The Impact of Age and Frailty on the Fischer-344 Rat Heart

Abstract

The purpose of this study was to develop a frailty index (FI) for rats, and characterize the impact of age and frailty on cardiac parameters at baseline and following cardioplegic arrest. Data on survival and 45 variables in health systems known to change with age were serially collected in a longitudinal study of male F344 rats to develop a 30-item FI. Frailty increased with age and was associated with an increase in mortality. Cardiac function was assessed in vivo, and in the isolated working heart. We also developed a novel method to assess diastolic function in the isolated working heart. Aged and frail hearts were more arrhythmic at baseline, however neither age nor frailty were associated with statistically significant changes in cardiac structure or function in vivo or in the isolated working heart. Functional recovery after arrest with del Nido cardioplegia was similar when compared by age and frailty.