HRJ: ICDs lack longevity, regardless of manufacturer
While implantable cardioverter-defibrillators (ICDs) have been known to reduce mortality rates in patients, an analysis of four manufactured devices published in the December edition of the Heart Rhythm Journal found that upgrades to these devices are needed in order to further improve patient care.
Principal investigator Beat Andreas Schaer, MD, of the department of cardiology at the University of Basel Hospital in Basel, Switzerland, and colleagues measured ICD device characteristics—manufacturer, pacing percentage and mode, capacitor reformation interval and size—and their impact on device longevity.
Researchers studied the aforementioned characteristics in 644 ICD devices implanted in 499 patients. Of those 499 patients, 86 percent were male and 63 percent had coronary artery disease. Patients were implanted with ICD devices from four different manufacturers: Medtronic (317), Guidant (now Boston Scientific) (189), St. Jude Medical (118) and Intermedics (20).
According to researchers, only eight previous studies have completed research that analyzed the effectiveness and longevity of ICD devices still in service, while most other studies analyzed only devices that have been replaced. "[D]isregarding information on devices that still are in service might lead to biased estimates of true device longevity, particularly because long lasting devices are disregarded,” the authors wrote.
While the researchers noted that today these ICD devices are being used as “standard treatment for primary and secondary prevention of sudden cardiac death in selected patients,” they still caution that the use of ICD therapy sometimes results in complications.
The investigators found, after a mean follow-up period of 3.2 years, that 139 devices had been replaced. Most of these ICD devices had a short life, which led to the increased need for device reimplementation, leading, in turn, to significantly increased rates of infection.
As Schaer and colleagues found on average the Medronic ICD devices lasted significantly longer than the Guidant and St. Jude devices, 7.6, 5 and 3.8 years, respectively. The authors also found that the elective replacement indicator (ERI), which when triggered advises a device replacement, was three to six times more likely in the Guidant and St. Jude devices compared to the Medtronic.
Researchers also compared older St. Jude ICD devices—Photon and Profile—to newer Atlas devices. They found survival rates in patients implemented with the Atlas device fared better than those implemented with the older devices after four years of patient follow up, 64 versus 33 percent, respectively.
The authors discovered that while parameters such as pace mode, pacing percentage, capacitor reform interval and time of implant had an influence on device longevity; device size did not.
They found that 70 percent of the implemented ICD devices were still in service after five years, and 62 percent after six years.
According to the authors, data from previous studies that examined ICD endurance showed that device longevity has increased from a mean of 19 months in 1980 to 48 months today.
In addition, while authors said these devices are known for being cost effective, these “calculations are based on ICD lifespan of seven years, a goal that is hardly achieved in daily practice.”
Based on their findings, researchers concluded, “ICD longevity is not quite satisfactory, as even the best longevity barely reaches a median of 7.5 years. Industry-projected longevity is an overestimation and does not accurately reflect real world longevity.”
The authors noted that industry manufacturers should focus on progressing the battery performance of these devices, something in which they said could increase device longevity by 10 years or more.
Principal investigator Beat Andreas Schaer, MD, of the department of cardiology at the University of Basel Hospital in Basel, Switzerland, and colleagues measured ICD device characteristics—manufacturer, pacing percentage and mode, capacitor reformation interval and size—and their impact on device longevity.
Researchers studied the aforementioned characteristics in 644 ICD devices implanted in 499 patients. Of those 499 patients, 86 percent were male and 63 percent had coronary artery disease. Patients were implanted with ICD devices from four different manufacturers: Medtronic (317), Guidant (now Boston Scientific) (189), St. Jude Medical (118) and Intermedics (20).
According to researchers, only eight previous studies have completed research that analyzed the effectiveness and longevity of ICD devices still in service, while most other studies analyzed only devices that have been replaced. "[D]isregarding information on devices that still are in service might lead to biased estimates of true device longevity, particularly because long lasting devices are disregarded,” the authors wrote.
While the researchers noted that today these ICD devices are being used as “standard treatment for primary and secondary prevention of sudden cardiac death in selected patients,” they still caution that the use of ICD therapy sometimes results in complications.
The investigators found, after a mean follow-up period of 3.2 years, that 139 devices had been replaced. Most of these ICD devices had a short life, which led to the increased need for device reimplementation, leading, in turn, to significantly increased rates of infection.
As Schaer and colleagues found on average the Medronic ICD devices lasted significantly longer than the Guidant and St. Jude devices, 7.6, 5 and 3.8 years, respectively. The authors also found that the elective replacement indicator (ERI), which when triggered advises a device replacement, was three to six times more likely in the Guidant and St. Jude devices compared to the Medtronic.
Researchers also compared older St. Jude ICD devices—Photon and Profile—to newer Atlas devices. They found survival rates in patients implemented with the Atlas device fared better than those implemented with the older devices after four years of patient follow up, 64 versus 33 percent, respectively.
The authors discovered that while parameters such as pace mode, pacing percentage, capacitor reform interval and time of implant had an influence on device longevity; device size did not.
They found that 70 percent of the implemented ICD devices were still in service after five years, and 62 percent after six years.
According to the authors, data from previous studies that examined ICD endurance showed that device longevity has increased from a mean of 19 months in 1980 to 48 months today.
In addition, while authors said these devices are known for being cost effective, these “calculations are based on ICD lifespan of seven years, a goal that is hardly achieved in daily practice.”
Based on their findings, researchers concluded, “ICD longevity is not quite satisfactory, as even the best longevity barely reaches a median of 7.5 years. Industry-projected longevity is an overestimation and does not accurately reflect real world longevity.”
The authors noted that industry manufacturers should focus on progressing the battery performance of these devices, something in which they said could increase device longevity by 10 years or more.