I used Quinn, popped a stim, kept sundering assault armor ignore at 5, blew my defensive and offensive cooldowns, got out of it's AOE, disrupt, and outlasted it. IMO evading it's AOE attack is the most critical aspect.
Utilizing push and choke to stop it's damage output for a few seconds allowing for the heals from Quinn to not be negated was very helpful as well. I'm running an immortal spec with a healer in tow so my damage output is lacking. Gold elite fights take a bit of time but alternating my interrupt and choke to interrupt specials leaves me with plenty of health after a fight.