* Symetis' Acurate devices complementary to Boston Scientific's Lotus valves

* Deal expected to close in Q2

* Boston Scientific shares dip 1.7 pct (Adds details from conf. call, analyst comments; updates shares)

By Divya Grover

March 30 (Reuters) - Boston Scientific Corp on Thursday agreed to buy Swiss medical device maker Symetis SA for $435 million, looking to bolster its presence in Europe after recalling a range of heart valves in the region.

Symetis is the fourth-largest player in transcatheter aortic valve replacement (TAVR), a minimally invasive procedure, to replace a narrowed aortic valve that fails to open properly.

The company's Acurate systems will broaden Boston Scientific's TAVR range to include additional designs and delivery methods that cover more physicians and patients, Needham & Co analyst Mike Matson said in a client note.

Boston Scientific recalled its Lotus heart valve devices from Europe and other regions in February following reports of a faulty locking mechanism.

"This is an offensive rather than a defensive move and not simply a "stop-gap" to address the Lotus recall, shortcomings with Lotus, or IP issues," Matson added.

Boston Scientific said it expects the Lotus valve devices to return to these markets in the fourth quarter.

The deal would not change the timeline of its Lotus device program, Boston Scientific said on a conference call.

The transaction is a bit of a head scratcher and will likely cause some concern on the Street about the program, J.P. Morgan analyst Michael Weinstein said.

Weinstein also noted Symetis had $40 million in TAVR sales in Europe last year and has seen limited growth in the last few years.

However, Jefferies analyst Raj Denhoy noted that even though the deal value seems "pretty high", Symetis sales will likely rise by more than 30 percent with Boston Scientific's backing.

Symetis said it halted its second attempt to go public, due to the deal, which is expected to close in the second quarter.

The company expected to raise up to 61.5 million euros ($66 million) and list on the Euronext Paris by March 31.

Boston Scientific said it expects the deal to slightly boost results in 2018 on an adjusted basis, and rise thereafter.

Shares of Boston Scientific, which competes with TAVR market leaders Edwards Lifesciences Corp and Medtronic Plc , were down 1.7 percent at $24.30 in late-morning trading.

($1 = 0.93 euros) (Reporting by Divya Grover in Bengaluru; Editing by Savio D'Souza, Sriraj Kalluvila and Martina D'Couto)