Exercise Capacity and Hospitalization Rates in Veterans

Background Cardiorespiratory fitness, or exercise capacity, has been shown in multiple retrospective studies to be inversely correlated with cardiovascular and all-cause mortality, even after adjustment for potentially confounding cardiovascular risk factors. Given the correlation of poor cardiovascular fitness with poorer medical outcomes (including mortality), it is likely that poor exercise tolerance is associated with a higher incidence of medical hospitalizations. In addition, lower exercise tolerance has also been associated with higher perioperative complication rates and prolonged length of stay after major elective surgery. This study evaluates fitness levels of veterans that underwent elective stress testing and assessed whether the highest fitness levels correlated with the lowest hospitalization rates and least severe illnesses in both cardiovascular and non-cardiovascular diagnoses. Factors such as length of hospital and ICU stay and inpatient mortality were used to assess this potential correlation. Methods This study is a retrospective chart review of all Veterans admitted to the general acute medicine, medicine telemetry, PCU or MICU services that underwent a symptom-limited exercise tolerance test at the Washington DC VAMC between January 1, 2000 and January 1, 2010, within a pre-existing database. Patients with an implanted pacemaker, those who failed to achieve at least 80% of predicted maximum heart rate and those who were unstable, developed a left bundle branch block or required emergent intervention during the stress test were excluded. Differences will be evaluated using a Pearson’s chi-square test and a one-way ANOVA. Results The results of this study are pending. Potential Implications Physicians generally understand that regular exercise and cardiorespiratory fitness help protect against cardiovascular diseases, but a correlation between higher fitness and fewer hospitalizations for non-cardiovascular diseases would be an interesting new finding, and one which might help guide physicians’ clinical decisions (placing more emphasis on exercise even in veterans without cardiovascular risk factors) as well as guide future research at the DC VAMC