Advertisement

CI-524-01 THE IMPACT OF SMART PASS ALGORITHM STATUS ON INAPPROPRIATE SHOCK RATES IN THE UNTOUCHED STUDY

      Background

      The current Subcutaneous ICD (S-ICD) incorporates SMART Pass (SP) to improve sensing and discrimination capabilities to reduce inappropriate shocks (IAS). SP status is programmable but may be disabled automatically based on electrogram (EGM) characteristics.

      Objective

      To evaluate SP status’ impact on IAS, appropriate shocks (AS), complications and mortality in the UNTOUCHED S-ICD trial.

      Methods

      Primary prevention patients (pts, n=1111) with ejection fraction ≤35% and no pacing requirement were followed for up to 18 months. SP status during a study visit was programmed ON or OFF and status between visits was either consistently OFF, ON, or automatically disabled (DIS). The impact of SP status on pt outcomes was evaluated using Kaplan-Meier (K-M) analysis. Multivariable proportional hazard analysis identified IAS predictors.

      Results

      Percent of pts with SP always ON, always OFF, ON with DIS, and OFF then ON with no DIS were 56, 16, 15, and 13%, respectively. High blood pressure (81.3%, p=.009) and kidney disease (17.0%, p=.059) were highest in pts with SP always OFF. Reasons for SP DIS included PVCs and low EGM amplitudes. K-M IAS rates differed significantly with SP status: pts post DIS had highest IAS rates (fig); SP ON vs OFF was a significant predictor of fewer IAS. While neither AS (p=0.58) nor complication (p=0.58) rates changed significantly, mortality differed significantly between pts with SP always ON, always OFF, ON with DIS, and OFF then ON with no DIS (4.8, 9.1, 3.1, and 3.7%, respectively; p=0.044).