Relationship of arterial stiffness value with hemodynamic parameters in patients undergoing cardiac surgery

Purpose: Hypotension, which is more common in the period between the induction of general anesthesia and the beginning of surgery, is associated with negative outcomes in both cardiac and non-cardiac surgery patients. The aim of our study is to examine the relationship of the arterial stiffness value obtained from Doppler ultrasonography (USG) and carotid/femoral pulse wave velocity measurements with hemodynamic parameters, mainly hypotension, time of stay in the hospital and intensive care unit, and mortality in patients undergoing cardiac surgery. Method: 121 patients who would undergo cardiac surgery were included in the study. In addition to routine monitoring, 3-lead electrocardiogram (ECG) cables of USG were connected to the patients. All patients were sedated before the measurement. Carotid/femoral pulse wave velocity was obtained by Doppler flow measurements from the right common carotid artery and femoral artery in the supine position. Maximum and minimum diameter measurements of the right common carotid artery and internal jugular vein (IJV) were made with USG M mode. Parameters were determined as arterial stiffness, stiffness index, IJV collapsibility index and IJV/carotid index. For pulse wave velocity measurements, the delay time between the starting point of the Doppler wave in both the common carotid artery and femoral artery and the R wave in the ECG was determined. Then, the distance between the common carotid artery and the femoral artery where the imaging was performed was measured. The distance between two points was proportional to the delay time. Measurements were made on three consecutive waves and averaged. The results obtained were described as pulse wave velocity (PWV) meters per second (m/s). This value was accepted as the degree of arterial stiffness. Stiffness index, IJV collapsibility index and IJV/carotid index were calculated from the maximum and minimum diameters of the common carotid artery and internal jugular vein with USG M mode. Standard anesthesia induction was provided to all patients. Various reductions in absolute and basal threshold values of systolic arterial pressure and mean arterial pressure were used to define hypotension. During the operation, hemodynamic response analyzes were performed using the vasoactive inotropic score. Postoperative hospital stay, intensive care unit stay and mortality rates were also recorded. Results: A weak correlation was observed between arterial stiffness and age and minimum carotid diameter, and between stiffness index and basal systolic arterial pressure and minimum carotid diameter (p˂0,05). The effect levels of arterial stiffness, stiffness index and IJV/carotid index parameters on mortality were examined and no significant effect profile or significant predictive feature was detected (p>0,05). The effect levels of arterial stiffness value on hypotension and their predictive ability for hypotension were analyzed, and logistic regression analysis was performed separately for each of the parameters. In the examinations based on the limits determined for hypotension, no significant effect level and/or predictive feature was observed in the parameters (p>0,05). Total vasoactive inotropic score (p=0,012) and length of stay in the intensive care unit (p=0,019) were seen to be higher in patients who died and were significant. Conclusion: In this study conducted on cardiac surgery patients, no significant relationship was found between arterial stiffness, stiffness index, IJV/carotid index and IJV collapsibility index evaluated by USG and hypotension, length of stay in the intensive care unit and hospital, and mortality. More comprehensive, prospective, randomized controlled studies are needed to use USG in arterial stiffness measurement and to use arterial stiffness value as a hemodynamic index indicator. Keywords: Arterial stiffness, cardiac surgery, doppler ultrasonography, hemodynamics, pulse wave velocity, stiffness index