This randomised, controlled clinical trial aims to evaluate the safety and efficacy of Cardiac Shockwave Therapy (CAST-HF) in patients with ischaemic heart failure requiring surgical revascularization. The main questions to answer are:

• Does cardiac shockwave therapy, in addition to CABG surgery, improve left ventricular ejection fraction?
• Is cardiac shockwave therapy in addition to CAGB surgery safe?

Participants will be randomised into intervention (cardiac shockwave therapy) and control (sham treatment with an inactive applicator) groups.

This study investigates the safety and performance characteristics of the Direct Epicardial Shockwave Therapy System (DESWT) as applied with the Cardiac Shockwave Probe (CSP).

Inclusion criteria

• Male or female patients between 21 and 90 years of age undergoing primary coronary artery bypass grafting
• Presentation with reduced left ventricular function, defined as LVEF ≤ 40% measured by cardiac MRI
• Presentation with regional left ventricular wall motion abnormalities
• Written informed consent from the patient for participation in the study

Exclusion criteria

• Significant concomitant aortic valve disease requiring surgical treatment (other than significant aortic valve disease not detected in preoperative cardiac ultrasound but detected during surgery)
• Serious radiographic contrast allergy
• Patient in cardiogenic shock or presenting with acute myocardial infarction (STEMI or NSTEMI)
• Patient with a contraindication for cardiac MRI
• History of significant ventricular arrhythmia, other than MI-associated arrhythmia
• Comorbidity reducing life expectancy to less than one year
• Presence of a ventricular thrombus
• Presence of a cardiac tumour
• Pregnancy

The masking is performed using opaque envelopes that are opened by an assistant at the end of the CABG procedure after the bypasses are fully established.