Hereditary Hemorrhagic Telangiectasia Center of Excellence at Johns Hopkins Hospital: Organization, Screening, and Treatment Results in Pediatric and Adult Patients from 2009 to 2013

To highlight the organization, screening paradigms, and treatment results at the Johns Hopkins Hereditary Hemorrhagic Telangiectasia (HHT) Center of Excellence. This retrospective study was conducted at the Johns Hopkins HHT Center of Excellence from March 2009 to October 2013. Patients with features of HHT were provided with subspecialty appointments for initial clinical evaluation and management of specific manifestations of HHT (e.g. epistaxis, gastrointestinal bleed, mucocutaneous telangiectasia). Agitated saline echocardiography (AS echo), 3D chest computed tomography angiography (CTA), and brain magnetic resonance imaging (MRI) were performed to evaluate for arteriovenous malformations. Genetic testing was also offered to all patients. A total of 286 patients (74 pediatric and 212 adults) were evaluated over a 5-year period, out of which 255 patients underwent screening for pulmonary AVMs (PAVMs) (62 pediatric and 193 adults). PAVMs were identified in 18 pediatric patients out of the 62 screened (29%) of which 17 had pulmonary angiography and 14 underwent PAVM embolization. PAVMs were identified in 87 adult patients out of the 193 screened (46%) of which 77 had pulmonary angiography and 70 underwent PAVM embolization. Brain MRI was positive for cerebral AVMs (CAVMs) in 8% of pediatric and adult patients screened for CAVM. Genetic testing revealed more ACVRL gene mutations (HHT type 2) than ENG gene mutations (HHT type 1) in pediatric and adult patients. PAVMs in our study population were more prevalent in pediatric and adult patients with Endoglin gene mutuations compared to patients with ACVRL gene mutations. The establishment of the Johns Hopkins HHT Center of Excellence has provided HHT patients with a unified multidisciplinary clinical team to effectively manage the many manifestations of this rare genetic disorder. Since its creation, we have experienced a surge in patients with HHT presenting to our center. We have demonstrated an efficient clinical workflow for initial evaluation and rapid triage to various subspecialties. In addition, we have developed a comprehensive screening paradigm for PAVMs and CAVMs.