Echocardiographic measurements of chemogenetic heart failure after treatment with sacubitril/valsartan or valsartan. A: representative M-mode echocardiographic images acquired from short-axis views of the left ventricle in rats infected with control or d-amino acid oxidase (DAAO) virus, treated as indicated with sacubitril/valsartan (Sac/val) or valsartan alone (Val). B: quantitative measurements of cardiac function in control (n = 4) and DAAO-expressing rats (n = 18) after 4 wk of treatment with d-alanine. *P < 0.05, ****P < 0.0001 for intergroup comparison and ###P < 0.001, ####P < 0.0001 for intragroup comparison. Data are represented as means ± SE. C: echocardiographic measurements describing functional parameters of control virus-infected rats treated with vehicle (water; n = 4), DAAO-expressing rats treated with water (n = 6), sacubitril/valsartan, or valsartan (n = 6 in each group). *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001 obtained by one-way ANOVA with Šídák’s test for multiple comparisons (compared with control) and #P < 0.05, ##P < 0.01, ###P < 0.001 for intragroup comparison. Data are represented as means ± SE. LV, left ventricular; NS, not significant; w, weeks.