Angiotensin receptor-neprilysin inhibition and improved ventricular-arterial coupling in heart failure with reduced ejection fraction.

Sacubitril/valsartan improves outcome in chronic heart failure (HF) with reduced ejection fraction (EF). The underlying mechanisms on left ventricular (LV) myocardial function are incompletely understood. In this study, 117 patients with symptomatic HF and LV-EF ≤ 40% were enrolled prospectively. Non-invasive pressure-volume analysis was calculated from transthoracic echocardiography with simultaneous arm-cuff blood pressure measurements. Primary outcome parameters were LV end-systolic elastance (Ees; a measure of LV contractility), effective arterial elastance (Ea; a measure of afterload), and the ventricular-arterial coupling ratio (Ea/Ees). Mean age was 65±13 years, 30% were female, and 54.7% had ischemic heart disease. During six months of follow-up, eight patients died, three withdrew their consent, and four were lost to follow-up. 102 patients were included in pressure-volume analyses. After six months of sacubitril/valsartan treatment, Ees increased (0.66mmHg/ml [IQR 0.45-0.94] vs. 0.78mmHg/ml [IQR 0.57-1.10], p=0.001), Ea decreased (1.76mmHg/ml [IQR 1.48-2.13] vs. 1.62mmHg/ml [IQR 1.36-1.96], p=0.014), and the Ea/Ees ratio improved (2.52 [IQR 1.88-4.05] vs. 1.93 [IQR 1.50-2.63], p<0.001). LV end-diastolic pressure and LV volumes were reduced, and LVEF increased from 33% to 43% (both p<0.001). Clinical improvement occurred in NYHA functional class, NT-proBNP level, and 6-minute walking distance. Change in LVEF correlated with change in Ees (r=0.33, p=0.0008), while change in NT-proBNP was associated with change in LVEDP (r=0.42, p<0.0001). In conclusion, sacubitril/valsartan is associated with improved ventricular-arterial coupling by enhancing LV contractility and reducing afterload. Beyond LV reverse remodeling, optimized ventricular-arterial interaction may contribute to the favorable outcome of sacubitril/valsartan treatment in HF with reduced EF.