Association between intraoperative cardiac cycle efficiency and postoperative high-sensitivity troponin elevation: a prospective exploratory study

Myocardial injury after noncardiac surgery (MINS) is a major determinant of perioperative morbidity and mortality. Its largely silent clinical course often makes early diagnosis difficult. Cardiac Cycle Efficiency (CCE) is a new parameter that reflects the energy efficiency of the cardiovascular system. This prospective observational study aimed to evaluate the relationship between intraoperative CCE values and postoperative myocardial injury in patients undergoing elective surgery. The study, which included 50 patients, was designed as an observational prospective study. The CCE parameters, including baseline CCE, minimum CCE, mean CCE, ΔCCE, and the duration and percentage of CCE < 0, were recorded continuously. High-sensitivity troponin I levels were measured on postoperative days 1, 2, and 3, and levels above the sex-specific 99th percentile were considered the primary endpoint. In our study, postoperative troponin levels were found to be above the reference limit in 11 patients (22%), and none had ischemic symptoms or new ischemic ECG changes. No significant between-group differences were observed in operative duration, blood loss, vasopressor use, or intraoperative hypotension (all p > 0.05).Comparison of CCE-derived parameters between the elevated and normal troponin groups yielded no statistically significant differences for any variable (Minimum CCE p = 0.87, Mean CCE p = 0.68, Delta CCE p = 0.69, baseline CCE p = 0.20, time with CCE < 0 p = 0.19, CCE < 0 percentage p = 0.51). Spearman rank correlation analysis similarly demonstrated no significant association between any CCE parameter and peak troponin levels. On ROC curve analysis, none of the CCE parameters exhibited meaningful discriminative ability, with the highest AUC recorded for cumulative time with CCE below zero (AUC = 0.63, 95% CI: 0.43–0.83, p = 0.19). In this small exploratory cohort, no statistically significant association was found between intraoperative CCE parameters and postoperative troponin elevation. The potential role of CCE should be tested in perioperative risk assessment in larger and higher-risk cohort studies.