When U.S. regulators advised doctors to routinely X-ray patients with a flawed St. Jude Medical Inc. heart device Thursday, top heart doctors asked, “why?” The agency doesn’t recommend that doctors treat patients any differently if they detect flaws, potentially subjecting thousands of people to unneeded medical tests, the Wall Street Journal reported.

The guidance covers St. Jude’s Riata defibrillator lead, a wire that connects the heart to devices that shock irregular rhythms back to normal. Wires inside Riata leads, which St. Jude stopped selling in 2010 and were recalled last year, are prone to breaking through their insulation. In an unknown share of cases with insulation problems, the leads also have life-threatening electrical malfunctions.

X-rays can detect the so-called “extruded” leads, revealing loose wires floating in the heart. But, removing them can be dangerous, and as St. Jude pointed out in a statement yesterday, many extruded or externalized leads continue working normally. So, the U.S. Food and Drug Administration suggested that doctors watch patients carefully—the same guidance they offer for normal Riata devices.

“They’re saying, if the cables are extruded, you should pretty much just watch the patient,” said Dr. Laurence Epstein, chief of the cardiac arrhythmia service at Brigham and Women’s Hospital in Boston.  “If the cables aren’t extruded, you should [still] pretty much just watch the patient.”

Epstein said you should only subject patients to the tests—which dose patients with a small blast of radiation and a potential co-pay—if “you’re going to have some actionable result.” Otherwise, “it’s not clinical care, its research,” he said. Epstein, an expert in so-called lead extraction, said he is removing leads with insulation problems on a case by case basis after discussing the risks with patients.

In an e-mail Friday, the FDA said, “we believe that imaging recommendations at this time help health care providers manage health care of their patients,” and could improve doctors understanding of the scope of the Riata problem. The agency is also requiring St. Jude to conduct new studies to gather more information about the failures and management of patients with Riata leads.

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