Long-Detection Programming in Single-Chamber Implantable Cardioverter Defibrillators Reduces Shocks and Pacing

Patients with single-chamber implantable cardioverter defibrillators (ICDs) benefitted from long-detection programming, according to a study subanalysis published in JACC: Clinical Electrophysiology.¹

Previously, the results of the ADVANCE III trial (Effect of Long-Detection vs Standard-Detection Interval for Implantable Cardioverter-Defibrillators on Antitachycardia Pacing and Shock Delivery; ClinicalTrials.gov identifier: NCT00617175) demonstrated that extending the duration of monitoring prior to therapy initiation reduced ICD therapies by 37% compared with conventional programming in patients with single-chamber ICDs, dual-chamber ICDs, and cardiac resynchronization therapy ICDs.²

In the current subanalysis, the researchers sought to evaluate this programming technique only in patients with single-chamber ICDs.

Of the ADVANCE III study cohort, 545 patients received single-chamber ICDs; 267 patients were randomly assigned to long-detection and 278 to a control group. Patients were followed for a median of 12 months. In the long-detection group, a total of 112 therapies (shocks and antitachycardia pacing) were used compared with 257 therapies in the control group.

Overall shocks were reduced by 40% in the long-detection arm (48 vs 24; 95% CI, 0.38-0.94; P =.026), and appropriate shocks by 51% (34 vs 74; 95% CI, 0.26-0.94; P =.033). In addition, patients in the long-detection group had a 27% probability of being hospitalized for any cause at 1 year compared with 36% in the control group (P =.04).

Although syncope was rare in both groups, long-detection improved survival rates. During follow-up, 8 patients in the long-detection group died vs 20 patients in the control group, which the researchers determined meant intervention was associated with a 59% reduction in mortality (hazard ratio 0.41; 95% CI, 0.17-0.99; P =.047).

Larger randomized trials with patients who have single-chamber ICDs are necessary to confirm the relationship between long-detection programming and mortality in this population, the researchers concluded.

References

1. Gasparini M, Lunati MG, Proclemer A, et al. Long detection programming in single chamber defibrillators reduces unnecessary therapies and mortality: the ADVANCE III trial [published online May 11, 2017]. JACC Clin Electrophisolol. doi:10.1016/j.jacep.2017.05.001
2. Gasparini M, Proclemer A, Klersy C, et al. Effect of long-detection vs standard-detection interval for implantable cardioverter-defibrillators on antitachycardia pacing and shock delivery — the ADVANCE III randomized clinical trial. JAMA. 2013;309:1903-1911.