CHORUS - Comprehensive HHT Outcomes Registry of the United States (Formerly OUR HHT Registry)

The goal of this study is to better understand HHT, the symptoms and complications it causes ("outcomes") and how the disease impacts people's lives. The investigators are aiming to recruit and gather information together in the Registry from 1,000 HHT patients from four HHT Centres of Excellence in North America. The Investigators will collect long-term information about the people in the Registry, allowing the investigators to understand how the disease changes over time, and what factors can influence those changes. Ultimately, this should help improve treatments for the disease.

Background and Rationale HHT has an estimated prevalence of 1 in 5000, affecting children and adults, in multiple organs. The disease is characterized by the presence of vascular malformations (VMs), including arteriovenous malformations (AVMs) of the lung, liver, brain, spinal cord and smaller mucosal lesions (telangiectasia) of the nose, mouth and GI tract. These lesions lead to acute and chronic bleeding, stroke, heart failure and death. Treatments are currently mostly limited to managing complications, while approximately 90% of adults have ongoing symptoms, despite best surgical and medical therapies. With recent drug development related to angiogenesis, there is hope for effective novel therapies. Investigators, experts, the International HHT Guidelines, Pharma representatives, the CDC and HHT patient advocates (curehht.org) all agree that there is an urgent need for natural history data in this disease, with characterization of clinical outcomes, to allow patients to benefit from the explosion of drug development in the field. As of August 27, 2023, the OUR HHT Registry has transitioned to the CHORUS platform (Studytrax) for ongoing data collection. Only select CHORUS-funded sites are currently enrolling. The Toronto site has completed enrollment but remains active with REB approval.

Inclusion Criteria: * Participants diagnosed with HHT by the Curacao criteria (either 3+ clinical diagnostic criteria or genetic diagnosis). * Capable of giving informed consent in person or via a substitute decision maker * \>18 years Exclusion Criteria: * Participants unable to give informed consent either in person or with a substitute decision maker