Implantable devices that shock hearts out of potentially fatal rhythms, like the one former Vice President Dick Cheney has had, have gotten very popular – too popular, according to a new analysis.
Gregory Marcus, MD/via Creative Commons
A normal chest X-ray after the implant of an cardioverter defibrillator.
A normal chest X-ray after the implant of an cardioverter defibrillator. Gregory Marcus, MD/via Creative Commons
The study, published in the Journal of the American Medical Association, looked at 112,000 implants of cardioverter defibrillators done over the past four years. Turns out 23 percent of them – more than 25,000 patients – didn't meet the criteria for getting the $30,000 devices.
According to guidelines, doctors shouldn't implant them in patients recovering from a heart attack or heart bypass surgery. Patients with a recent diagnosis of heart failure or those with severe symptoms of heart failure are also ineligible.
But lots of those patients are having defib implants anyway. And some of them are apparently dying as a result, says the report. The mortality risk is small – less than one percent – but it was three times higher among patients who didn't meet the guidelines. Those patients also had higher complication rates.
"No risk is acceptable if a procedure has no demonstrated benefit," say the study authors, who include researchers from Duke, Yale, Stanford and the Mayo Clinic.
When the researchers combed through data from 2006 to 2009 in a national registry that keeps track of defibrillator implants in most hospitals, they found a lot of difference among hospitals in their compliance with the guidelines. In many hospitals, more than 40 percent of implants were inappropriate.
That spells a big problem in doctors' and hospitals' compliance with "evidence-based" medicine – the new buzzword in medical quality- and cost-control.
The new study offers an important clue as to why so many implants are being done outside the guidelines: A third of them are done by doctors without special training in heart-rhythm problems. These non-specialists had much higher percentages of inappropriate implants.
An editorial in JAMA says some implants outside the guidelines are OK – maybe around six percent – because of patients' special circumstances. But not anywhere near one-in-four.
Wall Street analysts who monitor the makers of these implantable defibrillators – companies such as Boston Scientific , Medtronic and St. Jude Medical – paid heed to the new study. In fact, one analyst jumped the gun on JAMA's release time for the study, causing the journal to lift the embargo early.
The companies' stocks took a modest hit on the news.