Download Analysis of time to first shock VF episodes in relation to

Analysis of time to first shock VF episodes in relation to detection settings in
ICD and CRT-D devices First results of the CareLink Analytics Device
Database
Stefan Winter1, D.Q. Nguyen1, C. Oehler1, R.Freeden2, W. Fehske1 1 St. Vinzenz-Hospital, Cologne,
Germany 2 Medtronic Germany GmbH, Meerbusch, Germany
INTRODUCTION:
Doubtlessly the inappropriate ICD-Therapy remains the main adverse effect of ICD-therapy, associated
with an increased risk of death or worsening of heart failure. Recently published literature suggests that
patients significantly benefit from prolonged NID settings in terms of reduced amount of ICD-shocks.
In our real-life patient cohort NID 30/40 has already been programmed in one part of the patients.
Patients treated earlier have devices with shorter detection intervals. Remote Monitoring resulted in a
data base which allows determination of the time to first shock depending on the programmed detection
interval.
METHODOLOGY: For this analysis follow-up data of 461 Medtronic ICD and CRT-D were by
CareLink® Analytics, a SQL database collecting follow-up data over a period of 2 years, including
programmed parameters, EGMs, episode- and trend-data.In this investigation the time-to-first shock of
VF episodes is analyzed according to programmed settings. An analysis of shock-free-survival for a 2
years observational period was performed using Kaplan Meier analysis and Long-rank test.
RESULTS: A total number of 2769 follow-ups from 461 Medtronic ICD and CRT-D devices between
December 2011 and October 2013 was analyzed, in total 509 device-years. 41 1-chamber ICD (9%),
213 2-chamber ICD (46%), and 207 3-chamber CRT-D (45%) devices were included. The patient
cohort was split into two groups: Group 1 consists with an NID setting of 30of40 (205 devices, 219
device-years); group2 all other NID settings (12of16, 28of24, 24of32) with in total 256 devices and 327
device years. In total, 49 first shocks for VF were counted in both groups, 11 in group 1 and 38 in
group 2. In this follow-up period devices in group 1 showed 0,06 (first) shock per device-year while
group2 resulted in 0,12 (first) shock per device year. The statistical analysis of the data showed that the
difference of the two groups is significant with a p-value of 3% in a long rank test, HR = 1,93.
CONCLUSION: Devices with NID settings of 30of40 showed a significantly longer time to first shock
compared to group2 with prolonged NID settings. The calculated hazard ratio defined as the average
difference in first shock rate in a follow-up period of 2 years is 1.93. The outcome of the Advance
III-trial is confirmed by this analysis of a real life population . Furthermore, the used data base provides
the opportunity to easily identify patients with short NID so that therapy improvement by
re-programming can be performed as the next step.