Part A of the study was successfully concluded. Part B of the study was not conducted in favor of redesigned new studies.

This is a study evaluating the effectiveness of CRD-740 in patients with either Heart Failure with Reduced Ejection Fraction (HFrEF) or Heart Failure with Preserved Ejection Fraction (HFpEF) after 12 weeks of treatment. The primary objective in Part A is to assess the effect of CRD-740 compared to placebo in plasma cGMP at Week 4 in HFrEF.

Part B of the study was not conducted in favor of redesigned new studies.

Inclusion Criteria:

1. Males or Females ≥18 years of age, at screening.

2. Diagnosis of clinical heart failure syndrome, New York Heart Association functional class II - III for at least 6 months prior to screening

3. For Part A:

   • Ejection Fraction ≤40% by echocardiography at screening.
   • NT-proBNP level ≥600 pg/ml at screening. Subjects with atrial fibrillation or flutter at screening are required to have an NT-proBNP level of ≥1000 pg/mL at screening.

5. Stable doses of guideline-directed heart failure therapy for a minimum of 4 weeks prior to screening that has been individually optimized according to standard practice guidelines and no addition of guideline-directed heart failure therapy within 3 months of screening.

Exclusion Criteria:

2. Recent HF exacerbation defined by hospitalization or requirement for intravenous diuretics within 60 days of screening.

3. Subjects with planned interventions (e.g., percutaneous coronary intervention, devices) etc. occurring during their involvement in this study.

4. Acute coronary syndrome, stroke, transient ischemic attack, cardiac, carotid or other major cardiovascular surgery or carotid angioplasty within 60 days of screening.

5. Subjects with clinical suspicion of infiltrative cardiomyopathy (e.g., amyloid, sarcoid), hypertrophic cardiomyopathy (obstructive or non-obstructive), or HF secondary to severe valvular disease, active myocarditis, active pericarditis, or clinically significant congenital heart disease.

6. Prior or planned orthotopic heart transplantation.

7. Presence of or plan for mechanical circulatory support.

Note: Other protocol defined Inclusion/Exclusion criteria may apply.