Evaluation of the concordance between hemodynamic variables obtained by Swan-Ganz catheterization and transthoracic echocardiography in patients after coronary revascularization surgery

Introduction: Currently, there is a trend towards non-invasive hemodynamic monitoring guided by echocardiography, however, in our center, in patients undergoing coronary revascularization surgery, invasive hemodynamic monitoring with Swan-Ganz catheter placement continues. Given that hemodynamic monitoring using non-invasive methods has been shown to be feasible, it is therefore expected that the hemodynamic variables obtained by echocardiography are consistent with the variables obtained by Swan-Ganz catheterization in this type of patient. The objective of the study is to evaluate the concordance that exists between the different hemodynamic variables obtained by Swan-Ganz catheterization, with the variables obtained by echocardiography. Methods: Observational, non-interventional, retrospective, cross-sectional and analytical study, non-randomized. Patients admitted to the Coronary Unit after coronary revascularization surgery were selected, who had a Swan-Ganz catheter on admission, all patients underwent measurement of the hemodynamic variables CO, RAP, PASP, PWP and later TTE was performed to obtain the same variables. Finally, the Concordance Correlation Coefficient described by Lin CCC= (A2+B2-C2) ÷(A2+B2+D2) and by the Bland-Altman method was used as a statistical tool. Results: 26 patients were included, with a mean age of 63.8 ± 6.2 years, 69.2% male. For the CO variable, an average absolute difference of 0.77 L/min and a CCC of 0.7334 were obtained; in the analysis of (B-A), an average difference is -0.4149 L/min. For the RAP an average difference of 2.11 mmHg, with a CCC = 0.8595 and in the analysis of B-A an average difference of -1.11 mmHg. For the PASP an average absolute difference of 5.11 mmHg was obtained with a CCC = 0.5444 and in the B-A analysis an average difference of 0.2944 mmHg. For PWP an average absolute difference of 2.78 mmHg with a CCC = 0.3842, in the analysis of B-A an average difference of 2.13 mmHg. When carrying out the analysis of the average differences obtained from each of the variables, with which a P value of 0.293 was obtained for the CO, 0.129 for the RAP, 0.308 for the PASP, and 0.017 for the PWP. Conclusions: A poor strength of agreement was observed for the CCC for each of the variables, however, these are not clinically significant, so they can be considered as interchangeable methods. It is important to mention that the TTE provides other relevant parameters in the management of these patients.