Exposure-based stratification of postoperative complications in major cardiac surgical procedures: a retrospective cohort study using the MOVER database

Objective Postoperative complications and perioperative physiologic stress remain major contributors to postoperative morbidity following complex cardiac surgery. This study aimed to evaluate perioperative exposure patterns and develop an exploratory exposure-based risk stratification framework for examining associations with postoperative complications among patients undergoing coronary artery bypass grafting (CABG) and major aortic surgical procedures using the MOVER database. Methods A retrospective cohort study was conducted using the EPIC_EMR component of the MOVER perioperative database. Among 65,728 surgical records, 639 major cardiac surgical procedures, including CABG and aortic procedures, from 609 unique patients were identified after applying inclusion criteria and data quality filtering. Baseline demographic characteristics, perioperative exposure variables, and diagnostic history were integrated for analysis. Logistic regression modeling was used to identify variables associated with postoperative complications. A composite perioperative exposure score (incorporating operating room duration, anesthesia duration, and diagnosis burden) was created to classify patients into low, intermediate, and high-exposure groups. Results The median patient age was 64 years (IQR 55.5–71.0), and 77.5% of patients were male. Median operating room and anesthesia durations were 423.0 min (IQR 374.0–487.0) and 437.0 min (IQR 389.0–505.0), respectively. Overall, postoperative complications occurred in 23 of 639 procedures (3.6%). In multivariable analysis, anesthesia duration (OR 1.006, 95% CI 1.002–1.010, p = 0.005) and operating room duration (OR 1.004, 95% CI 1.001–1.008, p = 0.021), remained associated with postoperative complications, whereas hospital length of stay was analyzed separately as a postoperative outcome rather than included as a predictor. Patients in the highest exposure tertile demonstrated 2.31-fold higher odds of complications (95% CI 1.12–4.76, p = 0.023) compared with the lowest exposure group. Conclusion Prolonged perioperative exposure is significantly associated with postoperative complications in major cardiac surgical procedures. Exposure-based perioperative metrics may serve as practical indicators of perioperative exposure burden and provide an exploratory framework for risk assessment in cardiac surgical populations.