Tacrolimus in Gastrointestinal Bleeding in a Young Boy With Hereditary Hemorrhagic Telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disease in which gastrointestinal bleeding is a rare presenting symptom in children. Gastrointestinal bleeding in children is treated locally by endoscopy. When a focus of bleeding cannot be reached by endoscopy, management of these patients can be challenging. Previous reports showed a favorable outcome of treatment with tacrolimus in an adult HHT patient with liver vascular malformations and epistaxis and in a HHT patient with pulmonary hypertension. We report the first pediatric HHT patient who benefited from tacrolimus treatment. Our case demonstrated a remarkable decline in blood transfusions and better quality of life during the period of tacrolimus treatment.

Clinical Phenotypes of Sarcoidosis-Associated Pulmonary Hypertension

BACKGROUND AND OBJECTIVE

Pulmonary hypertension (PH) is a known complication of pulmonary sarcoidosis and its aetiology is unclear. Different pathophysiological mechanisms in sarcoidosis-associated pulmonary hypertension (SAPH) are known. Clinical phenotyping can aid clinicians in choosing the optimal treatment strategy. This study aimed to describe clinical phenotypes of SAPH and their characteristics.

METHODS

A retrospective cohort study was performed on all SAPH patients at a tertiary referral centre. All patients were extensively analysed and discussed case by case in a multidisciplinary expert team to determine the most likely pathophysiological mechanism of PH. Patients were then classified into conceptual clinical phenotypes.

RESULTS

Forty (40) patients with SAPH were identified between 2010 and 2019. Three (3) patients were classified as the postcapillary phenotype. Of the remaining 37 patients with precapillary PH, six were classified as 'compression of pulmonary vasculature', 29 as 'parenchymal', one as 'suspected vasculopathy', and one as 'chronic pulmonary emboli' phenotypes. Of the patients with compression of pulmonary vasculature, four showed compression by fibrotic disease and two by active sarcoidosis-based disease. Within the parenchymal phenotype, 20 patients (69%) showed pulmonary vascular resistance >3.0 Wood Units (WU) and had significantly lower diffusing capacity of the lung for carbon monoxide compared with the nine patients (31%) with pulmonary vascular resistance ≤3.0 WU.

CONCLUSION

SAPH had multiple pathophysiological mechanisms and clinical phenotypes in this retrospective study. Further studies are necessary to examine how these phenotypes can affect appropriate treatment and prognosis.

Pulmonary Vascular Complications in Hereditary Hemorrhagic Telangiectasia and the Underlying Pathophysiology

In this review, we discuss the role of transforming growth factor-beta (TGF-β) in the development of pulmonary vascular disease (PVD), both pulmonary arteriovenous malformations (AVM) and pulmonary hypertension (PH), in hereditary hemorrhagic telangiectasia (HHT). HHT or Rendu-Osler-Weber disease is an autosomal dominant genetic disorder with an estimated prevalence of 1 in 5000 persons and characterized by epistaxis, telangiectasia and AVMs in more than 80% of cases, HHT is caused by a mutation in the ENG gene on chromosome 9 encoding for the protein endoglin or activin receptor-like kinase 1 (ACVRL1) gene on chromosome 12 encoding for the protein ALK-1, resulting in HHT type 1 or HHT type 2, respectively. A third disease-causing mutation has been found in the SMAD-4 gene, causing a combination of HHT and juvenile polyposis coli. All three genes play a role in the TGF-β signaling pathway that is essential in angiogenesis where it plays a pivotal role in neoangiogenesis, vessel maturation and stabilization. PH is characterized by elevated mean pulmonary arterial pressure caused by a variety of different underlying pathologies. HHT carries an additional increased risk of PH because of high cardiac output as a result of anemia and shunting through hepatic AVMs, or development of pulmonary arterial hypertension due to interference of the TGF-β pathway. HHT in combination with PH is associated with a worse prognosis due to right-sided cardiac failure. The treatment of PVD in HHT includes medical or interventional therapy.

Second International Guidelines for the Diagnosis and Management of Hereditary Hemorrhagic Telangiectasia

DESCRIPTION

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disease with an estimated prevalence of 1 in 5000 that is characterized by the presence of vascular malformations (VMs). These result in chronic bleeding, acute hemorrhage, and complications from shunting through VMs. The goal of the Second International HHT Guidelines process was to develop evidence-based consensus guidelines for the management and prevention of HHT-related symptoms and complications.

METHODS

The guidelines were developed using the AGREE II (Appraisal of Guidelines for Research and Evaluation II) framework and GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology. The guidelines expert panel included expert physicians (clinical and genetic) in HHT from 15 countries, guidelines methodologists, health care workers, health care administrators, patient advocacy representatives, and persons with HHT. During the preconference process, the expert panel generated clinically relevant questions in 6 priority topic areas. A systematic literature search was done in June 2019, and articles meeting a priori criteria were included to generate evidence tables, which were used as the basis for recommendation development. The expert panel subsequently convened during a guidelines conference to conduct a structured consensus process, during which recommendations reaching at least 80% consensus were discussed and approved.

RECOMMENDATIONS

The expert panel generated and approved 6 new recommendations for each of the following 6 priority topic areas: epistaxis, gastrointestinal bleeding, anemia and iron deficiency, liver VMs, pediatric care, and pregnancy and delivery (36 total). The recommendations highlight new evidence in existing topics from the first International HHT Guidelines and provide guidance in 3 new areas: anemia, pediatrics, and pregnancy and delivery. These recommendations should facilitate implementation of key components of HHT care into clinical practice.

The clinical and genetic features of hereditary haemorrhagic telangiectasia (HHT) in central South Africa-three novel pathogenic variants

Hereditary haemorrhagic telangiectasia (HHT) is supposedly rare in Africa, with only three pathogenic variants documented to date. We describe the clinical and genetic features of HHT patients in central South Africa, who fulfilled the Curaçao criteria. Sixteen patients (median age 38.5 years, range 12-65 years), from six families were included. Fifteen patients were of African descent and one was of Afrikaner descent. The mean epistaxis severity score was 3.18, and the median haemoglobin was 9.5 g/dL (range 3.5-13.5 g/dL). On transthoracic contrast echocardiography 69% had a shunt grade ≥ 1, but only 20% had pulmonary arteriovenous malformations (AVMs) on computed tomography of the chest. Hepatic AVMs were found in 13% of patients, while 13% had brain vascular malformations. Four patients were HIV positive, of whom two had worsening epistaxis while they had opportunistic infections and poor HIV control. We identified six pathogenic variants (four in ENG and two in ACVRL1) in the six probands, three of which had been described previously. Three variants have apparently not been reported previously: ENG c.[1336_1337dup];[ =] p.[(Asp446fs)];[( =)], ENG c.[ 690?_816+?del] p.[(?)], and ACVRL1 c.[268_274delins57];[ =] p.[(Cys90fs)];[( =)]. We confirmed the diagnosis of HHT in sixteen patients and identified pathogenic variants in ENG or ACVRL1 in all six probands in central South Africa, where HHT has been underreported. We describe three pathogenic variants: two of ENG and one of ACVRL1. We will be able to implement pre-symptomatic screening of patients in our area, and improve their management.

Safety of macitentan in sarcoidosis-associated pulmonary hypertension: a case-series

Background:

Pulmonary hypertension (PH) is a known complication of pulmonary sarcoidosis and is associated with higher morbidity and mortality. Currently, there are no approved PH-targeted therapies for sarcoidosis-associated pulmonary hypertension (SAPH). Macitentan is frequently used as treatment for pulmonary arterial hypertension, but no results are known in the SAPH population.

Objective:

We investigated the safety and effect of macitentan as treatment for SAPH.

Methods:

We retrospectively reviewed our patient database for all SAPH patients receiving macitentan as treatment, with a minimum follow-up of twelve months for monitoring safety. Safety outcomes included reported side-effects, hospitalisations and mortality. Furthermore, six-minutes walking distance, New York Heart Association functional class and NT-proBNP levels were collected.

Results:

Six cases (three men) with a median age of 64 years (range 52-74 years) were identified. During macitentan treatment, one patient experienced side effects and aborted therapy after five days of treatment and died 16 months later. Three patients were hospitalised during treatment for congestive heart failure. Four patients showed improvement of their functional class and three patients in exercise capacity after 12 months of therapy.

Conclusion:

Macitentan was well tolerated in five out of six cases with severe pulmonary sarcoidosis and PH. Functional capacity improved in four cases. Prospective controlled trials are warranted before therapeutic recommendations can be made. (Sarcoidosis Vasc Diffuse Lung Dis 2020; 37 (1): 74-78)

Sarcoidosis-Associated Pulmonary Hypertension

Pulmonary hypertension (PH) is a well-known complication of sarcoidosis, defined by a mean pulmonary artery pressure of ≥25 mm Hg. Since both PH and sarcoidosis are rare diseases, data on sarcoidosis-associated PH (SAPH) is retrieved mostly from small retrospective studies. Estimated prevalence of SAPH ranges from 3% in patients referred to a tertiary center up to 79% in patients awaiting lung transplant. Most patients with SAPH show advanced parenchymal disease as the underlying mechanism. However, some patients have disproportional elevated pulmonary artery pressure, and PH can occur in sarcoidosis patients without parenchymal disease. Other mechanisms such as vascular disease, pulmonary embolisms, postcapillary PH, extrinsic compression, and other sarcoidosis-related comorbidities might contribute to SAPH. The diagnosis of PH in sarcoidosis is challenging since symptoms and signs overlap. Suspicion can be raised based on symptoms or tests, such as pulmonary function tests, laboratory findings, electrocardiography, or chest CT. PH screening mainly relies on transthoracic echocardiography. Right heart catheterization should be considered on a case-by-case basis in patients with clinical suspicion of PH, taking into account clinical consequences. Treatment options are considered on patient level in a PH expert center, and might include oxygen therapy, immunosuppressive, or PH-specific therapy. However, qualitative evidence is scarce. Furthermore, in a subset of patients, interventional therapy or eventually lung transplant can be considered. SAPH is associated with high morbidity. Mortality is higher in sarcoidosis patients with PH compared with those without PH, and increases in patients with more advanced stages of sarcoidosis and/or PH.

Prevalence and diagnostic value of nail fold capillary microscopy in hereditary hemorrhagic telangiectasia: A retrospective study

Abnormal vasculature is a key feature of hereditary hemorrhagic telangiectasia (HHT) and can also present in the nail fold capillary beds. However, the exact prevalence and the clinical diagnostic value in HHT are still largely unknown. The nail fold can be easily and noninvasively inspected with a capillary microscope. We therefore retrospectively assessed the prevalence and diagnostic value of abnormal nail fold capillaries in all patients who were screened between January 2000 and July 2017 for the presence of HHT and underwent capillary microscopy in St Antonius Hospital, The Netherlands. Capillary microscopy results and clinical characteristics were extracted from medical files and the prevalence of abnormal nail fold capillaries was calculated and the diagnostic value of the Curaçao criteria with and without capillary microscopy results was assessed. Of the 1761 individuals screened, 923 (52%) were diagnosed with a clinical and/or genetic HHT diagnosis. In these patients, capillary microscopy was normal in 23% (n = 218), enlarged loops were seen in 11% (n = 99), and giant loops in 66% (n = 606). The sensitivity and specificity of the Curaçao criteria for the diagnosis of HHT without capillary microscopy results were 96% and 90%, respectively. The addition of the presence of giant loops to the Curaçao criteria led to a small increase in sensitivity to 97% without affecting the specificity. In conclusion, the prevalence of nail fold abnormalities in patients with HHT is high. Capillary microscopy can be a useful, easy, and noninvasive diagnostic tool in HHT.

Long-term real world clinical outcomes of macitentan therapy in chronic thromboembolic pulmonary hypertension

BACKGROUND

Macitentan treatment for chronic thromboembolic pulmonary hypertension (CTEPH) in the routine clinical setting is increasing. However, 'real world' macitentan experience is scarce and is needed to differentiate from controlled clinical trial settings.

OBJECTIVE

We describe our outcomes and clinical 'real world' experience of macitentan mono- and combination therapy with riociguat or sildenafil in CTEPH.

METHODS

We included all consecutive CTEPH patients, either non-operated or with residual PH after pulmonary endarterectomy (PEA), treated with macitentan in the St. Antonius hospital in Nieuwegein, the Netherlands, between 01-2014 and 11-2019. We describe clinical outcomes and adverse events (AEs) until 2 years after macitentan initiation.

RESULTS

In total 73 CTEPH patients on macitentan were included, of which 18 patients were clinically inoperable (n = 7 declined PEA, n = 11 nonacceptable risk-benefit) and 55 had technically inoperable CTEPH (n = 48)/residual PH (n = 7). Clinically inoperable patients (mean age 72.4 ± 10.2 years, 61% female, 28% macitentan monotherapy, observation period 2.0 (1.9-2.0) years) had a survival of 100% and clinical worsening (CW)-free survival of 88% at 2-year follow-up respectively, with a significant increased 6-min walking distance (6MWD). Technically inoperable/residual PH patients (mean age 62.1 ± 14.1 years, 60% female, 27% macitentan monotherapy, observation period 2.0 (1.0-2.0) years) had a 2-year survival and CW-free survival of 86% and 68% respectively, with significant improved 6MWD and NT-proBNP. Nonsevere AEs were reported in 30% of all patients.

CONCLUSION

Macitentan mono- and combination therapy in non-operated CTEPH and residual PH is safe and improves clinical outcomes till 2-year follow-up.

Intranasal Efudix reduces epistaxis in hereditary hemorrhagic telangiectasia

BACKGROUND

Local application of fluorouracil (Efudix, 5-FU) induces sclerosis in patients with sinonasal tumors and superficial basocellular skin carcinoma. As a 'back against the wall' treatment, we investigated the local effect of nasally applied 5-FU and whether this could decrease the burden of severe epistaxis in patients with hereditary hemorrhagic telangiectasia (HHT).

METHODS

HHT patients with severe and frequent epistaxis, subsequent anemia and a necessity for blood and/or iron infusions were treated with a nasal tampon with 5-FU. This tampon was placed unilaterally in the nasal cavity on the side of the most severe epistaxis and replaced once weekly during 4 weeks. Outcome measures were safety and side effects, the aspect of the nasal mucosa measured with the mucosal HHT score, the epistaxis severity score (ESS), hemoglobin and ferritin plasma levels, and quality of life assessment pre-treatment, one and three months post-treatment.

RESULTS

Six HHT patients participated. During treatment and follow-up, the nasal mucosa turned more pale and sclerotic and the number of telangiectases diminished. The mucosal HHT score improved and the ESS declined (p = 0.01). The decline of ESS persisted up to 3 months post-5-FU treatment. Moreover, mean hemoglobin levels increased from 6.0 pre-5-FU to 6.8 after one month post-5-FU.

CONCLUSION

Unilateral application of 5-FU on a nasal tampon diminished the severity and frequency of epistaxis in all HHT patients. This effect sustained up to three months post-treatment, despite the fact that the contralateral side remained untreated. Subsequently, hemoglobin levels increased. Intranasal 5-FU is a promising entity for further research on epistaxis treatment in HHT patients.

Safety and efficacy of balloon pulmonary angioplasty in chronic thromboembolic pulmonary hypertension in the Netherlands

Background

Balloon pulmonary angioplasty (BPA) is an emerging treatment in patients with chronic thromboembolic pulmonary hypertension (CTEPH) and chronic thromboembolic disease (CTED). We describe the first safety and efficacy results of BPA in the Netherlands.

Methods

We selected all consecutive patients with inoperable CTEPH and CTED accepted for BPA treatment who had a six-month follow-up in the St. Antonius Hospital in Nieuwegein and the Amsterdam University Medical Center (UMC) in Amsterdam. Functional class (FC), N‑terminal pro-brain natriuretic peptide (NT-proBNP), 6‑minute walking test distance (6MWD) and right-sided heart catheterisation were performed at baseline and six months after last BPA. Complications for each BPA procedure were noted.

Results

A hundred and seventy-two BPA procedures were performed in 38 patients (61% female, mean age 65 ± 15 years). Significant improvements six months after BPA treatment were observed for functional class (63% FC I/II to 90% FC I/II, p = 0.014), mean pulmonary artery pressure (−8.9 mm Hg, p = 0.0001), pulmonary vascular resistance (−2.8 Woods Units (WU), p = 0.0001), right atrial pressure (−2.0 mm Hg, p = 0.006), stroke volume index (+5.7 ml/m², p = 0.009) and 6MWD (+48m, p = 0.007). Non-severe complications occurred in 20 (12%) procedures.

Conclusions

BPA performed in a CTEPH expert centre is an effective and safe treatment in patients with inoperable CTEPH.

Executive summary of the 12th HHT international scientific conference

Hereditary hemorrhagic telangiectasia is an autosomal dominant trait affecting approximately 1 in 5000 people. A pathogenic DNA sequence variant in the ENG, ACVRL1 or SMAD4 genes, can be found in the majority of patients. The 12th International Scientific HHT Conference was held on June 8-11, 2017 in Dubrovnik, Croatia to present and discuss the latest scientific achievements, and was attended by over 200 scientific and clinical researchers. In total 174 abstracts were accepted of which 58 were selected for oral presentations. This article covers the basic science and clinical talks, and discussions from three theme-based workshops. We focus on significant emergent themes and unanswered questions. Understanding these topics and answering these questions will help to define the future of HHT research and therapeutics, and ultimately bring us closer to a cure.

Bosentan or Macitentan Therapy in Chronic Thromboembolic Pulmonary Hypertension?

OBJECTIVE

Research comparing bosentan and macitentan in chronic thromboembolic pulmonary hypertension (CTEPH) is scarce, although macitentan might have superior pharmacologic properties. We present the first real-world, 2-year follow-up results and compare clinical outcomes of both drugs in CTEPH.

METHODS

All consecutive, technical inoperable or residual CTEPH patients receiving bosentan or macitentan, diagnosed in our multidisciplinary team between January 2003 and January 2019, were included. We report and compare survival, clinical worsening (CW), adverse events, WHO FC, NT-proBNP and 6-min walking test (6MWT) until 2 years after medication initiation.

RESULTS

In total, 112 patients receiving bosentan or macitentan (58% female, mean age 62 ± 14 years, 68% WHO FC III/IV, 51% bosentan) could be included. Mean treatment duration was 1.9 ± 0.4 years for bosentan and 1.2 ± 0.6 years for macitentan. Two-year survival rate was 91% for bosentan and 80% for macitentan (HR mortality macitentan 1.85 [0.56-6.10], p = 0.31). Two-year CW-free survival was 81% and 58%, respectively (HR CW macitentan 2.16 [0.962-4.87], p = 0.06). Right atrial pressure, cardiac output (for mortality alone) and 6MWT lowest saturation were multivariate predictors at baseline. Overall adverse event rates were comparable and WHO FC, NT-proBNP and 6MWT distance improved similar for both drugs till 2-year follow-up.

CONCLUSION

CTEPH patients receiving bosentan or macitentan have improved clinical outcomes till 2-year follow-up, without significant differences in outcomes between both therapies.

Decreased Expression of Vascular Endothelial Growth Factor Receptor 1 Contributes to the Pathogenesis of Hereditary Hemorrhagic Telangiectasia Type 2

BACKGROUND

Hereditary Hemorrhagic Telangiectasia type 2 (HHT2) is an inherited genetic disorder characterized by vascular malformations and hemorrhage. HHT2 results from ACVRL1 haploinsufficiency, the remaining wild-type allele being unable to contribute sufficient protein to sustain endothelial cell function. Blood vessels function normally but are prone to respond to angiogenic stimuli, leading to the development of telangiectasic lesions that can bleed. How ACVRL1 haploinsufficiency leads to pathological angiogenesis is unknown.

METHODS

We took advantage of Acvrl1^+/- mutant mice that exhibit HHT2 vascular lesions and focused on the neonatal retina and the airway system after Mycoplasma pulmonis infection, as physiological and pathological models of angiogenesis, respectively. We elucidated underlying disease mechanisms in vitro by generating Acvrl1^+/- mouse embryonic stem cell lines that underwent sprouting angiogenesis and performed genetic complementation experiments. Finally, HHT2 plasma samples and skin biopsies were analyzed to determine whether the mechanisms evident in mice are conserved in humans.

RESULTS

Acvrl1^+/- retinas at postnatal day 7 showed excessive angiogenesis and numerous endothelial "tip cells" at the vascular front that displayed migratory defects. Vascular endothelial growth factor receptor 1 (VEGFR1; Flt-1) levels were reduced in Acvrl1^+/- mice and HHT2 patients, suggesting similar mechanisms in humans. In sprouting angiogenesis, VEGFR1 is expressed in stalk cells to inhibit VEGFR2 (Flk-1, KDR) signaling and thus limit tip cell formation. Soluble VEGFR1 (sVEGFR1) is also secreted, creating a VEGF gradient that promotes orientated sprout migration. Acvrl1^+/- embryonic stem cell lines recapitulated the vascular anomalies in Acvrl1^+/- (HHT2) mice. Genetic insertion of either the membrane or soluble form of VEGFR1 into the ROSA26 locus of Acvrl1^+/- embryonic stem cell lines prevented the vascular anomalies, suggesting that high VEGFR2 activity in Acvrl1^+/- endothelial cells induces HHT2 vascular anomalies. To confirm our hypothesis, Acvrl1^+/- mice were infected by Mycoplasma pulmonis to induce sustained airway inflammation. Infected Acvrl1^+/- tracheas showed excessive angiogenesis with the formation of multiple telangiectases, vascular defects that were prevented by VEGFR2 blocking antibodies.

CONCLUSIONS

Our findings demonstrate a key role of VEGFR1 in HHT2 pathogenesis and provide mechanisms explaining why HHT2 blood vessels respond abnormally to angiogenic signals. This supports the case for using anti-VEGF therapy in HHT2.

Pulmonary Arterial Hypertension and Hereditary Haemorrhagic Telangiectasia

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.

SMAD4 gene mutation increases the risk of aortic dilation in patients with hereditary haemorrhagic telangiectasia

BACKGROUND

Mutations in the genes ENG, ACVRL1 and SMAD4 that are part of the transforming growth factor-beta signalling pathway cause hereditary haemorrhagic telangiectasia (HHT). Mutations in non-HHT genes within this same pathway have been found to associate with aortic dilation. Therefore, we investigated the presence of aortic dilation in a large cohort of HHT patients as compared to non-HHT controls.

METHODS

Chest computed tomography of consecutive HHT patients (ENG, ACVRL1 and SMAD4 mutation carriers) and non-HHT controls were reviewed. Aortic root dilation was defined as a z-score>1.96. Ascending and descending aorta dimensions were corrected for age, gender and body surface area.

RESULTS

In total 178 subjects (57.3% female, mean age 43.9±14.9years) were included (32 SMAD4, 47 ENG, 50 ACVRL1 mutation carriers and 49 non-HHT controls). Aortopathy was present in a total of 42 subjects (24% of total). Aortic root dilatation was found in 31% of SMAD4, 2% of ENG, 6% of ACVRL1 mutation carriers, and 4% in non-HHT controls (p<0.001). The aortic root diameter was 36.3±5.2mm in SMAD4 versus 32.7±3.9mm in the non-SMAD4 group (p=0.001). SMAD4 was an independent predictor for increased aortic root (β-coefficient 3.5, p<0.001) and ascending aorta diameter (β-coefficient 1.6, p=0.04).

CONCLUSIONS

SMAD4 gene mutation in HHT patients is independently associated with a higher risk of aortic root and ascending aortic dilation as compared to other HHT patients and non-HHT controls.

Reproducibility of right-to-left shunt quantification using transthoracic contrast echocardiography in hereditary haemorrhagic telangiectasia

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.

Screening children for pulmonary arteriovenous malformations: Evaluation of 18 years of experience

BACKGROUND

Hereditary Hemorrhagic Telangiectasia (HHT) is an autosomal dominant disease with multi-systemic vascular dysplasia. Early diagnosis through screening is important to prevent serious complications. How best to screen children of affected parents for pulmonary arteriovenous malformations (PAVMs) is often subject to debate. Transthoracic contrast echocardiogram (TTCE) is considered optimal in screening for PAVMs in adults. Guidelines for the screening of children are not specific, reflecting the lack of scientific evidence on the best method to use.

OBJECTIVE

Aims of this study are (i) to evaluate our current screening method, consisting of history, physical examination, pulse oximetry, and chest radiography and (ii) to assess whether postponing more invasive screening for PAVMs until adulthood is safe.

METHODS

This is a prospective observational cohort study using a patient database.

RESULTS

Over a period of 18 years (mean follow-up 9.21 years, SD 4.72 years), 436 children from HHT families were screened consecutively. A total of 175/436 (40%) children had a diagnosis of HHT. PAVMs were detected in 39/175 (22%) children, 33/39 requiring treatment by embolotherapy. None of the screened children suffered any PAVM-associated complications with this screening method.

CONCLUSION

This study shows that a conservative screening method during childhood is sufficient to detect large PAVMs and protect children with HHT for PAVM-related complications. Postponing TTCE and subsequent chest CT scanning until adulthood to detect any smaller PAVMs does not appear to be associated with major risk.

Follow-up of pulmonary right-to-left shunt in hereditary haemorrhagic telangiectasia

Pulmonary arteriovenous malformations (PAVMs) are associated with severe neurological complications in hereditary haemorrhagic telangiectasia (HHT). Transthoracic contrast echocardiography (TTCE) is recommended for screening of pulmonary right-to-left shunts (RLS). Although growth of PAVMs is shown in two small studies, no studies on follow-up with TTCE exist.All HHT patients underwent a second TTCE 5 years after initial screening. Patients with a history of PAVM embolisation were excluded. Pulmonary RLS grade on TTCE after 5 years was compared to the grade at screening.200 patients (53.5% female, mean±sd age at screening 44.7±14.1 years) were included. Increase in RLS grade occurred in 36 (18%) patients, of whom six (17%) underwent embolisation. The change in grade between screening and follow-up was not more than one grade. Of patients with nontreatable pulmonary RLS at screening (n=113), 14 (12.4%) underwent embolisation. In patients without pulmonary RLS at initial screening (n=87), no treatable PAVMs developed during follow-up.Within 5 years, no treatable PAVMs developed in HHT patients without pulmonary RLS at initial screening. Increase in pulmonary RLS grade occurred in 18% of patients, and never increased by more than one grade. Of patients with nontreatable pulmonary RLS at initial screening, 12% underwent embolisation.

Life expextancy of parents with Hereditary Haemorrhagic Telangiectasia

Background

Hereditary Haemorrhagic Telangiectasia (HHT) is an autosomal dominant disease associated with epistaxis, arteriovenous malformations and telangiectasias. Disease complications may result in premature death.

Method

We investigated life-expectancies of parents of HHT patients compared with their non-HHT partners using self- or telephone-administered questionnaires sent to their children. Patients were extracted from the databases of 2 participating HHT Centres: the Toronto HHT Database (Toronto, Canada) and the St. Antonius Hospital HHT Database (Nieuwegein, The Netherlands).

Results

Two hundred twenty five/407 (55 %) of respondents were included creating HHT- (n = 225) and control groups (n = 225) of equal size. Two hundred thirteen/225 (95 %) of the HHT group had not been screened for organ involvement of the disease prior to death. The life expectancy in parents with HHT was slightly lower compared to parents without (median age at death 73.3 years in patients versus 76.6 years in controls, p0.018). Parents with ACVRL 1 mutations had normal life expectancies, whereas parents with Endoglin mutations died 7.1 years earlier than controls (p = 0.024). Women with Endoglin mutations lived a median of 9.3 years shorter than those without (p = 0.04). Seven/123 (5 %) of deaths were HHT related with a median age at death of 61.5 years (IQ range 54.4–67.7 years).

Conclusion

Our study showed that the life expectancy of largely unscreened HHT patients was lower than people without HHT. Female patients with Endoglin mutations were most strikingly at risk of premature death from complications. These results emphasize the importance of referring patients with HHT for screening of organ involvement and timely intervention to prevent complications.

Interaction Between ALK1 Signaling and Connexin40 in the Development of Arteriovenous Malformations

OBJECTIVE

To determine the role of Gja5 that encodes for the gap junction protein connexin40 in the generation of arteriovenous malformations in the hereditary hemorrhagic telangiectasia type 2 (HHT2) mouse model.

APPROACH AND RESULTS

We identified GJA5 as a target gene of the bone morphogenetic protein-9/activin receptor-like kinase 1 signaling pathway in human aortic endothelial cells and importantly found that connexin40 levels were particularly low in a small group of patients with HHT2. We next took advantage of the Acvrl1(+/-) mutant mice that develop lesions similar to those in patients with HHT2 and generated Acvrl1(+/-); Gja5(EGFP/+) mice. Gja5 haploinsufficiency led to vasodilation of the arteries and rarefaction of the capillary bed in Acvrl1(+/-) mice. At the molecular level, we found that reduced Gja5 in Acvrl1(+/-) mice stimulated the production of reactive oxygen species, an important mediator of vessel remodeling. To normalize the altered hemodynamic forces in Acvrl1(+/-); Gja5(EGFP/+) mice, capillaries formed transient arteriovenous shunts that could develop into large malformations when exposed to environmental insults.

CONCLUSIONS

We identified GJA5 as a potential modifier gene for HHT2. Our findings demonstrate that Acvrl1 haploinsufficiency combined with the effects of modifier genes that regulate vessel caliber is responsible for the heterogeneity and severity of the disease. The mouse models of HHT have led to the proposal that 3 events-heterozygosity, loss of heterozygosity, and angiogenic stimulation-are necessary for arteriovenous malformation formation. Here, we present a novel 3-step model in which pathological vessel caliber and consequent altered blood flow are necessary events for arteriovenous malformation development.

Follow-up of Thalidomide treatment in patients with Hereditary Haemorrhagic Telangiectasia

BACKGROUND

Patients with a hereditary vascular disorder called Rendu-Osler-Weber syndrome (Hereditary Haemorrhagic Telangiectasia, HHT) haemorrhage easily due to weak-walled vessels. Haemorrhage in lungs or brain can be fatal but patients suffer most from chronic and prolonged nosebleeds (epistaxis), the frequency and intensity of which increases with age. Several years ago, it was discovered serendipitously that the drug Thalidomide had beneficial effects on the disease symptoms in several of a small group of HHT patients: epistaxis and the incidence of anaemia were reduced and patients required fewer blood transfusions. In addition, they reported a better quality of life. However, Thalidomide has significant negative side effects, including neuropathy and fatigue.

METHODS

We followed up all HHT patients in the Netherlands who had been taking Thalidomide at the time the original study was completed to find out (i) how many had continued taking Thalidomide and for how long (ii) the nature and severity of any side-effects and (iii) whether side-effects had influenced their decision to continue taking Thalidomide.

RESULTS

Only a minority of patients had continued taking the drug despite its beneficial effects on their symptoms and that the side effects were the primary reason to stop.

CONCLUSION

Despite symptom reduction, alternative treatments are still necessary for epistaxis in HHT patients and a large-scale clinical trial is not justified although incidental use in the most severely affected patients can be considered.

Follow-up of Thalidomide treatment in patients with Hereditary Haemorrhagic Telangiectasia

BACKGROUND

Patients with a hereditary vascular disorder called Rendu-Osler-Weber syndrome (Hereditary Haemorrhagic Telangiectasia, HHT) haemorrhage easily due to weak-walled vessels. Haemorrhage in lungs or brain can be fatal but patients suffer most from chronic and prolonged nosebleeds (epistaxis), the frequency and intensity of which increases with age. Several years ago, it was discovered serendipitously that the drug Thalidomide had beneficial effects on the disease symptoms in several of a small group of HHT patients: epistaxis and the incidence of anaemia were reduced and patients required fewer blood transfusions. In addition, they reported a better quality of life. However, Thalidomide has significant negative side effects, including neuropathy and fatigue.

METHODS

We followed up all HHT patients in the Netherlands who had been taking Thalidomide at the time the original study was completed to find out (i) how many had continued taking Thalidomide and for how long (ii) the nature and severity of any side-effects and (iii) whether side-effects had influenced their decision to continue taking Thalidomide.

RESULTS

Only a minority of patients had continued taking the drug despite its beneficial effects on their symptoms and that the side effects were the primary reason to stop.

CONCLUSION

Despite symptom reduction, alternative treatments are still necessary for epistaxis in HHT patients and a large-scale clinical trial is not justified although incidental use in the most severely affected patients can be considered.

Pulmonary hypertension in hereditary haemorrhagic telangiectasia

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.

Percutaneous left atrial appendage closure-An alternative strategy for anticoagulation in atrial fibrillation and hereditary hemorrhagic telangiectasia?

Many patients with hereditary hemorrhagic telangiectasia (HHT) are unable to sustain oral anticoagulation (OAC) because of severe epistaxis, gastrointestinal (GI) bleeding and the risk of life-threatening bleeding from cerebral arteriovenous malformations (CAVMs) or pulmonary arteriovenous malformations (PAVMs). In patients with atrial fibrillation (AF), most thromboembolic complications arise from the left atrial appendage (LAA) and percutaneous transcatheter LAA closure proved to be non-inferior to OAC at mid-term follow-up. We report our experience with LAA closure in HHT with a follow-up of 12 months. Percutaneous LAA closure was performed in five patients with both HHT and high thromboembolic risk AF (CHA2DS2-VASc score ≥2) without peri-procedural complications. At 3 months no thromboembolic event occurred. After 12 months one patient had a transient ischemic attack while another patient had recurrence of stroke, this latter patient had a significant stenosis of the carotid artery and an incomplete closure of the LAA without any signs of thrombus on echocardiogram. Both patients had a non-treatable pulmonary right-to-left shunt (RLS). Percutaneous closure of the LAA may provide an alternative strategy to long-term OAC therapy in HHT patients with AF induced high stroke risk and intolerance for OAC.

Clinical implications of pulmonary shunting on saline contrast echocardiography

Pulmonary right-to-left shunting can be encountered using transthoracic contrast echocardiography (TTCE) with agitated saline. Diseases associated with pulmonary shunting on saline TTCE include hereditary hemorrhagic telangiectasia (HHT), hepatopulmonary syndrome, and some congenital heart defects after partial or complete cavopulmonary anastomosis. Furthermore, small pulmonary shunts on saline TTCE are also documented in a proportion of healthy individuals. Pulmonary shunting carries the risk for severe neurologic complications due to paradoxical embolization. In HHT, additional chest computed tomography is recommended in case of any pulmonary shunt detected on saline TTCE, to evaluate the feasibility for transcatheter embolotherapy of pulmonary arteriovenous malformations. Furthermore, antibiotic prophylaxis is advised in case of any pulmonary shunt on saline TTCE to prevent brain abscesses after procedures with risk for bacteremia. The present review provides an overview of important aspects of pulmonary shunting and its detection using saline TTCE. Furthermore, advances in understanding the clinical implications of different pulmonary shunt grades on saline TTCE are described. It appears that small pulmonary shunts on saline TTCE (grade 1) lack any clinical implication, as these shunts cannot be used as a diagnostic criterion for HHT, are not associated with an increased risk for neurologic complications, and represent pulmonary arteriovenous malformations too small for subsequent endovascular treatment. This implies that additional chest computed tomography could be safely withheld in all persons with only small pulmonary shunts on saline TTCE and sets the stage for further discussion about the need for antibiotic prophylaxis in these subjects. Besides further optimization of the current screening algorithm for the detection of pulmonary arteriovenous malformations in HHT, these observations can be of additional clinical importance in other diseases associated with pulmonary shunting and in those healthy individuals with documented small pulmonary shunts on saline TTCE.

Direct haemodynamic effects of pulmonary arteriovenous malformation embolisation

BACKGROUND

Transcatheter embolisation is widely used to close pulmonary arteriovenous malformations (PAVMs) in patients with hereditary haemorrhagic telangiectasia (HHT). Data on the direct cardiovascular haemodynamic changes induced by this treatment are scarce.

OBJECTIVES

We investigated the direct haemodynamic effects of transcatheter embolisation of PAVMs, using non-invasive finger pressure measurements.

METHODS

During the procedure, blood pressure, heart rate (HR), stroke volume (SV), cardiac output (CO), total peripheral resistance (TPR) and delta pressure/delta time (dP/dt) were continuously monitored using a Finometer®. Potential changes in these haemodynamic parameters were calculated from the pressure registrations using Modelflow® methodology. Absolute and relative changes were calculated and compared using the paired sample t-test.

RESULTS

The present study includes 29 HHT patients (mean age 39 ± 15 years, 11 men) who underwent transcatheter embolotherapy of PAVMs. The total number of embolisations was 72 (mean per patient 2.5). Directly after PAVM closure, SV and CO decreased significantly by -11.9 % (p = 0.01) and -9.5 % (p = 0.01) respectively, without a significant change in HR (1.8 %). Mean arterial blood pressure increased by 4.1 % (p = 0.02), while the TPR and dP/dt did not increase significantly (5.8 % and 0.2 %, respectively).

CONCLUSIONS

Significant haemodynamic changes occur directly after transcatheter embolisation of PAVMs, amongst which a decrease in stroke volume and cardiac output are most important.

Predicting the size of pulmonary arteriovenous malformations on chest computed tomography: a role for transthoracic contrast echocardiography

This study aimed to investigate whether pulmonary shunt grade on transthoracic contrast echocardiography (TTCE) predicts the size of pulmonary arteriovenous malformations (PAVMs) on chest computed tomography (CT) and subsequent feasibility for transcatheter embolotherapy. We prospectively included 772 persons with possible or definite hereditary haemorrhagic telangiectasia, who underwent both TTCE and chest CT for screening of PAVMs. A quantitative three-point grading scale was used to classify the pulmonary shunt size on TTCE (grade 1-3). Transcatheter embolotherapy was performed for PAVMs deemed large enough for endovascular closure on chest CT. TTCE documented pulmonary shunting in 510 (66.1%) patients. The positive predictive value of a pulmonary shunt grade 1, 2 and 3 on TTCE for presence of PAVMs on chest CT was 13.4%, 45.3% and 92.5%, respectively (p<0.001). None of the 201 persons with a pulmonary shunt grade 1 on TTCE had PAVMs on chest CT large enough for transcatheter embolotherapy, while 38 (25.3%) and 123 (77.4%) individuals with a pulmonary shunt grade 2 and 3 on TTCE, respectively, underwent endovascular closure of PAVMs. Pulmonary shunt grade on TTCE predicts the size of PAVMs on chest CT and their feasibility for subsequent transcatheter embolotherapy. Chest CT can be safely withheld from all persons with a pulmonary shunt grade 1 on TTCE, as any PAVM found in these subjects will be too small for transcatheter embolotherapy.

Grade of pulmonary right-to-left shunt on contrast echocardiography and cerebral complications: a striking association

BACKGROUND

A pulmonary right-to-left shunt (RLS) carries the risk of cerebral paradoxical embolization and severe neurologic complications. Recognizing patients at risk is important to facilitate appropriate management strategies, but a direct relation between pulmonary shunt size and risk of complications remains controversial. This study evaluated the potential relation between pulmonary shunt grade on transthoracic contrast echocardiography (TTCE) and prevalence of cerebral manifestations in patients screened for hereditary hemorrhagic telangiectasia (HHT).

METHODS

We conducted a two-center, cross-sectional study of all consecutive patients screened for HHT between 2004 and 2011. Pulmonary shunt grading on TTCE (grade 0, no microbubbles; grade 1, &lt; 30 microbubbles; grade 2, 30-100 microbubbles; grade 3, &gt; 100 microbubbles) was performed according to contrast opacification of the left ventricle. Cerebral complications were defined as ischemic stroke, transient ischemic attack, or brain abscess diagnosed by a neurologist and confirmed by appropriate imaging techniques.

RESULTS

A pulmonary RLS was present in 530 out of 1,038 patients (51.1%; mean age, 44.3 ± 15.6 years; 58.6% women). The presence of a cerebral manifestation (n = 51) differed significantly among pulmonary shunt grades on TTCE: 1.4%, 0.4%, 6.5%, and 20.9% for grades 0, 1, 2 and 3, respectively. A pulmonary shunt grade 1 was not associated with an increased prevalence of cerebral manifestations (OR, 0.44; 95% CI, 0.05-4.13; P = .47), whereas pulmonary shunt grade 2 (OR, 4.78; 95% CI, 1.14-20.0; P = .03) and grade 3 (OR, 10.4; 95% CI, 2.4-45.3; P = .002) were both independent predictors for the prevalence of a cerebral ischemic event or brain abscess.

CONCLUSIONS

The pulmonary RLS grade on TTCE is strongly associated with the prevalence of cerebral complications in patients screened for HHT.

[A young man with intestinal polyposis and epistaxis]

BACKGROUND

Germline mutations in the SMAD4 gene lead to both juvenile polyposis syndrome and hereditary haemorrhagic telangiectasia (HHT).

CASE DESCRIPTION

A 23-year-old man underwent colectomy with ileo-anal pouch anastomosis at the age of 12 due to colorectal juvenile polyposis. At follow-up, recurrent juvenile polyps in the pouch were removed. No gastric polyps were found. The family history was negative for intestinal polyposis. In addition, the patient had recurrent epistaxis. DNA testing revealed a pathogenic SMAD4 mutation: c.1558G>T; p.(Glu520*). Further examination confirmed suspected HHT.

CONCLUSION

DNA testing in patients with juvenile polyposis is important for subclassification of this syndrome with implications for the management of patients and family members.

Guideline adherence for empirical treatment of pneumonia and patient outcome. Treating pneumonia in the Netherlands

INTRODUCTION

According to the Dutch guidelines, severity of community acquired pneumonia (CAP) (mild, moderate-severe, severe) should be based on either PSI, CURB65 or a 'pragmatic' classification. In the last mentioned, the type of ward of admission, as decided by the treating physician, is used as classifier: no hospital admission is mild, admission to a general ward is moderate-severe and admission to an intensive care unit (ICU) is severe CAP. Empiric antibiotic recommendations for each severity class are uniform. We investigated, in 23 hospitals, which of the three classification systems empirical treatment of CAP best adhered to, and whether a too narrow spectrum coverage (according to each of the systems) was associated with a poor patient outcome (in-hospital mortality or need for ICU admission).

PATIENTS AND METHODS

Prospective observational study in 23 hospitals.

RESULTS

271 (26%) of 1047 patients with CAP confirmed by X-ray were categorised in the same severity class with all three classification methods. Proportions of patients receiving guideline-adherent antibiotics were 62.9% (95% CI 60.0-65.8%) for the pragmatic, 43.1% (95% CI 40.1-46.1%) for PSI and 30.5% (95% CI 27.8-33.3%) for CURB65 classification. 'Under-treatment' based on the pragmatic classification was associated with a trend towards poor clinical outcome, but no such trend was apparent for the other two scoring systems.

CONCLUSIONS

Concordance between three CAP severity classification systems was low, implying large heterogeneity in antibiotic treatment for CAP patients. Empirical treatment appeared most adherent to the pragmatic classification. Non-adherence to treatment recommendations based on the PSI and CURB65 was not associated with a poor clinical outcome.

Role of transthoracic contrast echocardiography in the clinical diagnosis of hereditary hemorrhagic telangiectasia

BACKGROUND

Hereditary hemorrhagic telangiectasia (HHT) can be diagnosed according to the four clinical Curaçao criteria, including the presence of pulmonary arteriovenous malformations (PAVMs). In the past few years, transthoracic contrast echocardiography (TTCE) replaced chest high-resolution CT (HRCT) imaging for the screening of PAVMs. The objective of this study was to determine whether the presence of any pulmonary shunt on TTCE can be accepted as a new clinical Curaçao criterion in diagnosing HHT.

METHODS

Between 2004 and 2012, we included 487 first-degree relatives of known HHT-causing mutation carriers who underwent both TTCE and chest HRCT imaging to screen for PAVMs. A quantitative three-point grading scale was used to differentiate among minimal, moderate, or extensive pulmonary shunt on TTCE (grade 1-3). Genetic testing was performed in all people and considered the gold standard for the diagnosis of HHT.

RESULTS

Chest HRCT imaging demonstrated PAVMs in 114 of 218 patients (52.3%) with a pulmonary shunt on TTCE. The addition of any pulmonary shunt on TTCE to the current clinical Curaçao criteria increased the number of positive criteria in 92 of 487 individuals (18.9%), which increased the sensitivity in diagnosing HHT from 88% to 94% at the expense of a decreased specificity from 74% to 70%. Accepting only pulmonary shunt grades ≥ 2 on TTCE as a diagnostic criterion for HHT enhanced the number of positive criteria in 30 (6.2%) individuals, which led to an increased sensitivity of 90% with no decrease in specificity (74%).

CONCLUSIONS

The addition of only pulmonary shunt grades ≥ 2 on TTCE to the current clinical Curaçao criteria increases its sensitivity without affecting specificity in the diagnosis of HHT.

Hereditary hemorrhagic telangiectasia: how accurate are the clinical criteria?

The clinical diagnosis of hereditary hemorrhagic telangiectasia (HHT) is based on the Curaçao criteria. Three out of four criteria are required for a definite clinical diagnosis HHT, two criteria are considered "possible" HHT, and 0 or 1 criterion makes the diagnosis unlikely. However, these consensus diagnostic criteria have not been validated. We report on the diagnostic accuracy of the clinical criteria. A total of 450 consecutive persons ≥16 years of age were screened for HHT between May 2004 and September 2009, including a chest CT to screen for pulmonary arteriovenous malformations (AVMs). We selected 263 first-degree relatives of disease-causing mutation carriers who underwent mutation analysis. Genetic test results were considered the gold standard. The family mutation was present in 186 patients (mean age 42.9 ± 14.6 yr; 54.8% female). A clinical diagnosis was definite, "possible", and unlikely in 168 (90.3%), 17 (9.1%), and 1 (0.5%) patient, respectively. In 77 persons the family mutation was absent (mean age 37.1 ± 12.3 yr, 59.7% female). In this group a clinical diagnosis was definite, possible, and unlikely in 0, 35 (45.5%), and 42 (54.5%) persons, respectively. The positive predictive value of a definite clinical diagnosis was 100% (95% CI 97.8-100), the negative predictive value of an unlikely diagnosis 97.7% (95% CI 87.9-99.6). Of 52 patients with "possible" HHT, 17 (32.7%) displayed an HHT-causing mutation. The Curaçao clinical criteria have a good diagnostic performance. Genetic testing is particularly helpful in patients with a "possible" clinical diagnosis HHT.

Real prevalence of pulmonary right-to-left shunt according to genotype in patients with hereditary hemorrhagic telangiectasia: a transthoracic contrast echocardiography study

BACKGROUND

Transthoracic contrast echocardiography (TTCE) can detect pulmonary right-to-left shunting (RLS) and is used to screen for pulmonary arteriovenous malformations (PAVMs) in patients with hereditary hemorrhagic telangiectasia (HHT). We studied the prevalence and size of pulmonary RLS in HHT type 1, HHT type 2, and HHT-negative controls, and its positive predictive value (PPV) and negative predictive value (NPV) for PAVMs that can be treated by embolotherapy.

METHODS

In 343 consecutive persons referred for possible HHT as first-degree family members of index patients a TTCE and chest CT scan were performed. All persons were offered genetic analysis.

RESULTS

An HHT-causing mutation was confirmed in 92 (mean age 41 ± 15 y; 59% female) HHT1 relatives and in 97 (mean age 47 ± 14 y; 52% female) HHT2 relatives. TTCE showed a pulmonary RLS in 78 (85%) HHT1- and 34 (35%) HHT2-related mutation carriers, respectively (P < .0001). In HHT1 relatives, 29 of 53 (55%) PAVMs and in HHT2 relatives three of 17 (18%) PAVMS were treated, resulting in a PPV of TTCE for treatable PAVMs of 36.3% and 8.3%, respectively. The accompanying NPV was 100%. A minimal, moderate, or large shunt was present in 12 (13%), 24 (26%), and 42 (46%) HHT1-related, and in 20 (21%), 6 (6%), and 8 (8%) HHT2-related mutation carriers, respectively (P for trend < .0001). A large shunt predicted treatable PAVMs in 55.8% of HHT1 relatives and 37.5% of HHT2 relatives. TTCE was positive in four (6%) of 63 persons without HHT.

CONCLUSIONS

A pulmonary shunt on TTCE is more prevalent and larger in HHT1- compared with HHT2-related mutation carriers. Shunt grading is helpful to predict treatable PAVMs, particularly in the HHT2 group. TTCE is also positive in a small fraction of persons without HHT.

International guidelines for the diagnosis and management of hereditary haemorrhagic telangiectasia

BACKGROUND

HHT is an autosomal dominant disease with an estimated prevalence of at least 1/5000 which can frequently be complicated by the presence of clinically significant arteriovenous malformations in the brain, lung, gastrointestinal tract and liver. HHT is under-diagnosed and families may be unaware of the available screening and treatment, leading to unnecessary stroke and life-threatening hemorrhage in children and adults.

OBJECTIVE

The goal of this international HHT guidelines process was to develop evidence-informed consensus guidelines regarding the diagnosis of HHT and the prevention of HHT-related complications and treatment of symptomatic disease.

METHODS

The overall guidelines process was developed using the AGREE framework, using a systematic search strategy and literature retrieval with incorporation of expert evidence in a structured consensus process where published literature was lacking. The Guidelines Working Group included experts (clinical and genetic) from eleven countries, in all aspects of HHT, guidelines methodologists, health care workers, health care administrators, HHT clinic staff, medical trainees, patient advocacy representatives and patients with HHT. The Working Group determined clinically relevant questions during the pre-conference process. The literature search was conducted using the OVID MEDLINE database, from 1966 to October 2006. The Working Group subsequently convened at the Guidelines Conference to partake in a structured consensus process using the evidence tables generated from the systematic searches.

RESULTS

The outcome of the conference was the generation of 33 recommendations for the diagnosis and management of HHT, with at least 80% agreement amongst the expert panel for 30 of the 33 recommendations.

The effect of N-acetylcysteine on epistaxis and quality of life in patients with HHT: a pilot study

BACKGROUND

Free O2- radicals may cause precapillary sphincter abnormalities, resulting in epistaxis in hemizygous knockout mice for Endoglin. The objective of this study was to test if antioxidants, like N-acetylcysteine (NAC), are have a role in the treatment of epistaxis in hereditary hemorrhagic telangiectasia (HHT).

METHODS

Forty-three patients participated in this study taking NAC 600 mg t.i.d for 12 weeks. Patients registered frequency, severity and duration of epistaxis and private and work-related quality of life (QOL), using a diary for two 6 weeks periods. The first period was prior to starting treatment and the second started after 6 weeks using NAC.

RESULTS

There was a decrease infrequency (p < 0.01) and severity (p < 0.01) of epistaxis during the day. The improvement was most remarkable in male patients and patients with an ENDOGLIN mutation. In women and patients with an ALK-1 mutation, only a trend for improvement was found. Nocturnal epistaxis did not improve. The effect of epistaxis on the ability to work (p = 0.02) was reduced.

CONCLUSION

This pilot study was conducted to investigate whether animal experiments can be translated to humans with HHT regarding epistaxis. The positive results with NAC are promising and justify a randomised clinical trial.

Grading of pulmonary right-to-left shunt with transthoracic contrast echocardiography: does it predict the indication for embolotherapy?

RATIONALE

Pulmonary arteriovenous malformations (PAVMs) are associated with severe neurologic complications in patients with hereditary hemorrhagic telangiectasia (HHT). Therefore, screening is warranted. Transthoracic contrast echocardiography (TTCE) can effectively detect a pulmonary right-to-left shunt (RLS).

OBJECTIVES

To determine prospectively the predictive value of TTCE grading to detect PAVMs on high-resolution CT (HRCT) scans of the chest and the indication for embolotherapy.

METHODS

Three hundred seventeen patients, referred for possible HHT, were screened for PAVMs. Patients who underwent both chest HRCT scanning and TTCE were included in the study (n = 281). For the purposes of this study we used a 3-point grading scale, and shunt grades 3 and 4 according to the classification model of Barzilai et al were combined. Embolotherapy was performed of all PAVMs judged large enough for treatment.

RESULTS

Echocardiographic criteria for a pulmonary RLS were present in 105 patients (41%) [mean (+/- SD) age, 43.7 +/- 15.7 years; female gender, 63%]. Chest HRCT scan findings were positive in 55 patients (52%) in this group. The positive predictive value of shunt grade for the presence of PAVMs on chest HRCT scans was 22.9% for grade 1 (n = 35), 34.8% for grade 2 (n = 23), and 83.0% for grade 3 (n = 47), respectively. None of the patients with PAVMs seen on chest HRCT scans and a TTCE grade 1 (n = 8) or 2 (n = 8) were candidates for embolotherapy. Of 39 patients with TTCE grade 3 and PAVMs seen on chest HRCT scans, 26 patients (67%) underwent embolotherapy.

CONCLUSION

An increased echocardiographic shunt grade correlates with an increased probability of PAVMs seen on chest HRCT scans. Only patients with a TTCE grade 3 displayed PAVMs on chest HRCT scans that were large enough for embolotherapy.

Screening for pulmonary arteriovenous malformations using transthoracic contrast echocardiography: a prospective study

Pulmonary arteriovenous malformations (PAVMs) are associated with severe neurological complications in patients with hereditary haemorrhagic telangiectasia (HHT). The objective of the present study was to prospectively establish the diagnostic value of transthoracic contrast echocardiography (TTCE) as a screening technique for PAVM using chest high-resolution computed tomography (HRCT) as the gold standard for PAVMs. All consecutive adult patients referred for HHT screening underwent a chest HRCT (n = 299), TTCE (n = 281), arterial blood gas analysis (n = 291), shunt fraction measurement (n = 111) and chest radiography (n = 296). TTCE was positive in 87 (58.8%), 12 (16.7%) and four (6.7%) patients, and chest HRCT was positive in 54 (36.5%), three (4.2%) and zero (0%) patients with a definite, possible and negative clinical diagnosis of HHT, respectively. Two patients with a negative TTCE were diagnosed with PAVMs after computed tomography; in both cases the PAVMs were too small to be treated by embolotherapy. The sensitivity of TTCE was 97% (95% confidence interval (CI) 93.6-98.3) and negative predictive value 99% (95% CI 96.9-99.8). The other diagnostic tests showed a considerable lower diagnostic value. The present prospective study shows that transthoracic contrast echocardiography has an excellent diagnostic value and can be used as an initial screening procedure for pulmonary arteriovenous malformations. The high false-positive rate of transthoracic contrast echocardiography possibly represents microscopic pulmonary arteriovenous malformations.

Endoglin Has a Crucial Role in Blood Cell–Mediated Vascular Repair

Background— Endoglin, an accessory receptor for transforming growth factor-β in vascular endothelial cells, is essential for angiogenesis during mouse development. Mutations in the human gene cause hereditary hemorrhagic telangiectasia type 1 (HHT1), a disease characterized by vascular malformations that increase with age. Although haploinsufficiency is the underlying cause of the disease, HHT1 individuals show great heterogeneity in age of onset, clinical manifestations, and severity.

Methods and Results— In situ hybridization and immunohistochemical analysis of mouse and human hearts revealed that endoglin is upregulated in neoangiogenic vessels formed after myocardial infarction. Microvascularity within the infarct zone was strikingly lower in mice with reduced levels of endoglin ( Eng +/− ) compared with wild-type mice, which resulted in a greater deterioration in cardiac function as measured by magnetic resonance imaging. This did not appear to be because of defects in host inflammatory cell numbers in the infarct zone, which accumulated to a similar extent in wild-type and heterozygous mice. However, defects in vessel formation and heart function in Eng +/− mice were rescued by injection of mononuclear cells from healthy human donors but not by mononuclear cells from HHT1 patients.

Conclusions— These results establish defective vascular repair as a significant component of the origin of HHT1. Because vascular damage or inflammation occurs randomly, it may also explain disease heterogeneity. More generally, the efficiency of vascular repair may vary between individuals because of intrinsic differences in their mononuclear cells.

A pulmonary right-to-left shunt in patients with hereditary hemorrhagic telangiectasia is associated with an increased prevalence of migraine

INTRODUCTION

Hereditary hemorrhagic telangiectasia (HHT) is a rare autosomal-dominant vascular dysplasia with a high prevalence of pulmonary arteriovenous malformation (PAVM). Recent studies report an increased prevalence of migraine in patients with a cardiac right-to-left shunt. The aim of our study was to evaluate whether there is also an increased prevalence of migraine in patients with a pulmonary right-to-left shunt (PAVM).

METHODS

All patients with HHT referred to our hospital till April 2004 with or without PAVM and with or without migraine were included in the study.

RESULTS

In total, 538 HHT patients (41.6% men; mean age +/- SD, 39.3 +/- 18.6 years) could be included. PAVM was present in 208 patients (38.7%; mean age, 39.3 +/- 17.6 years). Significantly more women were present in the PAVM subgroup compared to the non-PAVM subgroup, 65.4% vs 53.9% (p = 0.009). Migraine occurred in 88 patients with HHT, a prevalence of 16.4%. The prevalence of migraine in women with HHT was significantly higher compared to men, 19.4% vs 12.1%, respectively (p = 0.03) The prevalence of migraine in patients with PAVM was 21.2%, which was significantly higher then in patients without PAVM, 13.3% (p = 0.02). The occurrence of PAVM in the patients with migraine is significantly higher than in those without migraine, 50.0% vs 36.4%, respectively (p = 0.02).

CONCLUSION

This study showed a higher prevalence of PAVM in patients with migraine and HHT. The right-to-left shunt due to the PAVM might play a causal role in the pathogenesis of migraine in patients with HHT. This needs to be determined in further studies.

Genotype-phenotype relationship in hereditary haemorrhagic telangiectasia

Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant disorder characterised by vascular malformations in multiple organ systems, resulting in mucocutaneous telangiectases and arteriovenous malformations predominantly in the lungs (pulmonary arteriovenous malformation; PAVM), brain (cerebral arteriovenous malformation; CAVM), and liver (hepatic arteriovenous malformation; HAVM). Mutations in the ENG and ALK-1 genes lead to HHT1 and HHT2 respectively. In this study, a genotype-phenotype analysis was performed. A uniform and well classified large group of HHT patients and their family members were screened for HHT manifestations. Groups of patients with a clinically confirmed diagnosis and/or genetically established diagnosis (HHT1 or HHT2) were compared. The frequency of PAVM, CAVM, HAVM, and gastrointestinal telangiectases were determined to establish the genotype-phenotype relationship. The analysis revealed differences between HHT1 and HHT2 and within HHT1 and HHT2 between men and women. PAVMs and CAVMs occur more often in HHT1, whereas HAVMs are more frequent in HHT2. Furthermore, there is a higher prevalence of PAVM in women compared with men in HHT1. In HHT1 and HHT2, there is a higher frequency of HAVM in women. HHT1 has a distinct, more severe phenotype than HHT2. There is a difference in the presence of symptoms between men and women. With these data, genetic counselling can be given more accurately when the family mutation is known.