This retrospective observational study investigates the association between intraoperative heart rate and 30-day postoperative mortality among patients undergoing non-cardiac surgery. The findings suggest that heart rate abnormalities during surgery may significantly affect short-term postoperative outcomes.

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.

Inclusion Criteria:

• Patients who underwent non-cardiac surgery at our medical center between March 2019 and February 2023
• Age ≥ 18 years
• Availability of complete laboratory data and perioperative vital signs
• Only the first surgery performed after hospital admission was included for patients with multiple

Exclusion Criteria:

• Cardiac-related surgical procedures
• Pregnancy at the time of surgery
• Age < 18 years
• Surgeries lasting less than 30 minutes
• Cadaveric procedures
• Missing or incomplete laboratory values or vital sign data

Adult patients (aged 18 years or older) who underwent non-cardiac surgery under general or regional anesthesia at a single tertiary medical center. Only the first surgery after admission was included for patients who underwent multiple procedures. Patients undergoing cardiac-related procedures, pediatric or obstetric cases, cadaveric surgeries, or those with incomplete vital signs or laboratory data were excluded.

The dataset used and/or analyzed during the current study is available from the corresponding author upon reasonable request.