Abstract 3549: Reduced Right Ventricular Systolic Function is the Best Predictor of Outcome in Patients with Prior Mitral Valve Surgery
Background: Right ventricular systolic dysfunction commonly occurs in patients with prior mitral valve replacement and long-standing pulmonary hypertension. We assessed the prognostic impact of RV function in patients with prior mitral valve surgery.
Methods: Fifty-eight patients with history of prior mitral valve surgery were evaluated by tissue Doppler imaging (TDI). Pulsed TDI measurements were obtained from the basal free wall of the RV at the tricuspid annulur level. Ejection velocity (S2) and the area under the systolic ejection velocity curve (TVI) were assessed as measures of RV systolic function. S2 was reported in cm/sec and TVI in cm which is equivalent to the extent of displacement of the lateral RV annulus towards the apex. Patients were retrospectively followed for events (heart failure, infarction, death).
Results: The mean age was 63 ± 16 years (55% women). Seventeen (30%) patients had prior mitral valve repair and 41 (70%) had valve replacement. The mean left ventricular ejection fraction (EF) was 50 ± 15 % and mean Right ventricular Systolic Pressure (RVSP) was 44 ± 16 mmHg. The mean S2 was 8.34 cm/sec and the mean TVI was 1.54 cm. Thirty one ( 53%) pts had reduced RV function based on TVI <2 cm and/or S2 < 8 cm/sec. During followup, 22 of 58 patients (38 %) had events. Significant (p < 0.10) univariate predictors of events included: calcium channel blocker use (p- 0.07), Fractional Area change (FAC) (p-0.07) and TVI (p-0.003). Beta blocker use, the degree of residual mitral valve regurgitation, EF, RVSP, and S2 were not predictive. Multivariate analysis showed TVI as the only independent predictor of outcome (p-0.004, RR 0.031, CI .003 - .31) (for every 1.0 cm increase in excursion of the RV free wall, risk decreases 30 fold).
Conclusion: In patients with preserved LV systolic function, RV systolic function assessed by TVI is the most important predictor of outcome. The results of this study suggest that assessment of RV systolic function by TDI should be considered as an essential part of the evaluation of patients with prior mitral valve surgery.