Intraoperative Heart Rate Thresholds and Postoperative Mortality

This is a retrospective cohort study conducted to evaluate the clinical impact of intraoperative heart rate on postoperative 30-day mortality in patients undergoing non-cardiac surgery. Patient data were extracted from a large institutional electronic medical record database, including demographic variables, comorbidities, anesthesia records, and perioperative outcomes. Heart rate was continuously recorded at 1-minute or 5-minute intervals during the surgery. Various heart rate parameters-such as minimum, maximum, average, and time-weighted average-were analyzed, and threshold-based metrics (e.g., minutes spent below or above defined thresholds) were computed using a piecewise cubic Hermite interpolating polynomial (PCHIP) method to smooth minute-by-minute fluctuations. The primary outcome was all-cause mortality within 30 days after surgery. Multivariable logistic regression and sensitivity analyses were performed to adjust for potential confounders. The study aimed to provide clinical insight into the prognostic value of intraoperative heart rate dynamics and to identify modifiable intraoperative risk factors for mortality.