AIMS: Cardiac surgery is the cornerstone of treatment of several heart conditions, but accurate risk stratification is critical. Commonly used scores do not include right ventricular (RV) function. We aimed to evaluate if 3D right ventricular ejection fraction (RVEF) predicts outcomes in patients undergoing cardiac surgery after adjusting for the EuroSCORE II. METHODS AND RESULTS: Prospective multicenter study of adult patients undergoing cardiac surgery at 3 centers. RV function parameters were analyzed with transesophageal echocardiogram before the surgery. We evaluated the association of 3D RVEF with the primary outcome (composite of in-hospital mortality or need of temporary ventricular assist device) after adjusting for the EuroSCORE II. Exploratory endpoints were time on mechanical ventilation and time on inotropes. We included 248 patients (median age 69 years
43% female). Sixty nine percent had normal RVEF (≥45%). RV function parameters (TAPSE, FAC and RVFWLS) were lower in the group of decreased RVEF (p<
0.001 for all). The primary outcome occurred in 28 patients (11%). After adjusting for the EuroSCORE II, decreased RVEF was independently associated with the primary outcome (HR 2.46, 95% CI 1.10, 5.50, p=0.028). Importantly, 3D RVEF was superior to all other parameters of RV systolic function to predict the primary outcome (p=0.006). At 30 days, survival free of the primary endpoint was 72±8% vs. 93±3% (p<
0.001) in decreased vs normal RVEF, respectively. RVEF was associated with shorter time on mechanical ventilation (r= -0.27, p<
0.001) and shorter time on inotropes (r= -0.20, p=0.01). CONCLUSIONS: Among the RV function parameters, 3D RVEF is the strongest predictor of in-hospital mortality or need of temporary ventricular assist device in patients undergoing cardiac surgery. This multicenter study suggests that 3D RVEF should be included in the evaluation of patients undergoing surgery because it might improve stratification.