Paul St Pierre, who has since lost his job with the health service, launched the sustained assault on gardener Steven Ferry on South Bridge after a gig by a renowned international DJ in 2010.
The High Court in Edinburgh heard that punches and kicks from St Pierre had left Mr Ferry, 23, with serious head injuries and that he still suffered medical problems, including difficulty with memory and irritability, more than 18 months after the violent attack.
St Pierre, 30, of Lawers Square, Penicuik, Midlothian, denied he was responsible, but a jury found him guilty of attempted murder at an earlier trial.
Defence advocate Michael Anderson said father-of-two St Pierre had “lost everything” as a result of the conviction, but still claimed he was innocent.
During the trial, the court heard that another unidentified man had helped beat up Mr Ferry at a bus stop.
But while sentencing him yesterday, judge Lord Pentland said it was clear from the evidence that St Pierre did not care whether his victim had lived or died.
Both men – who were known to each other but were not friends – had spent the evening of November 28, 2010 at the City Nightclub, in Market Street, where former Radio One DJ Eddie Halliwell was performing. St Pierre said he was heading home after the gig when someone ran into him, causing him to fall down in the snow.
He claimed he chased the man, only to remonstrate with him, and found that it was Mr Ferry.
The IT specialist insisted someone else grabbed Mr Ferry and pulled him into a bus shelter on South Bridge where the attack began.
He said his own efforts to stop the fight were unsuccessful and he was told to “mind his own business”.
Mr Ferry was repeatedly punched and kicked, thrown against a window, then punched and kicked again as he lay on the ground and his attackers repeatedly stamped on his head.
Lord Pentland said CCTV footage had shown that St Pierre had the opportunity to walk away from the incident but did not, instead returning more than once to the scene of the attack.
“Witnesses said you played a part in what was described as a violent and sustained assault,” said the judge.
“Attempted murder is a very grave crime and it is all the more grave when the victim suffers severe and permanent impairment.”
He added: “Evidence at the trial as to what lay behind this assault was somewhat limited.”