To the Editor:
We read with interest the study by de la Hoz et al., focusing on the association between intraoperative hypotension and postoperative complications in the field of cardiac surgery. We strongly agree with the importance of perfusion pressure during cardiac surgery with cardiopulmonary bypass. However, considering hemodynamic concepts and recent literature, we believe that the definition of hypotension used could be discussed. The authors used a mean arterial pressure (MAP) value of 65 mmHg as the hypotension threshold for all patients. Although this value is used as a threshold for organ perfusion in clinical situations such as septic shock or the perioperative period randomized data showed that a higher threshold should be obtained in hypertensive patients to avoid acute kidney injury in specific settings. In the described cohort of cardiac surgery patients, hypertensive patients represent 79% of the population. The trend of individualizing the arterial pressure goal to the reference baseline of each patient is inspired by the pathophysiologic rightward shift of the perfusion autoregulation curve in hypertensive patients. In cardiac surgery, few randomized data using individualized MAP as a target exist, but a recent trial showed that adapting the MAP to the autoregulation curve of the patient, determined by cerebral Doppler monitoring, improved neurologic outcome. Given these elements, we are intrigued by the use of an absolute hypotension threshold definition of 65 mmHg in the specific setting of cardiac surgery. More randomized trials are needed to further address the optimal MAP during cardiac surgery, such as the Perioperative Individualized Optimization of Mean Arterial Pressure in Cardiac Surgery trial (ClinicalTrials.gov Identifier: NCT05403697).