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 (grouptime
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 GPower 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.