Ventricular Energetics Early after Surgery for Chronic Mitral Regurgitation: Repair versus Replacement

Background and aim of the study: The study aim was to compare the effects of mitral valve (MV) repair and replacement with partial (posterior leaflet only) chordal preservation on left ventricular (LV) performance in chronic degenerative mitral regurgitation (MR) by assessing ventricular energetics.

Methods: Contractility (end-systolic elastance), afterload (effective arterial elastance), and ventricular efficiency (ventriculoarterial coupling and the ratio of stroke work to pressure-volume area were determined using transthoracic echocardiography data obtained before and at one month after surgery in 29 patients undergoing MV repair, and in 12 patients undergoing partial chordalsparing MV replacement. A two-way analysis of variance with repeated measures was used for comparisons among patients who underwent MV surgery (valve repair versus valve replacement).

Results: The LV diastolic volume index was decreased

significantly in both groups (p <0.0001), whereas the LVsystolic volume index did not change significantly (p = 0.956). Despite the similar remarkable decrease in ejection fraction (p <0.0001) in both groups, end-systolic elastance remained unchanged (p = 0.312). Effective arterial elastance was increased significantly in both groups (p <0.0001). Ventriculoarterial coupling and the ratio of stroke work to pressure-volume area deteriorated similarly in both groups (p <0.0001 and p <0.0001). Conclusion: Compensation of LV geometry after correction of chronic MR preserved ventricular contractility. Furthermore, the results of MV repair were not superior to those of MV replacement with partial chordal preservation in the early postoperative period. This suggested that partial chordal-sparing MV replacement is an effective method for the treatment of chronic MR in selected patients.

The Journal of Heart Valve Disease 2013;22:804-809