Screening for pulmonary and brain vascular malformations is the North American standard of care for patients with hereditary hemorrhagic telangiectasia (HHT): A survey of HHT Centers of Excellence

De Novo Brain Vascular Malformations in Hereditary Hemorrhagic Telangiectasia

BACKGROUND

Approximately 10% of people with hereditary hemorrhagic telangiectasia (HHT) have brain vascular malformations (VMs). Few reports describe de novo brain VM formation. International HHT Guidelines recommend initial brain VM screening upon HHT diagnosis in children but do not address rescreening. We aimed to confirm whether brain VMs can form de novo in patients with HHT.

METHODS

The Brain Vascular Malformation Consortium HHT project is a 17-center longitudinal study enrolling patients since 2010. We analyzed the database for de novo VMs defined as those detected (1) on follow-up neuroimaging in a patient without previous brain VMs or (2) in a location distinct from previously identified brain VMs and reported those in whom a de novo VM could be confirmed on central neuroimaging review.

RESULTS

Of 1909 patients enrolled, 409 (21%) had brain VMs. Seven patients were recorded as having de novo brain VMs, and imaging was available for central review in four. We confirmed that three (0.7% of individuals with brain VMs) had de novo brain VMs (two capillary malformations, one brain arteriovenous malformation) with intervals of six, nine, and 13 years from initial imaging. Two with de novo brain VMs were <18 years. The fourth patient, a child, did not have a de novo brain VM but had a radiologically confirmed increase in size of an existing brain arteriovenous malformation.

CONCLUSIONS

Brain VMs can, albeit rarely, form de novo in patients with HHT. Given the potential risk of hemorrhage from brain VMs, regular rescreening in patients with HHT may be warranted.

Hereditary hemorrhagic telangiectasia in a 42-year-old Ethiopian man presenting with severe anemia and high-output heart failure: A case report with literature review

Key Clinical Messages

Hereditary hemorrhagic telangiectasia (HHT), a rare hereditary disorder, can cause recurrent massive epistaxis and gastrointestinal bleeding leading to severe anemia. Early diagnosis of HHT is essential to provide timely interventional therapies.

Abstract

HHT is a rare autosomal dominant hereditary disease that results in abnormal vasculogenesis in the skin, mucous membranes, and visceral organs such as the liver, lungs, and brain. Clinical diagnosis of HHT is made using the Curacao criteria, which include recurrent spontaneous nosebleeds, mucocutaneous telangiectasias, visceral organ involvement, and first-degree family history of HHT. Here, we report a patient with HHT from Ethiopia, who presented with recurrent epistaxis and gastrointestinal bleeding, and severe anemia requiring frequent blood transfusions as well as cauterization. The presented case is a 42-year-old Black Ethiopian man with frequent hospitalization for severe anemia and high-output heart failure requiring frequent blood transfusions. His mother had bilateral epistaxis since her early adulthood. Physical examination was significant for tachycardia, pale conjunctivae, and tiny erythematous lesions over his tongue, ejection systolic murmur and peripheral edema. Laboratory investigations revealed severe anemia with iron deficiency picture. Upper gastrointestinal endoscopy showed multiple telangiectasia spots and abdominal Doppler ultrasound showed hepatic arterio-venous malformations. He received supportive management and electrocauterization of nasal, gastric, and duodenal telangiectasias. To the best of our knowledge, this is the first case of HHT to be reported from Ethiopia. High degree of suspicion and early diagnosis of HHT is essential to start preventive screening and surveillance and provide timely interventional therapies. HHT can cause recurrent massive epistaxis and gastrointestinal bleeding leading to severe anemia and high-output heart failure. In resource limited settings, selective cauterization of telangiectasia will help to control bleeding, although it does not avoid recurrent bleeding.

Comparing Characteristics and Treatment of Brain Vascular Malformations in Children and Adults with HHT

Hereditary hemorrhagic telangiectasia (HHT) is a rare autosomal dominant disease characterized by the development of vascular malformations (VMs) in organs such as the brain and lungs, as well as telangiectases on mucosal surfaces. Prophylactic treatment of organ VMs may prevent potential complications, such as hemorrhage. However, brain VM treatment-surgical resection, embolization, and/or radiosurgery-is not recommended for all patients due to the associated risks. Given the scarcity of data regarding HHT-related brain VM presentation and treatment trends in pediatric patients, we aim to describe the clinical presentations and the patterns of treatment of HHT-related brain VMs in a pediatric cohort, and compare pediatric trends to those of adults. Demographic and clinical data were analyzed in 114 pediatric patients with HHT-related brain VMs and compared with a cohort of 253 adult patients enrolled in the multicenter Brain Vascular Malformation Consortium HHT Project. Our data demonstrated that a higher proportion of pediatric patients with HHT-related brain VMs were symptomatic at presentation (p = 0.004). Moreover, a higher proportion of pediatric patients presented with intracranial hemorrhage (p < 0.001) and seizure (p = 0.002) compared to adult patients. Surgical resection was the most common brain VM treatment modality in both children and adults. We conclude that pediatric patients may be more likely to present with symptoms and complications from brain VMs, supporting the case for screening for brain VMs in children with HHT.

Multidisciplinary coordinated care of hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu disease)

Hereditary hemorrhagic telangiectasia (HHT), also known as Osler-Weber-Rendu disease, is a rare disorder with a case prevalence as high as one in 5000, causing arteriovenous malformations in multiple organ systems. HHT is familial with autosomal dominant inheritance, with genetic testing allowing confirmation of the diagnosis in asymptomatic kindreds. Common clinical manifestations are epistaxis and intestinal lesions causing anemia and requiring transfusions. Pulmonary vascular malformations predispose to ischemic stroke and brain abscess and may cause dyspnea and cardiac failure. Brain vascular malformations can cause hemorrhagic stroke and seizures. Rarely, liver arteriovenous malformations can cause hepatic failure. A form of HHT can cause juvenile polyposis syndrome and colon cancer. Specialists in multiple fields may be called to care for one or more aspects of HHT, but few are familiar with evidence-based guidelines for HHT management or see a sufficient number of patients to gain experience with the unique characteristics of the disease. Primary care physicians and specialists are often unaware of the important manifestations of HHT in multiple systems and the thresholds for their screening and appropriate management. To improve familiarity, experience, and coordinated multisystem care for patients with HHT, the Cure HHT Foundation, which advocates for patients and families with this disease, has accredited 29 centers in North America with designated specialists for the evaluation and care of patients with HHT. Team assembly and current screening and management protocols are described as a model for evidence-based, multidisciplinary care in this disease.

Imaging Manifestations and Interventional Treatments for Hereditary Hemorrhagic Telangiectasia

Hemorrhagic hereditary telangiectasia (HHT) is a rare autosomal dominant disorder that causes multisystem vascular malformations including mucocutaneous telangiectasias and arteriovenous malformations (AVMs). Clinical and genetic screening of patients with signs, symptoms, or a family history suggestive of HHT is recommended to confirm the diagnosis on the basis of the Curaçao criteria and prevent associated complications. Patients with HHT frequently have epistaxis and gastrointestinal bleeding from telangiectasias. Pulmonary AVMs are common right-to-left shunts between pulmonary arteries and veins that can result in dyspnea and exercise intolerance, heart failure, migraine headaches, stroke or transient ischemic attacks, brain abscesses, or in rare cases, pulmonary hemorrhage. Primary neurologic complications from cerebral AVMs, which can take on many forms, are less common but particularly severe complications of HHT. Multimodality imaging, including transthoracic echocardiography, Doppler US, CT, and MRI, is used in the screening and initial characterization of vascular lesions in patients with HHT. Diagnostic angiography is an important tool in characterization of and interventional treatments for HHT, particularly those in the lungs and central nervous system. A multidisciplinary approach to early diagnosis, treatment, imaging, and surveillance at high-volume HHT Centers of Excellence is recommended. Although a variety of idiopathic, traumatic, or genetic conditions can result in similar clinical and imaging features, the Curaçao criteria are particularly useful for the proper diagnosis of HHT. Imaging and treatment options are reviewed, with a focus on screening, diagnosis, and posttreatment findings, with the use of updated international guidelines. Online supplemental material is available for this article. ^©RSNA, 2021.

Utility of modified Rankin Scale for brain vascular malformations in hereditary hemorrhagic telangiectasia

Background

Approximately 10% of hereditary hemorrhagic telangiectasia (HHT) patients harbour brain vascular malformations (VMs). Intracranial hemorrhage (ICH) from brain VMs can lead to death or morbidity, while treatment options for brain VMs also have associated morbidity. The modified Rankin Scale (mRS) may provide an approach to identifying HHT-brain VM patients with poor outcomes, and their predictors. We aimed to measure the relationship between mRS score and brain VM, brain VM number, as well as other aspects of HHT, at enrollment and during prospective follow-up.

Methods

1637 HHT patients (342 with brain VMs) were recruited from 14 HHT centres of the Brain Vascular Malformation Consortium since 2010 and followed prospectively (mean = 3.4 years). We tested whether the presence of brain VM, other HHT organ involvement, and HHT mutation genotype were associated with worse mRS scores at baseline and during follow-up, using linear mixed models, adjusting for age, sex, and year of visit.

Results

Presence of brain VMs was not associated with worse mRS score at baseline and there was no significant worsening of mRS with prospective follow-up in these patients; 92% had baseline mRS of 0–2. HHT-related gastrointestinal (GI) bleeding was associated with worse mRS scores at baseline (0.37, 95% CI 0.26–0.47, p < 0.001), as were history of anemia (0.35, 95% CI 0.27–0.43, p < 0.001) and liver VMs (0.19, 95% CI 0.09–0.30, p < 0.001). Presence of pulmonary arteriovenous malformations (AVMs) was not associated with worse mRS scores at baseline. mRS score was not associated with either HHT genotype (Endoglin vs ACVRL1). Only GI bleeding was associated with a significantly worsening mRS during prospective follow-up (0.64, 95% CI 0.21–1.08, p = 0.004).

Conclusion

Most HHT-brain VM patients had good functional capacity (mRS scores 0–2) at baseline that did not change significantly over 3.4 mean years of follow-up, suggesting that mRS may not be useful for predicting or measuring outcomes in these patients. However, HHT patients with GI bleeding, anemia history or liver VMs had worse mRS scores, suggesting significant impact of these manifestations on functional capacity. Our study demonstrates the insensitivity of the mRS as an outcomes measure in HHT brain VM patients and reinforces the continued need to develop outcomes measures, and their predictors, in this group.

Thresholds of Endoglin Expression in Endothelial Cells Explains Vascular Etiology in Hereditary Hemorrhagic Telangiectasia Type 1

Hereditary Hemorrhagic Telangiectasia type 1 (HHT1) is an autosomal dominant inherited disease characterized by arteriovenous malformations and hemorrhage. HHT1 is caused by mutations in ENDOGLIN, which encodes an ancillary receptor for Transforming Growth Factor-β/Bone Morphogenetic Protein-9 expressed in all vascular endothelial cells. Haploinsufficiency is widely accepted as the underlying mechanism for HHT1. However, it remains intriguing that only some, but not all, vascular beds are affected, as these causal gene mutations are present in vasculature throughout the body. Here, we have examined the endoglin expression levels in the blood vessels of multiple organs in mice and in humans. We found a positive correlation between low basal levels of endoglin and the general prevalence of clinical manifestations in selected organs. Endoglin was found to be particularly low in the skin, the earliest site of vascular lesions in HHT1, and even undetectable in the arteries and capillaries of heterozygous endoglin mice. Endoglin levels did not appear to be associated with organ-specific vascular functions. Instead, our data revealed a critical endoglin threshold compatible with the haploinsufficiency model, below which endothelial cells independent of their tissue of origin exhibited abnormal responses to Vascular Endothelial Growth Factor. Our results support the development of drugs promoting endoglin expression as potentially protective.