CLS ALGORITHM IS ASSOCIATED WITH SIGNIFICANT COGNITIVE IMPROVEMENTS IN A SMALL SAMPLE OF ELDERLY PATIENTS

Introduction: CLS (Closed Loop Stimulation)algorithm showed to provide a rate-adaptive stimulation in response to haemodynamic demand due to emotional upheaval in chronotropically incompetent patients. We hypothesized that the hemodynamic benefits supplied by CLS algorithm may extend to neuro-cognitive functioning through enhanced cerebral blood perfusion. Methods: In order to test this hypothesis, we conducted a small-scale three-arm randomized controlled clinical trial involving 45 implanted patients randomly assigned to three pacing configurations: CLS (n = 15), Accelerometer Sensor (AS) mode (n = 15) and non rateadaptive mode (n = 15). A pool of ten neuropsychological tests tapping main neuro-cognitive domains (memory, attention, language, visuospatial skills and executive function) was administered to each participant before randomization and one year after. Mean change scores in cognitive measures were compared among the three pacing configurations at 1-year follow-up. Results: Statistically significant differences in change scores were found on attention and executive functioning measures. On average, patients in CLS configuration showed significant improvements on such measures, while patients in AS and non rate-adaptive modes showed non-significant deterioration trends. No statistically significant difference was found in change scores for the other neuro-cognitive parameters. Conclusion: CLS algorithm showed to be effective in improving attention and executive functioning in a small sample of chronotropically incompetent patients one year after pacing configuration. Large-scale trials are needed to corroborate such preliminary and novel results.