Charity Watkins sensed something was deeply wrong when she experienced exhaustion after her daughter was born.

At times, Watkins, then 30, had to stop on the stairway to catch her breath. Her obstetrician said postpartum depression likely caused the weakness and fatigue. When Watkins, who is Black, complained of a cough, her doctor blamed the flu.

About eight weeks after delivery, Watkins thought she was having a heart attack, and her husband took her to the emergency room. After a 5½-hour wait in a North Carolina hospital, she returned home to nurse her baby without seeing a doctor.

When a physician finally examined Watkins three days later, he immediately noticed her legs and stomach were swollen, a sign that her body was retaining fluid. After a chest X-ray, the doctor diagnosed her with heart failure, a serious condition in which the heart becomes too weak to adequately pump oxygen-rich blood to organs throughout the body. Watkins spent two weeks in intensive care.

She said a cardiologist later told her, “We almost lost you.”

Watkins is among 12 million adults misdiagnosed every year in the U.S.

In a study published Jan. 8 in JAMA Internal Medicine, researchers found that nearly 1 in 4 hospital patients who died or were transferred to intensive care had experienced a diagnostic error. Nearly 18% of misdiagnosed patients were harmed or died.

In all, an estimated 795,000 patients a year die or are permanently disabled because of misdiagnosis, according to a study published in July in the BMJ Quality & Safety periodical.

Some patients are at higher risk than others.

Women and racial and ethnic minorities are 20% to 30% more likely than white men to experience a misdiagnosis, said David Newman-Toker, a professor of neurology at Johns Hopkins School of Medicine and the lead author of the BMJ study. “That’s significant and inexcusable,” he said.

Researchers call misdiagnosis an urgent public health problem. The study found that rates of misdiagnosis range from 1.5% of heart attacks to 17.5% of strokes and 22.5% of lung cancers.

Weakening of the heart muscle — which led to Watkins’ heart failure — is the most common cause of maternal death one week to one year after delivery, and is more common among Black women.

Heart failure “should have been No. 1 on the list of possible causes” for Watkins’ symptoms, said Ronald Wyatt, chief science and chief medical officer at the Society to Improve Diagnosis in Medicine, a nonprofit research and advocacy group.

Maternal mortality for Black mothers has increased dramatically in recent years. The United States has the highest maternal mortality rate among developed countries. According to the Centers for Disease Control and Prevention, non-Hispanic Black mothers are 2.6 times as likely to die as non-Hispanic white moms. More than half of these deaths take place within a year after delivery.

Research shows that Black women with childbirth-related heart failure are typically diagnosed later than white women, said Jennifer Lewey, co-director of the pregnancy and heart disease program at Penn Medicine. That can allow patients to further deteriorate, making Black women less likely to fully recover and more likely to suffer from weakened hearts for the rest of their lives.

Watkins said the diagnosis changed her life. Doctors advised her “not to have another baby, or I might need a heart transplant,” she said. Being deprived of the chance to have another child, she said, “was devastating.”

Racial and gender disparities are widespread.

Women and minority patients suffering from heart attacks are more likely than others to be discharged without diagnosis or treatment.

Black people with depression are more likely than others to be misdiagnosed with schizophrenia.

Minorities are less likely than whites to be diagnosed early with dementia, depriving them of the opportunities to receive treatments that work best in the early stages of the disease.

Misdiagnosis isn’t new. Doctors have used autopsy studies to estimate the percentage of patients who died with undiagnosed diseases for more than a century. Although those studies show some improvement over time, life-threatening mistakes remain all too common, despite an array of sophisticated diagnostic tools, said Hardeep Singh, a professor at Baylor College of Medicine who studies ways to improve diagnosis.

“The vast majority of diagnoses can be made by getting to know the patient’s story really well, asking follow-up questions, examining the patient, and ordering basic tests,” said Singh, who is also a researcher at Houston’s Michael E. DeBakey VA Medical Center. When talking to people who’ve been misdiagnosed, “one of the things we hear over and over is, ‘The doctor didn’t listen to me.’”

Racial disparities in misdiagnosis are sometimes explained by noting that minority patients are less likely to be insured than white patients and often lack access to high-quality hospitals. But the picture is more complicated, said Monika Goyal, an emergency physician at Children’s National Hospital in Washington, D.C., who has documented racial bias in children’s health care.

In a 2020 study, Goyal and her colleagues found that Black kids with appendicitis were less likely than their white peers to be correctly diagnosed, even when both groups of patients visited the same hospital.

Although few doctors deliberately discriminate against women or minorities, Goyal said, many are biased without realizing it.

“Racial bias is baked into our culture,” Goyal said. “It’s important for all of us to start recognizing that.”

Demanding schedules, which prevent doctors from spending as much time with patients as they’d like, can contribute to diagnostic errors, said Karen Lutfey Spencer, a professor of health and behavioral sciences at the University of Colorado-Denver. “Doctors are more likely to make biased decisions when they are busy and overworked,” Spencer said. “There are some really smart, well-intentioned providers who are getting chewed up in a system that’s very unforgiving.”

Doctors make better treatment decisions when they’re more confident of a diagnosis, Spencer said.

In an experiment, researchers asked doctors to view videos of actors pretending to be patients with heart disease or depression, make a diagnosis, and recommend follow-up actions. Doctors felt far more certain diagnosing white men than Black patients or younger women.

“If they were less certain, they were less likely to take action, such as ordering tests,” Spencer said. “If they were less certain, they might just wait to prescribe treatment.”

It’s easy to see why doctors are more confident when diagnosing white men, Spencer said. For more than a century, medical textbooks have illustrated diseases with stereotypical images of white men. Only 4.5% of images in general medical textbooks feature patients with dark skin.

That may help explain why patients with darker complexions are less likely to receive a timely diagnosis with conditions that affect the skin, from cancer to Lyme disease, which causes a red or pink rash in the earliest stage of infection. Black patients with Lyme disease are more likely to be diagnosed with more advanced disease, which can cause arthritis and damage the heart. Black people with melanoma are about three times as likely as whites to die within five years.

The covid-19 pandemic helped raise awareness that pulse oximeters — the fingertip devices used to measure a patient’s pulse and oxygen levels — are less accurate for people with dark skin. The devices work by shining light through the skin; their failures have delayed critical care for many Black patients.

Seven years after her misdiagnosis, Watkins is an assistant professor of social work at North Carolina Central University in Durham, where she studies the psychosocial effects experienced by Black mothers who survive severe childbirth complications.

“Sharing my story is part of my healing,” said Watkins, who speaks to medical groups to help doctors improve their care. “It has helped me reclaim power in my life, just to be able to help others.”

KFF Health News is a national newsroom that produces in-depth journalism about health issues and is one of the core operating programs at KFF—an independent source of health policy research, polling, and journalism. Learn more about KFF.

Subscribe to KFF Health News’ free Morning Briefing.

In 2013, the FDA approved an implantable device to treat leaky heart valves. Among its inventors was Mehmet Oz, the former television personality and former U.S. Senate candidate widely known as “Dr. Oz.”

In online videos, Oz has called the process that brought the MitraClip device to market an example of American medicine firing “on all cylinders,” and he has compared it to “landing a man on the moon.”

MitraClip was designed to spare patients from open-heart surgery by snaking hardware into the heart through a major vein. Its manufacturer, Abbott, said it offered new hope for people severely ill with a condition called mitral regurgitation and too frail to undergo surgery.

“It changed the face of cardiac medicine,” Oz said in a video.

But since MitraClip won FDA approval, versions of the device have been the subject of thousands of reports to the agency about malfunctions or patient injuries, as well as more than 1,100 reports of patient deaths, FDA records show. Products in the MitraClip line have been the subject of three recalls. A former employee has alleged in a federal lawsuit that Abbott promoted the device through illegal inducements to doctors and hospitals. The case is pending, and Abbott has denied illegally marketing the device.

The MitraClip story is, in many ways, a cautionary tale about the science, business, and regulation of medical devices.

Manufacturer-sponsored research on the device has long been questioned. In 2013, an outside adviser to the FDA compared some of the data marshaled in support of its approval to “poop.”

The FDA expanded its approval of MitraClip to a wider set of patients in 2019, based on a clinical trial in which Abbott was deeply involved and despite conflicting findings from another study.

In the three recalls, the first of which warned of potentially deadly consequences, neither the manufacturer nor the FDA withdrew inventory from the market. The company told doctors it was OK for them to continue using the recalled products.

In response to questions for this article, both Abbott and the FDA described MitraClip as safe and effective.

“With MitraClip, we’re addressing the needs of people with MR who often have no other options,” Abbott spokesperson Brent Tippen said. “Patients suffering from mitral regurgitation have severely limited quality of life. MitraClip can significantly improve survival, freedom for hospitalization and quality of life via a minimally invasive, now common procedure.”

An FDA spokesperson, Audra Harrison, said patient safety “is the FDA’s highest priority and at the forefront of our work in medical device regulation.”

She said reports to the FDA about malfunctions, injuries, and deaths that the device may have caused or contributed to are “consistent” with study results the FDA reviewed for its 2013 and 2019 approvals.

In other words: They were expected.

Inspiration in Italy

When a person has mitral regurgitation, blood flows backward through the mitral valve. Severe cases can lead to heart failure.

With MitraClip, flaps of the valve — known as “leaflets” — are clipped together at one or more points to achieve a tighter seal when they close. The clips are deployed via a catheter threaded through a major vein, typically from an incision in the groin. The procedure offers an alternative to connecting the patient to a heart-lung machine and repairing or replacing the mitral valve in open-heart surgery.

Oz has said in online videos that he got the idea after hearing a doctor describe a surgical technique for the mitral valve at a conference in Italy. “And on the way home that night, on a plane heading back to Columbia University, where I was on the faculty, I wrote the patent,” he told KFF Health News.

A patent obtained by Columbia in 2001, one of several associated with MitraClip, lists Oz first among the inventors.

But a Silicon Valley-based startup, Evalve, would develop the device. Evalve was later acquired by Abbott for about $400 million.

“I think the engineers and people at Evalve always cringe a little bit when they see Mehmet taking a lot of, you know, basically claiming responsibility for what was a really extraordinary team effort, and he was a small to almost no player in that team,” one of the company’s founders, cardiologist Fred St. Goar, told KFF Health News.

Oz did not respond to a request for comment on that statement.

As of 2019, the MitraClip device cost $30,000 per procedure, according to an article in a medical journal. According to the Abbott website, more than 200,000 people around the world have been treated with MitraClip.

Oz filed a financial disclosure during his unsuccessful run for the U.S. Senate in 2022 that showed him receiving hundreds of thousands of dollars in annual MitraClip royalties.

Abbott recently received FDA approval for TriClip, a variation of the MitraClip system for the heart’s tricuspid valve.

Endorsed ‘With Trepidation’

Before the FDA said yes to MitraClip in 2013, agency staffers pushed back.

Abbott had originally wanted the device approved for “patients with significant mitral regurgitation,” a relatively broad term. After the FDA objected, the company narrowed its proposal to patients at too-high risk for open-heart surgery.

Even then, in an analysis, the FDA identified “fundamental” flaws in Abbott’s data.

One example: The data compared MitraClip patients with patients who underwent open-heart surgery for valve repair — but the comparison might have been biased by differences in the expertise of doctors treating the two groups, the FDA analysis said. While MitraClip was implanted by a highly select, experienced group of interventional cardiologists, many of the doctors doing the open-heart surgeries had performed only a “very low volume” of such operations.

FDA “approval is not appropriate at this time as major questions of safety and effectiveness, as well as the overall benefit-risk profile for this device, remain unanswered,” the FDA said in a review prepared for a March 2013 meeting of a committee of outside advisers to the agency.

Some committee members expressed misgivings. “If your right shoe goes into horse poop and your left shoe goes into dog poop, it’s still poop,” cardiothoracic surgeon Craig Selzman said, according to a transcript.

The committee voted 5-4 against MitraClip on the question of whether it proved effective. But members voted 8-0 that they considered the device safe and 5-3 that the benefits of the device outweighed its risks.

Selzman voted yes on the last question “with trepidation,” he said at the time.

In October 2013, the FDA approved the MitraClip Clip Delivery System for a narrower group of patients: those with a particular type of mitral regurgitation who were considered a surgery risk.

“The reality is, there is no perfect procedure,” said Jason Rogers, an interventional cardiologist and University of California-Davis professor who is an Abbott consultant. The company referred KFF Health News to Rogers as an authority on MitraClip. He called MitraClip “extremely safe” and said some patients treated with it are “on death’s door to begin with.”

“At least you’re trying to do something for them,” he said.

Conflicting Studies

In 2019, the FDA expanded its approval of MitraClip to a wider set of patients.

The agency based that decision on a clinical trial in the United States and Canada that Abbott not only sponsored but also helped design and manage. It participated in site selection and data analysis, according to a September 2018 New England Journal of Medicine paper reporting the trial results. Some of the authors received consulting fees from Abbott, the paper disclosed.

A separate study in France reached a different conclusion. It found that, for some patients who fit the expanded profile, the device did not significantly reduce deaths or hospitalizations for heart failure over a year.

The French study, which appeared in the New England Journal of Medicine in August 2018, was funded by the government of France and Abbott. As with the North American study, some of the researchers disclosed they had received money from Abbott. However, the write-up in the journal said Abbott played no role in the design of the French trial, the selection of sites, or in data analysis.

Gregg Stone, one of the leaders of the North American study, said there were differences between patients enrolled in the two studies and how they were medicated. In addition, outcomes were better in the North American study in part because doctors in the U.S. and Canada had more MitraClip experience than their counterparts in France, Stone said.

Stone, a clinical trial specialist with a background in interventional cardiology, acknowledged skepticism toward studies sponsored by manufacturers.

“There are some people who say, ‘Oh, well, you know, these results may have been manipulated,’” he said. “But I can guarantee you that’s not the truth.”

‘Nationwide Scheme’

A former Abbott employee alleges in a lawsuit that after MitraClip won approval, the company promoted the device to doctors and hospitals using inducements such as free marketing support, the chance to participate in Abbott clinical trials, and payments for participating in “sham speaker programs.”

The former employee alleges that she was instructed to tell referring physicians that if they observed mitral regurgitation in their patients to “just send it” for a MitraClip procedure because “everything can be clipped.” She also alleges that, using a script, she was told to promote the device to hospital administrators based on financial advantages such as “growth opportunities through profitable procedures, ancillary tests, and referral streams.”

The inducements were part of a “nationwide scheme” of illegal kickbacks that defrauded government health insurance programs including Medicare and Medicaid, the lawsuit claims.

The company denied doing anything illegal and said in a court filing that “to help its groundbreaking therapy reach patients, Abbott needed to educate cardiologists and other healthcare providers.”

Those efforts are “not only routine, they are laudable — as physicians cannot use, or refer a patient to another doctor who can use, a device that they do not understand or in some cases even know about,” the company said in the filing.

Under federal law, the person who filed the suit can receive a share of any money the government recoups from Abbott. The suit was filed by a company associated with a former employee in Abbott’s Structural Heart Division, Lisa Knott. An attorney for the company declined to comment and said Knott had no comment.

Reports to the FDA

As doctors started using MitraClip, the FDA began receiving reports about malfunctions and cases in which the product might have caused or contributed to a death or an injury.

According to some reports, clips detached from valve flaps. Flaps became damaged. Procedures were aborted. Mitral leakage worsened. Doctors struggled to control the device. Clips became “entangled in chordae” — cord-like structures also known as heartstrings that connect the valve flaps to the heart muscle. Patients treated with MitraClip underwent corrective operations.

As of March 2024, the FDA had received more than 17,000 reports documenting more than 22,000 “events” involving mitral valve repair devices, FDA data shows. All but about 200 of those reports mention one iteration of MitraClip or another, a KFF Health News review of FDA data found.

Almost all the reports came from Abbott. The FDA requires manufacturers to submit reports when they learn of mishaps potentially related to their devices.

The reports are not proof that devices caused problems, and the same event might be reported multiple times. Other events may go unreported.

Despite the reports’ limitations, the FDA provides an analysis of them for the public on its website.

MitraClip’s risks weren’t a surprise.

Like the rapid-fire fine print in television ads for prescription drugs, the original product label for the device listed more than 60 types of potential complications.

Indeed, during clinical research on the device, about 6% of patients implanted with MitraClip died within 30 days, according to the label. Almost 1 in 4 — 23.6% – were dead within a year.

The FDA spokesperson, Harrison, pointed to a study originally published in 2021 in The Annals of Thoracic Surgery, based on a central registry of mitral valve procedures, that found lower rates of death after MitraClip went on the market.

“These data confirmed that the MitraClip device remains safe and effective in the real-world setting,” Harrison said.

But the study’s authors, several of whom disclosed financial or other connections to Abbott, said data was missing for more than a quarter of patients one year after the procedure.

A major measure of success would be the proportion of MitraClip patients who are alive “with an acceptable quality of life” a year after undergoing the procedure, the study said. Because such information was available for fewer than half of the living patients, “we have omitted those outcomes from this report,” the authors wrote.

If you’ve had an experience with MitraClip or another medical device and would like to tell KFF Health News about it, click here to share your story with us.

KFF Health News audience engagement producer Tarena Lofton contributed to this report.

KFF Health News is a national newsroom that produces in-depth journalism about health issues and is one of the core operating programs at KFF—an independent source of health policy research, polling, and journalism. Learn more about KFF.

Subscribe to KFF Health News’ free Morning Briefing.