Abstract 1887: Effect of Exercise Training on Ventricular compliance in Patients with Congestive Heart Failure and Preserved Systolic Function
Background: Congestive heart failure (CHF) is the leading cause of hospitalizations in the elderly. Up to half of these patients have a preserved ejection fraction (HF-nlEF). It is possible that the age related changes in diastolic function, specifically loss of ventricular compliance may predispose the elderly population to CHF. We have previously demonstrated that this loss of compliance is preventable by lifelong endurance training. In this study we evaluated the effect of one year of exercise training in potentially reversing the effects of diastolic dysfunction in elderly subjects with HF-nlEF.
Methods: 6 healthy but sedentary (SED) female seniors (68±3 years) and 6 female seniors with HF-nlEF by echocardiography (74±7 years) were enrolled. The SED individuals were excluded if they participated in endurance exercise for greater than 90 min/week. All subjects were rigorously screened for valvular and ischemic heart disease. Each subject underwent measurement of PCWP by right heart catheterization with simultaneous echocardiographic measurements of LVEDV at 5 different levels of cardiac filling, both below and above supine baseline, before and after a year long progressive exercise training program. These data from pre and post testing were used to construct mean compliance curves modeled on an exponential equation.
Results: Mean baseline PCWP (12.2±2.2 mmHg CHF vs. 10.2±2.1 mmHg SED, p=0.03) was higher in the CHF subjects, while the baseline LVEDV, indexed by lean body mass, was smaller in HF-nlEF (1.43±0.21 ml/kg; CHF vs. 1.47±0.26 ml/kg SED), consistent with decreased dynamic compliance and distensibility. In contrast, prior to exercise training, static LV chamber stiffness of the HF-nlEF was surprisingly less than the SED subjects (stiffness constant: CHF 0.014±0.007; SED 0.040±0.016, p=0.003); but after training the stiffness was the same between the two groups (CHF 0.030±0.014, SED 0.026±0.012).
Conclusions: HF-nlEF patients have increased dynamic chamber stiffness, though static compliance is clearly not worse (and may be better) than healthy sedentary controls. One year of exercise training, up to 4 – 6 hrs/week, improves distensibility (volume at a given pressure) without improving chamber compliance.