Hemodynamic basis of exercise limitation in patients with heart failure and normal ejection fraction

Objectives: The purpose of this study was to invasively investigate the hemodynamic response to exercise in patients with heart failure with normal ejection fraction (HFNEF) and to evaluate the ability of the peak early diastolic transmitral velocity to peak early diastolic annular velocity ratio (E/e') to reflect exercise hemodynamics.

Background: There is little information regarding the hemodynamic response to exercise in HFNEF.

Methods: Patients with HFNEF (n = 14) and asymptomatic controls (n = 8) underwent right-side heart catheterization at rest and during supine cycle ergometer exercise and echocardiography with measurement of resting and peak exercise E/e'.

Results: Resting pulmonary capillary wedge pressure (PCWP) (10 +/- 4 mm Hg vs. 10 +/- 4 mm Hg; p = 0.94) was similar in HFNEF patients and controls, but stroke volume index (SVI) (p = 0.02) was lower, and systemic vascular resistance index (SVRI) (p = 0.01) was higher in patients. Patients stopped exercise at lower work rate (0.63 +/- 0.29 W/kg vs. 1.13 +/- 0.49 W/kg; p = 0.006). Although peak exercise PCWP was similar in both groups (23 +/- 6 mm Hg vs. 20 +/- 7 mm Hg; p = 0.31), the peak PCWP/work rate ratio was higher in patients compared with controls (46 +/- 31 mm Hg/W/kg vs. 20 +/- 9 mm Hg/W/kg; p = 0.03). Peak exercise SVI (p = 0.001) was lower and SVRI was higher (p = 0.01) in patients. Resting E/e' was modestly elevated in patients (13.2 +/- 4.1 vs. 9.5 +/- 3.4; p = 0.04). Peak exercise E/e' did not differ between the groups (11.1 +/- 3.4 vs. 9.4 +/- 3.4; p = 0.28).

Conclusions: The HFNEF patients achieved a similar peak exercise PCWP to that of asymptomatic controls, at a much lower workload. This occurs at a lower SVI and in the setting of higher SVRI. The E/e' does not reflect the hemodynamic changes during exercise in HFNEF patients.