Background and Goal of Study: Reduced right ventricular function (RVF) is correlated with unfavorable outcome in multiple settings [1, 2]. 3D echocardiography allows global evaluation of right ventricular volumes and function and has been successfully validated against cardiac MRI [3]. In this study we hypothesized that 3D TEE derived parameters of RVF correlate with patient outcome after cardiac surgery. 

Materials and Methods: After approval by the institutional review board (IRB) a retrospective analysis in the institutional echo database was performed. 126 patients undergoing cardiac surgery with cardiopulmonary bypass between November 2013 and June 2016 at the University Hospital Tübingen, Germany were identified to have complete preoperative 3D datasets. 17 patients were excluded due to low frame rate or right sided cardiac surgery. A 4D model of the right ventricle (RV) was generated using the Tomtec 4D RV Function® Software (Ver.2, TomTec Imaging Systems GmbH, Unterschleissheim, Germany). End-diastolic (RVEDVI) and end-systolic (RVESVI) volume and ejection fraction (RVEF) were calculated. TAPSE and global longitudinal strain of the RV free wall (GLS-fw) were obtained from an optimally aligned 4-chamber view, generated with the 3D dataset. Patient demographics, surgical procedures and laboratory parameters were collected from the clinical records. Unfavorable outcome was defined as an ICU stay greater than 48 hours, acute renal failure (AKIN stage 1 or higher) or death during the hospital stay. 

Results and Discussion: 109 patients [78 male (71.6%) and 31 female (28.4%), median age: 64±15.7SD, BSA 1.93±0.25SD] were included in the analysis. Procedures included coronary artery bypass grafting (CABG; 28.4%), aortic or mitral valve repair/replacement (35.8%), combination of CABG and valve surgery (15.6%), left ventricular assist device implantation (LVAD; 15.6%) or thoracic aortic surgery (4.6%). 66 patients (60.6%) had an unfavorable outcome. They had a significantly elevated preoperative RVEDVI (79.01±27.65SD vs. 62.56±17.53SD, p< 0,05), a significantly reduced preoperative 3D RVEF (32.68%±9.5SD vs. 37.53%±7.07SD, p<0.05) and a significantly reduced GLS-fw (-12.76%±6.64SD vs. -16.16%±6.33SD), p<0.05). Whereas the tricuspid annular plane systolic excursion (TAPSE) was not significantly different in both groups (11.73±5.45SD vs. 13.17±5.94SD, p=0.37). 

Conclusions: 3D TEE derived parameters of RV size and function seem to correlate with patient outcome in a heterogeneous group of cardiac surgery procedures. 3D echocardiography might help to identify patients at risk for unfavorable outcome after cardiac surgery in the future.

References:
1) Meyer P et.al.; Circulation 2010; 121:252-258
2) Maslow A et.al.; Anesth Analg 2012; 1507-18
3) Medvedofsky D et.al.; J Am Soc Echocardiogr 2015; 1222-31

Preoperative 3D right ventricular function correlates with patient outcome after cardiac surgery