Bosentan therapy for pulmonary arterial hypertension associated with hereditary haemorrhagic telangiectasia

Long Term Survival of Heritable Pulmonary Arterial Hypertension Associated with Hereditary Hemorrhagic Telangiectasia: A Case Series

Hereditary hemorrhagic telangiectasia (HHT) is a hereditary disease characterized by recurrent epistaxis, mucocutaneous telangiectasias, and visceral arteriovenous malformations. Multiple genetic mutations have been linked to this rare disease, including ENG, ALK1 (ACVRL1), and MADH4. Pulmonary hypertension is a potential complication of HHT, with the most common phenotypes being World Health Organization (WHO) group 1 heritable pulmonary arterial hypertension (PAH), which is typically associated with ALK1 mutation; WHO group 2 pulmonary hypertension due to high output heart failure from hepatic arteriovenous malformations and/or anemia; and WHO group 2 due to high pulmonary artery wedge pressure. There is scarce evidence to help guide treatment of heritable PAH in HHT, and observational literature suggests that patients with HHT and heritable PAH have a worse prognosis compared to patients with idiopathic PAH. We describe the diagnosis, pulmonary hemodynamics, and detailed treatment courses of three patients with ALK1-associated HHT and PAH, who all exhibited objective clinical improvement with parenteral prostacyclins and oral agents.

Pulmonary hypertension in hereditary hemorrhagic telangiectasia: A clinical review

Hereditary hemorrhagic telangiectasia (HHT) is a rare autosomal dominant hereditary disorder characterized by recurrent spontaneous epistaxis, mucocutaneous telangiectasias, and solid organ arteriovenous malformations (AVMs). Pulmonary hypertension (PH) is an increasingly recognized complication in patients with HHT, most often precipitated by high-output heart failure in the presence of hepatic AVMs as well as pulmonary arterial hypertension in the form of a proliferative vasculopathy. The presence of PH in patients with HHT is associated with significant elevations in rates of morbidity and mortality. Additionally, there is growing recognition of a thromboembolic propensity in this population that increases the risk of chronic thromboembolic PH, posing unique clinical considerations regarding the use of anticoagulation. Patients with HHT are also at risk of PH due to disorders commonly seen in the general population, including left-sided heart and lung disease. The etiology of PH in HHT is multifaceted and complex; the diagnostic approach and treatment strategies must consider the underlying pathophysiology of HHT. This comprehensive review summarizes current knowledge of PH in HHT, detailing the pathogenesis of known etiologies, diagnostic evaluation, and suggested treatment modalities as well as emerging therapies that may be of future interest.

Update on pulmonary arteriovenous malformations

This review aimed to provide an overview of pulmonary arteriovenous malformations, including the major clinical and radiological presentations, investigation, and treatment algorithm of the condition. The primary etiology of pulmonary arteriovenous malformations is hereditary hemorrhagic telangiectasia (HHT), also known as Rendu-Osler-Weber syndrome, with mutations in the ENG gene on chromosome 9 (HHT type 1) or in the ACVRL1/ALK1 complex (HHT type 2). Epistaxis should always be evaluated when repeated, when associated with anemia, and in some cases of hypoxemia. In the investigation, contrast echocardiography and chest CT are essential for evaluating this condition. Embolization is the best treatment choice, especially for correction in cases of hypoxemia or to avoid systemic infections. Finally, disease management was addressed in special conditions such as pregnancy. CT follow-up should be performed every 3-5 years, depending on the size of the afferent and efferent vessels, and antibiotic prophylactic care should always be oriented. Ultimately, knowledge of the disease by health professionals is a crucial point for the early diagnosis of these patients in clinical practice, which can potentially modify the natural course of the disease.

Treatment of pulmonary hypertension in patients with Hereditary Hemorrhagic Telangiectasia - A case series and systematic review

RATIONALE

Pulmonary Arterial Hypertension (PAH), a rare complication of HHT is associated with poor outcome. There are no trials to date that have investigated whether pulmonary vasodilator therapy improves hemodynamics or survival in this disease.

OBJECTIVE

To determine whether pulmonary vasodilator therapy improves survival, exercise capacity, or hemodynamics in HHT patients with pre-capillary PH.

METHODS

We performed a before-and-after observational study on a multicenter cohort of subjects with HHT-PAH who received intravenous prostanoid therapy. We then conducted a systematic review, searching Medline and EMBASE through December 2019. Studies that enrolled HHT-PAH subjects and reported treatment outcomes were selected. PROSPERO #158179.

RESULTS

Twenty-one articles were selected. Studies were before-and-after observational studies, case reports, and case series. Among all subjects with HHT-PAH, both mPAP (65 ± 19 pre-treatment vs 51 ± 16 mmHg post-treatment p = 0.04) and PVR (12 ± 6 pre-treatment vs 8 ± 4 WU post-treatment p = 0.01) improved with treatment. The mPAP improved with either oral (57 ± 17 pre-treatment versus 44 ± 13 mmHg post-treatment, p = 0.03) or intravenous (80 ± 15 pre-treatment versus 64 ± 16 mmHg post-treatment, p = 0.017) therapy. PVR also improved with either oral (10 ± 4 pre-treatment versus 6 ± 3 WU post-treatment, p = 0.004) or intravenous (17 ± 5 pre-treatment versus 10 ± 4 WU post-treatment, p = 0.04) therapy. Survival among HHT-PAH patients who received oral or intravenous therapy was not different (p = 0.2). Unadjusted survival among HHT-PAH patients was longer than that of IPAH patients (p = 0.008). There was no difference in side effects among HHT-PAH patient who received oral or intravenous therapy (p = 0.1).

CONCLUSION

Pulmonary vasodilator therapy is effective in improving hemodynamics of subjects with HHT-PAH and was not associated with increased risk of side effects.

Syncope in a Child with Pulmonary Hypertension and Positive Gene Tests for Hereditary Hemorrhagic Telangiectasia and Long QT Syndrome

We present a 10-year-old boy with syncope who was found to have long-QT syndrome and severe Pulmonary Hypertension (PH) both in the absence of a secondary cause; to our knowledge, this is the first report with this unusual coexistence. His genetic tests were positive for hereditary hemorrhagic telangiectasia and Long QT Syndrome (LQTS) without any family history of PH or LQTS. We demonstrated that digital subtraction pulmonary angiography was more useful compared to CT angiogram to demonstrate pulmonary vascular changes which correlated with a noresponse to acute vasoreactivity testing during right heart catheterization. He has been stable for the last 2 years on Ambrisentan, Sildenafil, and Nadolol without recurrence of symptoms.

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.

Pulmonary hypertension subtypes associated with hereditary haemorrhagic telangiectasia: Haemodynamic profiles and survival probability

BACKGROUND

Different pulmonary hypertension (PH) mechanisms are associated with hereditary haemorrhagic telangiectasia (HHT).

METHODS AND RESULTS

We conducted a retrospective study of all suspected cases of PH (echocardiographically estimated systolic pulmonary artery pressure [sPAP] ≥ 40 mmHg) in patients with definite HHT recorded in the French National Reference Centre for HHT database. When right heart catheterization (RHC) was performed, PH cases were confirmed and classified among the PH groups according to the European guidelines. Among 2,598 patients in the database, 110 (4.2%) had suspected PH. Forty-seven of these 110 patients had RHC: 38/47 (81%) had a confirmed diagnosis of PH. The majority of these had isolated post-capillary PH (n = 20). We identified for the first time other haemodynamic profiles: pre-capillary pulmonary arterial hypertension (PAH) cases (n = 3) with slightly raised pulmonary vascular resistances (PVR), and combined post- and pre-capillary PH cases (n = 4). Compared to controls, survival probability was lower in patients with PAH.

CONCLUSION

This study revealed the diversity of PH mechanisms in HHT. The description of combined post- and pre-capillary PH with/or without high cardiac output (CO) suggests either a continuum between the pre- and post-capillary haemodynamic profiles or a different course in response to high CO.

Pulmonary vascular complications of hereditary haemorrhagic telangiectasia

PURPOSE OF REVIEW

The purpose of this study is to present the latest advances and recommendations in the diagnosis and treatment of pulmonary vascular complications associated with hereditary haemorrhagic telangiectasia (HHT): pulmonary arteriovenous malformations (PAVMs), pulmonary arterial hypertension (PAH), pulmonary hypertension associated with high output cardiac failure or liver vascular malformations, haemoptysis, haemothorax and thromboembolic disease.

RECENT FINDINGS

Transthoracic contrast echocardiography has been validated as a screening tool for PAVM in patients with suspected HHT. Advancements in genetic testing support its use in family members at risk as a cost-effective measure. Therapy with bevacizumab in patients with high output cardiac failure and severe liver AVMs showed promising results. PAH tends to be more aggressive in HHT type 2 patients.

SUMMARY

Patients suffering from this elusive disease should be referred to HHT specialized centres to ensure a standardized and timely approach to diagnosis and management.

BMPR2 gene mutation in pulmonary arteriovenous malformation and pulmonary hypertension: a case report

The transforming growth factor-β superfamily signaling pathway is thought to be involved in the pathogenesis of pulmonary arteriovenous malformation (PAVM). However, the association between bone morphogenetic protein receptor type 2 (BMPR2) gene mutations and PAVM remains unclear. We present a case of concurrent PAVM and pulmonary arterial hypertension (PAH), with a deletion mutation in exon 6 and exon 7 of the BMPR2 gene. Drug treatment for PAH improved the patient's hemodynamics and exercise capacity, but worsened oxygenation. This case suggests that BMPR2 gene mutation may be associated with the complex presentation of PAVM combined with PAH.

Clinical and genetic characteristics of Chinese patients with hereditary haemorrhagic telangiectasia-associated pulmonary hypertension

BACKGROUND

Mutations in activin receptor-like kinase-1 (ACVRL-1) or endoglin (ENG) are mostly identified in patients with hereditary haemorrhagic telangiectasia (HHT) associated with pulmonary hypertension (PH), but have not yet been studied in Chinese patients.

MATERIAL AND METHODS

In this study, we investigated the clinical and molecular genetic features of Chinese patients with HHT-associated PH and analysed genotype/phenotype correlations in 14 probands and their relatives. Mutation analyses in ACVRL-1, bone morphogenetic protein receptor type 2 (BMPR2) and ENG were performed in 14 Chinese Han patients with HHT-associated PH.

RESULTS

The overall mutation rate was 71·4%, including 8 ACVRL-1 mutations and 2 ENG mutations, 6 of which were novel. Six patients were identified with arteriovenous malformations (AVMs), including four patients with pulmonary AVMs and two patients with liver AVMs. Five of the patients with AVMs were identified with mutations. Most patients received targeted therapy for PH.

CONCLUSIONS

Our findings have revealed the clinical phenotype and molecular genetic features of HHT-associated PH in Chinese Han patients and indicate that mutations of ACVRL-1 and ENG are genetic predisposing factors in Chinese patients. Our data further addressed clinical management and have provided limited experience in treating this group of disorders.

High prevalence of pulmonary hypertension in patients with hereditary hemorrhagic telangiectasia

OBJECTIVE

Hereditary hemorrhagic telangiectasia (HHT) is a vascular disorder causing mucocutaneous telangiectases and visceral arteriovenous malformations (AVMs). Pulmonary hypertension (PH) is considered an uncommon complication of HHT whose impact on the survival of these patients is currently unknown.

METHODS

From January 1995 to December 2008, 29 hospitalized patients with definite HHT were included and followed until January 2011. Data on demographics, clinical symptoms and survival were recorded. PH was classified according to echocardiographic probability.

RESULTS

A CT angiogram was performed in 24 of the 29 patients with HHT and AVMs were detected in 16 of them (67%): hepatic in 58%, pulmonary in 33% and spinal in 3%; 37% had both pulmonary and hepatic AVMs. Transthoracic Doppler echocardiography (TTE) was performed in 21 patients. PH was considered possible in 4 (14%) and probable in 9 (31%). The mean age at diagnosis was lower in patients with PH than in patients without PH (54±16.5 years vs 73±8.8 years, p=0.002). PH was more prevalent in patients with AVMs (56 vs. 23%, p=0.036). The mean follow-up of the entire cohort was 6±4.4 years (range: 2 months-17 years), during this time 18 patients died (62%; mean age 73±8.1 years). Patients with PH died at a younger age (68±8.4 vs. 79±2.7 years, p=0.015) than those without PH.

CONCLUSIONS

PH is a severe condition that significantly reduces survival on HHT patients. PH should be suspected in all HHT patients with dyspnea and hepatic AVMs.

Successful bosentan therapy for pulmonary arterial hypertension associated with hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is a hereditary vascular disease with multiple arterial venous malformations. Pulmonary arterial hypertension is occasionally associated with HHT; however, there is no evidence of targeted therapy for this subgroup of patients. This report describes a 37-year-old woman who presented with dyspnea on exertion. She was finally diagnosed with pulmonary arterial hypertension associated with HHT (HHT2, MIM 600376), and had multiple arterial venous malformations in the lung, liver and pancreas. An oral dual endothelin receptor (ET(A)/ET(B)) antagonist, bosentan, was prescribed, and her symptoms, exercise capacity and laboratory findings improved greatly after treatment. Pulmonary arterial pressure also decreased. Endothelin receptor antagonist is a possible treatment option for pulmonary arterial hypertension associated with HHT.

Arterial embolisation and coiling for high-output heart failure and pulmonary hypertension ınduced by hepatic arteriovenous fistula in a patient with hereditary hemorrhagic telengiectasia

Hereditary hemorrhagic telangiectasia (HHT) is a genetic vascular disorder characterised by epistaxis, telangiectases, and visceral arteriovenous malformations. Hyperdynamic blood flow associated with arteriovenous malformations may lead to pulmonary hypertension, global heart failure, and valvular insufficiencies. We report a patient who had HHT with severe heart failure (New York Heart Association [NYHA] class III-IV) and pulmonary hypertension caused by an hepatic arteriovenous fistula. After successful transarterial embolisation of the right branch of the hepatic artery with polyvinyl alcohol (PVA) particles and coils, 4 to 7 mm in size, the patient was discharged with functional class II (NYHA) heart failure.