Cardiac cycle-dependent changes in aortic area and distensibility are reduced in older patients with isolated diastolic heart failure and correlate with exercise intolerance

OBJECTIVES The goal of this study was to determine if cardiac cycle-depende nt changes in proximal thoracic aortic area and distensibility are associat ed with exercise intolerance in elderly patients with diastolic heart failu re (DHF). BACKGROUND Aortic compliance declines substantially with age. We hypothesiz ed that a reduction in cardiac cycle-dependent changes in thoracic aortic a rea and distensibility (above that which occurs with aging) could be associ ated with the exercise intolerance that is prominent in elderly diastolic h eart failure patients. METHODS Thirty subjects (20 healthy individuals [10 < 30 years of age and 1 0 > 60 years of age] and 10 individuals > the age of 60 years with DHF) und erwent a magnetic resonance imaging (MRI) study of the heart and proximal t horacic aorta followed within 48 h by maximal exercise ergometry with expir ed gas analysis. RESULTS The patients with DHF had higher resting brachial pulse and systoli c blood pressure, left ventricular mass, aortic wall thickness and mean aor tic flow velocity, and, compared with healthy older subjects, they had a si gnificant reduction in MRI-assessed cardiac cycle-dependent change in aorti c area and distensibility (p < 0.0001) that correlated with diminished peak exercise oxygen consumption (r = 0.79). After controlling for age and gend er in a multivariate analysis, thoracic aortic distensibility was a signifi cant predictor of peak exercise oxygen consumption (p < 0.04). CONCLUSIONS Older patients with isolated DHF have reduced cardiac cycle-dep endent changes in proximal thoracic aortic area and distensibility (beyond that which occurs with normal aging), and this correlates with and may cont ribute to their severe exercise intolerance. (C) 2001 by the American Colle ge of Cardiology.