The UK prevalence of hereditary haemorrhagic telangiectasia and its association with sex, socioeconomic status and region of residence: a population-based study

Non-invasive CT screening for pulmonary arteriovenous malformations in children with confirmed hereditary hemorrhagic telangiectasia: Results from two pediatric centers

BACKGROUND

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant genetic disorder that is caused by mutations in mainly two genes, that is ENG, encoding endoglin (HHT1), or ACVRL1, encoding activin receptor-like kinase 1 (ALK-1/HHT2). HHT is characterized by recurrent epistaxis, mucocutaneous telangiectasia, and vascular visceral dysplasia responsible for visceral arteriovenous malformations (AVM).

AIM

to report the experience of two university hospitals (Trousseau, Paris, and CHIC, Creteil) with screening children for HHT and pulmonary AVM (PAVM) using high resolution computed tomography (HRCT).

METHODS

parents with confirmed HHT were offered to have their children screened for the mutation identified in their family, and informed consent was obtained. Children carrying the same mutation as their parents underwent HRCT of the chest without contrast.

RESULTS

between 2008 and 2015, 99 children were screened for HHT mutations. Mutations were identified in 59 patients, that is 24 HHT1 and 35 HHT2. Radiologic and clinical screening was possible in 52 patients (21 HHT-1 and 31 HHT-2). Among those, PAVM was identified in 13 patients (25%; n = 8 HHT1; n = 5 HHT2), and four of them required embolization therapy.

CONCLUSION

This study highlights the usefulness of genetic screening in children with known HHT family. It also suggests that a non-invasive protocol such as HRTC is an efficient approach to detect non-symptomatic lesions that are present early on in children carrying the ENG (HHT1), but also the ACVRL1 mutations (HHT2). Pediatr Pulmonol. 2017;52:642-649. © 2017 Wiley Periodicals, Inc.

Pulmonary arteriovenous malformations: evidence of physician under-education

Pulmonary arteriovenous malformations (PAVMs) are abnormal blood vessels that connect pulmonary arteries direct to pulmonary veins, thus bypassing the pulmonary capillaries which are essential to filter, process and oxygenate blood [1]. Population-wide screening programmes using thoracic computed tomography scans suggest a prevalence of 1 in 2630 (95% CI 1 in 1315–1 in 5555) [2], although the condition is subject to substantial under-ascertainment [3].

PAVMs pose unique management challenges; publication patterns indicate their importance remains poorly recognisedhttp://ow.ly/7iIT304WYl2

The Prevalence of Malformations of Cortical Development in a Pediatric Hereditary Hemorrhagic Telangiectasia Population

BACKGROUND AND PURPOSE

Brain AVM, cerebral abscess, and ischemic stroke are among the well known neurologic manifestations of hereditary hemorrhagic telangiectasia. However, recently reported data suggest an additional association with malformations of cortical development. The purpose of this study was to determine the prevalence of malformations of cortical development in a population of pediatric patients with hereditary hemorrhagic telangiectasia.

MATERIALS AND METHODS

A retrospective review of brain MRIs from 116 pediatric patients was performed. Each patient was referred from our institution's Hereditary Hemorrhagic Telangiectasia Clinic. Each MRI included a 3D sequence, most frequently MPRAGE. The 3D sequence was evaluated by a neuroradiology fellow, with specific attention to the presence or absence of malformations of cortical development. Positive studies were subsequently reviewed by 2 attending neuroradiologists, who rendered a final diagnosis.

RESULTS

Fourteen of 116 (12.1%) patients were found to have a malformation of cortical development. Among these 14, there were 12 cases of polymicrogyria and 2 cases of bifrontal periventricular nodular heterotopia.

CONCLUSIONS

Pediatric patients with hereditary hemorrhagic telangiectasia have a relatively high prevalence of malformations of cortical development, typically perisylvian polymicrogyria.

Effect of Center Volume on Outcomes in Hospitalized Patients With Hereditary Hemorrhagic Telangiectasia

OBJECTIVE

To determine whether hospitalized patients with hereditary hemorrhagic telangiectasia (HHT) had better outcomes at high-volume treatment centers (HVCs).

PATIENTS AND METHODS

The Nationwide Inpatient Sample (2000-2011) was used to identify HHT-related hospitalizations. Hospitals were classified based on quartiles of annual HHT discharge volume. The 75th percentile cutoff value (third quartile) was used to classify hospitals as low-volume centers (1-7 HHT discharges per year) or as HVCs (≥8 discharges per year. Demographic features, complication rates, and outcomes were compared between the 2 groups.

RESULTS

We identified 9440 hospital discharges in patients with HHT. Of these patients, 6856 (72.6%) were admitted to low-volume centers and 2584 (27.4%) to HVCs. The former were more likely to be of white race, older, and with higher income levels (P<.001 for each). The HVCs had higher rates of anemia, epistaxis, congestive heart failure, pulmonary hypertension, and cerebral and pulmonary arteriovenous malformations and lower rates of ischemic stroke and myocardial infarction. After adjusting for baseline differences in a multivariate model, patients treated at HVCs were more likely to be discharged home (odds ratio [OR]=1.35; 95% CI, 1.21-1.52; P<.001) and less likely to be discharged to short-term rehabilitation facilities (OR=0.45; 95% CI, 0.31-0.64; P<.001). Patients treated at HVCs also had a significantly lower risk of in-hospital mortality (OR=0.51; 95% CI, 0.34-0.74; P<.001).

CONCLUSION

Patients with HHT hospitalized at HVCs had better outcomes, with lower in-hospital mortality and higher home discharge rates. These findings strongly support ongoing efforts to expand access to HHT centers of excellence in the United States and worldwide.

20-year follow-up study of Danish HHT patients-survival and causes of death

Background

Hereditary Haemorrhagic Telangiectasia (HHT) is a dominantly inheritable disorder, with a wide variety of clinical manifestations due to presence of multiple arteriovenous manifestations. The most common mutations are found in HHT1 (ENG) and HHT2 (ACVRL1) patients, causing alterations in the TGF-β pathway which is responsible for angiogenesis. Modulations of angiogenesis may influence cancer rates. The objective of the study was to evaluate 20-year survival according to HHT subtype, as well as to evaluate differences in causes of death comparing HHT patients and controls. We also wanted to investigate whether cancer morbidity among HHT patients differs from that among controls.

Results

We included all HHT patients in the County of Fyn, Denmark, prevalent as of January 1st 1995 in total 73 HHT patients. In addition three age- and sex- matched controls per HHT patient were evaluated, in total 218 controls (one was lost due to registration failure). The controls were defined at start of follow-up in 1995. Information on lifestyle factors was not available. A total of 32 (44%) HHT patients and 97 (44%) controls passed away during follow-up. The survival curves were evenly distributed showing similar survival rates in the two groups. Cancer diagnoses had been registered in the follow-up period in 4 (5%) HHT patients and in 38 (17%) controls.

Conclusion

The mortality was not increased among Danish HHT patients compared to controls. This study is based on a clinical unselected series of HHT patients with the whole spectrum of severity, independent of need for medical care. Our data also suggest that HHT patients to a lesser degree than the background population are affected by cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s13023-016-0533-9) contains supplementary material, which is available to authorized users.

Screening for arteriovenous malformations in hereditary haemorrhagic telangiectasia

OBJECTIVE

To determine whether patients with hereditary haemorrhagic telangiectasia were being screened according to international guidelines, and to review recent evidence in order to provide up-to-date guidelines for the initial systemic management of hereditary haemorrhagic telangiectasia.

METHODS

A retrospective case note analysis was conducted, assessing patients in terms of screening for: genetics, cerebral arteriovenous malformations, pulmonary and hepatic arteriovenous malformations, and gastrointestinal telangiectasia. Databases searched included Medline, the Cumulative Index to Nursing and Allied Health Literature, and Embase.

RESULTS

Screening investigations were most frequently performed for hepatic arteriovenous malformations and least frequently for genetics. Recent data suggest avoiding routine genetic and cerebral arteriovenous malformation screening because of treatment morbidities; performing high-resolution chest computed tomography for pulmonary arteriovenous malformation screening; using capsule endoscopy (if possible) to reduce complications from upper gastrointestinal endoscopy; and omitting routine liver enzyme testing in favour of Doppler ultrasound.

CONCLUSION

Opportunities for systemic arteriovenous malformation screening are frequently overlooked. This review highlights the need for screening and considers the form in which it should be undertaken.

Signs and genetics of rare cancer syndromes with gastroenterological features

Although the genetic bases of most hereditary cancer syndromes are known, and genetic tests are available for them, the incidence of the most rare of these syndromes is likely underestimated, partially because the clinical expression is neither fully understood nor easily diagnosed due to the variable and complex expressivity. The clinical features of a small pool of rare cancer syndromes include gastroenterological signs, though not necessarily tumors, that could require the intervention of a gastroenterologist during any of the phases of the clinical management. Herein we will attempt to spread the knowledge on these rare syndromes by summarizing the phenotype and genetic basis, and revising the peculiar gastroenterological signs whose underlying role in these rare hereditary cancer syndromes is often neglected. Close collaboration between geneticists and gastroenterologists could facilitate both the early identification of patients or relatives at-risk and the planning of multidisciplinary and tailored management of these subjects.

A postal survey of hereditary hemorrhagic telangectasia in the northeast of England

The aim of this study is to identify the demographics and epistaxis burden of hereditary hemorrhagic telangiectasia (HHT). A questionnaire was sent to participants with HHT who were recruited from a prospectively maintained respiratory clinic data base in a tertiary hospital. Details on demographics, HHT symptoms, family history, epistaxis severity, and treatment received were recorded. There were 34 of 60 responses (57%). Two responses were from families of the deceased. Of the 32 evaluable patients (men, 14; women 18), the average age was 51 years (range, 23-78 years). The average age of HHT diagnosis was 31 years (range, 3-61 years). The diagnosis of HHT was made by the respiratory team in 13 patients; neurologist (2); ear, nose, and throat (ENT) specialist (4); general practitioner (5); hematologist (4); gastroenterologist (1); and not mentioned in two patients. Twenty-seven of 32 patients (84%) had a positive family history of HHT. Only 13 patients had formal genetic testing (4 endoglin, 1 activin receptor-like kinase, 8 unknown gene). All patients who presented to the respiratory clinic had a background of epistaxis, which was noted on presentation. The average age at initial epistaxis was 14 years (range, 2-50 years). The frequency of epistaxis was daily 63% (n = 20), weekly 9% (3), monthly 16% (5), and a few times a year 10% (3), and unstated in one patient. Nine of 32 patients (28%) required a transfusion. Six patients thought that they were unable to perform daily activities due to epistaxis. Only 15 of 32 patients (47%) were under the care of an ENT specialist. The treatment plan for epistaxis management was deemed good by 7 patients, adequate in 8, poor in 6, and not stated by 11 patients. In conclusion, this survey is the first to quantify the epistaxis burden within the northeast of England. The management of epistaxis needs specific education and treatment to optimize the quality of life among these patients.

Complications and mortality in hereditary hemorrhagic telangiectasia: A population-based study

OBJECTIVES

Studies report that the risks of significant neurologic complications (including stroke, cerebral abscess, and migraine) and hemorrhagic sequelae are high in patients with hereditary hemorrhagic telangiectasia (HHT), and that life expectancy in this cohort is reduced. However, most published cohorts derive from specialist centers, which may be susceptible to bias.

METHODS

We used a population-based approach to estimate the risks of developing neurologic and hemorrhagic complications of HHT, the association of a diagnosis of HHT with common cardiovascular and malignant comorbidities, and also long-term survival of those with the disease.

RESULTS

From a UK primary care database of 3.5 million patients (The Health Improvement Network), we identified 675 cases with a diagnosis of HHT and compared them with 6,696 controls matched by age, sex, and primary care practice. Risks of stroke (odds ratio [OR] 1.8, 95% confidence interval [CI] 1.2-2.6), cerebral abscess (OR 30.0, CI 3.1-288), and migraine (OR 1.7, CI 1.3-2.2) were elevated over controls. Bleeding complications including epistaxis (OR 11.6, CI 9.1-14.7) and gastrointestinal hemorrhage (OR 6.1, CI 2.8-13.4) were more common in cases with HHT. Survival of cases with HHT was poorer than controls with a hazard ratio for death of 2.0 (CI 1.6-2.6) and a median age at death 3 years younger.

CONCLUSIONS

Patients with HHT are at substantially increased risk of serious neurologic and hemorrhagic complications of the disease. Because a diagnosis of HHT is associated with a significantly poorer survival compared with those who have no disease, evaluation of new strategies to improve clinical management is required.

Pulmonary arteriovenous malformations

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.

Targeting under-diagnosis in hereditary hemorrhagic telangiectasia: a model approach for rare diseases?

Background

Hereditary hemorrhagic telangiectasia (HHT), a rare autosomal dominant disease, is considered under-diagnosed. Our primary objective was to provide evidence of under-diagnosis of HHT in a North American population. We hypothesized that variation would exist in the diagnosed prevalence (D-prevalence) across regions in the province of Ontario, Canada and across age groups, due to under-diagnosis in certain groups. Our secondary objective was to collect data regarding contact and local access to consult specialists by HHT patients to help guide potential future diagnostic programs.

Methods

Primary objective- 556 adult patients with a definite HHT diagnosis seen at the Toronto HHT Centre were identified and geocoded with postal codes. Prevalence rates were calculated using Canadian census data. Secondary objective- A driving network model was developed in ArcGIS. Service area buffers around ear, nose and throat (ENT) clinics in Ontario were generated to evaluate the proportion of the Ontario population with access to these clinics. A survey was also sent to the email contact list of HHT Foundation International, targeting people with diagnosed HHT, regarding consultation with ENT physicians for epistaxis and timing of HHT diagnosis.

Results

Primary objective- D-prevalence rates varied among regions, from no cases to 1.1 cases per 5000 in large Ontario cities. There were no significant differences between urban and rural prevalence rates. Variation in prevalence was seen across age groups, with greater prevalence in older adults (≥50 years-old) compared with adults 20–49 years-old (0.36 versus 0.26 per 5000, p < 0.0005). Secondary objective- Most Ontarians had access to ENT clinics within a 30, 60 and 90 minute modeled drive time (92.7%, 97.8% and 98.6%, respectively). Nearly 40% of surveyed patients consulted an ENT physician for their epistaxis, on average 13.9 ± 12.2 years prior to being diagnosed with HHT.

Conclusions

The prevalence of HHT in Ontario is highly variable across regions and age-groups, suggesting under-diagnosis. Given that patients with HHT frequently consult ENT physicians for epistaxis prior to HHT diagnosis, and that there is almost universal access to ENTs in Ontario, we propose targeting ENT clinics as a province-wide approach to detect undiagnosed HHT patients and families.