The Impact of Blood Pressure Below Personalized Lower Cerebral Autoregulation Limit on Outcomes After Cardiac Surgery: A Retrospective Study.

Abstract

Objective: The clinical importance of individualized blood pressure management in optimizing cerebral perfusion during cardiac surgery has been well established. However, consensus on blood pressure goals is lacking. The authors studied the associations between cerebral autoregulation metrics, hemodynamic parameters, and postoperative outcomes, and hypothesized that increased time of mean arterial pressure (MAP) below the lower limit of autoregulation (LLA) is associated with major morbidity and mortality (MMOM) incidence.

Design: A retrospective, observational study.

Setting: A university hospital.

Participants: A total of 686 cardiovascular surgeries were included.

Intervention: None.

Measurement and main results: The area under the time-pressure curve (AUC) for MAP < LLA and time below LLA (AUC_{ABP) were analyzed for associations with stroke, acute kidney injury, low cardiac output syndrome, mechanical ventilation lasting >48 hours, and postoperative mortality (ie, MMOM). There was no significant association between AUCABP and MMOM (p > 0.05). Relationships were observed between components of MMOM-operative mortality (p < 0.05) and low cardiac output syndrome (p < 0.05)-and AUCABP, when controlling for preoperative hemoglobin levels and logistic EuroSCORE.}

Conclusions: These findings indicate that LLA-related metrics have limited utility for predicting MMOM. Future research should explore their applicability in various contexts and patient cohorts.