The Heart Rhythm Society (HRS) began its 33rd annual scientific sessions in early May in Boston, offering a four-day event packed with presentations. Device failure and patient management took center stage in several sessions. Here are some highlights.
Riata leads worse off in terms of survival
A late-breaking trial showed that survival for Riata (St. Jude Medical), but not Riata ST leads was significantly lower than that of the Quattro Secure leads (Medtronic).
Researchers conducted a seven-center trial assessing 1,081 patients with an 8F Riata lead (774 patients, average follow-up of 4.2 years) or 7F Riata ST lead (307 patients, 3.3 years) between 2002 and 2010. No multicenter trial data exist that examine the incidence of Riata or Riata ST lead failure, said Raed Abdelhadi, MD, of the Minneapolis Heart Institute. "Without such data, it is impossible to design advanced paced management strategies for these patients or to advise these patients of the risk."
They reported that Riata leads saw significantly worse survival when compared with the Quattro Secure; however, Riata ST lead survival rates were not significantly different from Quattro Secure leads. Abdelhadi noted that the follow-up period of the Riata ST lead was shorter than that of the Riata lead. Very few Riata ST leads had a follow-up that was beyond four years.
Revising ICD leads during surgery may cut costs, risk
The Sprint Fidelis implantable cardioverter-defibrillator (ICD) lead was recalled in 2007 after a high fracture rate was found, but understanding how to best manage patients who are implanted with these leads remains controversial. Performing device removal during elective surgery for a generator change could prove cost-effective and reduce risk for these patients.
Jamil Bashir, MD, of the University of British Columbia in Vancouver, and colleagues used five-year data from two Canadian centers to analyze the costs of elective or urgent lead procedures based on whether the patient presented with lead dysfunction. During the time span, 346 Sprint Fidelis leads were placed in 342 patients. Researchers reported 47 fractures and nearly 80 patient operations.
Bashir et al found that elective procedures that revise the lead during a generator change are cheaper than those of a patient experiencing a lead fracture. In the study, 46 urgent procedures and 34 elective procedures were evaluated. The average costs for lead fracture cases were double that of an elective procedure to revise the lead, $32,869 vs. $15,212, respectively. The incremental cost-effectiveness ratio was reported to be $7,187 per failure avoided.
Bashir said that in this population, leads should be dealt with at the time of the generator change. "This solves two problems: it's cheaper and the patient isn't walking around with a recalled lead," he said.
Atrial overdrive pacing fails in AF prevention
Dynamic Atrial Overdrive (DAO) does not prevent new-onset atrial fibrillation (AF), is often not well tolerated and increases the risk of premature battery depletion, based on the results of ASSERT, a late-breaking clinical trial. Therefore, the study authors recommended that implantable devices no longer be developed with this software.
Researchers prospectively randomized 2,343 hypertensive patients at least 65 years of age, who were receiving a St. Jude Medical pacemaker or an ICD for standard indications. Three months following device implantation and study enrollment, patients receiving pacemakers were randomized to have the DAO (St. Jude) algorithm turned on or off.
The primary endpoint was the development of symptomatic or asymptomatic atrial tachyarrhythmia (AT)/AF more than six minutes documented by surface ECG or surface rhythm strip.
Hohnloser et al found that the primary endpoint occurred in 60 patients in the DAO "ON" group (annual incidence 1.96 percent) compared with 45 in the DAO "OFF" group (annual incidence 1.44 percent). Also, they reported no difference in the mean atrial tachyarrhythmia burden: 2.59 percent of the time in the DAO "ON" group and 1.97 percent in the DAO "OFF" group.
Over the course of the study, Hohnloser reported that the pacemaker generator had to be replaced for battery depletion in 4.4 percent of patients randomized to DAO "ON" as compared with 2.5 with of patients assigned to DAO "OFF."