Real World Performance of an Individualized Antitachycardia Pacing Algorithm.

Background: A novel individualized antitachycardia pacing (IATP) algorithm using the post-pacing interval for real-time control has been introduced. Performance information is limited to a small safety and feasibility study with additional single-center and case studies. A larger-scale analysis is needed to better understand algorithm performance.

Methods: Deidentified remote monitoring transmissions from devices with the IATP therapy applied were randomly selected. Rhythms were classified and effects of the novel algorithm were assessed. For monomorphic ventricular tachycardias (MVTs) proportions of successful therapy, shock-free episodes, and acceleration were calculated using generalized estimating equations to correct for multiple episodes and compute statistics of the algorithm's performance.

Results: There were 2259 MVT episodes in 336 patients. IATP succeeded in 87.1% of MVT episodes with 89.9% of MVT episodes ultimately free of shock therapy. Based on multivariate analysis, significant factors in therapy success were programming of at least the recommended number of sequences (90% at least recommended vs 73%, p = 0.00088) and female sex (95% for females vs 86%, p = 0.002). A trend to higher success was found for MVT with a cycle length of 320 ms or greater (90% vs. 83%, p = 0.10). The IATP accelerated 3.6% of MVT episodes. None of the available factors was significantly associated with acceleration in the multivariate analysis.

Conclusions: The IATP algorithm succeeded in a large proportion of MVT episodes and with low acceleration in patients randomly selected from remote monitoring transmissions. Using at least the recommended number of sequences had the strongest association with successful therapy.