BACKGROUND: A pathological decrease in the serum prealbumin level is closely associated with the severity of various diseases and complications after surgery. Many patients suffer from a systemic inflammatory response and local myocardial ischemia after off-pump coronary artery bypass grafting, which is related to an adverse prognosis. This study aimed to explore the relationship between the serum prealbumin level and early complications following off-pump coronary artery bypass grafting, in addition to its predictive value. METHODS: Data were retrospectively collected on patients undergoing off-pump coronary artery bypass grafting from January 2014 to July 2019. The serum prealbumin level was assessed within 6-12 h after the operation. Patients were classified into two groups: the "normal" level group (≥17 mg/dl) and the "low" level group (<
17 mg/dl). Univariate and multivariable analyses were performed to evaluate the predictive value of a low serum prealbumin level. RESULTS: Of the 1,002 patients, 553 (55.2%) had a low serum prealbumin level. The rate of pulmonary infection in the low group was significantly higher than in the normal group. Univariate analysis and multivariable analysis indicated that a low serum prealbumin level was associated with the increased incidence of postoperative pulmonary infection, pleural effusion, and new-onset atrial fibrillation. CONCLUSION: The serum prealbumin level following off-pump coronary artery bypass grafting serves as a crucial predictor for early major postoperative complications, such as pulmonary complications and new-onset atrial fibrillation. Early identification of high-risk patients by assessing serum prealbumin levels, in addition to the timely adjustment of treatment and care strategies, can improve patient prognosis, shorten hospital stays, and reduce healthcare expenses.