Impaired myocardial relaxation with exercise determines peak aerobic exercise capacity in heart failure with preserved ejection fraction.

ESC Heart Fail. 2017 Aug;4(3):351-355. doi: 10.1002/ehf2.12147. Epub 2017 May 6.

Trankle C, Canada JM, Buckley L, Carbone S, Dixon D, Arena
R, Van Tassell B, Abbate A

BACKGROUND: Heart failure with preserved ejection fraction (HFpEF) is a clinical
syndrome characterized by impaired exercise capacity due to shortness of breath
and/or fatigue. Assessment of diastolic dysfunction at rest and with exercise may
provide insight into the pathophysiology of exercise intolerance in HFpEF.
AIMS: To measure echocardio-Doppler-derived parameters of diastolic function as
they relate to various indices of aerobic exercise capacity in HFpEF.
METHODS: We selected 16 subjects with clinically stable HFpEF, no evidence of
volume overload, but impaired functional capacity by cardiopulmonary exercise
testing [peak oxygen consumption (VO2 )]. We measured the transmitral E and A
flow velocities, E/A ratio, and E deceleration time (DT) and tissue Doppler E’
velocity. We also indexed the E’ to the DT, as additional measure of impaired
relaxation (E’DT ), and calculated the diastolic functional reserve index (DFRI),
as the product of E’ at rest and change in E’ with exercise.
RESULTS: E’ velocity, at rest and peak exercise, as well as the DFRI positively
correlated with peak VO2 , whereas DT, E’DT , and E/E’ with exercise inversely
correlated with peak VO2 . Of note, the E’DT at rest also significantly predicted
E’ velocity at peak exercise (R = +0.81, P < 0.001). Exercise E’ was the only
independent predictor of peak VO2 at multivariable analysis (R = +0.67,
P = 0.005).
CONCLUSIONS: The E’ velocity at peak exercise is a strong and independent
predictor of aerobic exercise capacity as measured by peak VO2 in patients with
HFpEF, providing the link between abnormal myocardial relaxation with exercise
and impaired aerobic exercise capacity in HFpEF..