Boston Scientific built its Watchman heart implant into a nearly $2 billion-a-year product by promoting it to a far wider group of patients than federal regulators approved it for, The Boston Globe’s Spotlight Team reported on Thursday.
The Marlborough, Mass., company has paid doctors more than $30 million over the past decade for consulting, for training colleagues and for spreading the word about the device, the Globe found. It has spent at least $23 million more on TV commercials aimed at patients, according to an industry estimate. More than 800,000 of the devices have been implanted worldwide.
The Watchman, about the size of a quarter and shaped like an umbrella, seals off a corner of the heart where clots tend to form in people with atrial fibrillation, or A-fib, an irregular heartbeat that raises the risk of stroke fivefold. The pitch is a single procedure in place of a daily blood thinner taken for the rest of a patient’s life.
The Globe based its findings on clinical studies, regulatory documents and years of financial and marketing records, and on interviews with more than two dozen cardiologists, clinicians and researchers. Many of them said the company’s sales push was producing procedures patients didn’t need.
“Many of us feel that sometimes they’re done inappropriately, that [providers] are too cavalier in how ready they are to place these devices,” said Dr. Gregory Marcus, a cardiologist at the University of California, San Francisco. “I don’t think it’s responsible medical practice to push for such a device in the great majority of A-fib patients.”
A doctor who sat on two early FDA advisory panels told the Globe that experts had worried then about “drift,” in which a device is used well beyond the patients it was proven in. He said he now believes that is happening.
The doubts grew in March, when The New England Journal of Medicine published two trials and two editorials. In one trial, CHAMPION-AF, 3,000 patients who could take blood thinners were randomly assigned to a Watchman FLX or a pill at 141 centers in 16 countries. After three years, 5.7 percent of the device group had a stroke, a systemic embolism or a cardiovascular death, compared with 4.8 percent on the drugs, according to a summary from the American College of Cardiology. That was close enough to meet the trial’s test for noninferiority. Bleeding was lower with the device, 10.9 percent against 19 percent, but ischemic strokes were slightly more common.
The second trial went worse for the device. CLOSURE-AF, run at 42 sites in Germany, enrolled 912 older patients at high risk of both stroke and bleeding and allowed several brands of closure device. Patients who got an implant had 16.8 primary events per 100 patient-years, compared with 13.3 for those on medical therapy, and the device failed to show it was as good as the drugs.
In an editorial that month, Dr. Petr Widimsky, a cardiologist, wrote that the devices were being implanted “on the basis of borderline evidence.”
The stakes for the company are large. Boston Scientific wants the Watchman recognized as a first-line treatment on par with blood thinners, and by its own estimate a change in guidance could raise the number of eligible patients worldwide from five million to more than 20 million.
Dr. Kenneth Stein, the company’s global chief medical officer, called the device a “proven alternative” in an interview with the Globe. He pointed to the 30 to 40 percent of A-fib patients who are estimated to be unable or unwilling to take blood thinners. “It’s a tragedy when people who could be prevented from having a stroke have a stroke because they’re left unprotected,” Dr. Stein said. “They deserve to be informed about the alternative and to make the decision themselves over whether they want that.”
Chanel Hastings, a company spokeswoman, told the Globe that Boston Scientific does not believe the device “is broadly overused” and remains “unwavering in our confidence” in it.
“The Watchman is emblematic of the flaws of how medical enterprise works,” said Dr. Gregory Katz, a cardiologist at NYU Langone Health. “We do a lot of things that may not actually be the right things for patients.”
The implant came from Atritech, a small Minnesota company. The FDA turned it down in 2010, finding early trial results inconclusive, and Boston Scientific bought Atritech the next year in a deal worth up to $375 million. The road to approval stayed rough. The agency twice asked for more data in 2013, and when the updated figures arrived in 2014, FDA officials wrote that they “raise new questions about the effectiveness of the device.”
Once the approval came, the company was ready. It set up regional heart centers, including one at a hospital in Manchester, N.H., where it gave deep discounts on cardiac devices, flew in a technician from Europe and put its representatives in the operating room to advise surgeons. By 2017 there were at least 200 Watchman centers around the country. In 2019 the company began a national TV campaign, rare for a high-risk surgical device, promising a “one-time implant that reduces stroke risk and bleeding worry — for life.”
Watchman sales reached nearly $2 billion in 2025, up about 30 percent from the year before, the Globe reported. The company put the growth at 29 percent on its February earnings call. Mike Mahoney, the chief executive, called the device “clearly a gem for Boston Scientific” on an investor call last year.
More than 10 million Americans have been diagnosed with A-fib. Implants of the Watchman and its rival, the Amulet, for which Medicare pays about $25,000, have grown about sevenfold nationally over six years.
CHAMPION-AF’s investigators plan to follow their patients for five years to see whether the device keeps up with blood thinners in preventing ischemic strokes and embolisms over the longer term.