Fig. 1

Flow chart of the study inclusion. Between March 2019 and March 2023, 98 patients underwent orthotopic heart transplantation at our center, and 96 patients were screened for study inclusion. Eight patients who met the exclusion criteria were excluded from this study: six cases were automatically excluded as enrolment reached the expected sample size for group D, two cases were younger than 18 years, one case had severe hypotension due to alveolar recruitment maneuver, and one case had hyperacute rejection with intraoperative veno-arterial extracorporeal membrane oxygenation assistance. Finally, an observational study of 88 patients was conducted over a 30-day follow-up period.