Real-World Performance of Intrinsic Antitachycardia Pacing: Primary Results from a Global Prospective Post Approval Registry Study

BACKGROUND: Antitachycardia pacing (ATP) can prevent defibrillator shocks and associated adverse outcomes. Opportunities to enhance ATP performance exist, particularly for rapid monomorphic ventricular tachycardia (MVT). Intrinsic ATP (iATP) is the first closed-loop algorithm that designs and auto-adjusts ATP therapy in real-time. OBJECTIVE: Evaluate iATP performance in a large, real-world cohort. METHODS: This global, prospective, observational study enrolled patients with an iATP-enabled ICD or CRT-D device. The primary objective, to demonstrate iATP could effectively terminate >60% of MVT episodes in the fast VT (FVT) zone, was analyzed using generalized estimating equations (GEE) method. Additional analyses included overall effectiveness and rate of MVT acceleration resulting in shock. A post-hoc analysis used GEE models to compare iATP data to standard ATP from a retrospective cohort. RESULTS: In total, 1875 enrolled patients were followed a total of 3200 patient-years yielding 2575 iATP-treated MVT episodes. Of 265 iATP-treated episodes in the FVT zone (73 patients), the GEE-estimated success rate was 89.7% (95% confidence interval (CI): 83.6-93.7%), exceeding the primary objective. The GEE-estimated rate of iATP-associated MVT acceleration resulting in shock was 2.3%. Compared to standard ATP, iATP almost doubled the odds of VT termination (adjusted odds ratio [aOR]= 1.87, 95% CI: 1.32-2.66; P=0.0005) and halved the odds of acceleration resulting in shock (aOR= 0.43, 95% CI: 0.25-0.74; P=0.0026). CONCLUSION: In routine practice, iATP was highly effective and safe across all VT rates. Although exploratory, iATP had overall superior termination rates and lower chance of acceleration resulting in shock compared to standard ATP.