Abbott Laboratories scored a legal victory in federal court in Minnesota last week when a judge ruled the company is not liable to third-party payers who paid hundreds of millions of dollars to implant, monitor and remove defective St. Jude Medical heart defibrillators in which the battery could die without warning.

U.S. District Judge David Doty ruled on Thursday that federal law will not allow a lawsuit to proceed against Abbott and St. Jude Medical, which Abbott acquired in 2017. Doty ruled Thursday that the lawsuit against Abbott violated a sweeping federal prohibition on product-liability litigation against makers of high-risk medical devices known as "pre-emption."

Because of past court decisions on pre-emption, Doty said he was required to dismiss the case, which was filed in federal court in Minnesota by an Alaska-based health and welfare fund for union workers called the ASEA/AFSCME Local 52 Health Benefits Trust. (The same case was previously filed in federal court in Illinois but was dismissed for jurisdictional reasons.)

No decision has been made about whether to appeal Doty's decision to dismiss the case with prejudice from the Minnesota federal court, said Karl Cambronne, a Minneapolis-based lawyer for the union's third-party health benefits group. Although the case was styled as a potential nationwide class-action, no ruling was made on whether it is eligible for class-action status.

At issue in the case are more than 250,000 St. Jude Medical implantable heart defibrillators of various makes and models sold in the U.S. between 2011 and 2016 that were recalled in October 2016. (The full list of affected Fortify, Unify and Quadra devices is available on the FDA website.)

Before being acquired by Abbott, St. Jude officials publicly acknowledged that they had detected a short-circuiting problem in certain defibrillator batteries and recalled the devices. The recall applied to devices that St. Jude sold between May 2015 and October 2016, even though the battery design was changed after May 2015 to avoid the short-circuiting problem. St. Jude officials publicly acknowledged that older devices continued to be implanted even after the design was changed.

The lawsuit from the ASEA trust said St. Jude officials should have known about the battery problem as early as 2011, but St. Jude officials at the time "ignored and concealed it."

Specifically, the lawsuit claimed that between 2011 and 2014, St. Jude officials analyzed 42 reports of premature battery depletion but ignored the evidence they generated and instead concluded the cause of the issue "could not be determined." Even after Aug. 27, 2014, when St. Jude received evidence that premature battery failure had led to a patient death, the company claimed the cause of the problem could not be determined.

But the situation could not withstand the scrutiny that comes with an acquisition, the lawsuit said. According to the complaint, Abbott's announcement in April 2016 that it intended to acquire St. Jude triggered a deep "due diligence" review of St. Jude's products. That led to a new investigation of premature battery depletion in May 2016 that included all past complaints and also examined the question of whether batteries could fail without setting off a notification for the patient, the lawsuit said.

It was that review that led St. Jude in August 2016 to do a field recall of the defective devices, the lawsuit said. The recall notice went out in October 2016 and was later classified by the Food and Drug Administration as a Class 1 recall, which means exposure to the product can lead to adverse health problems including death. The FDA did not recommend all devices be immediately removed, but it did recommend not implanting any more of the affected devices. Abbott acquired St. Jude the following January.

The ASEA trust filed its lawsuit under state and federal law to recover money it paid for implanting and removing defective devices, plus any costs for medical monitoring of patients.

However, Abbott's attorneys argued that the claim was nothing more than an attempt to convert a regulatory problem into a personal liability, which goes against the concept of pre-emption.

"At its core, the complaint seeks civil liability for alleged regulatory violations. Federal pre-emption does not allow this. Only the FDA may enforce its regulations, and state law claims must yield if [like here] they create obligations or requirements that differ from or add to federal requirements," Abbott's attorneys wrote in legal filings, using parentheses in their original text.

Doty ruled Thursday that Abbott was correct, based on similar cases that were decided in other device makers' favor in the same jurisdiction.

"Thus, under [three precedent cases], the court is constrained to conclude that plaintiff's claims are preempted," Doty wrote. "As a result, the court must dismiss the case."