Clinical Trials

Inclusion Criteria:

• Completed HF rehabilitation (i.e., physically capable to perform exercise) and referred to HF service. That is: Individuals with heart failure who are aged over 18 years, a confirmed diagnosis of HF as per the National Heart Foundation of Australia and Cardiac Society of Australia and New Zealand HF guidelines¹, clinically stable and deemed suitable to participate in an exercise program, and New York Heart Association functional classification I to II.

• NYHA class I-II, heart failure with reduced HFrEF and preserved ejection fraction (HFpEF)

• Aged ≥ 18 years

• No exacerbations of HF-related symptoms or changes in medications within the past 3 months.

• Free from unstable angina, recent myocardial infarction or severe valvular disease.

• No skin conditions that would prevent limb immersion in water bath.

• No contraindications or increased risks for undertaking exercise tests (see below) as per standard guidelines⁹

  • Contraindications for exercise testing

    • Early phase after acute coronary syndrome (up to 2 days)

    • Untreated life-threatening cardiac arrhythmias

    • Acute heart failure (during the initial period of haemodynamic instability)

    • Uncontrolled hypertension

    • Advanced atrioventricular block

    • Acute myocarditis and pericarditis

    • Symptomatic aortic stenosis

    • Severe hypertrophic obstructive cardiomyopathy

    • Acute systemic illness

    • Intracardiac thrombus

    • Progressive worsening of exercise tolerance or dyspnoea at rest over previous 3–5 days

    • Significant ischaemia during low-intensity exercise (<2 METs, <50 W)

    • Uncontrolled diabetes

    • Recent embolism

    • Thrombophlebitis

    • New-onset atrial fibrillation/atrial flutter

  • Increased risk for exercise testing

    • >1.8 kg increase in body mass over the previous 1 – 3 days

    • Concurrent, continuous, or intermittent dobutamine therapy

    • Decrease in systolic blood pressure with exercise

    • Complex ventricular arrhythmia at rest or appearing with exertion

    • Supine resting heart rate >100 bpm

    • Pre-existing co-morbidities limiting exercise tolerance.

Exclusion Criteria:

• Participants who have not been referred/participated in HF rehabilitation

• NYHA class III and IV

• Participants younger than 18 years

• Participants with exacerbation of HF symptoms or changes in medications within the past 3 months

• HF participants with unstable angina, recent myocardial infarction or severe valvular disease

• HF participants with skin conditions that would prevent limb immersion in water bath.

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

Eligibility last updated 7/23/2025. Questions regarding updates should be directed to the study team contact.