Benefits in projected pacemaker longevity and in pacing related costs conferred by automatic threshold tracking

The aim of this study was to calculate the battery current drain of different VVI-VVIR pulse generators, with and without automatic adjustment of stimulation output, from the same manufacturer, and obtain projections on pacemaker longevity and pacing related costs. Twenty-five patients who had received a VVIR pacemaker (Microny SR+ 2425T) with Autocapture function, an algorithm able to provide automatic adaptation of device output coupled with continuously monitored capture threshold, were analyzed. Calculations of current drain and projections of device longevity were based on diagnostic data retrieved from device memory and on comparisons of multiple programmed settings of the same device (Microny SR+ 2425T with Autocapture, Low Output [output = 2 x Autocapture threshold, but not less than 2.4 V] versus Standard Output [5 V]). In addition, devices with Autocapture but with different battery capacities (0.35 Ah and 0.79 Ah, Microny and Regency, respectively) were compared to a standard device (battery capacity = 0.78 Ah) at 2.5-V and 5-V output settings. According to a series of assumptions, Autocapture increased device longevity by 53% (Microny) and by 245% (Regency) over a 15-year follow-up with a consequent reduction in pacing related costs of 25% (Microny) and of 57% (Regency) compared to the standard settings of a VVIR device from the same manufacturer. In conclusion, pacing with constant adaptation of generator output coupled with continuous monitoring of stimulation threshold has the potential to increase generator longevity and to reduce pacing related costs as compared to a standard device from the same manufacturer.