A hallmark of ageing is the diminished ability to recover from stress. Cardiac surgery imposes a major oxidative stress on the heart that is predictable in magnitude and timing. Although many elderly patients respond well to this stress, others of the same chronological age do not. Our aims were: 1. To identify molecular markers of biological age that would predict the response to surgical stress. 2. To devise therapeutic strategies to improve the post-surgical response of the heart.
Pectinate trabeculae from 52 patients were analysed for the abundance of multiple mitochondrial (mt)DNA mutations and for mtDNA copy number, these measures were then correlated with contractile force recovery in the same sample after simulated ischaemia in vitro. Univariate analysis showed: 1. A low abundance (0.008%) of the "common" mtDNA4977 deletion in trabeculae; 2. A negative correlation of post-ischaemic recovery with abundance of mtDNA4977 (r2 = 0.068 P
To test whether surgical oxidative stress can be minimised we are currently trialing holistic preconditioning therapy for elderly patients to prepare the cardiovascular system to optimally recover from surgery using metabolic (antioxidants), physical (exercise training) and mental (relaxation/stress management) strategies.