Introduction: Lifelong caloric restriction (CR) results in life extension and delays age-associated changes in many organs. Moderate caloric restriction improves cardiac function in young Dahl SS rats. However, it is unknown whether CR started at senescence can still improve cardiac function.

Methods: Left ventricular (LV) samples were obtained from young (10 months) and senescent (30 months) rats after 6 months of CR (-40 %) or control-diet. LV function, mitochondrial function and the expression of apoptotic markers were measured.

Results: In control-fed senescent rats, LV function and mitochondrial function are depressed and expression of proapoptotic genes or procaspase activation are enhanced compared to young control animals.CR results in a significant improvement in LV function and survival in senescent rats. This improvement in LV function is associated with a significant reduction in serum BNP and a decrease in proapoptotic activation of the myocardium. LV and mitochondrial function are not modified in young animals under CR.

Conclusion: Basic cardioprotective mechanisms of CR are preserved in senescent hearts and their activation results in an improvement of survival and LV function. Therefore, drugs activating these mechanisms may also yield a promising strategy to improve cardiac function in older patients.