Abstract 3556: Changes in Arrhythmia Occurrence and Antitachycardia Pacing Efficacy During Cardiac Resynchronization Therapy: Results of the Advance CRT-D Substudy
Background: The ADVANCE CRT-D trial investigated the efficacy and safety of antitachycardia pacing (ATP) delivered from right and left ventricle (BIV) simultaneously vs. conventional right ventricular (RV) ATP in a prospective randomised controlled trial of patients receiving and CRT-D. The aim of this substudy was to assess time dependent changes in arrhythmia occurrence and ATP efficacy during CRT in the whole study cohort.
Methods: We enrolled 526 pts (follow-up (FU) 12 months) with the same detection window programming (320≥FVT≥240ms, 420 ≥VT≥320 ms cycle length (CL)). We analyzed baseline LVEF, detected episodes of ventricular tachycardia (VTA), and the efficacy of ATP (GEE adjusted), considering four three-months periods (Q1–Q4) past implantation of the device.
Results: In the overall population, 107 pts experienced 550 VTA. The number of VTA decreased during FU (202 in Q1 and 106 in Q4) with a stable median CL for VT and FVT, while the EF increased from Q1 to Q4 (p<0.0001), ATP efficacy remained considerable (Table⇓, p=0.505). Moreover, no correlation of ATP success and the change in EF during FU could be detected. A significant reversal towards the occurrence of VT was demonstrated (p=0.022).
Conclusions: ATP to stop VTA in pts with CRT is highly effective during cardiac reverse remodeling. A significant decrease of VTA could be demonstrated after one year without losing efficacy of ATP. The significant decrease of the amount of VT might be caused by CRT induced myocardial changes. Due to the results of this prospective trial, no adaptations in the ATP setting to terminate life threatening FVT are necessary in pts with CRT-D devices in the first year after device implantation.