Dual Angiotensin Receptor-Neprilysin Inhibition With Sacubitril/Valsartan Attenuates Systolic Dysfunction in Experimental Doxorubicin-Induced Cardiotoxicity

BACKGROUND: Doxorubicin (DOX) induces cardiotoxicity in part by activation of matrix metalloproteinases (MMPs). Sacubitril/valsartan (Sac/Val) exerts additive cardioprotective actions over renin-angiotensin-aldosterone inhibitors in preclinical models of myocardial infarction and in heart failure patients. We hypothesized that Sac/Val would be more cardioprotective than Val in a rodent model of progressive DOX-induced cardiotoxicity, and this benefit would be associated with modulation of MMP activation. OBJECTIVES: We sought to investigate the efficacy of Sac/Val for the treatment of anthracycline-induced cardiotoxicity. METHODS: Male Wistar rats received DOX intraperitoneally (15 mg/kg cumulative) or saline over 3 weeks. Following the first treatment, control animals were gavaged daily with water (n = 25), while DOX-treated animals were gavaged daily with water (n = 25), Val (31 mg/kg; n = 25) or Sac/Val (68 mg/kg; n = 25) for either 4 or 6 weeks. Echocardiography was performed at baseline, and 4 and 6 weeks after DOX initiation. In addition, myocardial MMP activity was assessed with (99m)Tc-RP805, and cardiotoxicity severity was assessed by histology at these time points in a subgroup of animals. RESULTS: Left ventricular ejection fraction decreased by 10% at 6 weeks in DOX and DOX + Val rats (both p < 0.05), while this reduction was attenuated in DOX + Sac/Val rats. MMP activity was increased at 6 weeks by 76% in DOX-alone rats, and tended to increase in DOX + Val rats (36%; p = 0.051) but was similar in DOX + Sac/Val rats as compared with time-matched control animals. Both therapies attenuated histological evidence of cellular toxicity and fibrosis (p < 0.05). CONCLUSIONS: Sac/Val offers greater protection against left ventricular remodeling and dysfunction compared with standard angiotensin receptor blocker therapy in a rodent model of progressive DOX-induced cardiotoxicity.