THE IMPACT OF AGE AND FRAILTY ON CARDIAC FUNCTION IN HEALTH AND DISEASE CONDITIONS IN NATURALLY AGEING MICE

Abstract

Frail people with cardiovascular disease experience worse outcomes and higher mortality than non-frail patients, but the links between frailty and myocardial function are unclear. Frailty was quantified as deficit accumulation in adult (≈8 mos) and aged (≈27 mos) C57BL/6 male mice using the mouse clinical Frailty Index (FI). Under basal conditions, left ventricular developed pressure plus +dP/dt and –dP/dt declined with age. Myocytes from aged mice had smaller contractions, Ca2+ transients and Ca2+ currents. Interestingly this age-dependent remodelling in the intact hearts and individual myocytes was graded by frailty. Aged hearts had better functional recovery than adult hearts following IR. Functional recovery was not correlated with frailty. These results show that age-dependent cardiac remodelling at the level of the intact heart and at the cellular and subcellular levels are graded by the overall health of the mouse and that there may be underlying mechanisms that protect against IR in ageing.