This Phase 2, randomized, placebo-controlled, multicenter outpatient study is designed to test the safety and tolerability of AC2592 as well as examine the effect of AC2592 on oxygen consumption during maximal tolerated exercise in adult subjects with chronic congestive heart failure.

Main Inclusion Criteria:

• Has heart failure classified as New York Heart Association (NYHA) Class III or Class IV at screening despite treatment with standard therapy.
• Is able to perform a treadmill test.
• Has an HbA1c of <= 11%.
• Is physically and mentally capable of operating the continuous subcutaneous infusion (CSCI) pump (i.e., adequate vision, manual dexterity, and mental capacity), or has a dedicated caretaker or adult family member who meets this requirement.

Main Exclusion Criteria:

• Has received metformin or nesiritide within 2 weeks prior to screening visit.
• Is currently participating in any other clinical study, or has received an investigational drug within 1 month of the screening period.
• Has participated previously in a study using GLP-1, exenatide, or exenatide LAR.
• Is using a left ventricular assist device or other mechanical circulatory support.