September 12th, 2011
Global Monitor: Early Signs of Possible Problems with ICD Leads, Dabigatran
Larry Husten, PHD
Reports from Ireland and New Zealand may herald new concerns about Riata defibrillator leads (St. Jude Medical) and dabigatran (Pradaxa).
A poster presented at the European Society of Cardiology meeting last month by researchers at the Royal Victoria Hospital in Belfast found that 15% of 212 patients who received Riata leads had an insulation breach on screening. The researchers reported that 20% of the patients had “clinically significant events.”
Quoted in an article in the Minneapolis Star Tribune, the chief of the Arrhythmia Service at Brigham and Women’s Hospital in Boston, Laurence Epstein, acknowledges the small size of the single-center study but states that “it could ultimately be a big issue… we’re just starting to scratch the tip of the iceberg of what the scope of the problem is.” Although the Riata leads were discontinued last year, more than 227,000 were sold worldwide.
In New Zealand, meanwhile, health authorities are struggling with a surge in bleeding complications following the government’s decision to fund dabigatran (Pradaxa). According to an article in the Star Times, the country’s drug monitoring agency “has received around 50 reports of people experiencing bleeding since the drug was introduced two months ago as a replacement” for warfarin.
The Star Times reports that about 56,000 people in New Zealand take warfarin and that thousands have been switched to dabigatran. The reports quotes an official of the country’s Haematology Society: “We do have concerns about the way it was rolled out. … It was rolled out very rapidly without a lot of forethought and planning. In particular the fact that general practitioners could have widespread access to this drug from day one was a concern to us, when some of them did not know how to use it.”
This is the problem when a new drug like dabigatran comes out–reports from anywhere and everywhere and with an unclear denominator. It will take weeks or months to sort this out.
The big concern is that we can’t monitor the drug in any way so far. There is no qujestion that couimadin is a bad drur for the followingb reasons;
1-Seniors quit the deug because of its baggage like worrying about K contentof foods , need to go to a clinic frequently, forgotten dosea
2 It is a very dangerous drug . If the senior gets sick with anorexia or diarrhea, up goes the INR
3 Concern about new drug impacting coumadin
4Seniors are forever breaking bones from falling
5 So, falling,forgotten doses, poor compliance, impact otf otherdiseases, other diseases,complicated dosology, is simply too much
Competing interests pertaining specifically to this post, comment, or both:
I have no conflicts of interest
J A BARRY,MD, FACP Geriatrician/Internist
The major problem with dabigatran in real-world practice appears to be its lack of reversibility with vitamin K (unlike coumadin). Only real-world surveillance can sort out whether patients are being admitted with intractable bleeding events that can be attributed to this property. Nonetheless this class of drugs represents a significant advance over coumadin in many ways given the inconvenience and unpredictability of INR monitoring.
The plural of anecdote isn’t data, but there has been one death of a female patient from irreversible pulmonary hemorrhage locally and another major bleed seen in the ER. The drug isn’t widely used in SE Arkansas yet due to cost.
The drug rep has become more circumspect.
Competing interests pertaining specifically to this post, comment, or both:
Only basic cynicism
One wonders about reporting bias. How many warfarin-related bleeds are being reported to FDA tonight? Or have we just come to expect the equation that warfarin = “increased rate of major hemorrhage”, and increasing degrees of INR in patients with abnormal connections between endothelium and epithelium (eg gastric ulcer, cerebral amyloid angiopathy) means increasing chance of catastrophic bleed. Conversely, because dabigatran is so new with so much publicity it is likely that ANY dabigatran-associated significant event is going to be noticed and reported. As Stephen Fleet declaimed, what is the denominator?
70 years of warfarin therapy means that no one is surprised when a patient comes in with a major warfarin-associated bleed. Why the double standard for dabigatran? Only RCT data can sort this out (and it shows less ICH and more gastric bleeding for dabigatran than warfarin).
New drugs: Never be the first…never be the last to use. Wait a little, until the real world use tell you what’s really happening
Competing interests pertaining specifically to this post, comment, or both:
no conflicts