Additional Antitachycardia Pacing Programming Strategies Further Reduce Unnecessary Implantable Cardioverter Defibrillator Shocks.

Abstract

BACKGROUND\nAntitachycardia pacing (ATP) is routinely used to terminate ventricular tachyarrhythmias. However, little guidance exists on the most effective programming of ATP.\n\n\nOBJECTIVE\nThis study evaluated whether additional ATP sequences are more effective in reducing ICD shocks.\n\n\nMETHODS\nIn patients from the Shock-Less trial, the number of overall shocks were compared between patients programmed to ≤3 ATP sequences (VT zone) and ≤1 ATP (FVT zone) (nominal group), and patients programmed to receive additional ATP sequences for VT (>3) or FVT (>1) zones.\n\n\nRESULTS\nAmong 4112 patients (15% secondary prevention, 77% male, mean age 65.9 ± 12.6 years), 1532 (37%) patients were programmed with additional ATP sequences (1025 with >3 ATP sequences in VT zone; 699 patients with >1 ATP sequences in FVT zone). Over a mean follow-up of 19.6 ± 10.7 months, 4359 VT/FVT episodes occurred in 591 patients. Compared with the nominal group, in patients with additional ATP, there was a 39% reduction in the number of shocked VT episodes (0.46 vs. 0.28 per patient-year; incidence rate ratio [IRR], 0.61; p<0.001), and a 44% reduction in the number of shocked FVT episodes (0.83 vs. 0.47 per patient-years; IRR, 0.56; p<0.001). The reduction in shocked VT episodes was observed in both primary (IRR, 0.68; 95% CI, 0.51-0.90; p=0.007) and secondary prevention patients (IRR, 0.51; 95% CI, 0.35-0.72; p<0.001).\n\n\nCONCLUSION\nProgramming more than the nominal number of ATP sequences in both the VT and FVT zones is associated with a lower occurrence of ICD shocks in clinical practice.