While some early research (of limited value due to the tiny number of patients studied) suggested a possible correlation between XLH and heart disease, some very recent research suggests that FGF23, the hormone that XLHers have in excess, may actually prevent/slow heart disease! https://phys.org/news/2018-01-anti-aging-hormone.html
The research is far too preliminary to be able to draw any conclusions about the XLH population's heart health. We hope our natural history study, launching later this year, will help us understand more about the incidence of heart disease in the XLH community.
In the meantime, take good care of your heart today and every day of the year!