Abstract 18118: High Intensity Interval Training Improves Diastolic Dysfunction in Patients with Heart Failure and Preserved Ejection Fraction

Abstract

Heart failure with preserved ejection fraction (HFPEF) is characterized by left ventricular diastolic dysfunction (LVDD) and is a major cause of morbidity and mortality in the elderly. Long-term moderate-intensity continuous exercise training programs have been shown to improve diastolic function in patients HFPEF; however, the effects of high-intensity interval training (HIIT) in patients with HFPEF are unknown.

Methods: Fifteen patients with HFPEF underwent a graded exercise treadmill test for determination of peak oxygen uptake (VO₂peak) and 2D-echocardiography (2D-echo) for assessment of LVDD before and after 4-weeks of exercise training, 3 days per week. Patients were randomized to either: (1) a program of HIIT (4 x 4 minutes at 85-90% peak heart rate, interspersed with 3 minutes of active recovery; n = 9), or (2) a commonly prescribed program of moderate-intensity continuous aerobic exercise training (30 minutes at 60-70% peak heart rate; n = 6).

Results: Four weeks of HIIT resulted in significant improvements in diastolic function as measured by 2D-echo (pre-training LVDD grade = 2.1 ± 0.3; post-training LVDD grade = 1.3 ± 0.7; p = 0.02). No change was observed following moderate-intensity training. The change in diastolic dysfunction grade was an independent predictor of change in peak exercise VE/VCO₂ (R² = 0.359, p = 0.02; ß = 2.73). Early mitral flow (E) improved in the HIIT group (pre-training = 0.92 ± 0.26 m/s; post-training = 0.78 ± 0.28 m/s; p = 0.02). A trend was observed for reduction in left atrial volume index following HIIT compared to moderate-intensity training (-3.3 ± 6.6 ml/m² vs. +5.8 ± 10.7 ml/m²; p = 0.06).

Conclusion: HIIT appears to be a time-efficient and safe strategy for improving diastolic function in patients with heart failure and preserved ejection fraction. These changes were correlated with improvements in peak exercise ventilatory efficiency.