Abstract 2263: Preoperative Regurgitant Volume Can Predict “Unexpected” Left Ventricular Dysfunction After Mitral Valve Repair for Chronic Mitral Regurgitation
Background: Left ventricular (LV) dysfunction after mitral valve (MV) repair in patients with chronic mitral regurgitation (MR) carries a poor prognosis. It has been previously described that LV dysfunction could be predicted using preoperative echocardiographic parameters such as LV size and ejection fraction (EF). However, we encounter MR patients who have unexpected postoperative LV dysfunction despite preoperatively normal LV size and function.
Methods: We retrospectively investigated pre- and post-operative (median 4th postoperative day) echocardiograms of 248 consecutive patients who underwent MV repair from June through December 2005 for degenerative MR without other heart complications except tricuspid regurgitation. Among these patients, 48 patients were excluded because of inadequate echo quality for regurgitant volume (RVol) quantitation. Our study consisted of the remaining 200 patients (mean age 57±13 years, 140 male) in whom we could clearly determine the preoperative RVol from either quantitative Doppler and/or proximal isovelocity surface area method.
Results: After MV repair, the median (interquartile range) EF was significantly decreased from 68 (61–75) to 54 (41–63) % (P<0.0001). Postoperative EF was significantly correlated with preoperative EF, end-systolic (LVDs), and diastolic LV diameter (LVDd) (all P<0.0005). Among 148 patients with both preoperative EF >60% and LVDs <40 mm (Group N), preoperative median RVol was 70 (59 – 87) ml. Forty-four patients (30%) showed postoperative LV dysfunction (EF <50%). Univariate analysis revealed preoperative LVDs (P<0.05), LVDd (P<0.005), and RVol (P<0.0001) to be predictive for LV dysfunction. In the multivariate analysis, RVol was only an independent predictor (OR 2.8, 95% CI 2.0–4.0 per 10 ml increase; P<0.0001). At a cut off value of 90 ml in preoperative RVol, we could predict LV dysfunction in Group N with positive and negative predictive value of 91 and 89%, respectively.
Conclusion: A very large regurgitant volume was a significant predictor of postoperative LV dysfunction after MV repair despite preoperatively normal LV size and function. Quantification of MR volume is strongly recommended for earlier indication of MV repair in patients with severe MR.