Study population
This was a single centre study at Rigshospitalet, Denmark. 356 patients
planned to undergo coronary artery by-pass grafting and/or aortic valve
replacement were enrolled from February 2016 to March 2018. A subgroup
of 50 patients, consecutively enrolled from October 2017 to January
2018, were used for the reproducibility studies. In order to reflect
daily clinical practice, patients were not excluded due to poor acoustic
window, dyspnoea, or obesity. The study was performed in accordance with
the Declaration of Helsinki and approved by the Ethics Committee for the
Capital Region Copenhagen. All patients provided written informed
consent.