Abstracts

Rationale: VNS Therapy has demonstrated overall cost savings in patients with drug-resistant epilepsy (DRE), by decreasing clinical resource utilization and epilepsy-related clinical events, resulting in a net cost savings after 1.5 years. This project evaluated the clinical and cost-effectiveness of the AspireSR^® VNS (Vagus Nerve Stimulation) Therapy system compared with previous models using retrospective patient data. AspireSR includes an AutoStim feature which delivers stimulation associated with specified heart rate increases that may be associated with seizures. Methods: Retrospective data were evaluated from patients at the University of Nebraska Medical Center who had a previous generation VNS model replaced with AspireSR.  Data were collected starting 12 months prior to VNS replacement (using EPIC®) to AspireSR to 12 months after implantation date in 3-month blocks to give quarterly data. Number of seizure-related ER visits, Hospitalizations, ICU admissions, Epilepsy clinic visits, telephone encounters made by the Epilepsy case managers, and Epilepsy clinic nurses were identified. Seizure frequency before and after the VNS replacement with AspireSR  as well as medication changes were identified from review of clinic notes Results: A total of 41 patients (>12 years of age) who had a VNS device and had replacement with AspireSR were identified. There was no significant difference in costs for ER visits, Clinic visits and Hospital admissions. There was a significant reduction in telephone call costs (p=0.04) and seizure frequency (p=.0057) in the pre and post AspireSR implant period. There was a non-significant downward trend in clinic usage in the post- implant period. 41.9% patients showed a reduction in self-reported seizure frequency. Among responders, mean seizure reduction was 70.5 %. Conclusions: Analysis of the above data revealed there were no demonstrable total cost savings within a 12 month period following replacement with AspireSR, but there was a significant reduction in seizure frequency in 41.9 % of patients within our cohort. From a clinical standpoint, it appears that the additional AutoStim feature of the AspireSR model has additional clinical benefit to patients who had already been treated with standard VNS Therapy as shown by the statistically significant drop in the median seizure frequency. It seems likely that this decreased seizure burden will translate into cost savings over a longer time horizon, and that initial implantation costs will be recouped over time.There was a non-significant downward trend in clinic usage in the post- implant period. This indicates that the 12 month time horizon may be too short to indicate cost savings. However, overall costs post-implantation showed a consistent downward trajectory, with approximation to pre-implantation costs within the 12 month timeframe. It is also important to realize that VNS experienced patients may take somewhat longer to demonstrate comparable benefit, as they already receive one dimension of VNS therapy compared to VNS naïve individuals. Funding: This study was funded by LivaNova through an Investigator-Initiated Research Award.