The largest pure-play medical devices maker just got larger. Medtronic (NYSE: MDT) announced this week that it signed a definitive agreement to acquire privately held Twelve, a replacement heart-valve manufacturer. Medtronic will pay up to $458 million for its new asset, with $408 million due at closing. The remainder will be paid when Twelve's valves receive the CE mark, the standard quality mark used in Europe. All monies are to be paid in cash.

Twelve's valves are designed to treat certain instances of mitral regurgitation, a condition in which the heart's mitral valve doesn't close normally, allowing blood to flow backward during the organ's contraction phase.

In the press release announcing the acquisition, Medtronic wrote that owning Twelve "will create a tremendous opportunity to leverage Medtronic's expertise and proven success in the structural heart space to advance the treatment of mitral regurgitation." The Twelve purchase is entirely in character for the acquisitive Medtronic. At the beginning of this year, the company closed its nearly $50 billion buyout of Ireland-based device maker Covidien, a transaction that saw it subsequently relocate its tax domicile to that country. And in June, it completed a smaller ($93 million) acquisition of yet another device manufacturer, CardioInsight Techologies.

Medtronic expects that owning Twelve will have a neutral impact on its earnings, "as the company intends to offset the dilutive impact of the transaction." It anticipates the acquisition to close in October.

The Twelve deal is another opportunistic buy for a company that likes making them. It's doing well and has the resources for such deals, so now is a good time to open the wallet. In spite of its apparent free-spending ways, Medtronic is actually being fairly careful to grab assets that compliment and broaden its existing product line. Twelve looks like it'll fit well into that portfolio.

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Eric Volkman has no position in any stocks mentioned.

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