Holly leaf drop and dying back

I would appreciate advice on how to deal with this problem. I had two 9ft Holly Alaska’s planted last November. I had to tie the stakes to the fence over the winter to support as the strong winds were uprooting them. They have lost all their leaves from the top half – for about 4ft. I now notice that both growing tips have started to die back and have turned brown from growing tip down 12/14 inches. Should I prune off the dieback?