A Hennepin County judge has dismissed 600 lawsuits filed by patients who claimed they were harmed by a faulty heart defibrillator lead made by Medtronic Inc. It was the second large batch of such cases to be dismissed in the wake of a U.S. Supreme Court ruling on liability law.

Ruling in favor of a Medtronic motion, District Judge Denise Reilly dismissed the claims on the basis of a 2008 high court ruling indicating that if the U.S. Food and Drug Administration has approved a medical device, then product liability lawsuits cannot be filed under state law, a legal doctrine known as preemption.

Medtronic recalled its popular Sprint Fidelis lead in October 2007 after a small number were found to fracture. At the time of the recall, more than 257,000 patients had been treated with the potentially defective product.

Defibrillators are $30,000, stopwatch-sized devices implanted in the chest that shock an errantly beating heart back into rhythm. A defibrillator is connected to the heart inside the body with an insulated wire, or lead. If a patient's Sprint Fidelis lead fractured, numerous shocks could be delivered to the heart unnecessarily. Or, in some cases, a fractured lead could render the device useless when it was needed to revive a patient.

To date, Medtronic has confirmed that 13 people have died as a result of a malfunctioning lead wire. An editorial in the New England Journal of Medicine in April indicated the FDA has logged 2,200 reports of serious injuries from the Sprint Fidelis lead.

After Medtronic recalled the lead, hundreds of patients filed suit against the Fridley-based company claiming, among other charges, that the device had harmed them.

In January, Judge Richard Kyle, also citing the high court's ruling, dismissed about 1,000 cases that had been filed in U.S. District Court in St. Paul by patients.

The medical device industry has argued that the cost of defending product liability lawsuits saps funds that would otherwise be used to develop new and innovative products.

Minneapolis lawyer Michael Johnson, who represented plaintiffs in the Hennepin County case, said the ruling was disappointing and that his clients plan to appeal.

"Besides denying our injured and deceased clients' families access to the courtroom, Medtronic's legal win costs taxpayers in Minnesota and the country hundreds of millions of dollars," he said. "Taxpayers and consumers, through Medicare, Medicaid and private insurers, pay the bill for the injuries caused by Medtronic's defective and recalled leads. We disagree that complete corporate immunity for these manufacturers is good for either our clients or the public."

A bill called the Medical Device Safety Act has been introduced in the House of Representatives. The bill calls for amending the Federal Food, Drug, and Cosmetic Act to prohibit preemption in cases involving medical devices.

Janet Moore • 612-673-7752