156: Prevalence, determinants and prognosis value of right ventricular function impairment in organic mitral regurgitation

Abstract

Pevalence, determinants and prognosis value of right ventricular (RV) ejection fraction (EF) in organic mitral regurgitation (MR). Two-hundred eight pts (62±13 years, 138 males, AF 57 pts) with organic MR referred to surgery underwent an echocardiography and left ventricular (LV) and RV radionuclide angiography. LV and RV regional function was assessed. Mean RV EF was 40.7±10.1%, ranging from 10 to 65%. Sixty pts (29%) had a RV EF ≤35%. In multivariate analysis, LV septal function (LV EF 8: β=0.56, P<0.0001; LV EF 9: β=0.22, P=0.046), LV EDD index (β=−0.27, P<0.0001) and PASP (r=−0.19, P=0.008) were predictors of RVEF. In the subgroup with MR quantitation (n=85) predictor of RV EF was mitral ERO (β=−0.30, P=0.007). After surgery, RV EF increased strongly (27.5±4.3 to 37.9±7.3, P<0.0001) in pts with preoperative RV EF ≤35% while it did not change in pts with RV EF>35% (46.0±6.9 to 46.1±8.2, P=0.91). Independent predictors of postoperative RV EF were preoperative RV EF (β=0.32, P=0.013) and TR ≥grade 2 (β=–0.22, P=0.036) while LV septal function (LV EF 8, β=0.24, P=0.069) was marginally predictive. Fifty-seven pts died during post-operative follow-up of 7.1±4.3 years. Pts with RV EF ≤35% compared with RVEF>35% had a similar survival rate at 10 years (63.6±8.7% versus 68.8±5.3%, P=0.68), but cardiovascular mortality was higher (25.3±8.0% versus 8.1±3.5%, P=0.03; HR=2.67, 95% CI 1.06-6.76, P=0.037). RV EF was not a predictive factor of operative mortality. In a Cox model, NYHA class, CABG, and left atrial diameter, but not RV EF, were independent predictors of overall mortality. In organic MR RV function depends not only on PASP but mainly on LV remodeling and septal function, and improves strongly after surgery. RV EF is a predictor of cardiovascular mortality in univariate but not in multivariate analysis. Hence, impaired RV EF before surgery is not a sufficient argument to deny surgery in patients with organic MR.