Need help replacing string contents using PHP

[ENIAC]

Sorry for the vague title... Anyway i have a string that conains my needed information in the middle. Let's say it looks like this:

sdfasdf asdf asd ffsd sd f <-- Important Information --> asdf s gfg sdf asdf .

So the "sasdd" garble could be anything and a long as possible. How do I select all the information inbetween the <- - and --> using php. I am guessing a wildcard and str_replace but i cannot get it to work. Any suggestions?

Thanks.