You might have to ask your regulator and/or operator about that. As far as i know RVSM has nothing to do with HF at all, but there are some weird rules around.
Just for info, in my MEL it states about HF Communications Transmitter and Receiver that they may be inoperatrive, provided that
a) VHF coverage is assured, and
b) that HF is not required for the intended flight.
Both things are the norm for more than 98% of our flights, the exception are some flights to Keflavik and required use of the Tango routes when the french are on strike again.