** Shares of heart valve maker Anteris Technologies rise as much as 6.8%; last up 4.2% at $5.84 in early trading

** Wall Street brokerages start coverage of AVR as IPO research quiet period comes to an end

** Barclays initiates coverage with "overweight" rating and $22 PT, a 292.2% upside to stock's last close

** Brokerage says AVR's transcatheter aortic valve replacement (TAVR) platform is positioned to capture 4%-5% of the U.S. TAVR market

** Adds that the timing for AVR's entry into TAVR could not look better

** TD Cowen initiates coverage with "buy" rating and $15 PT, a 167.4% upside to stock's last close

** Brokerage says AVR's TAVR platform has disruptive potential that fills unmet needs in the industry

** Adds that AVR should capture meaningful share in the ~$10 bln TAVR market

** TD Cowen, Barclays and Cantor were the joint book-running managers for AVR's IPO

** As of last close, AVR shares down 6.5% since Nasdaq debut on Dec. 13

(Reporting by Arasu Kannagi Basil in Bengaluru)

((ArasuKannagi.Basil@thomsonreuters.com;))