Pulmonary Arteriovenous Malformations in Patients with Hereditary Hemorrhagic Telangiectasia

Pulmonary arteriovenous malformations (PAVMs) associated with hereditary hemorrhagic telangiectasia may cause severe cerebral complications that may be prevented by embolization therapy. We retrospectively compared the diagnostic value of noninvasive tests for the screening of treatable (amenable to embolization) PAVMs in a series of 105 patients, using chest computerized tomography (CT) and/or pulmonary angiography as a "gold standard." Patients had assessment of dyspnea, chest radiograph, alveolar-arterial PO2 gradient under 100% oxygen (AaPO2), contrast echocardiography, and radionuclide perfusion lung scanning. Contrast echocardiography in the supine position was the most sensitive test (93%). The sensitivity of self-reported dyspnea (59%), chest radiograph alone (70%), measurement of AaPO2 by the 100% oxygen method (62%), or radionuclide lung scanning (71%), was not suitable for efficient screening. A 100% sensitivity and negative predictive value could be obtained when combining anteroposterior chest radiograph and contrast echocardiography. Our data support a screening algorithm based on the combined use of contrast echocardiography and anteroposterior chest radiograph, followed by chest CT if either test is positive. An alternative is to screen directly by chest CT. However, this algorithm may obviate the need for chest CT in patients without PAVM, who represent a majority of patients with hereditary hemorrhagic telangiectasia.