The goal of this study is whether the T-REX Twente precautions have a positive impact on the quality of life (MAcNew QLMI), level of physical activity, and reduction of fear of movement in heart patients after a total median sternotomy compared to the (current) standard precautions? Do these precautions also have no adverse effects on pain, wound healing, and/or postoperative complications?

Participants will be instructed by the physiotherapist to both groups immediately postoperatively and are constantly repeated by the involved disciplines during the hospital stay.

The control group is not allowed to lift, push, or pull for the first 6 weeks. There is little to no evidence for the current strict precautions currently implemented in the department.

The intervention group receives the new T-REX Twente precautions, allowing for more independent activities through the use of the tube model (keeping elbows close to the sides).

All patients receive three questionnaires (MacNew QLMI, Numeric Pain Rating Scale, and Tampa Scale for Kinesiophobia) preoperatively, on the 4th day postoperatively, on the first day of cardiac rehabilitation, and at the end of cardiac rehabilitation, taking approximately 10 minutes each time. Additionally, during the clinical admission immediately postoperatively, two AX3 accelerometers are placed on the patient, one lateroproximal on the right upper arm and one anterodistal on the right upper leg.

Researchers will compare heart patients after a total median sternotomy with T-REX Twente precautions (intervention group) to the (current) standard precautions (control group).

Each year, more than 1000 open-heart surgeries (OHO) are performed at Thorax Centrum Twente (TCT), with 860 of them involving a total median sternotomy. Some patients present themselves at the cardiac care unit with unexplained complaints after discharge, possibly caused by anxiety and insecurity.

There is no consensus regarding postoperative sternal precautions following a total median sternotomy. Studies in the United States and Canada have indicated that these precautions might be too strict, and alternative, less restrictive precautions through the use of the "Keep your Move in the Tube" (KYMITT) approach have been shown safe and without adverse consequences.

Although no statistically significant differences were observed in all outcomes, patients following the new approach (KYMITT) reported fewer issues with functional mobility.

This is a prospective randomized double blind study, collecting data from patients undergoing a total median sternotomy from November 2023 to November 2025 at TCT and concurrently participating in outpatient cardiac rehabilitation under the guidance of TCT.

Previous research using the MacNew quality of life questionnaire among 677 cardiac rehabilitation patients indicated that the difference in response was normally distributed with a standard deviation of 0.25. The KvL-H is the Dutch (validated) translation of the MacNew QLMI. Assuming an effect size of 0.15 (small effect size) across the 4 measurement moments (T0, T2, T4) between the two groups (group*time interaction), a total of 154 patients were needed, i.e. 77 per group. This was based on a Repeated measures ANOVA with an alpha of 0.05, a power of 0.80 and a nonsphericity correction of 1, calculated with G*Power 3.1.9.7. To account for a 10% dropout, 77 patients per group will be included.

A previous study on intensified walking during cardiac rehabilitation after acute myocardial infarction showed a KvL-H increase of 0.9 at the time of discharge (our study: T3) to intake cardiac rehabilitation (our study: T4) from 5.2 to 6.1 at the time of T5. A KvL-H increase of at least 0.15 points is expected in our T-REX Twente sternal precautions group (intervention group); a minimal clinical difference corresponding to a standarized response mean of 0.2.

For the second primary endpoint, the relative percentage of daytime (between 6:00 and 23:00) non-bedtime up to and including 4 days postoperatively on the ICU and nursing ward is examined. From previous research in a similar population, it was observed that a relative rate of lying in bed of 60% is measured on day 1 after discharge from ICU, with a decrease of 6.5% per day (p < 0.001). Assuming a reduction on day 1 to 50%, the medium f2 effect size of 0.5 with a linear mixed model, two-sided testing, alpha of 0.05, power of 0.80 and two predictors (time and group), results in 14 patients needed per group.

The highest number of patients will be retained, i.e. 77 patients per group.

Inclusion Criteria:

• Adult patients who are preoperatively included if they are undergoing a total median sternotomy at Thorax Centrum Twente (TCT)
• Patients with their treating cardiologist also working for TCT.

Exclusion Criteria:

• >72 hours of admission to the Intensive Care Unit (ICU)
• Postoperative delirium (diagnosed with Diagnostic and Statistical Manual of Mental Disorders (DSM) version V
• Patients with dementia (or other significant cognitive disorders)
• Dutch language barriers
• Patients with a cardiologist from a location other than TCT

It is not yet known if there will be a plan to make individual participant data (IPD) available.

Study protocol and statistical analysis plan might be published.

Protocol is expected to be submitted for publication in 2024

Principal Investigator generally supports Open Access publishing and data sharing.

Patients will not be actively informed on their study arm, but will receive conventional or interventional rehabilitation instructions, and might be able to deduct their allocation arm.

The researcher will be blinded for intervention or control group allocation.