Platelet Counts, Acute Kidney Injury, and Mortality after Coronary Artery Bypass Grafting Surgery

• Published in: Anesthesiology (Philadelphia) Vol. 124; no. 2; pp. 339 - 352
• Main Authors: Kertai, Miklos D, Zhou, Shan, Karhausen, Jörn A, Cooter, Mary, Jooste, Edmund, Li, Yi-Ju, White, William D, Aronson, Solomon, Podgoreanu, Mihai V, Gaca, Jeffrey, Welsby, Ian J, Levy, Jerrold H, Stafford-Smith, Mark, Mathew, Joseph P, Fontes, Manuel L
• Format: Journal Article
• Language: English
• Published: United States Copyright by , the American Society of Anesthesiologists, Inc. Wolters Kluwer Health, Inc 01.02.2016
• Subjects: Acute Kidney Injury - epidemiology; Coronary Artery Bypass - statistics & numerical data; Hospital Mortality; Humans; Incidence; Kaplan-Meier Estimate; North Carolina - epidemiology; Platelet Count - statistics & numerical data; Postoperative Complications - epidemiology; Proportional Hazards Models; Retrospective Studies; Risk Factors; Treatment Outcome; North Carolina
• ISSN: 0003-3022; 1528-1175
• DOI: 10.1097/ALN.0000000000000959

BACKGROUND:Cardiac surgery requiring cardiopulmonary bypass is associated with platelet activation. Because platelets are increasingly recognized as important effectors of ischemia and end-organ inflammatory injury, the authors explored whether postoperative nadir platelet counts are associated with acute kidney injury (AKI) and mortality after coronary artery bypass grafting (CABG) surgery. METHODS:The authors evaluated 4,217 adult patients who underwent CABG surgery. Postoperative nadir platelet counts were defined as the lowest in-hospital values and were used as a continuous predictor of postoperative AKI and mortality. Nadir values in the lowest 10th percentile were also used as a categorical predictor. Multivariable logistic regression and Cox proportional hazard models examined the association between postoperative platelet counts, postoperative AKI, and mortality. RESULTS:The median postoperative nadir platelet count was 121 × 10/l. The incidence of postoperative AKI was 54%, including 9.5% (215 patients) and 3.4% (76 patients) who experienced stages II and III AKI, respectively. For every 30 × 10/l decrease in platelet counts, the risk for postoperative AKI increased by 14% (adjusted odds ratio, 1.14; 95% CI, 1.09 to 1.20; P < 0.0001). Patients with platelet counts in the lowest 10th percentile were three times more likely to progress to a higher severity of postoperative AKI (adjusted proportional odds ratio, 3.04; 95% CI, 2.26 to 4.07; P < 0.0001) and had associated increased risk for mortality immediately after surgery (adjusted hazard ratio, 5.46; 95% CI, 3.79 to 7.89; P < 0.0001). CONCLUSION:The authors found a significant association between postoperative nadir platelet counts and AKI and short-term mortality after CABG surgery.