Hereditary Hemorrhagic Telangiectasia
A number of laboratory based and clinical research projects are ongoing in HHT. The brain vascular malformation consortium (BVMC) project on HHT is an NIH funded multicenter study on the natural history of brain AVMs in HHT that has been ongoing for 10 years. A prospective study on the efficacy of pomalidomide in HHT related bleeding was recently funded by the NIH. A prospective clinical trial on the effectiveness of pazopanib in the management of HHT related bleeding is soon to start.
The International HHT Treatment Guidelines were developed in 2009. These are being revised to reflect recent developments and the updated guidelines will be released at the end of 2019 or in early 2020.
Unanswered questions (a few of many):
- Does HHT confer increased thrombotic risk independent of therapy? There are 2 publications that suggest an increased risk, but further data and mechanistic insight are needed.51,52
- Is menorrhagia a feature of HHT? There are no data on this and it is not a recognized manifestation of HHT. However, our single center experience suggests a higher prevalence of menorrhagia in HHT patients.
- When do we intervene in patients with brain AVMs? The ARUBA study in non-HHT patients with unruptured AVMs favored conservative management.53 Are patients patient at higher risk and would they benefit from intervention?
- Should we routinely screen for liver AVMs now that more effective medical treatments are available?
- Does antiangiogenic therapy impact/shrink brain and PAVMs?
- Long-term consequences of chronic maintenance antiangiogenic therapy?