Faulty pacemaker raises concerns over medical device testing

The first person in Britain to receive what was heralded as a revolutionary pacemaker has told of her nightmare after it stopped working and surgeons were unable to extract the implant from her heart.

Maureen McCleave, 82, from Chingford in Essex, said she felt “so lucky” when in 2014 she was offered the Nanostim device, which is a 10th the size of a traditional model and the first of its kind to be approved.

However, within three years McCleave began suffering from dizziness, palpitations and exhaustion.

Doctors discovered the pacemaker’s battery, which was meant to last 10 years, had died. McCleave was one of dozens of patients placed at risk due to this technical flaw, which prompted an official safety alert.

The cases raise questions about whether the device was sufficiently tested before being approved and whether patients who were fitted with the pacemaker were fully aware of the risks.

“I’d like to know why it stopped working,” she told BBC Panorama, one of the Guardian’s partners in the investigation. “I was just assured that [it] would last me until I died.”

More than 700,000 pacemakers are implanted annually worldwide, including about 35,000 in the UK. The estimated market revenue from pacemakers worldwide is projected to reach $12bn (£9.4bn) by 2021.

Nanostim was developed by a small Californian tech company and brought to market by St Jude Medical, a device company that was acquired by the US healthcare firm Abbott last year.

Nanostim graphic

The pacemaker was billed as a radical departure from traditional models, in which up to three electrical leads run into the heart from a separate battery pack that sits under the collarbone. Nanostim, which is the size of an AAA battery, has no leads and is anchored directly inside one of the heart’s chambers.

It is delivered by a catheter threaded up the femoral vein from a small incision in the leg. The minimally invasive procedure can be performed under local anaesthetic in less than 10 minutes.

McCleave was waiting to have a conventional pacemaker to treat an irregular heartbeat, when in January 2014 she says she received a phone call from Prof Richard Schilling, a cardiologist at St Bartholomew’s and the Royal London NHS trust.

He asked if she would like to become the first person in the country to receive a new, advanced pacemaker. “He said … what a breakthrough it was,” she said. “I just thought it was a really, really good thing. I was really pleased that I’d been picked to have it done.”

She was told the pacemaker would last at least 10 years and recalled joking with her doctors that it would “see her out”.

She was given the Nanostim weeks after it was awarded its CE (Conformité Européenne) safety mark by Britain’s leading approval body, the British Standards Institution.

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In the application, St Jude submitted data from a three-month trial involving 33 patients, one of whom had died due to a heart perforation during the implantation procedure. A year earlier, Nanostim was turned down for a CE mark by the German licensing body, which was concerned that, at that time, the device had only been tested in sheep.

In the weeks after the procedure, McCleave had regular contact from a St Jude representative who asked her to do media interviews with the Mail on Sunday, ITV’s The Alan Titchmarsh Show, BBC radio and others. She said she agreed because she felt so grateful to have the implant.





Maureen McCleave



Maureen McCleave: ‘I don’t like the fact that there’s something in my heart that shouldn’t be in there and it’s not doing anything.’ Photograph: BBC Panorama

In 2014, St Jude was forced to temporarily suspend a Nanostim trial after doctors reported six instances of perforation, including two patient deaths, out of more than 200 implants. Then in October 2016, St Jude issued a safety alert telling doctors to halt implantations of Nanostim after receiving 34 reports of premature battery failure, out of 1,423 patients who had received the implants.

McCleave received a letter about the battery issue but said she assumed she was unaffected. But in January 2017 she began to suffer dizziness, palpitations and exhaustion and felt “something, somewhere was wrong”.

When she attended hospital, doctors discovered the battery on her pacemaker had drained prematurely and she was sent for urgent revision surgery. Although Nanostim was marketed as retrievable, McCleave was advised it could not be taken out and a conventional pacemaker was added in alongside it.

“I don’t like the fact that there’s something in my heart that shouldn’t be in there and it’s not doing anything,” she said. She bled profusely during surgery, due to being on the blood-thinning drug warfarin, had extensive bruising and needed to stay in hospital for several days.

She said St Jude did not get in touch to explain what had gone wrong or why it had happened. “I felt like a bit of trash that had been thrown to one side,” she said. “When it went wrong, I just felt like I’d been dismissed. At least someone could have sent a letter to say we’re sorry that things went wrong.”

In November 2017, Abbott, which had acquired St Jude, issued a further safety notice warning of a problem with the docking button that was designed to allow doctors to extract the device. This included three reports of the button detaching and in one case migrating into an artery.

Francis Murgatroyd, the director of cardiac electrophysiology at King’s College hospital in London, said he feared St Jude was “in a rush” to bring Nanostim to market ahead of a competing leadless pacemaker being developed by a rival medical device company, Medtronic. “My impression was that the company was very, very pushy.”

In the US, the Food and Drug Administration has not approved Nanostim for use on patients, despite the device having been initially developed in the US.

Abbott declined to comment when asked about fears Nanostim may have been rushed on to the market.

It said in a statement: “Many patients have been helped by leadless pacing systems and many more will benefit from this technology in the future.

“In accordance with the European CE mark approval process, the Nanostim leadless pacing system was approved based on strong performance and safety data. In addition, upon CE mark approval Nanostim was further assessed through a European post-market clinical follow-up study.”

A Barts Health NHS trust spokesperson said: “At no time did we wish to make Mrs McCleave feel under pressure to have the Nanostim leadless device implanted, and we are sorry that she now feels this way. We believe that her treatment options were made clear, including that we would be happy to implant a conventional pacemaker if she preferred.”

The trust said it wrote to McCleave immediately after being notified of potential problems and that she was seen in clinic two weeks later to allow her time to consider having a replacement device.

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