Conference Coverage
Longer ICD Detection Window Reduces Inappropriate Shocks
Major Finding: The incidence rate ratio of ICD therapy (antitachycardia pacing or shocks) was 37% lower among patients with implantable...
For patients receiving implantable cardioverter-defibrillators, programming the devices to have prolonged rather than standard-length arrhythmia detection intervals lowers the rate of antitachycardia pacing and shocks delivered, as well as the number of inappropriate shocks, according to the results of ADVANCE III, published in the May 8 issue of JAMA.
In a 2-year clinical trial conducted at 94 medical centers in Europe, the Middle East, Russia, and Africa, 1,902 patients who received single-, dual-, or triple-chamber ICDs for either primary or secondary prevention were randomly assigned to have the devices programmed to deliver therapies at standard detection intervals (954 subjects) or at prolonged detection interval (948 subjects). "The delay allowed nonsustained events to self-terminate, thus avoiding unnecessary therapies," without excessively delaying therapies if they were still needed, said Dr. Maurizio Gasparini of Humanitas Clinical and Research Center, Rozzano (Italy), and his associates in the ADVANCE III (Avoid Delivering Therapies for Nonsustained Arrhythmias in ICD Patients III) study. As this news organization reported, Dr. Gasparini first presented these results last May at the annual meeting of the Heart Rhythm Society in Boston.
During a median follow-up of 1 year, the long-detection–interval group had a significantly lower rate of therapies delivered and a significantly lower rate of inappropriate shocks delivered. They also had a significantly lower rate of hospitalizations (42 vs. 52/100 person-years). But these benefits did not come at the cost of more episodes of syncope, since those rates did not differ significantly between the two study groups (3.1 vs. 1.9/100 person-years, respectively), the investigators said (JAMA 2013;309:1903-11).
"At present, the ‘out of the box’ settings used by some ICD manufacturers may be too conservative, with nominal treatment delays as short as 1-3 seconds. On the basis of previous evidence and the current findings, it seems reasonable that a long-detection interval may be preferable in the majority of patients," they noted.
In an editorial accompanying this report, Dr. Merritt H. Raitt of Portland Veterans Administration Medical Center and Oregon Health and Science University said, "This trial is important in that it extends the study population to include patients with both primary and secondary indications for ICD implants as well as to those with single-chamber ICDs."
Moreover, the findings add "important new information to the evidence base of ICD programming," he said (JAMA 2013;309:1937-8).
"Regardless of whether these programming intervals lead to reduced mortality, the unequivocal reduction in ICD shocks and the reduction in hospitalization without an increase in adverse events such as syncope suggests that this programming approach should be considered for adoption in the care of patients with ICDs and clinical characteristics similar to those enrolled in these studies," Dr. Raitt said.
ADVANCE III was funded by Medtronic. Dr. Gasparini reported ties to Medtronic and Boston Scientific, and his associates reported ties to Medtronic, Sorin, Boston Scientific, St. Jude Medical, Boehringer-Ingelheim, Biotronik, and Biosense-Webster.