osler weber rendu is associated with high output heart failure from hepatic AVM
- related: Pulmonology
- tags: #literature #boards
This patient has HHT, also known as Osler-Weber-Rendu syndrome, with high output heart failure as a consequence of extensive hepatic arteriovenous malformations (AVMs). Liver transplantation is definitive therapy in this setting (choice C is correct).
HHT is an autosomal dominant vascular disorder that most commonly results in severe epistaxis (frequently resulting in iron deficiency anemia), mucocutaneous telangiectasias, and AVMs in the lung, brain, and liver. AVMs can also occur in other organs such as the GI tract, where significant chronic GI blood loss can result. Most cases of HHT are due to pathogenic sequence variants of the genes ENG or ACVRL1, resulting in abnormalities in the proteins endoglin or activin receptor-like kinase 1, respectively.
Hepatic involvement occurs in up to two-thirds of patients with HHT and is usually silent, but in some individuals (such as this patient), the volume of blood being shunted via abnormal arteriovenous connections results in high output heart failure. The antivascular endothelial growth factor (VEGF) monoclonal antibody bevacizumab may result in transient shrinkage of AVMs and improvements in high output heart failure; however, many patients, such as this one, fail to respond or have responses that are short lived. In situations (such as this patient’s) of progressive high output heart failure that does not respond to medical management, liver transplantation is the treatment of choice. Liver transplantation also may be required when HHT involvement of the liver results in portal hypertension or acute biliary necrosis syndrome.
While embolotherapy (deployment of coils or other materials via an angiographic catheter to deliberately occlude feeding arteries) is the mainstay of treatment for pulmonary AVMs, the use of this approach for hepatic AVMs leads to an unacceptably high rate of potentially fatal hepatic necrosis and is not recommended (choice B is incorrect). Tamoxifen may be useful in reducing the frequency and volume of blood loss in HHT patients with epistaxis but is not useful in managing hepatic AVMs (choice D is incorrect).
While a subset of patients with HHT develop WHO group 1 pulmonary arterial hypertension, this patient’s abnormal pulmonary hemodynamics are due only to her high cardiac output state, as evidenced by her normal pulmonary vascular resistance (PVR). Because her elevated pulmonary arterial pressures are not a consequence of pulmonary vascular remodeling as a primary process (which would result in an elevated PVR), epoprostenol will not be helpful in treating her condition (choice A is incorrect).1