Association Between Aortic Stiffness and Exercise Tolerance in Patients at the Risk Stage of Heart Failure

Background: The number of patients with heart failure (HF) has increased, and it is crucial to prevent the development of HF in patients at risk of HF. The present study aimed to risk stratify patients in Stage A and B HF based on associations between exercise -induced changes in aortic stiffness and exercise tolerance. Methods and Results: Patients in Stage A and B HF who performed a cardiopulmonary exercise test were enrolled in the study (n=106; median age 65.0 years [interquartile range 52.8-73.0 years]). Exercise tolerance was examined by the percentage of pre-dicted peak oxygen consumption (%(V) over dot (O2peak)). The ascending aortic pressure waveform was estimated non-invasively. Aortic stiff-ness was assessed using the augmentation index (AIx) and reflection magnitude (RM). Multivariable regression analysis showed that AIx measured both before and after exercise was significantly associated with %(V) over dot(O2peak) (0=-0.221 [P=0.049] and 0=-0.342 [P=0.003], respectively). When participants were divided into %(V) over dot(O2peak) subgroups using a cut-off value of 60%, RM decreased immediately after exercise and remained lower 5 min after exercise in the group with preserved exercise tolerance, but recovered to baseline levels 5 min after exercise in the group with reduced exercise tolerance. Conclusions: Exercise-induced increases in aortic stiffness were associated with exercise tolerance in patients at risk of HF, sug-gesting that exercise-induced changes in aortic stiffness may be useful to stratify high-risk patients.