Systolic papillary muscle dyssynchrony predicts recurrence of mitral regurgitation in patients with ischemic cardiomyopathy (ICM) undergoing mitral valve repair.

ABSTRACT

OBJECTIVE: We investigated the impact of papillary muscle dyssynchrony (DYS-PAP) in predicting recurrent mitral regurgitation (MR) in patients with ischemic cardiomyopathy (ICM) undergoing undersized mitral ring annuloplasty (UMRA). METHODS: One hundred forty-four ICM patients (left ventricular ejection fraction <35%) in sinus rhythm undergoing UMRA between January 2001 and December 2010 at three Institutions (University Hospital, Maastricht, The Netherlands; Careggi Hospital, Florence, Italy; Civic Hospital, Brescia, Italy) were recruited. The primary endpoint was the recurrence of MR at the latest echocardiographic study defined as insufficiency ≥2+ in patients with no/trivial MR at discharge. The assessment of DYS-PAP was performed by applying two-dimensional (2D) speckle-tracking imaging. RESULTS: In patients with MR recurrence, DYS-PAP significantly worsened (84.1 ± 8.8 msec vs.65.4 ± 8.8 msec at baseline, P < 0.001) whereas in patients with no MR recurrence, DYS-PAP did not vary (22.3 ± 5.3 msec vs. 25.9 ± 7.2 msec at baseline, P = 0.8). Recurrent MR was positively correlated with preoperative DYS-PAP (P < 0.001), baseline anterior mitral leaflet tethering angle α (P < 0.001) and tethering symmetry index α/ß before surgery (P < 0.001). There was no significant correlation between MR recurrence and other echocardiographic parameters. Logistic regression analysis revealed that baseline values of DYS-PAP (OR 5.4 [95% CI 3.1-7.7], P < 0.001), α (OR 5.0 [2.6-6.7], P < 0.001), and α/ß (OR 3.9 [2.5-5.7], p < 0.001) were predictors of recurrent MR. A DYS-PAP value ≥ 58 msec predicted recurrence of MR with 100% sensitivity and 83% specificity (area under the curve [AUC] 0.92 [0.7-1], P < 0.001). CONCLUSIONS: A DYS-PAP cutoff value of 58 msec is useful to identify patients in whom UMRA is likely to fail. That way decision making in ischemic functional MR might be facilitated.