Sacubitril/valsartan Inhibits Obesity-associated Diastolic Dysfunction through Suppression of Ventricular-vascular Stiffness

Abstract

Objective: Both cardiac diastolic dysfunction (DD) and arterial stiffness are early manifestations of obesity-associated prediabetes and serve as risk factors for the development of heart failure with preserved ejection fraction (HFpEF). Since the incidence of DD and arterial stiffness are increasing worldwide due to exponential growth in obesity, an effective treatment is urgently needed to blunt their development and progression. Here we investigated whether the combination of an inhibitor of neprilysin (sacubitril), a natriuretic peptide-degrading enzyme, and an angiotensin II type 1 receptor blocker (valsartan), suppresses DD and arterial stiffness in an animal model of prediabetes more effectively than valsartan monotherapy.Methods: Sixteen week-old male Zucker Obese rats (ZO; n=64) were assigned randomly to 4 different groups: Group 1: saline control (ZOC); Group 2: sacubitril/valsartan (sac/val; 68 mg•kg-1•day-1; ZOSV); Group 3: valsartan (31 mg•kg-1•day-1; ZOV) and Group 4: hydralazine, an anti-hypertensive drug (30 mg•kg-1•day-1; ZOH). Six Zucker Lean (ZL) rats that received saline only (Group 5) served as lean controls (ZLC). Drugs were administered daily for 10 weeks by oral gavage.Results: Sac/val improved echocardiographic parameters of impaired left ventricular (LV) stiffness in untreated ZO rats, without altering the amount of food consumed or body weight gained. In addition to improving DD, sac/val also decreased aortic stiffness and reversed impairment of nitric oxide-induced vascular relaxation seen in ZO rats. However, sac/val had no impact on LV hypertrophy. Notably, sac/val was more effective at ameliorating DD compared to val. Although, hydralazine was as effective as sac/val in improving these parameters, it adversely affected LV mass index. Further, proteomics revealed distinct effects of sac/val, including marked suppression of Notch-1 by both valsartan and sac/val suggesting that cardiovascular protection afforded by both share some common mechanisms; however, sac/val increased IL-4 which is increasingly been recognized for its cardiovascular protection, possibly contributing, in part, to more favorable effects of sac/val over val alone in improving obesity associated DD.Conclusions: These studies suggest that sac/val is superior to val in reversing obesity-associated DD. It is an effective drug combination to blunt progression of asymptomatic DD and vascular stiffness to HFpEF development in a preclinical model of obesity-associated prediabetes.