Abstract 14279: Improved Pressure-Flow Relationship With Sacubitril/Valsartan: A 6-min Walk Stress Echocardiographic Study

Abstract

Background: In the clinical setting, there are various techniques for stress echocardiography, of which the 6-minute walk (6MW) test is a straightforward and utilized one. An abnormal hemodynamic response to exercise is indicated by a ΔmPAP/ΔCO slope of greater than 3 mmHg/L/min between rest and exercise. This response is associated with impaired prognosis in patients with exercise dyspnea and several cardiovascular diseases. Hypothesis: Our hypothesis was that pressure-flow relationship of the pulmonary circulation obtained by 6MW stress echocardiography would be enhanced with treatment. Aims: The aim of this study was to assess the effects of administration of Sacubitril/Valsartan on cardiac function in heart failure. Methods: We prospectively enrolled 39 patients with heart failure. The 6MW test was performed indoors in a flat, straight corridor. The peak tricuspid regurgitation jet, early diastolic transmitral flow velocity and early diastolic mitral motion were obtained by echocardiography post-6MW. We calculated the slope of ΔmPAP/ΔCO as a parameter of pulmonary hypertension. Follow-up echocardiographic studies were performed after 1 year. Results: Left ventricular diameter and volume were significantly reduced (LVDd; 59.3±7.7mm vs 56.0±8.6mm, P<0.001, LVEDV; 160.7±49.6ml vs 136.0±54.3ml, P<0.001), and LVEF was significantly improved (37.6±11.3% vs 44.9±11.5%, P<0.001). Among the 31 patients who underwent 6MW stress echocardiographic study at baseline and 1 year later, 6MW distance increased after treatment (380m vs 430m, P=0.003). The ΔmPAP/ΔCO by 6MW stress decreased with treatment (6.9mmHg/L/min vs 2.8mmHg/L/min, P=0.002). Conclusions: Initiation of Sacubitril/Valsartan was associated with improvement of left ventricular size and LVEF. Additionally, the 6MW distance increased and the ΔmPAP/ΔCO was improved to within normal range with treatment. Sacubitril/Valsartan distinctly improved cardiac reactivity to exercise.