Incremental prognostic value of echocardiography in patients with prior mitral valve surgery.

Background and aim of the study: Patients with prior mitral valve surgery are at increased risk for events late after surgery. The study aim was to investigate the value of assessing clinical variables, and left and right heart anatomy and function, to predict outcome in these patients. Methods: Two-dimensional echocardiography, Doppler echocardiography and tissue Doppler imaging (TDI) were performed in 84 patients at a mean of 7.3 +/- 7.1 years after mitral valve surgery. The left ventricular ejection fraction (LVEF) was 50 +/- 15%, and 30% of patients were in NYHA class III/IV (congestive heart failure; CHF). Follow up was obtained for events that included repeat mitral or tricuspid valve surgery, and death. Results: During a follow up period of 4.3 +/- 2.0 years, 28 patients suffered events, the univariate clinical predictors of which were NYHA class, calcium antagonist therapy, hyperlipidemia, and tobacco smoking. Left heart predictors included the mean mitral valve gradient (MMVG), left atrial volume index, and lateral wall TDI systolic velocity. Right heart predictors were atrial and right ventricular (RV) dimensions, RV systolic pressure, tricuspid regurgitation (TR) severity, RV free wall TDI E-velocity and E/e' ratio. Multivariate analysis showed that NYHA class (p = 0.02; RR 1.8 (1.1-2.9)), MMVG (p <0.001; RR 1.16 (1.08-1.24)) and RV dimensions (p = 0.001; RR = 3.2 (1.7-6.2)) were independent predictors of events. A step-wise analysis of independent predictors showed that MMVG added an incremental value to NYHA class (p = 0.003), while RV size added additional value (p = 0.007) to the combination of NYHA class and MMVG. Conclusion: Echocardiographic assessments of the left and right heart can add significant prognostic value to the clinical assessment of patients after mitral valve surgery.