The Calgary skip made his move in the seventh end with a nice takeout in a crowded four-foot to score three. Gushue scored a pair in the eighth end but Koe's deuce in the ninth end put the game away.
"We struggled last year and to come back, have a great year and top it off with a Brier is awesome,'' Koe said.
Koe won the Brier in 2010 and 2014 but this is his first title with current teammates Marc Kennedy, Brent Laing and Ben Hebert. Hebert, Koe's lead, hails from Regina.
Gushue won Olympic gold at the 2006 Turin Games but he has yet to win a Brier in 13 career appearances. His St. John's team included Mark Nichols, Brett Gallant and Geoff Walker.
Koe was aggressive from the start and forced Gushue to go for a double runback that was just slightly off, allowing Alberta to steal a single in the first end. Koe stole another in the second before Gushue halved the lead with a hit for one in the third.
|Regina's Ben Hebert|
A Koe deuce in the fourth end gave Alberta a 4-1 lead. He didn't let up in the fifth, coming through with a nice double takeout to force Gushue to hit for a single.
Newfoundland and Labrador stole one back in the sixth end before Koe's big end.
Earlier in the day, Northern Ontario's Brad Jacobs put a couple of tough losses behind him by edging Manitoba's Mike McEwen 7-6 to win the bronze medal.
Announced attendance was 7,183 for the early game and 8,419 for the final. The tournament total was 115,047.
Koe will represent Canada at the men's world curling championship next month in Basel, Switzerland.
In addition, he qualifies for this year's Canada Cup in Brandon, Man., the 2017 Continental Cup in Las Vegas and will return as Team Canada at next year's Brier in St. John's.
Koe's team will receive $225,000, including $144,000 in Sport Canada funding over two years. Gushue's rink will earn $61,000.
Koe will also get 88.678 points in the Canadian Team Ranking System. Gushue gets 69.676 points and Jacobs picked up 53.840 points.
Alberta's Chelsea Carey won the women's national title last month in Grande Prairie, Alta. She will represent Canada at the upcoming world women's curling championship in Swift Current, Sask.