Patients with ischemic heart disease (IHD) awaiting coronary artery bypass graft (CABG) surgery often face challenges like advanced age, frailty, comorbidities, and physical inactivity. These factors, combined with the physiological and psychological stress of surgery, can hinder postoperative recovery. Traditionally, strategies to improve surgical outcomes focus on the intra- and postoperative periods. However, the pre-surgery waiting period offers a "window of opportunity" for prehabilitation, which aims to enhance patients' functional capacity through exercise, nutrition, and psychological support.

The CABGpreHAB feasibility study evaluates the feasibility of a home-based multimodal prehabilitation intervention for patients awaiting elective CABG surgery. This randomized pilot study compares the intervention plus usual care to usual care alone, assessing feasibility outcomes like recruitment, retention, attrition, fidelity, and adherence. The study aims to optimize a subsequent full-scale randomized controlled trial (RCT) and improve patient outcomes by leveraging the pre-surgery period for prehabilitation.

Advanced age, frailty, comorbidity, and physical inactivity are often present in patients with ischemic heart disease (IHD) awaiting coronary artery bypass graft surgery (CABG). These characteristics, as well as the physiological impact of having surgery, are significant homeostatic disturbances where patients postoperatively suffer from physical symptoms and a lack of return to independence. Cardiac surgery invariably induces varying degrees of physiological stress, impacting multiple organ systems, and imposes a psychological burden. As age increases, patient complexity and comorbid burden grow more common in patients undergoing cardiac surgery; innovative strategies are required to alleviate the risk of adverse outcomes. Strategies to improve outcomes from surgery and accelerate return to baseline levels have traditionally focused on the intra- and postoperative period, nevertheless, the waiting period before surgery might offer an opportunity for improving the safety and outcome of the surgical intervention and improving patients' motivation in postoperative rehabilitation and recovery time. Prehabilitation is a newly introduced term that reflects a proactive process of enhancing an individual's functional capacity between diagnosis and scheduled surgery, intending to improve the patient's capacity to withstand the upcoming physiologic stress of surgery and thus avoid complications. This period of awaiting surgery is proposed as a "window of opportunity" to address poor nutritional status, low physical fitness, and high emotional distress. The role of multimodal prehabilitation combining exercise training, nutritional optimization, and psychological support, in patients with IHD awaiting CABG surgery, is sparse and unknown in a Danish setting

Objective:

This CABG preHAB feasibility study is conducted to evaluate the feasibility of delivering a homebased multimodal prehabilitation intervention for patients awaiting elective CABG surgery with the purpose to optimize a subsequent full-scale RCT.

Design:

The CABGpreHAB feasibility study is designed as a randomized pilot study, aiming to assess the feasibility of a multimodal prehabilitation intervention plus usual care versus usual care alone in patients awaiting elective CABG surgery. It is an investigator-initiated study designed as an open-label, single-center randomized controlled feasibility study (allocation ratio 1:1) with blinded outcome assessment, designed to assess the method proposed for use in a larger RCT.

Study population:

Patients aged more than 18 years awaiting elective CABG-surgery

Primary outcomes:

Feasibility outcomes include:

Recruitment and retention rates. The recruitment rate will be determined by the number of individuals participating in the study out of those who are eligible/admissible but refuse to participate. First, the investigators will evaluate the number of patients that can be included in the study during the inclusion period. A proportion of 60% or more of patients awaiting elective CABG surgery who are eligible for the study is acceptable. Retention will be assessed by the percentage of participants who remain in the study from the beginning to the end of the study (30 days post-surgery).

Attrition rates. Attrition is defined by the number of individuals who consent to participate in the study but drop out before the end of the intervention period, regardless of group allocation.

Fidelity. Fidelity of delivery of the webcam-based exercise training intervention will be assessed qualitatively by 8-10 semi-structured interviews, the day before surgery, by a research nurse.

Adherence to the interventions will be measured by using the number of telephone counselling and tele-exercise sessions delivered out of the theoretical number that could have been delivered based on the surgical wait time of each participant. Adherence to the home-based tele-exercise training sessions and telephone counselling by assessing the number of sessions applied in the intervention group. This will be collected by the patient's recorded physical activity logbook, by weekly phone calls, and by accelerometer data. Adherence with the prehabilitation program will be assessed against the target of individuals achieving > 70% of the prescribed exercise program (self-reported) + during the study follow-up with phone calls. Inclusion in the CABGpreHAB study must be attractive to at least 30% of eligible patients who meet the inclusion criteria. The interventions must be widely accepted, with at least 70% of included participants completing 70% or more of the planned sessions in the intervention group. Safety of the intervention will be determined based on the number and nature of adverse events (AE).

Secondary outcomes:

Secondary outcomes will assess the patients' responses to the multimodal prehabilitation programme, and data will be collected on explorative outcomes, measured at baseline, the day before surgery and 30 days PO.

Inclusion Criteria:

• Planned to have elective isolated first-time CABG surgery.
• 18 years or older
• Two weeks or more before surgery
• Speaks and understands Danish.
• Gives written informed consent.

Exclusion Criteria:

• Patient with unstable angina pectoris and/ or MI during the last two weeks.
• Left main stem stenosis >50%
• Left ventricular ejection fraction < 35%
• Significant ventricular arrhythmia
• Orthopedic or neurologic preconditions precluding exercise training.
• Inability to attend the prehabilitation program due to physical limitations.
• Patients who have cognitive deficits that would disqualify prehabilitation.
• Severe heart failure, NYHA Class IV
• Lack of capacity to consent