Right Ventricular Systolic Function in Organic Mitral Regurgitation: Impact of Biventricular Impairment
Background—To assess the prevalence, determinants and prognosis value of right ventricular (RV) ejection fraction (EF) impairment in organic mitral regurgitation (MR).
Methods and Results—Two-hundred-eight patients (62±12 years, 138 males) with chronic organic MR referred to surgery underwent an echocardiography and bi-ventricular radionuclide angiography with regional function assessment. Mean RV EF was 40.4±10.2%, ranging from 10 to 65%. RV EF was severely impaired (≤35%) in 63 patients (30%), and biventricular impairment (LV EF<60% and RV EF≤35%) was found in 34 patients (16%). Pathophysiologic correlates of RV EF were LV septal function (β-hat=0.42, P<0.0001), LV end diastolic diameter index (β-hat =-0.22, P=0.002) and PASP (β-hat =-0.14, P=0.047). Mitral effective regurgitant orifice size (n=84) influenced RV EF (β-hat =-0.28, P=0.012). In 68 patients examined after surgery, RV EF increased strongly (27.5±4.3 to 37.9±7.3, P<0.0001) in patients with depressed RV EF while it did not change in others (P=0.91). RV EF≤35% impaired 10-year cardiovascular survival (71.6±8.4% versus 89.8±3.7%, P=0.037). Biventricular impairment dramatically reduced 10-year cardiovascular survival (51.9±14.3% versus 90.3±3.2%, P<0.0001; HR: 5.2, P<0.0001) even after adjustment for known predictors (HR: 4.6, P=0.004). Biventricular impairment reduced also 10-year overall survival (34.8±13.0% versus 72.6±4.5%, P=0.003; HR: 2.5, P=0.005) even after adjustment for known predictors (P=0.048).
Conclusions—In patients with organic MR referred to surgery RV function impairment is frequent (30%) and depends weakly on PASP but mainly on LV remodelling and septal function. RV function is a predictor of postoperative cardiovascular survival while biventricular impairment is a powerful predictor of both cardiovascular and overall survival.
- Received December 29, 2012.
- Accepted February 15, 2013.