Additional antitachycardia pacing programming strategies further reduce unnecessary implantable cardioverter-defibrillator shocks

Background: Antitachycardia pacing (ATP) is routinely used to terminate ventricular tachyarrhythmias (VTs). However, little guidance exists on the most effective programming of ATP. Objective: This study evaluated whether additional ATP sequences are more effective in reducing implantable cardioverter-defibrillator shocks. Methods: In patients from the Shock-Less study, the number of overall shocks were compared between patients programmed to ≤3 ATP sequences (VT zone) and ≤1 ATP sequence (fast ventricular tachycardia [FVT] zone) (nominal group) and patients programmed to receive additional ATP sequences in VT (>3) or FVT (>1) zones. Results: Of the 4112 patients (15% receiving secondary prevention; 77% men; mean age 65.9 ± 12.6 years), 1532 patients (37%) were programmed with additional ATP sequences (1025 with >3 ATP sequences in the VT zone; 699 patients with >1 ATP sequence in the FVT zone). Over a mean follow-up period of 19.6 ± 10.7 months, 4359 VT/FVT episodes occurred in 591 patients. Compared with the nominal group, in patients with additional ATP programming, there was a 39% reduction in the number of shocked VT episodes (0.46 episodes per patient-year vs 0.28 episodes per patient-year; incidence rate ratio [IRR] 0.61; P < .001) and a 44% reduction in the number of shocked FVT episodes (0.83 episodes per patient-year vs 0.47 episodes per patient-year; IRR 0.56; P < .001). The reduction in shocked VT episodes was observed in both primary (IRR 0.68; 95% confidence interval 0.51–0.90; P = .007) and secondary (IRR 0.51; 95% confidence interval 0.35–0.72; P < .001) prevention patients. Conclusion: Programming more than the nominal number of ATP sequences in both the VT and FVT zones is associated with a lower occurrence of implantable cardioverter-defibrillator shocks in clinical practice.