You need a better understanding of what "Heartbleed" is.
It is a bug in the software used on *some* web sites that is used to authenticate web sites (server) to web browsers (client). This is the software that turns on the little "lock" icon in your browser before you login to enable a secure exchange of your password and user information. You should be looking for this icon on any site you consider important (bank, bill payment, facebook, ...).
The bug allows a client access to some memory in the server. Since this memory is often used by the same software that handles passwords, the client *may* be able to get access to passwords and other encryption keys. This is very bad, thus the news around heartbleed. The fix is to correct the server software so it does not allow access to memory other than what is part of the security protocol.
Back to your question, "Does FIOS have any vulnerability to Heartbleed?" It depends on what you mean by "FiOS." If you're discussing the FiOS network that moves data around, the answer is no. That's because the network isn't involved in the client / sever protocol. The easiest way to understand this is to know that you don't "login" to the FiOS network, you simply use it to exchange data. It's the servers you exchange passwords with that may have the buggy software.
If you're asking about the various web sites that Verizon provides to manage FiOS accounts and other features, those could be susceptible to Heartbleed. You can easily check to see if a site has the bug. Google "heartbleed checker" to find several sites that will do this check. Here's one that looks good:
https://lastpass.com/heartbleed/
As far as getting an offical word from Verizon, I suggest you check their press releases.
Enjoy!