You could wait another couple of weeks to see if there's any sign of life on the 'dead parts' but Acers do get dieback, and that part may have died. If it has, then yes, you should cut off the dead parts, but although its usual to cut into the live wood, just beyond the dead parts, this cannot be done at this time of year because the live part will bleed excessively, so you're stuck with simply pruning back as close as possible to anything live.

Thank you for that I will leave it for this summer and see what happens [ maybe grow a clematis up the dead bit]