Remote Ischaemic Conditioning (RIC) in Heart Failure

Effects of Chronic Remote Ischaemic Conditioning on Coronary and Peripheral Vascular Function in Patients With Heart Failure

This study will test the impact of remote ischaemic conditioning combined with exercise on myocardial perfusion in patients with or at risk of heart failure

Heart failure (HF) is a disease which affects the heart's ability to pump or fill with blood. It can affect a person's quality of life and their ability to exercise. Recent work has shown that a reduction in the blood supply to the heart may contribute to the problem. It is therefore possible that improving the blood supply to the heart may help patients with HF. One possible way that this might be achieved is with a method called remote ischaemic conditioning (RIC). This involves placing a cuff on a person's arm (identical to a blood pressure cuff) and inflating it for a few minutes to reduce the blood flow in a person's arm. This is thought to release chemicals into the bloodstream which can have positive effects on the heart. This has been studied in patients with other forms of heart disease, but is yet to be tested properly in patients with heart failure. It is hypothesized that combining the RIC procedure with a low level of arm exercise may result in further improvements in the person's blood vessels and heart. This will be tested in a single-centre prospective study.

Inclusion Criteria:

• Age >18 years
• Ability to provide written consent
• clinical diagnosis of HFpEF (LVEF ≥50%; symptoms and signs of heart failure [HF] caused by a structural and/or functional abnormality, and at least one: elevated natriuretic peptides; ambulatory; BNP ≥35 pg/mL or NT-proBNP ≥125 pg/mL or hospitalised; BNP ≥100 pg/mL or NT-proBNP ≥300 pg/mL, and objective evidence of cardiogenic pulmonary or systemic congestion) OR stable type 2 diabetes (determined by formal diagnosis in hospital or GP case records with diagnostic oral glucose tolerance test or glycated haemoglobin level ≥6.5%) and with ACC/AHA stage B HF (structural disorder of the heart but no current or previous symptoms of HF) OR confirmed diagnosis of dilated cardiomyopathy

Exclusion Criteria:

• Absolute contraindications to MRI or contrast (e.g. severe claustrophobia, pregnancy, ferromagnetic implants, inability to lie flat, severe renal impairment eGFR<30ml/min/m2)
• Moderate to severe valvular heart disease
• Confirmed coronary artery disease (>50% narrowing in any major epicardial coronary artery on invasive or computed tomography coronary angiography, previous myocardial infarction, previous percutaneous intervention or coronary bypass surgery)
• Known arterial stenosis of the upper extremity