621 Preoperative Platelet to Lymphocyte Ratio as a Predictor for Readmission to ICU and ICU Length of Stay in Patients undergoing Coronary Artery Bypass Graft Surgery

Abstract

Platelet to lymphocyte ratio (PLR) is emerging as a prognostic marker for cardiovascular outcomes. In this study, we examined the prognostic value of elevated PLR in predicting poor outcomes in a population of patients undergoing coronary artery bypass grafting (CABG). We included 525 eligible patients undergoing CABG at St Vincent’s Hospital Melbourne from May 2012 to December 2019. High and low PLR groups were defined as patients having preoperative PLR values in the highest quartile (≥165.7) and lower three quartiles (<165.7) respectively. The high PLR group was significantly associated with readmission to ICU (p=0.01), and ICU length of stay (p=0.01). The high PLR group had mean (±SD) ICU time of 54.2 (±67.1) hours versus 43.1 (±67.9) hours for the low PLR group. On multivariate logistic regression analysis, the high PLR group independently predicted readmission to ICU (OR 3.1; p=0.04) after adjustment for theoretically and statistically significant risk factors for ICU stay. There was no significant association with 30-day mortality, 30-day readmission and major adverse cardiovascular events (MACE). PLR independently predicted ICU readmission and ICU length of stay in CABG patients. The longer ICU time has clear implications to patient health and financial burdens. Detailed assessment of this easily accessible biomarker is warranted as a prognostic marker in CABG patients.