Medtronic Sprint Fidelis Wire Leads Fracturing In Defibrillators May Have Caused Five Deaths

Events Leading Up To October 2007 FDA Recall Include A Little Noticed March 2007 "Dear Doctor" Letter And July 2007 Medical Journal Article About Model 6949

(Posted by Tom Lamb at DrugInjuryWatch.com)

An October 16, 2007 article in The Wall Street Journal about the Fidelis Sprint leads recall presented the current situation:

In announcing the recall early yesterday, Medtronic said that its Sprint Fidelis leads have broken at a rate apparently higher than that of competing leads, including another from Medtronic....

When the lead fractures, it can have serious consequences: Some patients can receive unnecessary and massive shocks, sometimes compared to the jolt of sticking a fork in a light socket. Other patients don't get the shock when they do need it to save their lives after cardiac arrest. Overall, five patients so far have died in cases Medtronic says may be related to the flaw.

So far, 2.3% of the implanted leads have malfunctioned over a 30-month period studied by Medtronic since the device's introduction in the fall of 2004. Most of these thousands of malfunctions are fractures.

While this fracturing or breaking problem with the Sprint Fidelis wire lead was the subject of a little noticed (and hard to find, now) March 2007 "Dear Doctor" letter from Medtronic, this emerging medical device safety issue only began to get some real public notice in July 2007.

First, Dr. Robert G. Hauser and some of his colleagues had a paper published in the July 2007 edition of Heart Rhythm about the Sprint Fidelis model 6949 having a higher than expected lead failure at their facility.  From the Abstract for this paper, "Early failure of a small-diameter high-voltage implantable cardioverter-defibrillator lead":

• OBJECTIVE: The aim of this study was to assess the performance of small-diameter Sprint Fidelis high-voltage ICD leads.
• RESULTS: The survival of 583 Sprint Fidelis 6949 leads implanted at our center between September 2004 and February 2007 was significantly less than 285 Sprint Quattro Secure model 6947 leads implanted by us between November 2001 and February 2007 (P = .005). Six patients presented with Sprint Fidelis lead failure 4-23 months after implant. Five of the six patients experienced multiple inappropriate shocks associated with pace-sense conductor and coil fractures; the sixth patient had a fixation mechanism failure. The [United States Food and Drug Administration Manufacturers and User Facility Device Experience (MAUDE) database] search rendered reports for 679 Sprint Fidelis leads. The most frequent complaints or observations were inappropriate shocks (33%), high impedance (33%), and fracture (35%). Of 125 leads analyzed by the manufacturer, 62 involved fracture of the pace-sense conductor or coil and the high-voltage (defibrillation) conductor.

Then, seemingly prompted by this medical journal article by Dr. Hauser, reporter Janet Moore of the Star-Tribune newspaper in Minnesota -- where Medtronic Inc. is headquartered -- picked up the Sprint Fidelis story in a July 30, 2007 article, "Medtronic device under scrutiny":

In late March [2007], Medtronic Inc. sent a letter to doctors advising them that the wire leads in a line of widely used heart defibrillators could tear at a "higher than expected" rate.

The "Dear Doctor" letter assured physicians that the performance of the Sprint Fidelis line of leads is consistent with similar products, and it offered suggestions about how to best implant it.

Four months later, several physicians in the Twin Cities have stopped using the leads, and Medtronic is investigating a patient's death in which a model of the Sprint Fidelis lead is "in question."

And it was Janet Moore at the Star-Tribune who apparently first reported on the Sprint Fidelis recall in her October 14, 2007 article, "Medtronic stops selling heart device":

Medtronic Inc. said today it has stopped selling a popular wire lead used with heart defibrillators because the lead may tear inside the body.

About 235,000 patients worldwide may be affected by the [Minnesota]-based company's action. Patients who believe they may have the device implanted in their chest should contact their doctor, but Medtronic does not recommend replacing it.

The Food and Drug Administration (FDA) said it has classified Medtronic's action as a recall, which means Medtronic must stop selling the devices.

For those interested in learning more about what is known at present about the problems associated with Sprint Fidelis leads, we provide these resources:

October 15, 2007 Statement from FDA

October 15, 2007 Consumer Q&As from FDA

October 15, 2007 "Dear Doctor" Letter from Medtronic

October 15, 2007 News Release from Medtronic

We will continue to monitor and report what is learned about the relatively high rate of breaks or fractures in Sprint Fidelis leads used with defibrillators -- even though it is a bit off-topic for us -- because of its importance and because it seems to be closely / coincidentally related to our October 15, 2007 post: "How Should Drug Companies And Their Ad Agencies Respond To Safety Signals?"

P.S.  Insofar that the March 2007 "Dear Doctor" letter reported the five deaths possibly related to faulty Sprint Fidelis leads one must wonder did the FDA wait to long to issue its October 2007 recall?  (10/18/07)

P.S.   Now U.S. Representative Henry Waxman wants to know what the FDA knew about the Sprint Fidelis defibrillator lead wire fractures and when they knew it.  On October 22, 2007, as Chairman of Committee on Oversight and Government Reform, this California Congressman sent a letter to FDA Commissioner Andrew von Eschenbach requesting the Medtronic information which the FDA had access to before its October 2007 Sprint Fidelis recall.  (10/23/07)