Coronary sinus collapsibility index and inferior vena cava collapsibility index can predict right atrial pressure in patients undergoing right heart catheterization

Background The aim of the study is to investigate the relationship between the diameters and collapsibility indices of coronary sinus (CS) and inferior vena cava (IVC) and invasively measured right atrial pressure (RAP), and to determine whether these parameters have predictive value on RAP. Methods A total of 136 patients undergoing right heart catheterization due to pulmonary arterial hypertension were included in the study prospectively. CS diameters, IVC diameters, CS collapsibility index (CSCI), and IVC collapsibility index (IVCCI) were measured by echocardiography before catheterization. Pearson correlation analysis was used to compare the parameters. Receiver operating characteristics (ROC) curve analysis was used to determine the predictive value of the CS and IVC collapsibility indices in predicting RAP. Results Patients were divided into two groups as invasively measured RAP >= 10 mm Hg (n:57) and RAP < 10 mm Hg (n:79). In the group with RAP >= 10 mm Hg, IVC and CS diameters were higher than in the group with RAP < 10 mm Hg, while the IVCCI and CSCI were lower (p < 0.001). A negative correlation was observed between CSCI and IVCCI and RAP. Also, a positive correlation was observed between CSCI and IVCCI. Optimal cut-off value for IVCCI was 46.1 with a sensitivity of 75%, and specificity of 79.7%. Optimal cut-off value for CSCI was 39.2 with a sensitivity of 75.4%, and specificity of 88.6%. Conclusion CS and IVC diameters and collapsibility indices measured by echocardiography were found to be associated with invasively measured RAP, and may be used together for estimating RAP.