Prediction of postoperative left ventricular systolic function in patients with chronic mitral regurgitation undergoing valve surgery--the role of deformation imaging

Abstract

Objective: Preoperative left ventricular systolic function is an important prognostic factor in patients undergoing mitral valve surgery. Preoperative myocardial deformation may be impaired without reduction in conventional indices such as ejection fraction (EF). Strain rate (SR) imaging is very sensitive in detecting regional systolic abnormalities and might allow diagnosis of subclinical changes in systolic left ventricular (LV) function before surgery. We aimed to investigate the value of preoperative regional myocardial peak systolic SR as a predictor of postoperative LV systolic function in patients with severe mitral regurgitation (MR) undergoing surgery.

Methods: A total of 62 patients (age 52±12) with chronic severe MR, who underwent mitral valve repair, were studied. A standard echo examination, extended with tissue Doppler, was performed before and at 12 months after surgery. For the evaluation of longitudinal function, mid-ventricular segment shortening was analysed for the septum, LV lateral wall and anterior and inferior walls.

Results: Patients were divided into two groups based on postoperative EF: group 1 with EF(post-op)>50% and group 2 with EF(post-op)<50%. Group 1 had a significantly (p=0.004) higher preoperative SR (LV lateral wall: -1.97±0.26s(-1); septum: -1.74±0.31s(-1); anterior wall: -1.94±0.30s(-1), inferior wall: -1.93±0.29s(-1)) compared to group 2 (LV lateral wall: -0.98±0.23s(-1); septum: -0.98±0.26s(-1); anterior wall: -0.94±0.30s(-1), inferior wall: -1.00±0.24s(-1)). When SR was corrected for size, the SR/EDV index (EDV is end diastolic volume) also showed significant changes (p=0.0007) at baseline between the groups. For detecting subclinical changes in deformation of the LV lateral wall, a cut-off value of the SR/EDV index<0.006 had 89% sensitivity and 93% specificity; for the anterior wall, SR/EDV index<0.005 had 88% sensitivity and 94% specificity.

Conclusions: SR imaging (corrected for geometry) can detect abnormalities in LV function at subclinical levels in patients with severe mitral regurgitation.