The Role of Right Ventricular Function in Mitral Valve Surgery

BACKGROUND: An impaired right ventricular function is associated with a poor survival rate in patients with heart failure. Few investigations have analyzed the prognostic value of right ventricular function on the outcomes of mitral valve (MV) surgery. The objectives of this study were to define the effect of right ventricular function on postoperative outcomes after MV repair (MVP) or replacement (MVR). METHODS: From September 2007 to February 2012, 335 consecutive patients underwent MVP or MVR at our institution. Preoperative transthoracic and transesophageal echocardiography (TEE) and postoperative TEE were used to define right ventricular function and MV performance. Preoperative right ventricular function was graded as normal to mild (grade 1-2) or as moderate to severe (grade 3-4). MV or tricuspid valve regurgitation was graded as non-trivial to mild (grade 0-2) or as moderate to severe (grade 3-4) preoperatively and postoperatively. Survival rate was evaluated at 1 year after surgery. RESULTS: Of the 334 patients in the study, 280 patients showed a normal to a mildly impaired right ventricular function preoperatively (group 1). Fifty-four patients presented with moderate to severe right ventricular dysfunction (group 2). Patients with a compromised right ventricular function were more likely to undergo MVR (28.6% versus 53.7%, P <.001). The mean pulmonary artery pressure was 23.6 mm Hg in group 1 and 34 mm Hg in group 2 (P <.001). The left atrial diameter was 4.6 cm in group 1 and 5.3 cm in group 2 (P <.001). The 2 groups were not different with respect to operative mortality, but the patients in group 2 experienced more transfusion of blood products (588.4 mL versus 1180.6 mL, P <.001), longer intensive care unit stays (83.9 versus 149.6 hours, P <.001), and hospital stays (8.9 versus 12.8 days, P = .005). The rate of postoperative MV regurgitation was significantly higher in group 2 (1.8 versus 14.8%, P <.001). The overall 1-year survival rate was 92.5% in group 1 and 94.5% in group 2 (P = .59). CONCLUSIONS: This study has shown that a dysfunctional preoperative right ventricular function uses more resources and is associated with postoperative MV regurgitation, but it is not associated short- and mid-term mortality after MV surgery.