A Delaware jury Tuesday ruled that some of the newest stents from Boston Scientific Corp. (BSX) infringe patents on vascular repair technology held by rival Johnson & Johnson Inc. (JNJ).

The eight-person jury deliberated only a few hours before handing down its verdict, one that marks the second recent defeat for Natick, Mass.-based Boston Scientific in federal court patent fights with New Brunswick, N.J.-based J&J and its Cordis Corp. (search) unit.

Earlier this year, another jury found Boston Scientific's Nir stent — a device that props up repaired arteries — infringed a J&J patent.

Tuesday's decision found that Boston Scientific's Express and Taxus Express stents as well as its Liberte stent infringed two patents held by J&J.

The Taxus Express and Liberte are leading Boston Scientific drug-eluting stents (search), a variation of the stent technology that has gained wide acceptance in the medical community. They are coated with drugs that help prevent restenosis, the tendency of clogged arteries to re-close after being opened through angioplasty.

The jury also found that the Liberte stent infringed not only J&J's landmark stent patent, which expires in November, but a second patent, which J&J obtained in connection with its Crown stent.

While the jury deliberated Tuesday morning, lawyers for Boston Scientific and J&J were picking jurors for their next patent trial, slated to start Wednesday.

In that case, Boston Scientific alleges J&J's newest stents infringe its patent on technology that transforms bare metal stents into drug-eluting stents.

J&J's Cypher drug-eluting stent is believed to have about 30 percent of the market, compared with about 60 percent for Boston Scientific's Taxus Express.

The question of damages is set to be tried in August, along with the issue of willfulness, which could escalate the damages.

In the first case, J&J is seeking at least $844 million, the amount of lost profits it claims can be traced to Boston Scientific's infringing products.

Boston Scientific says J&J should be limited to reasonable royalties, in part because it allegedly would not have been able to supply the whole market demand for stents due to manufacturing troubles.

If the second trial ends in a finding of infringement, J&J also will face a damages trial in August.