Etiology and Programming Effects on Shock Efficacy in ICD Recipients

Clinical impact of applying strategic programming in patients with implantable cardioverter-defibrillators beyond reducing inappropriate shocks

Background

The incidence of inappropriate shocks remains high at 30% in patients with implantable cardioverter-defibrillators (ICDs). This retrospective study sought to examine the efficacy of strategic programming (ICD programming with a long detection interval and high-rate cutoff) in reducing electrical storm, inappropriate shocks, and unexpected hospital visits in patients with ICDs with/without cardiac resynchronization therapy with defibrillator (CRT-Ds).

Methods

This was a single tertiary center retrospective study, evaluating the clinical outcomes, especially regarding inappropriate therapies in patients with ICDs or CRT-Ds. Enrolled patients underwent ICD or CRT-D implantations from January 2008 to May 2016. Clinical information was attained by a thorough chart review.

Results

We analyzed 155 defibrillator patients from January 2008 to May 2016 (124 patients had ICDs and 31 had CRT-Ds). Since we adopted this strategic programming as a default programming from 2015 implanted ICDs and CRT-Ds, we divided the patients into two groups: devices implanted before 2015 (group A, n = 94) versus implanted after 2015 (group B, n = 61). During a median of 1289 days of follow-up, electrical storms occurred in three patients (eight events) in group B versus 11 (28 events) in group A (P = 0.18); appropriate therapies were delivered in 27 patients (56 events) in group A versus 7 (15 events) in group B (P = 0.72); inappropriate therapies were delivered in 15 patients (21 events) in group A versus 1 with 1 episode in group B (P = 0.03); and 5 unexpected hospitalizations occurred in four patients in group B versus 36 in 24 patients in group A (P = 0.02).

Conclusion

The clinical application of strategic programming reduced inappropriate shocks and unexpected hospitalizations in ICD and CRT-D patients.