<p><strong>Background: </strong>Myocardial injury after noncardiac surgery (MINS) increases the risk of 30-day mortality. Intraoperative hemodynamic events (i.e., tachycardia, bradycardia, hypotension, and hypertension) may contribute to developing MINS.</p> <p><strong>Objectives: </strong>To determine if the addition of the duration spent within predefined intraoperative systolic blood pressure (BP; mmHg) (i.e.,160-199 and ≥200) and heart rate (HR; bpm) (i.e.,100-140 and >140) hemodynamic bands improved the prediction of Day 1 MINS (i.e., postoperative troponin T elevation ≥0.03 ng/ml within the first day after surgery) beyond preoperative risk model prediction.</p> <p><strong>Methods: </strong> Prospective observational data was used to developed a baseline risk model to predict Day 1 MINS. Preoperative HR, systolic BP, and hemoglobin as well as intraoperative duration spent within each predefined hemodynamic band were explored to identify optimal thresholds for the prediction of Day-1 MINS. Preoperative variables were added to the baseline risk model to create a preoperative model. Intraoperative variables were then added to the preoperative risk model to create the final model. Models were compared using discrimination (c-statistic) and net reclassification index (NRI).</p> <p><strong>Results: </strong>Adding preoperative hemoglobin ≤105 g/dL, systolic BP110 improved baseline model discrimination (0.783 to 0.792, p5min; HR >100 for >147min; systolic BP59min and systolic BP >160 for >42min further improved discrimination (0.8; p</p> <p><strong>Conclusion:</strong> Adding intraoperative hemodynamic durations significantly improved Day-1 MINS model discrimination and risk stratification compared to the baseline risk model.</p> / Master of Health Sciences (MSc)