Peripheral Vascular Thrombosis Research Articles

Effect of smoking on thrombotic antiphospholipid syndrome: a 10-year prospective cohort study.

Cigarette smoking is an established risk factor for autoimmune diseases. However, whether smoking plays a clear role in thrombotic antiphospholipid syndrome (TAPS) has not been determined. We aimed to investigate the effects of smoking on clinical characteristics and prognosis of TAPS. This was a prospective cohort study from 2013 to 2022. During the study period, 297 patients were diagnosed with TAPS, including 82 smokers and 215 non-smokers. After propensity score matching, 57 smokers and 57 non-smokers matched by age and sex were analysed. Overall, smokers with TAPS had more cardiovascular risk factors (CVRFs) than non-smokers, including hypertension (36.59% vs. 14.42%, P<0.001), obesity (15.85% vs. 7.44%, P=0.029), dyslipidaemia (64.63% vs. 48.37%, P=0.012), and hyperhomocysteinaemia (62.20% vs. 36.28%, P<0.001). Arterial thrombotic events were more common in smokers at diagnosis (62.20% vs. 46.05%, P=0.013), especially myocardial infarction, visceral thrombosis, and peripheral vascular thrombosis. After matching, smokers showed balanced CVRFs with non-smokers at baseline, but retained a higher prevalence of arterial thrombosis (59.65% vs. 33.33%, P=0.005), mainly distributed in cerebral vascular, cardiovascular, and retinal vascular territories. During follow-up, smokers presented a tendency for more recurrent arterial thrombosis and less recurrent venous thrombosis. Smokers had significantly poorer outcomes for organ damage with higher DIAPS (median, 2.00 vs. 1.00, P=0.008), especially in the cardiovascular (26.32% vs. 3.51%, P=0.001), gastrointestinal (15.79% vs. 1.75%, P=0.016), and ophthalmologic (10.53% vs. 00.00%, P=0.027) systems. Smoking is related to increased arterial events and poor prognosis in TAPS patients. Patients with TAPS should be fully encouraged to avoid smoking.

Risk Factors, Clinical Presentation, Therapeutic Trends, and Outcomes in Arterial Thrombosis Complicating Unvaccinated COVID-19 Patients: A Systematic Review.

Data on characteristics and outcomes of coronavirus (COVID)-19 patients complicated with arterial thrombosis (AT) are scarce. Therefore, we carried out a systematic review (PRISMA, PROSPERO statements; PubMed, Scopus, and Web of Science) to identify risk factors, clinical presentation, treatment, and outcomes. We included publications from December 2019 to October 2020. Groups: (a) ischemic stroke, (b) thrombotic storm, (c) peripheral vascular thrombosis, (d) myocardial infarction, and (e) left cardiac thrombus or in-transit thrombus (venous system thrombus floating or attaching to the right heart). We considered 131 studies. The most frequent cardiovascular risk factors were: hypertension, diabetes, and dyslipidemia. A high proportion presented with asymptomatic, mild, or moderate COVID-19 (n = 91, 41.4%). We identified a high percentage of isolated ischemic stroke and thrombotic storm. Groups with higher mortality rate: intracardiac thrombus (1/2, 50.0%), thrombotic storm (18/49, 36.7%), and ischemic stroke (48/131, 36.6%). A small number received thromboprophylaxis. Most patients received antithrombotic treatment. The most frequent bleeding complication was intracranial hemorrhage, primarily with isolated stroke. Overall mortality was 33.6% (74/220). Despite a wide range of COVID-19 severity, a high proportion had AT as a complication of non-severe disease. AT can affect different vascular territories; mortality is associated with stroke, intensive care unit stay, and severe COVID-19.

Abstract LB077: Reengineering ponatinib to minimize cardiovascular toxicity

Abstract Introduction and Purpose of the Study: The advent of small molecule Tyrosine Kinase Inhibitors (TKIs) has revolutionized cancer treatment and greatly improved patient survival. However, the life-threatening cardiovascular toxicity of many TKIs present major concerns. Ponatinib is the most effective treatment for patients harboring the common T315I mutation of BCR-ABL that drives Chronic Myeloid Leukemia (CML) yet is one of the most cardiotoxic of TKIs. Ponatinib-induced events include myocardial infarction, heart failure, stroke, peripheral vascular disease and venous thrombosis. The aim of this study is to reengineer the chemical structure of ponatinib to minimize its adverse cardiovascular effects by using in vitro and in vivo models of cardiovascular toxicity. Experimental Procedures: We developed in vitro cardiovascular toxicity assays using human iPSC-cardiomyocytes (hiPSC-CMs) and human microvascular endothelial cells (HMVECs), and assessed anti-tumor efficacy in T315I mutated K562 CML cells. The cardiotoxicity was determined by impairment of cardiomyocyte contractility function, the vascular toxicity was defined by inability to form capillary-like networks in vasculogenesis assays. In vitro screening of ponatinib analogues probed chemical moieties responsible for its cardiovascular toxicity that were confirmed using mice xenograft mice models with human T315I mutant K562 cells. Summary of Unpublished Data: Compared to ponatinib, refined analogues showed markedly decreased adverse effects on HMVECs vasculogenesis and hiPSC-CMs contractility in vitro. The therapeutic window was increased in vivo, leading to regression of human T315I mutant CML xenografts comparable to ponatinib but without increasing serum levels of cardiac troponin. The kinase inhibition profiles of the “safe” analogues compared to ponatinib identified candidate mediators of ponatinib-induced toxicity. Validation by selective knockdown revealed likely mediators of cardiotoxicity, including FGFR. Conclusions: We succeeded in engineering a cardiovascular safe TKI that retained effective therapeutic properties against BCR-ABL T351 mutated form of CML, but with substantially decreased cardiovascular toxicity. Citation Format: Anna Pavlovna Hnatiuk, Arne A. Bruyneel, Dhanir Taylor, Mallesh Pandrala, Arpit Dheeraj, Wendy Li, Ricardo Serrano Fernandez, Dries A. Feyen, Michelle M. Wu, Prashila Amatya, Isabel Morgado, Volker Wiebking, Matthew H. Porteus, Sanjay Malhotra, Mark Mercola. Reengineering ponatinib to minimize cardiovascular toxicity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr LB077.

Thrombocytopenia in a cohort of primary and secondary antiphospholipid syndrome patients: Relation to clinical, laboratory manifestations and damage index.

Objectives This study aims to evaluate the prevalence of thrombocytopenia in a cohort of patients with primary and secondary antiphospholipid syndrome (APS) and to examine the relation of thrombocytopenia to the clinical, laboratory findings, and damage index for antiphospholipid syndrome (DIAPS).Patients and methods Between August 2018 and February 2019, a total of 168 patients (16 males, 152 females; mean age: 32.5±8.4 years; range, 18 to 59 years) who were followed in our clinic for APS were retrospectively analyzed. Medical records of the patients were screened and clinical data, laboratory investigations, and treatments applied were recorded. The DIAPS was calculated for all patients. The patients were divided into two groups according to the presence or absence of thrombocytopenia and both groups were compared regarding clinical, laboratory findings and DIAPS. Further subgroup analysis was done for patients with primary APS.Results The most common clinical manifestations in our patients were obstetric manifestations (77.4% in pregnant women), musculoskeletal manifestations (69%) and peripheral vascular thrombosis (54.8%). The prevalence of thrombocytopenia in our study was 42.3%, and it was significantly associated with musculoskeletal manifestations (p=0.043), vascular thrombosis (p=0.043), neurological manifestations (p=0.030), cutaneous manifestations (p=0.006), and use of immunosuppressives (p=0.047). The DIAPS was significantly higher in the thrombocytopenia group (p=0.034). Further subgroup analysis of patients with primary APS revealed that neurological manifestations (p=0.010) were significantly higher in the thrombocytopenia group, while the DIAPS was higher in the thrombocytopenia group, but it did not reach statistical significance (p=0.082).Conclusion Thrombocytopenia may be associated with a higher incidence of vascular thrombosis, neurological manifestations, musculoskeletal manifestations, use of immunosuppressive treatment, and DIAPS. In primary APS patients, thrombocytopenia may be a risk for neurological manifestations.

Simultaneous Transcatheter Closure of the Left Atrial Appendage and Congenital Interatrial Communication Closure

Background: Left atrial appendage closure (LAAC) with simultaneous interventional occlusion therapy for congenital interatrial communication has become a new focus of patients with nonvalvular atrial fibrillation. Little is known about the results of mid-and long-term results. Objective: The aim of this study was to evaluate the midand long-term safety and effectiveness of simultaneous transcatheter closure of the left atrial appendage (LAA) and congenital interatrial communication closure in atrial fibrillation (AF) patients. Methods: From Jan 2016 to June 2017, 27 patients with AF were treated with simultaneous transcatheter closure of the LAA and atrial septal defect (ASD, n = 22), patent foramen ovale (PFO, n = 5). Results: The perioperative closure success rate was 96.3%, except for cardiac tamponade occurred in one ASD patient. During the median 37.6-month follow-up period, no cases of cerebrovascular or peripheral vascular embolism, bleeding, infective endocarditis or thrombosis along the occluders were observed. Of the 21 patients with NYHA Class III, nineteen had significant improvements to NYHA Classes I or II, and 81.5% of patients were free from major or minor adverse events during midand long-term follow-up. Conclusions: Simultaneous closure of the LAA and congenital interatrial communication closure is a viable option for patients with nonvalvular atrial fibrillation who are at risk of stroke or systemic embolism, and it is effective and yields excellent mid-and long-term results.

Correlation between Breast Ultrasound Microcalcification and the Prognosis of Breast Cancer.

Breast cancer is a common gynecological disease, and its incidence and mortality are higher than those of other common malignant tumors. Breast ultrasound technology is a new surgical method, which has the advantages of reducing postoperative complications, improving the quality of life of patients, and improving the prognosis of patients. Breast microcalcification is a new method for the treatment of tumors. Its mechanism is that the proliferation of breast cancer cell walls increases the inflammatory factors in the cancer tissues and enhances the formation of tumors and peripheral vascular thrombosis. Breast microcalcification in the treatment of breast cancer patients will have a more significant impact compared to ordinary antibiotics alone. For this reason, the microcalcification performance of breast ultrasound is worthy of study, and related research on prognosis is also indispensable. The purpose of this study is to improve the understanding of the ultrasound manifestations of breast cancer microcalcification and the prognosis of breast cancer. This article mainly applied statistical analysis as well as experimental and survey methods to conduct breast ultrasound examination on 100 patients and analyzed the ultrasound manifestations of breast cancer MCs from three aspects: location, shape, and distribution. The experimental results show that there is no correlation between the location and distribution of breast cancer MCs and the diameter of the cancer foci, but there is a certain correlation between the morphology (non-gravel-like calcification) and the diameter of the cancer foci (>5 cm). Among them, HER-2 overexpression accounted for 11.9% in the grit-like MCs group and 51% in the non-grit-like MCs group.

Erratum: Peripheral vascular system thrombosis and COVID-19: A chilling revelation

Erratum: Peripheral vascular system thrombosis and COVID-19: A chilling revelation

Peripheral vascular system thrombosis and COVID-19: A chilling revelation

Introduction: As the COVID-19 pandemic reaches, its zenith a worrying trend has been noticed of late, that is arterial and venous thrombosis in patients presenting with COVID-19. Arterial and venous thrombosis was found in patients with asymptomatic state to severe affliction and most of them had a delayed presentation. Materials and Methods: An observational study was carried out by the Department of Vascular Surgery, Madurai Medical College. There were around 15200 total admissions between March 15, 2020, to September 30, 2020, in corona specialty hospital and trauma care center affiliated to Madurai medical college, out of which: (1) Acute deep venous thrombosis (DVT) was seen in 349 patients. (2) Acute limb ischemia (ALI) was found in 75 patients, out of which 70 patients had lower limb involvement and 5 patients had upper limb involvement. (a) Class 3–50 patients. (b) Class 2b–15 patients, (c) Class 1–10 patients. (3) Acute mesenteric ischemia was seen in 8 patients. Conclusion: COVID-19 is associated with an increased incidence of arterial and venous thrombosis of peripheral vascular system wherein arterial thrombosis, presenting, as ALI is profound and has a multi fold increased incidence than in non-COVID-19 patients and venous thrombosis is much higher than the non COVID-19 state.

Did we turn a blind eye? The answer is simply there. Peripheral pulmonary vascular thrombosis in COVID-19 patients explains sudden worsening of clinical conditions

AbstractCOVID-19 patients suffering sudden worsening of clinical conditions have an atypical peripheral pulmonary arterial obstruction at computed tomography pulmonary angiogram (CTPA), poorly associated to deep venous thrombosis (DVT), suspicious for thrombotic in situ nature rather than embolic.

Trombose vascular periférica no período gestacional

A Trombose Vascular Periférica (TVP) é uma doença caracterizada pelo desenvolvimento de trombos em vasos da periferia, especificamente nos membros inferiores. Categorizar os principais fatores de riscos que levam o surgimento da Trombose Vascular Periférica na gravidez e indicar medidas profiláticas para as possíveis complicações desta da doença. Pesquisa qualitativa, de caráter exploratório e explicativo, com orientação integrativa, mediante a busca de artigos científicos nos bancos de dados NCBI, PUBMED e SCIELO. Analisando os fatores extrínsecos e intrínsecos, diabetes mellitus interage com alguns mecanismos ligados a hemostasia; a obesidade é um fator extrínseco extremamente ligado no desenvolvimento da trombose na gestação; os contraceptivos são medicamentos que aumenta a probabilidade de desenvolver trombos nos vasos; a deficiência da antitrombina I, favorece eventos trombóticos tanto na gestação quanto no puerpério. As medidas profiláticas como heparina de baixo peso molecular (HBPM) um fármaco que interage com a antitrombina aumentando a sua atividade, e as meias de compressão, agem diminuindo a estase venosa. A trombose vascular na gestação está inteiramente ligada a fatores intrínsecos em concomitância com fatores extrínsecos. A HBPM é um medicamento preferível nesse período, bem como as meias de compressão.

Clinical analysis of lower limb thrombosis caused by paraquat poisoning

Objective: To investigate the causes of peripheral vascular thrombosis in patients with paraquat poisoning. Methods: The patients with paraquat poisoning who were admitted to our department in recent two years were observed to screen out the patients with large vessel thrombosis. The data on toxic exposure history, clinical features, and treatment were collected to analyze the causes of thrombosis in the patients with paraquat poisoning. Results: Three patients had typical lower limb thrombosis. There was one case of right common femoral vein thrombosis, one case of bilateral calf muscle vein thrombosis, and one case of right calf superficial vein thrombosis and right calf muscle vein thrombosis. Conclusions: After paraquat poisoning, the blood is in a hypercoagulable state and prolonged bed rest may increase the risk of thrombosis.

Evidence-based hemorheology. Doesitexist?Applying evidence fromclinical studies to the individual patient.

Clinicians are used to treat individual patients, and therefore may feel that clinical trials and systematic reviews do not give information for optimal treatment of the single patient.Evidence Based Medicine (EBM) is the integration of research evidence (from clinically relevant studies conducted using sound methodology) with clinical expertise (clinician's cumulated experience) and patient values (personal preferences and unique concerns and expectations).The practical steps of EBM include: 1)assess the patient, 2)ask the clinical question, 3)acquire the evidence, 4)critically appraise the evidence, 5)apply the results to the patient and 6)self-evaluate one's practice.Clinical studies in clinical hemorheology include - among other - interventions in vascular medicine: coronary disease, stroke, peripheral vascular disease, venous insufficiency and thrombosis, etc.Of these, we will present some practical steps on how to apply therapy results of stroke studies to the individual patient (this addresses step number 5 in the previous definition of EBM practice).We will do this by discussing the differences between internal and external validity of clinical trials, and defining the importance of baseline risks to choose therapy using the data from the best and most useful studies available. In the end, clinicians will understand how to use evidence effectively.

Antiplatelet and anticoagulant agents for preventing recurrence of peripheral vascular thrombosis in patients with Antiphospholipid syndrome

Antiplatelet and anticoagulant agents for preventing recurrence of peripheral vascular thrombosis in patients with Antiphospholipid syndrome

Hospital admissions due to diseases of arteries and veins peaked at physiological equivalent temperature -10 to 10 °C in Germany in 2009-2011.

We aimed to understand relationships of the weather as biometeorological and hospital admissions due to diseases of arteries and veins by subtypes, which have been scarcely studied, in a national setting in recent years. This is an ecological study. Ten percent of daily hospital admissions from the included hospitals (n = 1,618) across Germany that were available between 1 January 2009 and 31 December 2011 (n = 5,235,600) were extracted from Statistisches Bundesamt, Germany. We identified I70-I79 Diseases of arteries, arterioles and capillaries and I80-I89 Diseases of veins, lymphatic vessels and lymph nodes by International Classification of Diseases version 10 as the study outcomes. Daily weather data from 64 weather stations that covered 13 German states including air temperature, humidity, wind speed, cloud cover, radiation flux and vapour pressure were obtained and generated into physiologically equivalent temperature (PET). Two-way fractional-polynomial prediction was plotted with 95 % confidence intervals. For most of the subtypes from diseases of arteries and veins, hospital admissions slightly peaked in spring and dropped when PET was at 10 °C. There were no other large differences across 12 months. Admissions of peripheral vascular diseases, arterial embolism and thrombosis, phlebitis and thrombophlebitis, oesophageal varices and nonspecific lymphadenitis peaked when PET was between 0 and −10 °C, while others peaked when PET was between 0 and 10 °C. More medical resources could have been needed on days when PETs were at −10 to 10 °C than on other days. Adaptation to such weather change for health professionals and the general public would seem to be imperative.Electronic supplementary materialThe online version of this article (doi:10.1007/s11356-015-5791-x) contains supplementary material, which is available to authorized users.

Utilization pattern of doppler ultrasound scan at the University of Benin Teaching Hospital

Introduction: The use of Doppler scan in the evaluation of patients is crucial. Doppler application has found a wide range of utilization in medicine especially in the evaluation of cardiovascular anomalies such as in the detection of peripheral vascular disease and deep vein thrombosis. The aim of this study is to document the patients' presenting complaints and the corresponding Doppler diagnosis made. Materials and Methods: The study was conducted at the University of Benin Teaching Hospital. The patients' data (including Doppler sonographic data) of all the 121 patients who had Doppler scans done within the year 2012 were pooled and analyzed. Consent for the study was approved by the ethical committee of the hospital. Statistical analysis was done using Statistical Package for the Social Sciences software (SPSS version 17.0). Results: There were males 61 (50.4%) and females 60 (49.6%) in the study group. The mean age was 52.9 ± 21 years (minimum age of 7 months and maximum of 100 years). The lower limb was the most common region of the body interrogated, accounting for 69.4% followed by the neck, 16.5%; abdomen, 8.3%; upper limb, 3.3%; scrotum, 1.7% and head, 0.8%. Leg swelling, peripheral vascular disease (PVD) and deep vein thrombosis (DVT) were the most common presenting complaints with a cumulative frequency of 38.8%, whereas PVD, DVT and carotid plaque were the most common diagnosis made with a cumulative frequency of 48.7%. Conclusion: The use of Doppler ultrasound may lead to various important vascular diagnoses, which have profound usefulness in multiple clinical settings, including the emergency management of DVT.

Is Transfusion Associated With Graft Occlusion After Cardiac Operations?

Packed red blood cell (RBC) transfusions are associated with increased mortality after coronary artery bypass grafting (CABG) but not after cardiac valve operations. Transfusions are associated with increased strokes and deep venous thromboses after cardiac operations as well as increased peripheral vascular graft thrombosis. The purpose of this study was to determine if RBC transfusions were associated with a greater hazard of an occluded graft developing after CABG. Patients who underwent symptom-driven coronary artery angiography after CABG were analyzed using Cox models and propensity scoring to compare outcomes based on the RBC transfusion status during their index CABG hospitalization. We analyzed 940 patients. We found that patients who received transfusions were more likely to have occluded grafts on angiography (hazard ratio [HR], 1.24; 95% confidence interval [CI], 1.03-1.50; p = 0.02). After adjusting for other factors, we found that RBC transfusion was associated with about a 20% increased hazard of graft occlusion (HR, 1.21; 95% CI,1.07-1.37; p = 0.003). Perioperative RBC transfusion is associated with graft occlusion after CABG at both the patient and graft levels. These results add to the growing body of evidence that homologous RBC transfusion is not risk free but is associated with a variety of adverse effects including midterm graft failure.

Spectrum of Pediatric Systemic Lupus Erythematosus at Queen Rania Al-Abdullah Hospital for Children

Objectives: The aim of this study is to describe clinical signs, symptoms, laboratory characteristics, and medication used in pediatric Systemic lupus Erythematosus, both at presentation and during the course of the disease in Jordanian children at Queen Rania Al-Abdulla Hospital for children. Methods: This is a retrospective descriptive study that included patients managed over a period of 11 years, from January 2000 to December 2010. The charts of 25 patients from the pediatric Rheumatology unit at Queen Rania Al-Abdulla Hospital for children, who met four or more of the revised American College of Rheumatology classification criteria for Systemic lupus Erythematosus were reviewed. Results: There were 22 females and three males with F: M ratio of 7.3:1. The mean age at diagnosis was 10.9 years (range 7-14 years) with only five patients (20%) below the age of 10 years. The mean time from the start of illness to diagnosis was 8.6 month (range 1-36 months). At presentation cutaneous manifestations were found in 17 (68%) patients, 60% of patients had arthritis. Serositis and neurological manifestations were seen in 24% of cases. Hematological dysfunctions were present in 48%. Renal involvement was found in 40% of cases. Kidney biopsy was done for seven patients with renal manifestations. Three had class IV, two class III and two class I World Health Organization nephritis stage classification. No organ damage was found in 18 patients with Systemic lupus Erythematosus, while three patients developed end stage renal disease, two had neuropsychiatric disease (one cerebrovascular accident and one with chorea), one had cataract and one had peripheral vascular thrombosis, and gangrene of the hands and feet. Antinuclear Antibodies was positive in all patients. Conclusion: To the best of our knowledge this is the first review of Systemic lupus Erythematosus in pediatric population in Jordan. Comparison of our cohort with other reports from our region and other parts of the world confirmed that more or less the pediatric Systemic lupus Erythematosus behavior in presentation and laboratory findings is comparable.

AB0524 Comparison of the Clinical Features between Patients with Primary and Secondary Antiphospholipid Syndrome: Results from the Serbian National Cohort Study

ObjectivesAntiphospholipid syndrome (APS) patients suffer from various clinical manifestations with the presence of antiphospholipid antibodies (aPL). APS may manifest itself as a primary disease (PAPS) or as a secondary disease...

Homocysteine modifies extracellular ATP availability in macrophages

Increased levels of plasma homocysteine (hyperhomocysteinemia-HHcy) are associated to the development of coronary artery disease (CAD), peripheral vascular disease and thrombosis. In addition, recent studies have shown that inflammation, probably mediated by macrophages, mediates the pathogenesis associated to high levels of homocysteine (Hcy). In the present study, we evaluated the Hcy effects in the ATP hydrolysis and its breakdown products in murine macrophages. The results showed that micromolar concentrations of Hcy increased the ATP, ADP and AMP hydrolysis. Additionally, our results show decreased inosine levels in the extracellular milieu of Hcy-exposed macrophages. The increasing in ATP, ADP and AMP hydrolysis are not explained by increased transcription or protein expression of NTPDases and ecto-5′-nucleotidase (ecto-5′-NT/CD73) enzymes. Moreover, the formation of reactive oxygen species did not interfere in the Hcy effects, which suggest that Hcy or Hcy metabolites act directly on the modulation of NTPDases and ecto-5′-NT/CD73 activities. In conclusion, Hcy induces the rapid breakdown of ATP, ADP and AMP to adenosine (ADO), which is classically known as an anti-inflammatory response in immune cells. However, by the action of these enzymes, the extracellular adenosine generated during Hcy treatment probably is uptaken into the cells, as evidenced by the decreased in inosine formation, and thus collaborating to the inflammatory complications associates to HHcy

Acute pulmonary and moderate cardiovascular responses of spontaneously hypertensive rats after exposure to single-wall carbon nanotubes

As a novel kind of nanomaterial with wide potential applications, the adverse effects of carbon nanotubes (CNTs) have recently received significant attention after respiratory exposure. In this study, single-wall carbon nanotubes (SWCNTs) containing different metal contents were intratracheally instilled into lungs of spontaneously hypertensive rats. Pulmonary and cardiovascular system alterations were evaluated at 24 and 72 h post-instillation. Biomarkers of inflammation, oxidative stress and cell damage in the bronchoalveolar lavage fluid (BALF) were increased significantly 24 h post-exposure of SWCNTs. The increased endothelin-1 levels in BALF and plasma and angiotensin I-converting enzyme in plasma suggested endothelial dysfunction in the pulmonary circulation and peripheral vascular thrombosis. These findings suggest that respiratory exposure to SWCNTs can induce acute pulmonary and cardiovascular responses and individuals with existing cardiovascular diseases are very susceptible to SWCNTs exposure. The co-existence of metal residues in SWCNTs can aggravate the adverse effects.