The age structure of the U.S. population is expected to change with the segment of the population aged over 65 years experiencing the largest increase in size. Given the expected change in the U.S. population, efforts aimed at screening and diagnosis, in addition to the prevention and treatment of diseases with a significant burden in older adults should be at the forefront of public health efforts. Accordingly, in order to obtain an appreciation of the significance of cardiovascular diseases in older adults we initially performed a literature review of the burden and prevention of cardiovascular diseases, the leading cause of morbidity and mortality in older adults. Subsequently, we focused our research efforts on cardiorespiratory fitness in older adults. Cardiorespiratory fitness is a determinant of morbidity and mortality in middle-aged and older adults which can be measured objectively by either exercise testing or walk-based tests. Few studies of community-dwelling older adults have characterized the relationship between fitness as assessed by exercise testing versus walk-based testing, with subclinical cardiovascular, or the prognostic significance of walk-based test performance. We sought to characterize these relationships among community-dwelling adults participating in the Cardiovascular Health Study (CHS). In an analysis of the Arterial Calcification in the Elderly (ACE-CHS), 6 Minute Walk test (6 MWT) performance was a useful measure of treadmill test capability and performance. A second analysis of ACE-CHS failed to identify subclinical cardiovascular disease as quantified by the coronary artery calcification score as a significant determinant of exercise duration in exercise treadmill testing. However, the coronary artery calcification score was associated with ischemia as detected by electrocardiographic changes during exercise testing. Finally, in the full CHS cohort, the 6 MWT performance was independently associated with all-cause mortality, demonstrating a prognostic value for submaximal fitness assessment using the 6 MWT across a wide range of function present in community-dwelling older adults. The public health relevance of these finding is the potential clinical utility of the 6 MWT, a quick, safe and inexpensive alternative to exercise treadmill testing, in the assessment of cardiorespiratory fitness and the prediction of mortality in community-dwelling older adults
