Medtronic, Inc. (NYSE:MDT) shares were off by 5% in early trading today after a federal court placed a temporary injunction on sales of its aortic heart valve replacement system in the U.S. market. The injunction will not be enforced for seven days in order for Medtronic to appeal the ruling.

Medtronic

The Federal District Court of Delaware ruling on Friday was related to earlier court decisions determining that Medtronic’s CoreValve infringed on Edwards Lifesciences Corp (NYSE:EW)’s heart valve patents.

Edwards Lifesciences Corp (NYSE:EW) shares were up more than 15% in morning trading today on the news.

Medtronic’s ethical issues

A number of analysts have expressed surprise at the ruling, and several have commented that the courts would still have to consider the “public interest” in making their final decision.

“How does a judge take a product off the market that has shown an ability to reduce mortality?” J.P. Morgan analysts wrote in a note to clients over the weekend.

Recent clinical trial data showed that Medtronic, Inc. (NYSE:MDT)’s CoreValve system for replacing damaged heart valves resulted in a significantly higher survival rate after a year than traditional open heart surgery in patients at high risk of death during surgery.

On the basis of that data, the FDA approved CoreValve in January of this year, but only to treat patients considered too frail to endure open heart surgery. Medtronic’s valve became the first device to compete against Edwards’ Sapien valve in the U.S. Medtronic, Inc. (NYSE:MDT)’s heart valve has not yet been compared in a head-to-head clinical trial with Edwards Lifesciences Corp (NYSE:EW)’s valve.

Court-ordered agreement

As part of the ruling, the judge also ordered both companies to negotiate an agreement designed to assist physicians in deciding which device to use. Doctors at hospitals and other medical facilities currently trained on CoreValve will need some some objective criteria to make an optimal clinical judgment as to which valve offers the most benefit to individual patients.