A Dose-Defining Study of CXL-1020 in Patients With Systolic Heart Failure

Each of the 3 strata are described below: Invasive Strata 1: This is a randomized, double-blinded stratum that will enroll up to 65 patients who are hospitalized with symptomatic heart failure who have indwelling PA catheters allowing invasive hemodynamic evaluation. Each patient will receive a six hour intravenous infusion of either placebo or CXL-1020. Non-Invasive Strata 2: This is a randomized, double-blinded stratum which will enroll up to approximately 72 patients (in several cohorts with 12-24 patients each) who neither require, nor have in place, an indwelling PA catheter for hemodynamic monitoring, but meet study entrance criteria for symptoms of heart failure, (dyspnea at rest)and systolic dysfunction by specific echocardiography criteria. Monitoring of drug effects will be performed by Echocardiography. Invasive-Strata 3: This is a randomized, double-blinded stratum that will begin after an evaluation of a substantial number of patients in Strata A and B and will enroll approximately 15-30 patients using the same general enrollment criteria as in Invasive Strata A.