Right ventricular systolic dysfunction and vena cava dilatation precede alteration of renal function in adult patients undergoing cardiac surgery

BACKGROUND: Several authors have suggested that right ventricular dysfunction (RVd) may contribute to renal dysfunction in nonsurgical patients. OBJECTIVES: We tested the hypothesis that RVd diagnosed immediately after cardiac surgery may be associated with subsequent development of renal dysfunction and tried to identify the possible mechanisms. DESIGN: A single-centre, prospective observational study. SETTING: Amiens University Hospital, France. PATIENTS: All adult patients undergoing cardiac surgery were considered eligible for participation. Patients who had undergone pulmonary or tricuspid valve surgery, repeat surgery or who underwent immediate postoperative renal replacement therapy were excluded. Data from 74 patients were analysed. MAIN OUTCOME MEASURES: Left ventricular and right ventricular function were assessed before surgery and on admission to ICU by transthoracic echocardiography (TTE): left ventricular and right ventricular ejection fractions (LVEF/RVEF), tricuspid annular plane systolic excursion (TAPSE), tricuspid annular systolic velocity (Sr(t)) and right ventricular dilatation. RVd was defined as values in the lowest quartile of at least two echocardiographic variables. Renal dysfunction was defined as an increase in serum creatinine concentration (sCr) on postoperative day 1. RESULTS: All right ventricular TTE variables decreased (P < 0.05) after surgery: RVEF from 50% (49 to 60) to 40% (35 to 50); TAPSE from 22.3 mm (19.4 to 25.3) to 12.2 mm (8.8 to 14.8); and Sr(t) from 15.0 cm s(-1) (12.0 to 18.0) to 8.1 cm s(-1) (6.3 to 9.2). Fourteen (19%) patients had right ventricular dilatation and RVd was present in 23 (31%) patients. Forty patients had a positive variation in sCr. In multivariate analysis, patients with RVd had an odds ratio (OR) of 12.7 95% confidence interval (95% CI) 2.6 to 63.4, P = 0.02 for development of renal dysfunction. Renal dysfunction was associated with increased central venous pressure but was not associated with cardiac index (CI). CONCLUSION: These results suggest that early postoperative RVd is associated with a subsequent increase of sCr and that the mechanism involved is congestion (vena cava dilatation/elevated CVP) rather than decreased CI.