US medical devices group Medtronic has filed a patent lawsuit in Republic challenging rival Guidant's Vision and Xience stents to treat clogged heart arteries.

The lawsuit alleges that the Guidant stents infringe patents licensed to Medtronic from Evysio Medical Devices, a private Canadian company.

Medtronic said it is seeking an injunction against the Vision and Xience stents and monetary damages, which a company spokesman declined to specify.

Guidant manufactures the stents in Ireland and the United States.

Medtronic and Guidant, both of which have large operations in Ireland, are gearing up to enter the $6 billion (€5 billion) US market for drug-coated stents now dominated by Johnson & Johnson and Boston Scientific, which in January agreed to buy Guidant for $27 billion.

The Vision stent is the foundation of Guidant's highly anticipated Xience drug-eluting stent, which plays a central role in the Boston Scientific deal.

Guidant's stent business is scheduled to be sold to Abbott Laboratories under the terms of the takeover in an effort to ease regualtory concerns.

Boston Scientific and Abbott are also among the larger US employers in Ireland.

The lawsuit in Ireland is the latest challenge by Medtronic against Guidant products involving the Evysio patents. Lawsuits have also been filed in US District Court in northern California and in France, where a court has ruled the Vision stent may infringe the Evysio patents.

A Guidant spokesman declined to comment on the litigation.

Last week, Citigroup analyst Matt Dodds wrote that the intellectual property challenges facing Guidant suggest Boston Scientific's acquisition of Guidant could be delayed - an assertion that Boston Scientific disputed.

Boston Scientific has said it expects its purchase of Guidant to close this week.