the concept of individualized thrombosis assessment and subsequent treatment for VTE. Larger cohorts are warranted to validate these findings and further define the most appropriate use of the molecular markers.

Malnutrition in Head and Neck Free Flap Reconstruction as a Predictor of Adverse Outcomes.

INTRODUCTION: Malnutrition is associated with increased mortality in patients with head and neck (H&N) cancer. Because albumin levels are used as a surrogate for nutritional status, the purpose of this study is to assess whether malnutrition is associated with adverse postoperative outcomes in H&N free flap reconstruction. MATERIALS AND METHODS: The 2006-2018 National Surgical Quality Improvement Program Database was queried for patients undergoing flap procedures of the H&N based on Current Procedure Terminology codes. Patients were included if they were operated on by an otolaryngologist or when the primary surgical site was H&N. Nutritional status was categorized as malnourished (preoperative albumin level <3.5 g/dL) or normal (preoperative albumin level ≥3.5 g/dL). Major complications included pulmonary complications, cardiac complications, deep vein thrombosis/pulmonary embolism, and sepsis/septic shock. Minor complications included surgical infection, urinary tract infection, bleeding, and dehiscence. Data were analyzed via univariate chi-square and multivariate regression analyses. RESULTS: Of the patients, 2532 (83.3%) had normal albumin and 506 (16.7%) had hypoalbuminemia. Patients with hypoalbuminemia were more likely to have smoking history (P = 0.008), pulmonary comorbidity (P < 0.001), renal comorbidity (P = 0.018), disseminated cancer (P < 0.001), steroid use (P < 0.001), recent weight loss (P < 0.001), bleeding disorder (P = 0.023), and preoperative transfusion (P < 0.001). After adjustment for preoperative variance, malnourished patients were more likely to experience death (P < 0.001), return to operating room (P < 0.001), free flap failure (P = 0.008), pulmonary complication (P < 0.001), deep vein thrombosis/pulmonary embolism (P = 0.019), wound disruption (P = 0.042), intraoperative transfusion (P < 0.001), minor complication (P < 0.001), major complication (P < 0.001), and extended length of stay (P < 0.001). Of the patients with normal albumin, 2.1% experienced flap failure compared with 6.3% of patients with hypoalbuminemia. It should be noted that malnourished patients were 3.370 times more likely to experience flap failure (95% confidence interval, 1.383-8.212; P = 0.008) and 3.975 times more likely to experience death (95% confidence interval, 1.700-9.626; P = 0.001) than those with normal albumin. CONCLUSION: Malnutrition is associated with death, flap failure, minor complications, and other major complications following H&N free flap surgery, even after controlling for preoperative variance. Optimizing preoperative nutrition status before free flap procedures may ameliorate morbidity and mortality in H&N patients.

Prevalence of Pulmonary Embolism in COVID-19 at Quaternary Hospital Running Head: Pulmonary Embolism in COVID-19.

Background: Patients with COVID-19 are at greater risk of pulmonary embolism. Objective: The aim of the present study was to evaluate the monthly prevalence of pulmonary embolism diagnosed by angiotomography and mortality between March 2020 and May 2021 in more than 6000 patients hospitalized with COVID-19 at a single institution. Methods: A clinical trial was conducted with evaluated medical records the patients hospitalized at the institution who developed pulmonary embolism determined by angiotomography. Monthly and overall mortality rates between March 2020 and May 2021 in this population were evaluated. Results: A total of 6040 patients were hospitalized in this period, 203 of whom (3.36%) had an angiotomographic diagnosis of pulmonary embolism and 119 of these patients (58.62%) died. The largest number of patients with pulmonary embolism occurred in the periods from July to September 2020 and March to May 2021. No significant difference was found between mortality and the two peaks of the pandemic (p = 0.9, Fisher's exact test). Conclusion: Pulmonary embolism is associated a higher mortality rate among patients with COVID-19. Therefore, one of the strategies is an emphasis on the prevention of thrombotic and embolic events.

Aspiration of thrombus for intermediate-risk subacute pulmonary embolism.

Pulmonary embolism is the most common cardiovascular disease after myocardial infarction and stroke. Konstantinides (Eur Heart J 41(4):543-603, 2020) Current guidelines categorize patients with PE as being at low, intermediate, and high risk of early death, with the intermediate-risk group experiencing the greatest uncertainty regarding treatment recommendations. Rapid reduction of the thrombus load by thrombolysis significantly reduces symptoms and decreases mortality, but is accompanied by a high risk of bleeding. Meyer (N Engl J Med 370(15):1402-11, 2014) Mechanical thrombectomy (CDTE) have been proven safe and efficient, yet current ESC guidelines suggest the utilization of catheter interventions only for hypotensive patients with high bleeding risk, failed systemic thrombolysis, and cardiogenic shock or if a patient does not respond to conservative therapy Konstantinides (Eur Heart J 41(4):543-603, 2020). Here, we report a case of an intermediate-risk patient with pulmonary embolism who underwent thrombus aspiration and showed significant improvement in symptoms after treatment.

Recombinant hirudin attenuates pulmonary hypertension and thrombosis in acute pulmonary embolism rat model.

Background: Acute pulmonary embolism (APE) is classified as a subset of diseases that are characterized by lung obstruction due to various types of emboli. Current clinical APE treatment using anticoagulants is frequently accompanied by high risk of bleeding complications. Recombinant hirudin (R-hirudin) has been found to have antithrombotic properties. However, the specific impact of R-hirudin on APE remains unknown. Methods: Sprague-Dawley (SD) rats were randomly assigned to five groups, with thrombi injections to establish APE models. Control and APE group rats were subcutaneously injected with equal amounts of dimethyl sulfoxide (DMSO). The APE+R-hirudin low-dose, middle-dose, and high-dose groups received subcutaneous injections of hirudin at doses of 0.25 mg/kg, 0.5 mg/kg, and 1.0 mg/kg, respectively. Each group was subdivided into time points of 2 h, 6 h, 1 d, and 4 d, with five animals per point. Subsequently, all rats were euthanized, and serum and lung tissues were collected. Following the assessment of right ventricular pressure (RVP) and mean pulmonary artery pressure (mPAP), blood gas analysis, enzyme-linked immunosorbnent assay (ELISA), pulmonary artery vascular testing, hematoxylin-eosin (HE) staining, Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) staining, immunohistochemistry, and Western blot experiments were conducted. Results: R-hirudin treatment caused a significant reduction of mPAP, RVP, and Malondialdehyde (MDA) content, as well as H2O2 and myeloperoxidase (MPO) activity, while increasing pressure of oxygen (PaO2) and Superoxide Dismutase (SOD) activity. R-hirudin also decreased wall area ratio and wall thickness to diameter ratio in APE rat pulmonary arteries. Serum levels of endothelin-1 (ET-1) and thromboxaneB2 (TXB2) decreased, while prostaglandin (6-K-PGF1α) and NO levels increased. Moreover, R-hirudin ameliorated histopathological injuries and reduced apoptotic cells and Matrix metalloproteinase-9 (MMP9), vascular cell adhesion molecule-1 (VCAM-1), p-Extracellular signal-regulated kinase (ERK)1/2/ERK1/2, and p-P65/P65 expression in lung tissues. Conclusion: R-hirudin attenuated pulmonary hypertension and thrombosis in APE rats, suggesting its potential as a novel treatment strategy for APE.

Target sign in COVID-19, radiological interpretation and diagnostic contribution of digital thoracic tomosynthesis.

INTRODUCTION: Our objectives are: To describe the radiological semiology, clinical-analytical features and prognosis related to the target sign (TS) in COVID-19. To determine whether digital thoracic tomosynthesis (DTT) improves the diagnostic ability of radiography. MATERIAL AND METHODS: Retrospective, descriptive, single-centre, case series study, accepted by our ethical committee. Radiological, clinical, analytical and follow-up characteristics of patients with COVID-19 and TS on radiography and DTT between November 2020 and January 2021 were analysed. RESULTS: Eleven TS were collected in 7 patients, median age 35 years, 57% male. All TS presented with a central nodule and a peripheral ring, and in at least 82%, the lung in between was of normal density. All TS were located in peripheral, basal regions and 91% in posterior regions. TS were multiple in 43%. Contiguous TS shared the peripheral ring. Other findings related to pneumonia were associated in 86% of patients. DTT detected 82% more TS than radiography. Only one patient underwent a CT angiography of the pulmonary arteries, positive for acute pulmonary thromboembolism. Seventy-one per cent presented with pleuritic pain. No distinctive laboratory findings or prognostic worsening were detected. CONCLUSIONS: TS in COVID-19 predominates in peripheral and declining regions and can be multiple. Pulmonary thromboembolism was detected in one case. It occurs in young people, frequently with pleuritic pain and does not worsen the prognosis. DTT detects more than 80 % of TS than radiography.

Impact of insertion into the left internal jugular vein in chemoport-associated infections: a retrospective single-center study of 1690 cases.

We analyzed chemoport insertion procedures to evaluate infectious morbidity and factors causing infection. This single-center retrospective study included 1690 cases of chemoport implantation between January 2017 and December 2020. Overall, chemoports were inserted in 1582 patients. The average duration of chemoport use was 481 days (range 1-1794, median 309). Infections occurred in 80 cases (4.7%), with 0.098 per 1000 catheter-days. Among the 80 cases in which chemoports were removed because of suspected infection, bacteria were identified in 48 (60%). Significantly more cases of left internal jugular vein punctures were noted in the infected group (15 [18.8%] vs. 147 [9.1%]; p = 0.004). Pulmonary embolism was significantly different between the infection groups (3 [3.8%] vs. 19 (1.2%), p = 0.048). The hazard ratio was 2.259 (95% confidence interval [CI] 1.288-3.962) for the left internal jugular vein, 3.393 (95% CI 1.069-10.765) for pulmonary embolism, and 0.488 (95% CI 0.244-0.977) for chronic obstructive pulmonary disease. Using the right internal jugular vein rather than the left internal jugular vein when performing chemoport insertion might reduce subsequent infections.

Advances in microRNA regulation of deep vein thrombosis through venous vascular endothelial cells (Review).

Deep vein thrombosis (DVT) is a prevalent clinical venous thrombotic condition that often manifests independently or in conjunction with other ailments. Thrombi have the propensity to dislodge into the circulatory system, giving rise to complications such as pulmonary embolism, thereby posing a significant risk to the patient. Virchow proposed that blood stagnation, alterations in the vessel wall and hypercoagulation are primary factors contributing to the development of venous thrombosis. Vascular endothelial cells (VECs) constitute the initial barrier to the vascular wall and are a focal point of ongoing research. These cells exert diverse stimulatory effects on the bloodstream and secrete various regulatory factors that uphold the dynamic equilibrium between the coagulation and anticoagulation processes. MicroRNAs (miRNAs) represent a class of non­coding RNAs present in eukaryotes, characterized by significant genetic and evolutionary conservation and displaying high spatiotemporal expression specificity. Typically ranging from 20 to 25 bases in length, miRNAs can influence downstream gene transcription through RNA interference or by binding to specific mRNA sites. Consequently, advancements in understanding the molecular mechanisms of miRNAs, including their functionalities, involve modulation of vascular­associated processes such as cell proliferation, differentiation, secretion of inflammatory factors, migration, apoptosis and vascular remodeling regeneration. miRNAs play a substantial role in DVT formation via venous VECs. In the present review, the distinct functions of various miRNAs in endothelial cells are outlined and recent progress in comprehending their role in the pathogenesis and clinical application of DVT is elucidated.

Influencing factors on the time to CT in suspected pulmonary embolism: an explorative investigation.

Pulmonary embolism is a potentially fatal condition with increased mortality if anticoagulation is delayed. This study aimed to find influencing factors on the duration from requesting a computed tomography (CT) pulmonary angiography (CTPA) to performing a CTPA in suspected acute pulmonary embolism. In 1849 cases, automatically generated time data were extracted from the radiological information system. The impact of the distance to the scanner, case-related features (sector of patient care, triage), and workload (demand for CTs, performed CTs, available staff, hospital occupancy) were investigated retrospectively using multiple regression. The time to CTPA was shorter in cases from the emergency room (ER) than in inpatients and outpatients at distances below 160 m and 240 m, respectively. While requests from the ER were also performed faster than cases from regular wards (< 180 m), no difference was found between the ER and intensive care units. Compared to "not urgent" cases, the workflow was shorter in "urgent" (- 17%) and "life-threatening" (- 67%) situations. The process was prolonged with increasing demand (+ 5%/10 CTs). The presented analysis identified relevant in-hospital influences on the CTPA workflow, including the distance to the CT together with the sector of patient care, the case triage, and the demand for imaging.

Successful Treatment Strategy for Duplicate Inferior Vena Cava and Deep Venous Thrombosis: Filter Placement and Thrombolysis Approach.

BACKGROUND Duplicate inferior vena cava (IVC) accompanied by deep venous thrombosis is rare. The optimal treatment plan is determined according to the results of imaging, including venography. In this report, we present a case of successful treatment of a patient with duplicate IVC and deep venous thrombosis (DVT). CASE REPORT An 84-year-old man with history of hypertension was admitted to the hospital because of 4 days of moderate left lower-limb edema. A thorough examination led to the diagnosis of the DVT. The duplicate IVC was discovered during venography. As the blood from the left common iliac vein mainly flowed to the left IVC, and there were no other communicating branches before the convergence of the left and right IVCs, which was located above the 1st lumbar vertebrae body near the junction of the hepatic vein and the IVC, the strategy of placing only 1 filter in the left inferior vena cava were chosen, rather than placing 1 filter above the confluence of bilateral IVC, or placing a filter in each IVC below the level of renal veins on each side. Following that, the DVT was safely treated with thrombolysis and aspiration without the risk of pulmonary embolism. CONCLUSIONS This case report presented the complete evaluation and management of a patient with lower-limb DVT accompanied by the malformation of duplicate IVC. The filter placement strategy with duplicate IVC in the literature was summarized. We concluded that even in emergency situations, with comprehensive consideration, it is possible to perform endovascular intervention successfully and achieve satisfactory treatment results.

Intermediate-Risk and High-Risk Pulmonary Embolism: Recognition and Management: Cardiology Clinics: Cardiac Emergencies.

Pulmonary embolism (PE) is the third most common cause of cardiovascular death. Every specialty of medical practitioner will encounter PE in their patients, and should be prepared to employ contemporary strategies for diagnosis and initial risk-stratification. Treatment of PE is based on risk-stratification, with anticoagulation for all patients, and advanced modalities including systemic thrombolysis, catheter-directed therapies, and mechanical circulatory supports utilized in a manner paralleling PE severity and clinical context.

Predictive factors of clot propagation in patients with superficial venous thrombosis towards deep venous thrombosis and pulmonary embolism: a systematic review and meta-analysis.

OBJECTIVE: A subset of patients with superficial venous thrombosis (SVT) experiences clot propagation towards deep venous thrombosis (DVT) and/or pulmonary embolism (PE). The aim of this systematic review is to identify all clinically relevant cross-sectional and prognostic factors for predicting thrombotic complications in patients with SVT. DESIGN: Systematic review. DATA SOURCES: PubMed/MEDLINE and Embase were systematically searched until 3 March 2023. ELIGIBILITY CRITERIA: Original research studies with patients with SVT, DVT and/or PE as the outcome and presenting cross-sectional or prognostic predictive factors. DATA EXTRACTION AND SYNTHESIS OF RESULTS: The CHecklist for critical Appraisal and data extraction for systematic Reviews of prediction Modelling (CHARMS) checklist for prognostic factor studies was used for systematic extraction of study characteristics. Per identified predictive factor, relevant estimates of univariable and multivariable predictor-outcome associations were extracted, such as ORs and HRs. Estimates of association for the most frequently reported predictors were summarised in forest plots, and meta-analyses with heterogeneity were presented. The Quality in Prognosis Studies (QUIPS) tool was used for risk of bias assessment and Grading of Recommendations, Assessment, Development and Evaluations (GRADE) for assessing the certainty of evidence. RESULTS: Twenty-two studies were included (n=10 111 patients). The most reported predictive factors were high age, male sex, history of venous thromboembolism (VTE), absence of varicose veins and cancer. Pooled effect estimates were heterogenous and ranged from OR 3.12 (95% CI 1.75 to 5.59) for the cross-sectional predictor cancer to OR 0.92 (95% CI 0.56 to 1.53) for the prognostic predictor high age. The level of evidence was rated very low to low. Most studies were scored high or moderate risk of bias. CONCLUSIONS: Although the pooled estimates of the predictors high age, male sex, history of VTE, cancer and absence of varicose veins showed predictive potential in isolation, variability in study designs, lack of multivariable adjustment and high risk of bias prevent firm conclusions. High-quality, multivariable studies are necessary to be able to identify individual SVT risk profiles. PROSPERO REGISTRATION NUMBER: CRD42021262819.

Sildenafil improves hemodynamic changes caused by acute pulmonary embolism by inhibiting Rho kinase activity.

OBJECTIVE: This study examined the effects of sildenafil on acute pulmonary embolism (APE) using a rat model. METHODS: Sprague-Dawley rats were randomly divided into the sham, pulmonary thromboembolism (PTE), and sildenafil groups. The sham and PTE groups received normal saline once daily via gavage for 14 consecutive days, whereas the sildenafil group received sildenafil (0.5 mg/kg/day) once daily via gavage for 14 consecutive days. Autologous emboli were prepared from blood samples collected from the left femoral artery of rats in each group on day 13, and autologous emboli were injected into the jugular vein cannula of rats in the PTE and sildenafil groups on day 14. Sham-treated rats received the same volume of saline. Right systolic ventricular pressure (RVSP) and mean pulmonary arterial pressure (MPAP) were used to assess pulmonary embolism, and western blotting and enzyme-linked immunosorbent assay were used to detect relevant markers. RESULTS: The Rho kinase signaling pathway was significantly activated in rats with APE, and sildenafil significantly inhibited this activation. CONCLUSIONS: Sildenafil protected against APE through inhibiting Rho kinase activity, thereby reducing pulmonary vasoconstriction and decreasing elevated pulmonary arterial pressure. These findings might provide new ideas for the clinical treatment of acute pulmonary thromboembolism.