Association of Preoperative High C-Reactive Protein to Albumin Ratio with Adverse Outcomes After Elective Non-Cardiac Surgery in Older Patients: A Multicenter Prospective Study.

Purpose: Although preoperative C-Reactive Protein to Albumin Ratio(CAR) is one of the important indicators for surgical risk assessment, the relationship between preoperative CAR and postoperative outcomes in older patients undergoing non-cardiac surgery is still unclear. Therefore, the purpose of this study is to explore the relationship between preoperative CAR and adverse postoperative outcomes in older patients undergoing non-cardiac surgery.

Patients and methods: We conducted a secondary analysis of data from the multicenter, prospective, longitudinal study called Early-Warning model of Perioperative Adverse Events for Elderly Patients (EPAE). A total of 2511 individuals from seven centers in Guangdong province were included in this study. The CAR was the latest blood counts measured within 3 days prior to surgery. The primary outcome of interest in this study was Clavien-Dindo grade III (CD3) complications. Secondary outcomes included: overall morbidity, reoperation and readmission. This cohort compared baseline characteristics and clinical data between different groups based on the quartile of CAR. Multivariate logistic regression and restricted cubic spline analysis (RCS) were used to explore the relationship between CAR and adverse postoperative outcomes. Further, the subgroup analyses were also conducted.

Results: Among the 2511 older patients enrolled in the study, 1524 individuals (60.7%) were females and the median age at admission was 69.0 years (65.0, 73.0). Multivariate logistic regression analysis and sensitivity analysis both revealed that high CAR is associated with a high incidence of CD3 complications, overall morbidity, and reoperation (P < 0.05). Furthermore, the restricted cubic spline analysis shows a non-linear relationship between CAR and overall morbidity (cut-off value = 0.034, P for nonlinear < 0.001). No significant interaction was found in the subgroup analyses (P for interaction >0.05).

Conclusion: In older patients with non-cardiac surgery, high CAR was significantly associated with adverse postoperative outcomes, including CD3 complications, overall morbidity and reoperation.