Comparison of ARNI to Alternate Oral Vasodilator Therapies in Patients With Low Cardiac Output

This is a prospective, randomized, non-blinded, single-center efficacy study of acutely decompensated heart failure patients with reduced ejection fraction (HFrEF), low cardiac index (\<2.2) as determined by pulmonary artery catheter (PAC) who have been hemodynamically stabilized and ready for transition to oral vasodilator therapy at the discretion of the clinician. The investigators would like to accomplish the following objectives with this study: 1. Establish the superiority of an upfront initiation strategy for sacubitril-valsartan at maintaining patients on ARNI therapy at one-month follow-up compared to usual care. 2. Establish the safety of initiating sacubitril-valsartan in an intensive care setting 3. Characterize the hemodynamic effect of sacubitril-valsartan on patients with low cardiac output 4. Expand the population of hospitalized patients that can be initiated on ARNIs and thus facilitate prior to hospital discharge patients who are on optimal goal-directed medical therapy (GDMT) for heart failure In this pragmatic study, the primary endpoint will be establishing the superiority of sacubitril-valsartan as an oral vasodilator in maintaining ARNI therapy at one-month post hospital discharge as compared to usual care. Given the overall mortality and heart failure hospitalization benefit of ARNI over ACEI and other vasodilators has been established in large-scale clinical trials, establishing that upfront initiation of ARNI therapy in patients with low cardiac output is safe and can be maintained post-discharge would be of significant clinical benefit. Adverse events including symptomatic hypotension (requiring cessation of drug), development of worsening renal function (requiring cessation of drug), hyperkalemia \[moderate (\> 5.5 mmol/L) or severe (\> 6 mmol/L)\], or re-initiation of IV vasodilator or IV inotropic therapy will be monitored and tracked.