The impact of preoperative weight loss on recovery after cardiac surgery.

To examine the impact of preoperative weight fluctuations on postoperative outcomes in patients underwent elective cardiovascular surgery. This retrospective study included 157 consecutive patients who underwent elective cardiovascular surgery between April 2018 and March 2023. We assessed weight changes during a median surgical waiting period of 42 days. The primary outcome was the postoperative length of hospital stay. Patients were stratified into two groups-weight loss and weight maintenance-based on a 1-standard deviation (SD) reduction in weight variability. Multiple regression analysis was performed with adjustments for confounding factors. The mean weight change was + 1.9%, and the threshold for definition of the 'weight loss' and 'weight maintenance' groups was set at 1 SD (- 1.5%). The weight loss group (n = 22, 14%), with a weight loss that exceeded 1.5%, had significantly length of hospital stay been prolonged by a median of 5.0 days compared to the weight maintenance group (n = 135, 86%) (21.0 [17.0, 28.0] vs 26.0 [19.3, 42]; p = 0.03). In a multivariate analysis, weight change of - 1.5% (p < 0.01), eGFR (p = 0.04), and intubation days (p < 0.01) were significantly associated. Unintentional preoperative weight loss exceeding 1.5% was associated with a longer hospital stay. The identification of unintentional preoperative weight loss could aid clinicians in preoperative guidance and risk stratification.