Results
3D-RV FWS analysis was feasible in 142 (95%) patients. All patients had a complete myocardial revascularization at the end of surgery and pericardial closure. None of the patients was pacemaker dependent or on inotropic or vasopressor support during echocardiographic evaluation. Baseline characteristics are presented in Table 1. Essential perioperative data are presented in Table 2.
No patient required intraoperatively inotropic or mechanical circulatory support after bypass, experienced shock or had a second run on CPB after termination of extracorporal circulation.
There were no postoperative complications in this patient population such as MACE, stroke, transitory ischemic attack, shock, pneumonia, or in-hospital death. No patient needed postoperatively renal replacement therapy, mechanical circulatory support, or redo CABG or percutaneous revascularization. Two patients (1.4%) had a ventilation time of more than 24 hours (34 and 39 hours, respectively) and ten patients (7.0%) developed atrial fibrillation postoperatively.
In our group of patients, median values with interquartile range (IQR) for 3D-RV FWS and 3D-RV EF were - 25.2 (IQR -29.9 - -21.8) and 46.3% (IQR 41.0 - 50.1%), respectively. RV FAC, RV S´ and TAPSE accounted for 39.7% (IQR 34.5 - 44.4%), 14.8cm/s (IQR 11.8 - 19.0cm/s) and 22 mm (IQR 20-25mm). There was no correlation of 3D-RV FWS and patient outcome, beside a small and clinically irrelevant correlation to prolonged in-hospital duration (r2=0.03, p=0.02), in our group of patients. Normal values (2.5% to 97.5% percentile) for 3D-RV FWS and 3D-RV EF were -37.1 to -12.8 and for 34.9% to 58.2%, respectively, and amounted 24.6% to 52.1% for RV FAC, 5.7cm/s to 34.3cm/s for RV S‘ and 15.6mm to 31.5mm for TAPSE.
In 22 patients (15%) 3D-RV FWS was more impaired than -20, as suggested cut-off value for two-dimensional-derived (2D) RV FWS by recent guidelines on chamber quantification5. Considering only patients with 3D-RV EF ≥45%, regarded as normal for TTE-assessed 3D-RV EF by same guidelines,5 we observed median values for 3D-RV FWS of -27.7 (IQR -31.5; -24.5) and a 2.5% to 97.5% - percentile of -38.5 to -17.1 in this subgroup of 86 patients.
Intraoperative values of 3D-RV FWS and the conventional echocardiographic parameters of RV function are presented in Table 3 and Figure 2 and 3.