Guidant Prizm II DR ICD Recall
The Guidant Prizm II DR ICD was introduced to the US market in 2000 . Early in 2002, Guidant became aware of a design flaw could cause the device to short-circuit during shock delivery , destroying the device. This came with no warning, and many patients continued life oblivious to the fact that their ICD could no longer provide effective
Figure 1: Guidant Ventak Prizm 2 DR ICD
therapy. Later that same year, changes were made to the device to prevent future failures. Nonetheless, devices manufactured prior to the design change were packaged and sold under the same pretense as updated devices; although Guidant informed the FDA of the change, no formal statement was issued to physicians or patients. As a result, many potentially defective devices were implanted even after the flaw had been discovered and corrected for. After the death of a patient in March 2005, Guidant revealed the design change, and issued a voluntary recall of over 26,000 units that was later upgraded to a class I recall. Today, many potentially defective devices remain implanted. Although Guidant did not violate any legal standards in this case, numerous ethical boundaries were crossed. As a result, the ICD industry was closely examined, and several changes were recommended by Guidant, the FDA, and independent committees.
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Over 26,000 Implantable cardioverter defibrillators (ICD’s) are implanted in the United States each year  to treat a variety of symptoms, mostly deriving from some form of cardiac arrhythmia in patients presenting with cardiomyopathy. The device is extremely similar to a pacemaker in appearance and surgical implantation, and shares some common functional features. Nearly all ICD’s are used to treat ventricular arrhythmia, or in the worst case fibrillation. Three different treatment methods are employed, usually sequentially. The first is a rudimentary pacing technique, similar to that utilized by VV- pacemakers. If that method is unable to restore ventricular rhythm, the device attempts cardioversion. This is essentially an attempt to ‘overdrive’ the heart, inducing it to beat faster than its internal electrical patterns would otherwise cause. Usually this allows the heart a chance to ‘reset’; a successful application of therapy means the heart rate can gradually be brought back down to normal levels as stimulation is discontinued. The third method used to restore cardiac function is defibrillation. This entails the delivery of a high energy shock to completely interrupt electrical transmission in the heart, and is functionally identical to external defibrillation using paddles; most internal units now even deliver biphasic shocks.
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Guidant met with trouble beginning in February 2002 when the company became aware of several similar failures of its Prizm 2 DR ICD. In particular, after analyzing units that had failed and been sent back to the manufacturer, it was found that degradation of the device’s internal electrical insulation could possibly cause short-circuiting upon shock delivery, rendering the ICD inoperable . With no prior warning, a short could occur between the ground wire connected to the device’s external lead, and the backfill tube, used to fill the device with helium during assembly. The backfill tube was additionally used as a positively charged test point to confirm the device’s ability to deliver a shock prior to shipping. The proximity of these two conductors can be seen in figure 2. Because these shorts created an
Figure 2: Prizm 2 DR schematic showing + backfill tube and – defibrillator feed wire 
essentially zero resistance path for the delivered pulse, the resulting electrical current was high enough to completely destroy several internal electrical components. More importantly, just when it was needed, no shock was delivered to the patient. Theoretically, it would be possible for a patient to continue with an inoperable device until his or her next follow-up appointment, unaware that any malfunction had ever occurred.
Guidant took the appropriate actions to satisfy its legal obligations, reporting all known device failures and malfunctions to the FDA in a timely fashion. In April 2002, the manufacturer revised the design of the Prizm 2 DR in order to correct for the short-circuiting risk. Nonetheless, any devices still left in inventory that were made prior to the design change continued to be sold and implanted in patients as though they presented no known risk of failure. In fact, the company failed to provide physicians or patients with any information regarding the design change or previous device failures; it was determined that the confirmed failure rate of roughly 1 in 1000 devices was not high enough to warrant any formal communications. It took the death of a relatively young
(21 years old) patient, coupled with the imminent release of a New York Times investigatory article for Guidant to finally come forward and publicly acknowledge the risk for short-circuiting in Prizm 2 DR ICD’s manufactured before April 2002 .
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On May 23, 2005 Guidant disclosed the potentially dangerous flaw in Prizm 2 DR devices manufactured prior to the April 2002 design change. This only came after the company was informed that the New York Times intended to print an article the next morning that detailed the corporation’s failure to inform doctors and patients of the risk for failure inherent in those devices. On June 17, Guidant issued a voluntary recall of some 26,000 devices, offering an updated replacement device at no cost, as well as $2,500 towards the cost of surgery associated with the swap – an amount drastically less than the actual surgical expense. The FDA upgraded the status of the recall to Class I on July 1, but still left the ultimate decision on removal of an affected device to patients and their physicians. Today, over 13,000 of these devices remain implanted in patients worldwide.
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Several panels were established following Guidant’s recall , both by the corporation and by independent organizations in order to pinpoint what went wrong in this particular case, and what could be done to prevent similar situations in the future. Since no legal rules had been broken, it was clear that changes needed to be made. One common finding was that the FDA had no appropriate system in place to monitor device performance once introduced into the market. While Guidant submitted several nearly identical MDR’s to the FDA long before the device recall, no action was taken. Furthermore, the FDA was made aware of changes made in the device’s design in order to prevent similar failures, but did not make this information available to the public. As a result, the FDA created a task force aimed specifically at setting guidelines for malfunction in pacemakers and defibrillators. It has been proposed that the FDA’s failure in this case was not intentional, but rather came from a lack of experience since the ICD market has only reached appreciable levels very recently.
It was further found that the ICD industry as a whole does not effectively pass information between manufacturers and physicians, or vice-versa. In the case of the Guidant ICD recall, the failure rate was likely much higher than actually observed. This results from the fact that the majority of failed devices are not returned to the manufacturer, but rather are simply discarded. If some standard system were in place that required all explanted devices to be thoroughly tested, a recall may have been issued far sooner, and affected fewer patients. On the manufacturer’s end, the decision to not to issue a public statement regarding ICD failures was kept entirely within Guidant’s executive and engineering branches. It has been recommended that manufacturers retain an independent review board that includes several practicing physicians. The purpose of this board would be to evaluate device performance data, and offer unbiased opinions on whether device changes, press releases, or recalls are warranted.
This was not the only Guidant ICD to fail in recent years. As a result, the corporation was given probationary status in December 2005 , which was lifted on April 13, 2007. During that period, Guidant and its parent corporation Boston Scientific (which acquired Guidant for $28 billion in 2006) were prohibited from introducing any new pacemaker or ICD designs into the market. Only after extensive inspections of its manufacturing facilities and techniques by the FDA was the ban lifted. Today numerous law firms are pursuing action against the manufacturer on behalf of over 5,000 patients, claiming it intentionally withheld vital information.
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 E Spitzer. Summons, People of The State of New York vs. Guidant Corporation. 2 November 2005. Available http://www.oag.state.ny.us/press/2005/nov/complaint%20-%20stamped%20&%20signed.pdf
 RG Hauser, BJ Maron. Lessons From the Failure and Recall of an Implantalbe Cardioverter-Defibrillator. Circulation. 2005;112:2040-2042.
 American Heart Association. Implantable Cardioverter Defibrillator. Available http://www.americanheart.org/presenter.jhtml?identifier=11227
 A Gorsett. Urgent medical device safety information and corrective action: Ventak Prizm 2 DR, model 1861. 17 June 2005. Available http://www.guidant.com/physician_communications/PRIZM2_DR.pdf
 R Steinbrook. The Controversy over Guidant’s Implantable Defibrillators. The New England Journal of Medicine. 21 July 2005;353:221-224.
 RJ Myerburg, DW Feigal, BD Lindsay. Life-Threatening Malfunction of Implantable Cardiac Devices. The New England Journal of Medicine. 1 June 2006;354:2309-2311.
 Winstein, Keith J. “Rules Eased on Device Firm.” The Wall Street Journal 17 April 2007: D2.
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Last Updated: April 30, 2007