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During normal aging, the heart undergoes functional, morphological and cellular changes. Although aging per se does not lead to the expression of heart failure, it is likely that age-associated changes lower the threshold for the manifestation of signs and symptoms of heart failure. In patients, the susceptibility, age of onset and pace of progression of heart failure are highly variable. The presence of conventional risk factors cannot completely explain this variability. Accumulation of DNA damage and telomere attrition results in an increase in cellular senescence and apoptosis, resulting in a decrease in the number and function of cells, contributing to the overall tissue and organ dysfunction. Biological aging, characterized by reduced telomere length, provides an explanation for the highly interindividual variable threshold to express the clinical syndrome of heart failure at some stage during life. In this review, we will elaborate on the current knowledge of aging of the heart, telomere biology and its potential role in the development of heart failure.

A striking variability exists in the susceptibility, age of onset and pace of progression of cardiovascular diseases. This is inadequately explained by the presence or absence of conventional risk factors. Differences in biological aging might provide an additional component of the observed variability. Telomere length provides a potential marker of an individual's biological age, shorter telomeres reflect a more advanced biological age. Telomere length at birth is mainly determined by genetic factors. Telomere attrition occurs as a consequence of cellular replication and can be accelerated by harmful environmental factors such as oxidative stress. When telomeres reach a critical threshold the cell will enter senescence and becomes dysfunctional. Telomeres are remarkably shorter in patients with aging associated diseases, including coronary artery disease and chronic heart failure. In addition, numerous conventional cardiovascular risk factors are associated with shorter telomere length. If telomeres can be proven to be not only associated but also causally involved in the pathogenesis of cardiovascular disease it might provide exciting new avenues for the development of future preventive and therapeutic strategies.

Background: Renal dysfunction is a frequent comorbidity associated with high mortality in patients with chronic heart failure (CHF). The intrinsic biological age might affect the ability of the kidney to cope with the challenging environment caused by CHF. We explored the association between leukocyte telomere length, a marker for biological age, and renal function in patients with CHF., Methods and Results: Telomere length was determined by a real-time quantitative polymerase chain reaction in 866 CHF patients. Renal function was estimated with the simplified Modification of Diet in Renal Disease equation. The median age was 74 (interquartile range 64-79) years, 61% male, left ventricular ejection fraction of 30 (23-44)%, and the estimated glomerular filtration rate was 53 (40-68) ml/min/1.73 m(2). Telomere length was associated with renal function (correlation coefficient 0.123, P < 0.001). This relationship remained significant after adjustment for age, gender, age of CHF onset (standardized-beta 0.091, P = 0.007). Also additionally adjusting for the severity of CHF and baseline differences did not change our findings., Conclusion: The association between shorter leukocyte telomere length and reduced renal function in heart failure suggests that intrinsic biological aging affects the ability of the kidney to cope with the systemic changes evoked by heart failure.

The striking variability in the age of onset of and the manifestation/ absence of manifestation of cardiovascular diseases is inadequately explained by conventional risk factors, but may be explained by variation in biological age. Telomere length is possibly a reliable marker of biological age, shorter telomeres reflecting more advanced age. The initial telomere length ofa person is mainly determined by genetic factors. Moreover, the telomere length shortens with each cell division, and exposition to harmful environmental factors also results in shorter telomeres. Leukocytes of patients with atherosclerosis and heart failure display remarkably shorter telomeres compared to leukocytes of healthy subjects of similar age. Conventional cardiovascular risk factors are also associated with telomere length. If telomeres are indeed causally involved in the pathogenesis of cardiovascular disease, this might provide new avenues for future preventive and therapeutic strategies.