Despite modern advances in treatment, heart failure continues to carry a poor prognosis with high morbidity and mortality rates. Hence, there remains a major interest in the development of novel therapeutic agents for this debilitating condition. Urocortins have recently shot into limelight with their potential role in the pathophysiology and treatment of heart failure.

Recent studies by the investigators group (REC no: 09/S1103/41) have confirmed that Urocortin 2 and 3 are potent arterial vasodilators, the effects of which are reproducible and well tolerated in healthy male volunteers. Previous studies using heart failure models in animals1-7, as well studies in heart failure patients (Urocortin 2), suggest that there is great scope for Urocortins as novel biomarkers and as potential therapeutic agents in heart failure. With this in mind, the investigators wish to study the local vasomotor effects of these peptides in greater detail in patients with heart failure.

Inclusion Criteria:

Patients with heart failure:

1. Patients with stable heart failure (NYHA class II-IV) on maximum tolerated doses of an ACE inhibitor and beta-blocker for at least 3 months.
2. Baseline echocardiographic parameters (echo performed within last 12 months) at recruitment: ejection fraction (EF) <35%, left ventricular end dimension >5.5cm and fractional shortening <20%
3. Age 18-80 years (inclusive) at recruitment

Healthy volunteers:

• Age and sex-matched healthy volunteers

Exclusion Criteria:

1. Lack of informed consent
2. Age <18 years and > 80 years
3. Current involvement in a clinical trial
4. Systolic blood pressure >190 mmHg or <90 mmHg, untreated malignant arrhythmias
5. Haemodynamically significant valvular heart disease
6. Severe or significant co-morbidity including bleeding diathesis, renal or hepatic failure
7. History of anaemia
8. Recent infective/inflammatory condition
9. Recent blood donation (prior 3 months)
10. Women of child bearing potential