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Farhan A, Latif MA, Minhas A, Weiss CR. Cardiac and Hemodynamic Manifestations of Hereditary Hemorrhagic Telangiectasia. Int J Angiol 2022; 31:75-82. [PMID: 35923582 PMCID: PMC9341259 DOI: 10.1055/s-0042-1745842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023] Open
Abstract
The autosomal dominant trait hereditary hemorrhagic telangiectasia (HHT) causes multiorgan dysplastic lesions of the vasculature that can activate multiple physiological cascades leading to a broad array of cardiovascular diseases. Up to 78% of patients with HHT develop hepatic arteriovenous malformations (AVMs), which cause a hyperdynamic circulatory state secondary to hepatic/portal shunting. This condition can eventually progress to high-output cardiac failure (HOCF) with continued peripheral tissue hypoxemia. Treatment for HOCF is often limited to supportive measures (diuretics and treatment of anemia); however, recent studies using systemic bevacizumab have shown promise by substantially reducing the cardiac index. In the context of liver AVMs and high cardiac output, the pulmonary vasculature can also experience high flow. Without adequate dilation of pulmonary vessels, post-capillary pulmonary hypertension can develop. Another form of pulmonary hypertension observed in HHT, pulmonary arterial hypertension, is caused by HHT-related mutations in ENG and ACVRL1 causing congestive arteriopathy. Post-capillary pathogenesis is addressed by reducing the high-output state, whereas the pre-capillary state is treated with supportive mechanisms (diuretics, oxygen) and agents targeting pulmonary vasoreactivity: endothelin-1 receptor antagonists and phosphodiesterase-5 inhibitors. If either form of pulmonary hypertension is left untreated or proves refractory and progresses, the common hemodynamic complication is right heart failure. Targeted right heart therapies involve similar strategies to those of pulmonary arterial hypertension, with several experimental approaches under study. In this review, we describe in detail the mechanisms of pathogenesis, diagnosis, and treatment of the hemodynamic complications and associated cardiovascular diseases that may arise in patients with HHT.
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Affiliation(s)
- Ahmed Farhan
- Division of Interventional Radiology, Russell H. Morgan Department of Radiology and Radiological Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Muhammad A. Latif
- Division of Interventional Radiology, Russell H. Morgan Department of Radiology and Radiological Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Anum Minhas
- Division of Cardiology, Heart and Vascular Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Clifford R. Weiss
- Division of Interventional Radiology, Russell H. Morgan Department of Radiology and Radiological Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland
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Esmat HA, Aien MT. Pulmonary arteriovenous malformations presenting with upper back pain in an adult: A case report and literature review. Radiol Case Rep 2021; 16:1988-1992. [PMID: 34158879 PMCID: PMC8203562 DOI: 10.1016/j.radcr.2021.05.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 05/04/2021] [Accepted: 05/04/2021] [Indexed: 11/29/2022] Open
Abstract
Pulmonary arteriovenous malformations (PAVMs) are the abnormal connections between the pulmonary artery and pulmonary veins branches without intervening in the pulmonary vascular bed. Although the most common cause of PAVMs is hereditary hemorrhagic telangiectasia, the etiology of single PAVMs appears to be idiopathic. Dyspnea, cyanosis, cerebrovascular events, and brain abscess are the common clinical manifestations of these lesions, though they may present with a nonspecific symptom as upper back pain. Computed tomography is the gold standard investigation for diagnosing pulmonary arteriovenous malformations, and demonstrating their size and extent before therapy. Transcatheter embolization is the first-choice treatment for patients without severe complications. Surgical intervention is reserved for the lesions not amenable to embolotherapy.
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Affiliation(s)
- Habib Ahmad Esmat
- Department of Radiology, Kabul University of Medical Sciences, Kabul, Afghanistan
| | - Mohammad Tahir Aien
- Department of Radiology, Kabul University of Medical Sciences, Kabul, Afghanistan
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Majumdar S, McWilliams JP. Approach to Pulmonary Arteriovenous Malformations: A Comprehensive Update. J Clin Med 2020; 9:E1927. [PMID: 32575535 PMCID: PMC7356967 DOI: 10.3390/jcm9061927] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 06/12/2020] [Accepted: 06/15/2020] [Indexed: 02/07/2023] Open
Abstract
Pulmonary arteriovenous malformations (PAVMs) are abnormal direct vascular communications between pulmonary arteries and veins which create high-flow right-to-left shunts. They are most frequently congenital, usually in the setting of hereditary hemorrhagic telangiectasia (HHT). PAVMs may be asymptomatic or present with a wide variety of clinical manifestations such as dyspnea, hypoxemia, or chest pain. Even when asymptomatic, presence of PAVMs increases patients' risk of serious, potentially preventable complications including stroke or brain abscess. Transcatheter embolotherapy is considered the gold standard for treatment of PAVMs. Though previous guidelines have been published regarding the management of PAVMs, several aspects of PAVM screening and management remain debated among the experts, suggesting the need for thorough reexamination of the current literature. The authors of this review present an updated approach to the diagnostic workup and management of PAVMs, with an emphasis on areas of controversy, based on the latest literature and our institutional experience.
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Salibe-Filho W, Piloto BM, Oliveira EPD, Castro MA, Affonso BB, Motta-Leal-Filho JMD, Bortolini E, Terra-Filho M. Pulmonary arteriovenous malformations: diagnostic and treatment characteristics. ACTA ACUST UNITED AC 2019; 45:e20180137. [PMID: 31241656 PMCID: PMC6733713 DOI: 10.1590/1806-3713/e20180137] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 10/29/2018] [Indexed: 02/04/2023]
Abstract
Objective: To present a case series of pulmonary arteriovenous malformations (PAVMs), describing the main clinical findings, the number/location of pulmonary vascular abnormalities, the clinical complications, and the treatment administered. Methods: This was a retrospective observational study evaluating patients with PAVM divided into two groups: hereditary hemorrhagic telangiectasia (HHT); and idiopathic PAVM (iPAVM). Results: A total of 41 patients were selected for inclusion, but only 33 had PAVMs. After clinical evaluation, 27 and 6 were diagnosed with HHT and iPAVM, respectively. In the HHT group, the mean age was 49.6 years and 88.9% were female. In that group, 4 patients had an SpO2 of < 90% and the most common clinical finding was epistaxis. In the iPAVM group, the mean age was 48.1 years and 83.3% were female. In that group, 3 patients had an SpO2 of < 90%. Computed tomographic pulmonary angiography showed that most of the PAVMs were in the lower lobes: 56.4% in the HHT group and 85.7% in the iPAVM group. Embolization was performed in 23 patients (in both groups). At this writing, 10 patients are scheduled to undergo the procedure. One of the patients who underwent embolization was subsequently referred for pulmonary resection. Conclusions: In both of the PAVM groups, there was a predominance of women and of fistulas located in the lower lobes. Few of the patients had respiratory symptoms, and most had an SpO2 > 90%. The treatment chosen for all patients was percutaneous transcatheter embolization.
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Affiliation(s)
- William Salibe-Filho
- . Divisão de Pneumologia, Instituto do Coração - InCor - Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo (SP) Brasil
| | - Bruna Mamprim Piloto
- . Divisão de Pneumologia, Instituto do Coração - InCor - Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo (SP) Brasil
| | - Ellen Pierre de Oliveira
- . Divisão de Pneumologia, Instituto do Coração - InCor - Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo (SP) Brasil
| | - Marcela Araújo Castro
- . Divisão de Pneumologia, Instituto do Coração - InCor - Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo (SP) Brasil
| | - Breno Boueri Affonso
- . Serviço de Radiologia Intervencionista, Instituto do Coração - InCor - Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo (SP) Brasil
| | - Joaquim Maurício da Motta-Leal-Filho
- . Serviço de Radiologia Intervencionista, Instituto do Coração - InCor - Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo (SP) Brasil
| | - Edgar Bortolini
- . Serviço de Radiologia Intervencionista, Instituto do Coração - InCor - Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo (SP) Brasil
| | - Mário Terra-Filho
- . Divisão de Pneumologia, Instituto do Coração - InCor - Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo (SP) Brasil
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Vorselaars VMM, Hosman AE, Westermann CJJ, Snijder RJ, Mager JJ, Goumans MJ, Post MC. Pulmonary Arterial Hypertension and Hereditary Haemorrhagic Telangiectasia. Int J Mol Sci 2018; 19:ijms19103203. [PMID: 30336550 PMCID: PMC6213989 DOI: 10.3390/ijms19103203] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 10/08/2018] [Accepted: 10/10/2018] [Indexed: 12/20/2022] Open
Abstract
Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant inherited disease characterised by multisystemic vascular dysplasia. Heritable pulmonary arterial hypertension (HPAH) is a rare but severe complication of HHT. Both diseases can be the result of genetic mutations in ACVLR1 and ENG encoding for proteins involved in the transforming growth factor-beta (TGF-β) superfamily, a signalling pathway that is essential for angiogenesis. Changes within this pathway can lead to both the proliferative vasculopathy of HPAH and arteriovenous malformations seen in HHT. Clinical signs of the disease combination may not be specific but early diagnosis is important for appropriate treatment. This review describes the molecular mechanism and management of HPAH and HHT.
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Affiliation(s)
| | - Anna E Hosman
- Department of Pulmonology, St. Antonius Hospital, 3435 CM Nieuwegein, The Netherlands.
| | | | - Repke J Snijder
- Department of Pulmonology, St. Antonius Hospital, 3435 CM Nieuwegein, The Netherlands.
| | - Johannes J Mager
- Department of Pulmonology, St. Antonius Hospital, 3435 CM Nieuwegein, The Netherlands.
| | - Marie-Jose Goumans
- Department of Molecular Cell Biology, Leiden University Medical Centre, 2333 ZA Leiden, The Netherlands.
| | - Marco C Post
- Department of Cardiology, St. Antonius Hospital, 3435 CM Nieuwegein, The Netherlands.
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Vorselaars VMM, Velthuis S, Huitema MP, Hosman AE, Westermann CJJ, Snijder RJ, Mager JJ, Post MC. Reproducibility of right-to-left shunt quantification using transthoracic contrast echocardiography in hereditary haemorrhagic telangiectasia. Neth Heart J 2018; 26:203-209. [PMID: 29497946 PMCID: PMC5876176 DOI: 10.1007/s12471-018-1094-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Aim Transthoracic contrast echocardiography (TTCE) is recommended for screening of pulmonary arteriovenous malformations (PAVMs) in hereditary haemorrhagic telangiectasia. Shunt quantification is used to find treatable PAVMs. So far, there has been no study investigating the reproducibility of this diagnostic test. Therefore, this study aimed to describe inter-observer and inter-injection variability of TTCE. Methods We conducted a prospective single centre study. We included all consecutive persons screened for presence of PAVMs in association with hereditary haemorrhagic telangiectasia in 2015. The videos of two contrast injections per patient were divided and reviewed by two cardiologists blinded for patient data. Pulmonary right-to-left shunts were graded using a three-grade scale. Inter-observer and inter-injection agreement was calculated with κ statistics for the presence and grade of pulmonary right-to-left shunts. Results We included 107 persons (accounting for 214 injections) (49.5% male, mean age 45.0 ± 16.6 years). A pulmonary right-to-left shunt was present in 136 (63.6%) and 131 (61.2%) injections for observer 1 and 2, respectively. Inter-injection agreement for the presence of pulmonary right-to-left shunts was 0.96 (95% confidence interval (CI) 0.9–1.0) and 0.98 (95% CI 0.94–1.00) for observer 1 and 2, respectively. Inter-injection agreement for pulmonary right-to-left shunt grade was 0.96 (95% CI 0.93–0.99) and 0.95 (95% CI 0.92–0.98) respectively. There was disagreement in right-to-left shunt grade between the contrast injections in 11 patients (10.3%). Inter-observer variability for presence and grade of the pulmonary right-to-left shunt was 0.95 (95% CI 0.91–0.99) and 0.97 (95% CI 0.95–0.99) respectively. Conclusion TTCE has an excellent inter-injection and inter-observer agreement for both the presence and grade of pulmonary right-to-left shunts. Electronic supplementary material The online version of this article (10.1007/s12471-018-1094-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- V M M Vorselaars
- Department of Cardiology, St. Antonius Hospital, Nieuwegein, The Netherlands.
| | - S Velthuis
- Department of Cardiology, St. Antonius Hospital, Nieuwegein, The Netherlands
| | - M P Huitema
- Department of Cardiology, St. Antonius Hospital, Nieuwegein, The Netherlands
| | - A E Hosman
- Department of Pulmonology, St. Antonius Hospital, Nieuwegein, The Netherlands
| | - C J J Westermann
- Department of Pulmonology, St. Antonius Hospital, Nieuwegein, The Netherlands
| | - R J Snijder
- Department of Pulmonology, St. Antonius Hospital, Nieuwegein, The Netherlands
| | - J J Mager
- Department of Pulmonology, St. Antonius Hospital, Nieuwegein, The Netherlands
| | - M C Post
- Department of Cardiology, St. Antonius Hospital, Nieuwegein, The Netherlands
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Shovlin CL, Buscarini E, Hughes JMB, Allison DJ, Jackson JE. Long-term outcomes of patients with pulmonary arteriovenous malformations considered for lung transplantation, compared with similarly hypoxaemic cohorts. BMJ Open Respir Res 2017; 4:e000198. [PMID: 29071074 PMCID: PMC5652477 DOI: 10.1136/bmjresp-2017-000198] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Revised: 05/03/2017] [Accepted: 05/18/2017] [Indexed: 12/22/2022] Open
Abstract
INTRODUCTION Pulmonary arteriovenous malformations (PAVMs) may not be amenable to treatment by embolisation or surgical resection, and many patients are left with significant hypoxaemia. Lung transplantation has been undertaken. There is no guidance on selection criteria. METHODS To guide transplantation listing assessments, the outcomes of the six patients who had been considered for transplantation were compared with a similarly hypoxaemic patient group recruited prospectively between 2005 and 2016 at the same UK institution. RESULTS Six patients had been formally considered for lung transplantation purely for PAVMs. One underwent a single lung transplantation for diffuse PAVMs and died within 4 weeks of surgery. The other five were not transplanted, in four cases at the patients' request. Their current survival ranges from 16 to 27 (median 21) years post-transplant assessment. Of 444 consecutive patients with PAVMs recruited between 2005 and 2016, 42 were similarly hypoxaemic to the 'transplant-considered' cohort (SaO2 <86.5%). Hypoxaemic cohorts maintained arterial oxygen content (CaO2) through secondary erythrocytosis and higher haemoglobin. The 'transplant-considered' cohort had similar CaO2 to the hypoxaemic comparator group, but higher Medical Research Council (MRC) dyspnoea scores (p=0.023), higher rates of cerebral abscesses (p=0.0043) and higher rates of venous thromboemboli (p=0.0009) that were evident before and after the decision to list for transplantation. CONCLUSIONS The non-transplanted patients demonstrated marked longevity. Symptoms and comorbidities were better predictors of health than oxygen measurements. While a case-by-case decision, weighing survival estimates and quality of life will help patients in their decision making, the data suggest a very strong case must be made before lung transplantation is considered.
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Affiliation(s)
- Claire L Shovlin
- NHLI Vascular Science, Imperial College London, London, UK
- Respiratory Medicine, and VASCERN HHT European Reference Centre, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, UK
| | - Elisabetta Buscarini
- Gastroenterology Department, and VASCERN HHT European Reference Centre, Maggiore Hospital, ASST Crema, Crema, Italy
| | | | - David J Allison
- Department of Imaging, Imperial College Healthcare NHS Trust, London, UK
| | - James E Jackson
- Department of Imaging, and VASCERN HHT European Reference Centre, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, UK
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Dupuis-Girod S, Cottin V, Shovlin CL. The Lung in Hereditary Hemorrhagic Telangiectasia. Respiration 2017; 94:315-330. [PMID: 28850955 DOI: 10.1159/000479632] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Hereditary hemorrhagic telangiectasia (HHT) is a dominantly inherited genetic vascular disorder with an estimated prevalence of 1 in 6,000, characterized by recurrent epistaxis, cutaneous telangiectasia, and arteriovenous malformations (AVMs) that affect many organs including the lungs, gastrointestinal tract, liver, and brain. Its diagnosis is based on the Curaçao criteria, and is considered definite if at least 3 of the 4 following criteria are fulfilled: (1) spontaneous and recurrent epistaxis, (2) telangiectasia, (3) a family history, and (4) pulmonary, liver, cerebral, spinal, or gastrointestinal AVMs. The focus of this review is on delineating how HHT affects the lung.
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Affiliation(s)
- Sophie Dupuis-Girod
- Service de génétique - centre de référence national pour la maladie de Rendu-Osler, Hôpital Femme-Mère-Enfants, Hospices Civils de Lyon, Bron, France
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Shovlin CL, Patel T, Jackson JE. Embolisation of PAVMs reported to improve nosebleeds by a subgroup of patients with hereditary haemorrhagic telangiectasia. ERJ Open Res 2016; 2:00035-2016. [PMID: 27730189 PMCID: PMC5005172 DOI: 10.1183/23120541.00035-2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 04/02/2016] [Indexed: 11/07/2022] Open
Abstract
Pulmonary arteriovenous malformations (PAVMs) are structurally abnormal vessels that provide direct capillary-free communications between the pulmonary and systemic circulations, and hence, right-to-left shunts [1]. Due to impaired gas exchange, hypoxaemia is common but exercise tolerance is usually preserved through haematological (erythrocytotic) and cardiovascular compensations [2, 3], and patients are frequently asymptomatic [1–3]. Treatment of PAVMs is recommended to prevent paradoxical embolic sequelae such as ischaemic strokes [4] and brain abscess [5], commonly improves migraine headaches [6], and is a successful emergency treatment for haemorrhage. Pulmonary AVM embolisation appears to improve nosebleed severity for nearly one in six people with HHThttp://ow.ly/4mJqip
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Affiliation(s)
- Claire L Shovlin
- NHLI Cardiovascular Sciences, Imperial College London, London, UK
| | - Trishan Patel
- NHLI Cardiovascular Sciences, Imperial College London, London, UK; Dept of Medicine, St George's, University of London, London, UK
| | - James E Jackson
- Dept of Imaging, Imperial College Healthcare NHS Trust, London, UK
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10
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Vorselaars VMM, Velthuis S, Snijder RJ, Vos JA, Mager JJ, Post MC. Pulmonary hypertension in hereditary haemorrhagic telangiectasia. World J Cardiol 2015; 7:230-237. [PMID: 26015855 PMCID: PMC4438464 DOI: 10.4330/wjc.v7.i5.230] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 12/26/2014] [Accepted: 02/11/2015] [Indexed: 02/06/2023] Open
Abstract
Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant inherited disorder characterised by vascular malformations in predominantly the brain, liver and lungs. Pulmonary hypertension (PH) is increasingly recognised as a severe complication of HHT. PH may be categorised into two distinct types in patients with HHT. Post-capillary PH most often results from a high pulmonary blood flow that accompanies the high cardiac output state associated with liver arteriovenous malformations. Less frequently, the HHT-related gene mutations in ENG or ACVRL1 appear to predispose patients with HHT to develop pre-capillary pulmonary arterial hypertension. Differentiation between both forms of PH by right heart catheterisation is essential, since both entities are associated with severe morbidity and mortality with different treatment options. Therefore all HHT patients should be referred to an HHT centre.
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Shovlin CL. Circulatory contributors to the phenotype in hereditary hemorrhagic telangiectasia. Front Genet 2015; 6:101. [PMID: 25914716 PMCID: PMC4391027 DOI: 10.3389/fgene.2015.00101] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 02/25/2015] [Indexed: 12/11/2022] Open
Abstract
Hereditary hemorrhagic telangiectasia (HHT) is mechanistically and therapeutically challenging, not only because of the molecular and cellular perturbations that generate vascular abnormalities, but also the modifications to circulatory physiology that result, and are likely to exacerbate vascular injury. First, most HHT patients have visceral arteriovenous malformations (AVMs). Significant visceral AVMs reduce the systemic vascular resistance: supra-normal cardiac outputs are required to maintain arterial blood pressure, and may result in significant pulmonary venous hypertension. Secondly, bleeding from nasal and gastrointestinal telangiectasia leads to iron losses of such magnitude that in most cases, diet is insufficient to meet the ‘hemorrhage adjusted iron requirement.’ Resultant iron deficiency restricts erythropoiesis, leading to anemia and further increases in cardiac output. Low iron levels are also associated with venous and arterial thromboses, elevated Factor VIII, and increased platelet aggregation to circulating 5HT (serotonin). Third, recent data highlight that reduced oxygenation of blood due to pulmonary AVMs results in a graded erythrocytotic response to maintain arterial oxygen content, and higher stroke volumes and/or heart rates to maintain oxygen delivery. Finally, HHT-independent factors such as diet, pregnancy, sepsis, and other intercurrent illnesses also influence vascular structures, hemorrhage, and iron handling in HHT patients. These considerations emphasize the complexity of mechanisms that impact on vascular structures in HHT, and also offer opportunities for targeted therapeutic approaches.
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Affiliation(s)
- Claire L Shovlin
- NHLI Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, Imperial College London London, UK ; Respiratory Medicine, Hammersmith Hospital, Imperial College Healthcare NHS Trust London, UK
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12
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Yasuda W, Jackson JE, Layton DM, Shovlin CL. Hypoxaemia, sport and polycythaemia: a case from Imperial College London. Thorax 2015; 70:601-3. [PMID: 25855611 PMCID: PMC4453632 DOI: 10.1136/thoraxjnl-2014-206381] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 02/25/2015] [Indexed: 11/24/2022]
Affiliation(s)
| | - James E Jackson
- Department of Imaging, Imperial College Healthcare NHS Trust, London, UK
| | - D Mark Layton
- Department of Haematology, Imperial College London, London, UK
| | - Claire L Shovlin
- NHLI Cardiovascular Sciences, Imperial College London, London, UK Department of Respiratory Medicine, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, UK
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13
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Shovlin CL. Pulmonary arteriovenous malformations. Am J Respir Crit Care Med 2014; 190:1217-28. [PMID: 25420112 PMCID: PMC4315816 DOI: 10.1164/rccm.201407-1254ci] [Citation(s) in RCA: 142] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 10/20/2014] [Indexed: 11/16/2022] Open
Abstract
Within the past decade, pulmonary arteriovenous malformations (PAVMs) have evolved from rare curiosities to not uncommon clinical states, with the latest estimates suggesting a prevalence of ~1 in 2,600. PAVMs provide anatomic right-to-left shunts, allowing systemic venous blood to bypass gas exchange and pulmonary capillary bed processing. Hypoxemia and enhanced ventilatory demands result, although both are usually asymptomatic. Paradoxical emboli lead to strokes and cerebral abscesses, and these commonly occur in individuals with previously undiagnosed PAVMs. PAVM hemorrhage is rare but is the main cause of maternal death in pregnancy. PAVM occlusion by embolization is the standard of care to reduce these risks. However, recent data demonstrate that currently recommended management protocols can result in levels of radiation exposure that would be classified as harmful. Recent publications also provide a better appreciation of the hematologic and cardiovascular demands required to maintain arterial oxygen content and oxygen consumption in hypoxemic patients, identify patient subgroups at higher risk of complications, and emphasize the proportion of radiologically visible PAVMs too small to treat by embolization. This review, therefore, outlines medical states that exacerbate the consequences of PAVMs. Chief among these is iron deficiency, which is commonly present due to concurrent hereditary hemorrhagic telangiectasia: iron deficiency impairs hypoxemia compensations by restricting erythropoiesis and increases the risk of ischemic strokes. Management of periodontal disease, dental interventions, pulmonary hypertension, and pregnancy also requires specific consideration in the setting of PAVMs. The review concludes by discussing to what extent previously recommended protocols may benefit from modification or revision.
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Affiliation(s)
- Claire L. Shovlin
- NHLI Cardiovascular Sciences, Imperial College, London; and
- Respiratory Medicine, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom
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14
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Merkus D. Pulmonary arteriovenous malformations: haemodynamics and shunt closure. Neth Heart J 2014; 22:326-7. [PMID: 24668220 PMCID: PMC4099439 DOI: 10.1007/s12471-014-0546-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- D. Merkus
- Department of Cardiology, Erasmus MC, PO Box 2040, 3000 CA Rotterdam, the Netherlands
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