Abstract 20150: High Intensity Aerobic Training Stimulus Over Two Years Improves Left Ventricular Stiffness
Background: Low fitness is a risk factor for heart failure, particularly heart failure with preserved ejection fraction (HFpEF). This risk may be mediated via increased cardiac stiffness which is also linked to low fitness. Prior studies of aerobic exercise in seniors failed to show a decrease in stiffness. We hypothesized a high volume and intensity aerobic training stimulus over two years in previously sedentary middle aged adults would improve left ventricular stiffness.
Methods: We recruited 61 (48% male) healthy but sedentary normotensive middle aged subjects (53 ± 5 yrs). Subjects were randomized to either aerobic exercise (Ex; n=34) or attention control/yoga (Yg; n=27). Fitness (peak VO2) and left ventricular stiffness from invasive hemodynamic construction of end-diastolic pressure volume relationship (EDPVR) was measured at baseline and 2 years after training. LV stiffness was calculated by curve fit of the diastolic portion of the pressure-volume curve using pulmonary capillary wedge pressure as end diastolic pressure and 3D echocardiography to measure LV end diastolic volume (LVEDV). Eight subjects withdrew over the course of the study.
Results: Adherence to prescribed exercise sessions was greater than 90% in the aerobic study arm. Baseline fitness was similar between groups (Ex: 29.0 ± 5.1; Yg: 29.5 ± 5.1 ml/kg/min). After 2 years, fitness improved by 18% in the aerobic group (Ex: 34.3 ± 6.5; Yg: 28.7 ± 5.4 p<0.001). LV stiffness decreased (rightward shift in EDPVR) in Ex group but was unchanged in Yg after 2 years. (Figure) Tracking improvement in stiffness, LVEDV increased by 19% in the aerobic group.
Conclusions: In sedentary healthy middle age adults, 2 years of high aerobic stimulus improved fitness and decreased cardiac stiffness. Decreases in stiffness tracked improvements in LVEDV. Regular aerobic exercise may mediate protection against future risk of HFpEF by decreasing cardiac stiffness.
Author Disclosures: S. Sarma: None. E.J. Howden: None. M. Samels: None. B. Everding: None. S. Livingston: None. M.D. Palmer: None. B.D. Levine: None.
- © 2016 by American Heart Association, Inc.