RV Myocardial Strain During Pre-Load Augmentation Is Associated With Exercise Capacity in Patients With Chronic HF

The aim of this study was to assess the relationship between right ventricular (RV) function during pre-load augmentation and exercise tolerance.

Peak oxygen uptake (VO₂) is a strong predictor of mortality in chronic heart failure. Cardiac function during pre-load augmentation is an important part of the phenomenon in the evaluation of exercise capacity.

We prospectively performed echocardiographic studies in 68 chronic heart failure patients with cardiopulmonary exercise testing (mean age 60 ± 12 years; 69% male). After resting evaluations, echocardiographic parameters were repeated during leg positive pressure (LPP). Exercise capacity was assessed by peak VO₂ in all patients (left ventricular ejection fraction: 43 ± 15%).

Patients with severely reduced exercise capacity (peak VO₂ <14 ml/kg/min) had significantly lower stroke volume index, left ventricular global longitudinal strain and RV strain and higher filling pressure (E/e' and pulmonary arterial systolic pressure) than the remainder. Stroke volume index (β = 0.49), global longitudinal strain (β = -0.61), E/e' (β = -0.32), pulmonary arterial systolic pressure (β = -0.57), and RV strain (β = -0.66) during LPP were independently correlated to peak VO₂ (all p < 0.01). RV strain during LPP was the most powerful predictor in identifying patients with severely reduced exercise capacity (cut off value: -17%; sensitivity: 81%; specificity: 88%; areas under the curve: 0.88; p < 0.001) compared with other variables including resting parameters.

RV strain during pre-load augmentation correlated independently to peak VO₂ and was a powerful predictor in identifying patients with severely reduced exercise capacity.