Copyright © 2019 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved. 910 www.ccmjournal.org July 2019 • Volume 47 • Number 7 Objectives: Hypotension thresholds that provoke renal injury, myocardial injury, and mortality in critical care patients remain unknown. We primarily sought to determine the relationship be- tween hypotension and a composite of myocardial injury (troponin T ≥ 0.03 ng/mL without nonischemic cause) and death up to 7 postoperative days. Secondarily, we considered acute kidney in- jury (creatinine concentration ≥ 0.3 mg/dL or 1.5 times baseline). Design: Retrospective cohort. Setting: Surgical ICU at an academic medical center. Patients: Two-thousand eight-hundred thirty-three postoperative patients admitted to the surgical ICU. Interventions: A Cox proportional hazard survival model was used to assess the association between lowest mean arterial pressure on each intensive care day, considered as a time-varying covariate, and outcomes. In sensitivity analyses hypotension defned as pres- sures less than 80 mm Hg and 70 mm Hg were also considered. Measurements and Main Results: There was a strong nonlinear (quadratic) association between the lowest mean arterial pres- sure and the primary outcome of myocardial injury after noncar- diac surgery or mortality, with estimated risk increasing at lower pressures. The risk of myocardial injury after noncardiac surgery or mortality was an estimated 23% higher at the 25th percentile (78 mm Hg) of lowest mean arterial pressure compared with at the median of 87 mm Hg, with adjusted hazard ratio (95% CI) of 1.23 (1.12–1.355; p < 0.001). Overall results were generally similar in sensitivity analyses based on every hour of mean arte- rial pressure less than 80 mm Hg and any mean arterial pressure less than 70 mm Hg. Post hoc analyses showed that the relation- ship between ICU hypotension and outcomes depended on the amount of intraoperative hypotension. The risk of acute kidney injury increased over a range of minimum daily pressures from 110 mm Hg to 50 mm Hg, with an adjusted hazard ratio of 1.27 (95% CI, 1.18–1.37; p < 0.001). Conclusions: Increasing amounts of hypotension (defned by low- est mean arterial pressures per day) were strongly associated with myocardial injury, mortality, and renal injury in postoperative critical care patients. (Crit Care Med 2019; 47:910–917) Key Words: hypotension; intensive care; mean arterial pressure; outcomes; postoperative; surgical M yocardial injury is the leading cause of attribut- able death after noncardiac surgery, accounting for about a quarter of all 30-day mortality (1). Acute kidney injury (AKI) also causes considerable morbidity and is associated with prolong hospitalization and mortality (2, 3). DOI: 10.1097/CCM.0000000000003763 1 Center for Critical Care, Department of Outcomes Research, Anesthesi- ology Institute, Cleveland Clinic, Cleveland, OH. 2 Department of Anesthesiology, Section on Critical Care Medicine, Wake Forest University School of Medicine, Wake Forest Baptist Medical Center, Winston-Salem, NC. 3 Department of Outcomes Research, Anesthesiology Institute, Cleveland Clinic, Cleveland, OH. 4 Department of Quantitative Health Sciences, Cleveland Clinic, Cleve- land, OH. This work was performed by the Center for Critical Care and the Depart- ments of General Anesthesiology & Outcomes Research at the An- esthesiology Institute, Cleveland Clinic, 9500 Euclid Avenue, G-58, Cleveland, OH. Supplemental digital content is available for this article. Direct URL cita- tions appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website (http://journals.lww.com/ ccmjournal). Supported, in part, by the La Jolla Pharmaceutical Company (La Jolla, CA). Dr. Khanna is a past awardee of the Foundation for Anesthesia Education & Research mentored research training grant in clinical and translational research; and consulted for La Jolla Pharmaceuticals. Drs. Maheshwari and Sessler consulted for Edwards Lifesciences. Cleveland Clinic re- ceived funding from La Jolla Pharmaceuticals. The remaining authors have declared that they do not have any conficts of interest. For information regarding this article, E-mail: ashish@or.org Copyright © 2019 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved. Association Between Mean Arterial Pressure and Acute Kidney Injury and a Composite of Myocardial Injury and Mortality in Postoperative Critically Ill Patients: A Retrospective Cohort Analysis Ashish K. Khanna, MD, FCCP, FCCM 1,2 ; Kamal Maheshwari, MD, MPH 3 ; Guangmei Mao, MS 3,4 ; Liu Liu, MS 3,4 ; Silvia E. Perez-Protto, MD 3 ; Praneeta Chodavarapu, MD 3 ; Yehoshua N. Schacham, MD 3 ; Daniel I. Sessler, MD 3