I'd start by getting really clear about why you want to reach them. These folks are in high demand so you have to hook them with something really compelling in order to get their attention.

Follow their work, retweet it, comment on it and let them know you're adding value for them. Then you can reach out with a bit of a warmer connection.

I'm not a PR person specifically, but I'd be happy to take a call with you to talk more about your strategy for reaching out to media.