Changing ICD generator elevates risk factor for Sprint Fidelis lead failuresJun 18, 2012 | Parker Waichman LLP
Patients relying on an implantable cardiac defibrillator (ICD) are more likely to experience malfunctions and failures with the Sprint Fidelis leads connecting it to the heart if they change the device's generator.
According to a report at TheHeart.org, new research from Emory University identified changing the generator on an ICD device while keeping the Sprint Fidelis leads would likely lead to a device failure. The Sprint Fidelis lead was recalled in 2007 following scores of reports of its failing heart patients. Thousands still rely on the leads attached to their ICD device to deliver life-saving shocks to their heart to keep it beating and regulate its rhythm. Some estimates suggest as many as 150,000 people still use the Medtronic Inc. device.
The device fails when it fractures, either delivering an unneccesary and powerful shock to a person not in need of one or failing to deliver a timely shock when necessary.
Since it was recalled, surgeons, cardiologists, regulators, and most importantly, patients, have wondered what is the best course of action for people still using Sprint Fidelis leads after they were recalled. A replacement surgery is risky and costly so research has been focused on identifying the risk factors that cause failures of the Sprint Fidelis. A surgery to replace a device and leads puts a patient at risk of suffering tears of their blood vessels, tissue, and heart. It is an invasive procedure and many patients worrying about the safety of the Sprint Fidelis leads have been told to avoid surgery until the device actually fails.
Despite using a relatively small study group, researchers at Emory, led by Dr. Joshua D. Lovelock, identified a failure rate with Sprint Fidelis leads of 20.8 percent when that patient had undergone a procedure to swap generators on their defibrillators but kept the Sprint Fidelis leads that connected to it. The failure rate on the leads was just 2.5 percent for patients who hadn't undergone a change of their generators. At least 60 percent of the failures occurred within three months of a procedure to change the generator.
"It is possible that manipulation of the proximal portion of the lead during the replacement can precipitate fracture of the conductor," Lovelock wrote in the study, cited by the report.
A study published earlier this year in Canada suggested that Sprint Fidelis leads be replaced in the same operation as one to replace the generator. Researchers for that study cited the age of the Sprint Fidelis lead and its increased likelihood to malfunction or break free of its insulated coating on the conductive end over time. Other studies on the overall failure rate of Sprint Fidelis leads found that it malfunctions in about 3.75 percent of patients annually, compared to one-half percent among other models.