Predicting recurrent mitral regurgitation after mitral valve repair for severe ischemic mitral regurgitation

Abstract

Objectives: The Cardiothoracic Surgical Trials Network recently reported no difference in the primary end point of left ventricular end-systolic volume index at 1 year postsurgery in patients randomized to repair (n = 126) or replacement (n = 125) for severe ischemic mitral regurgitation. However, patients undergoing repair experienced significantly more recurrent mitral regurgitation than patients undergoing replacement (32.6% vs 2.3%). We examined whether baseline echocardiographic and clinical characteristics could identify those who will develop moderate/severe recurrent mitral regurgitation or die.

Methods: Our analysis includes 116 patients who were randomized to and received mitral valve repair. Logistic regression was used to estimate a model-based probability of recurrence or death from baseline factors. Receiver operating characteristic curves were constructed from these estimated probabilities to determine classification cut-points maximizing accuracy of prediction based on sensitivity and specificity.

Results: Of the 116 patients, 6 received a replacement before leaving the operating room; all other patients had mild or less mitral regurgitation on intraoperative echocardiogram after repair. During the 2-year follow-up period, 76 patients developed moderate/severe mitral regurgitation or died (53 mitral regurgitation recurrences, 13 mitral regurgitation recurrences and death, and 10 deaths). The mechanism for recurrent mitral regurgitation was largely mitral valve leaflet tethering. Our model (including age, body mass index, sex, race, effective regurgitant orifice area, basal aneurysm/dyskinesis, New York Heart Association class, history of coronary artery bypass grafting, percutaneous coronary intervention, or ventricular arrhythmias) yielded an area under the receiver operating characteristic curve of 0.82.

Conclusions: The model demonstrated good discrimination in identifying patients who will survive 2 years without recurrent mitral regurgitation after mitral valve repair. Although our results require validation, they offer a clinically relevant risk score for selection of surgical candidates for this procedure.

Trial registration: ClinicalTrials.gov NCT00807040.

FIGURE 1

Echocardiographic measures of MV tethering. A, MV tenting area (hashmark area) and MV tenting height (gold arrow). B, Anterior and posterior leaflet angle measurements (yellow angle). LA, Left atrium; LV, left ventricle.

FIGURE 2

Tethering mechanism for recurrent MR after repair. Mitral leaflets remain tethered (large arrows) after MV ring annuloplasty (small arrows show ring) with moderate MR (blue and red color flow).

FIGURE 3

A, Moderate/severe MR at different time intervals. This bar graph depicts patients who were alive and had documented moderate/severe MR recurrence at that time point. Patients with missing echocardiograms are not included. B, Patients experiencing moderate/severe MR recurrence or death over 2 years. This histogram shows the cumulative proportion of patients who had moderate/severe MR recurrence or death at any point over the 2-year follow-up period. The denominator is 116 patients. MR, Mitral regurgitation.

FIGURE 4

Basal aneurysm. Inferior basal aneurysm delineated by black arrows.

FIGURE 5

ROC curves of fitted models. A, ROC generated by reduced model of recurrence and/or death. B, ROC generated by fitted model of recurrence alone. AUC, Area under the curve.